ACKNO WLEDGEMENT

We would like to express our sincere appreciation to

Argonne National Laboratory and QSS Group, Inc., 

for their artistic and technical contributions in 

preparing and publishing this report.

In addition, we would like to thank all our program

participants for their contributions to the programs

and all the authors who prepared the project

abstracts that comprise this report.
U.S. Department of Energy

1000 Independence Avenue, S.W.

Washington, D.C. 20585-0121

FY 2002

Progress Report for Hydrogen, Fuel Cells, and

Infrastructure Technologies Program

Energy Efficiency and Renewable Energy

Office of Hydrogen, Fuel Cells, and Infrastructure Technologies 

Approved by Steven Chalk

November 2002
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

iii

CONTENTS

I. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

II. Hydrogen Production and Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

A. Biological Processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

1. Biological Water Gas Shift Development, National Renewable Energy Laboratory . . . . . . . . . 21

2. Maximizing Photosynthetic Efficiencies in H2 Production in Microalgal Cultures, University of 

California Berkeley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3. Efficient H2 Production Using Enzymes of the Pentose Phosphate Pathway, Oak Ridge National 

Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

4. Bio-H2 Production from Renewable Organic Wastes, Iowa State University . . . . . . . . . . . . . . . 38

5. Photobiological Algal H2 Production, National Renewable Energy Laboratory . . . . . . . . . . . . 42

B. Biomass-Based . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

1. H2 Production by Catalytic Reforming of Pyrolysis Vapors, National Renewable Energy 

Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

2. Supercritical Water Partial Oxidation, General Atomics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

3. Biomass-Derived H2 from a Thermally Ballasted Gasifier, Iowa State University. . . . . . . . . . . 63

4. Techno-Economic Analysis of H2 Production by Gasification of Biomass, Gas Technologies 

Institute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

C. Fossil-Based . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

1. Production of H2 by Superadiabatic Decomposition of H2 Sulfide, Gas Technologies Institute 71

2. Thermal Dissociation of Methane Using a Solar-Coupled Aerosol Flow Reactor, University of 

Colorado . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

3. Thermocatalytic CO2-free Production of H2 from Hydrocarbon Fuels, Florida Solar Energy 

Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

4. Novel Catalytic Fuel Processing Using Micro-channel Steam Reforming and Advanced 

Separations Technology, InnovaTek. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

5. ITM Syngas and ITM H2: Eng. Dev. of Ceramic Membrane Reactor Systems for Converting..., Air 

Products and Chemicals Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92

6. Integrated Ceramic Membrane System for H2 Production, Praxair . . . . . . . . . . . . . . . . . . . . . . 97

7. Low Cost H2 Production Platform, Praxair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

8. Effects of Fuel Constituents on Fuel Processor Catalysts, Argonne National Lab. . . . . . . . . . . 106

9. Separation Membrane Development, Westinghouse Savannah River Tech. Center . . . . . . . . . . 111

10. Defect-free Thin Film Membranes for H2 Separation & Isolation, Sandia National Laboratories

115

11. DFMA Cost Estimates of Fuel-Cell/Reformer Systems at Low/Medium/High Production Rates, 

Directed Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

D. Electrolytic Processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

1. Photoelectrochemical Systems for H2 Production, National Renewable Energy Laboratory . . 125

2. Photoelectrochemical H2 Production, University of Hawaii . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

3. Photoelectrochemical H2 Production Using New Combinatorial Chemistry Derived Materials, 

University of California Santa Barbara . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

4. Combinatorial Discovery of Photocatalysts for H2 Production, SRI International. . . . . . . . . . . 144
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

iv

CONTENTS (Continued)

II. Hydrogen Production and Delivery (Continued)

D. Electrolytic Processes (Continued)

5. Low Cost, High Efficiency Reversible Fuel Cell Systems, Technology Management Incorporated

148

6. High-Efficiency Steam Electrolyzer, Lawrence Livermore National Laboratory . . . . . . . . . . . 152

7. Enabling Science for Advanced Ceramic Membrane Electrolyzers, Los Alamos National 

Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

8. H2 Production Through Electrolysis, Proton Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161

E. Hydrogen Fueling Systems and Infrastructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

1. Development of a Turnkey Commercial Hydrogen Fueling Station, Air Products and Chemicals, 

Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

2. Autothermal Cyclic Reforming-Based Fueling System, GE Energy . . . . . . . . . . . . . . . . . . . . . 170

3. Development of a Natural Gas to Hydrogen Fuel Station, Gas Technologies Institute . . . . . . . 175

4. Distributed H2 Fueling Systems Analysis, Directed Technologies Inc. . . . . . . . . . . . . . . . . . . . 179

5. Technical Analysis: Integrating a H2 Energy Station into a Federal Building, TIAX . . . . . . . . 184

F. Crosscutting Hydrogen Production and Delivery Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

1. Hydrogen Technical Analysis, TIAX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189

2. Hydrogen Infrastructure Studies, Longitude 122 West . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194

III. Hydrogen Storage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199

A. High Pressure Tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201

1. H2 Composite Tank Program, Quantum Technologies Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201

2. H2 Storage Using Lightweight Tanks, Lawrence Livermore National Laboratory . . . . . . . . . . 205

3. Hydrogen Storage in Insulated Pressure Vessels, Lawrence Livermore National Laboratory. . 210

4. Advanced Thermal H2 Compression, Ergenics Inc.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

5. Development of a Compressed Hydrogen Gas Integrated Storage System for Fuel Cell Vehicles, 

Johns Hopkins University/Lincoln . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218

6. Low Permeation Liner for Hydrogen Gas Storage Tanks, Idaho National Energy and 

Environmental Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223

B. Carbon Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226

1. Hydrogen Storage in Carbon Single-Wall Nanotubes, National Renewable Energy Laboratory226

2. Doped Carbon Nanotubes for H2 Storage, Westinghouse Savannah River Tech. Center. . . . . . 231

3. Hydrogen Storage in Metal-Modified Single-Walled Carbon Nanotubes, California Institute of 

Technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235

C. Hydrides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239

1. Catalytically Enhanced H2 Storage Systems, University of Hawaii. . . . . . . . . . . . . . . . . . . . . . 239

2. Complex Hydrides for Hydrogen Storage, Florida Solar Energy Center . . . . . . . . . . . . . . . . . 244

3. High-Density Hydrogen Storage Demonstration Using NaAlH4-Based Complex Compound 

Hydrides, UTC Fuel Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247

4. Standardized Testing Program for Emergent Chemical Hydride and Carbon Storage Technologies, 

Southwest Research Institute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

v

CONTENTS (Continued)

III. Hydrogen Storage (Continued)

C. Hydrides (Continued)

5. H2 Fueled ICE Scooter with On-Board Metal Hydride Storage, Energy Conversion Devices. . 255

6. Hydride Development for Hydrogen Storage, Sandia National Laboratories . . . . . . . . . . . . . . 260

IV. Fuel Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265

A. Transportation Power Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267

1. Atmospheric Fuel Cell Power System for Transportation, UTC Fuel Cells . . . . . . . . . . . . . . . . 267

2. Fuel Cell Systems Analysis, Argonne National Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270

3. Fuel Cell Vehicle Systems Analysis, National Renewable Energy Laboratory . . . . . . . . . . . . . 275

4. Cost Analyses of Fuel Cell Stacks/Systems, TIAX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279

B. Stationary Power Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283

1. Alkaline Fuel Cell Development, Oak Ridge National Laboratory . . . . . . . . . . . . . . . . . . . . . . 283

2. Development of Advanced, Low-Cost PEM Fuel Cell Stack and System Design for Operation on 

Reformate, Teledyne . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285

3. Proton Exchange Membrane Fuel Cell Power System on Ethanol, Caterpillar . . . . . . . . . . . . . 290

4. Fuel Cell Distributed Power Package Unit: Fuel Processing Based on Authermal Cyclic 

Reforming, GE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294

5. R&D on an Ultra-Thin Composite Membrane for High-Temperature Operation in PEMFCs, Fuel 

Cell Energy, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297

C. Fuel Processing Subsystem and Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300

1. Next-Millennium Fuel ProcessorTM for Transportation Power System, Nuvera . . . . . . . . . . . . 300

2. Multi-Fuel Processor for Fuel Cell Electric Vehicle Applications, McDermott . . . . . . . . . . . . . 305

3. Quick-Starting of Fuel Processors, Argonne National Laboratory . . . . . . . . . . . . . . . . . . . . . . . 309

4. Microchannel Fuel Processor Development, Pacific Northwest National Laboratory. . . . . . . . 313

5. Plate-Based Fuel Processing System, Catalytica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320

6. Fuel Processors for PEM Fuel Cells, University of Michigan. . . . . . . . . . . . . . . . . . . . . . . . . . . 325

7. Evaluation of Partial Oxidation Fuel Cell Reformer Emissions, TIAX . . . . . . . . . . . . . . . . . . . . 328

8. Catalysts for Autothermal Reforming, Argonne National Laboratory . . . . . . . . . . . . . . . . . . . . 332

9. Fuel Processing of Diesel Fuel for Auxiliary, National Energy Technology Laboratory . . . . . . 337

10. Testing of Fuels in Fuel Cell Reformers, Los Alamos National Laboratory. . . . . . . . . . . . . . . . 342

11. Sulfur Removal from Reformate, Argonne National Laboratory . . . . . . . . . . . . . . . . . . . . . . . . 348

12. Nanoscale Water Gas Shift Catalysts, NexTech. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352

13. Water-Gas Shift Catalysis, Argonne National Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356

14. Transition Metal Carbide Water Gas Shift Catalysts, University of Michigan . . . . . . . . . . . . . . 360

15. Development of Novel Water-Gas-Shift Membrane Reactor, University of Kentucky . . . . . . . . 364

D. Fuel Cell Stack Subsystem and Components. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369

1. R&D of a 50-kW, High-Efficiency, High Power Density, CO-Tolerant PEM Fuel Cell Stack 

System, Honeywell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369

2. Development of Comprehensive Computer Models for Simulation of Fuel Cell Systems, 

University Of Miami . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

vi

CONTENTS (Continued)

IV. Fuel Cells (Continued)

D. Fuel Cell Stack Subsystem and Components (Continued)

3. High-Performance, Matching PEM Fuel Cell Components and Integrated Pilot Manufacturing 

Processes, 3M . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379

4. Design and Installation of a Pilot Plant for High-Volume Electrode Production, Southwest 

Research Institute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386

5. Integrated Manufacturing for Advanced Membrane Electrode Assemblies, De Nora. . . . . . . . 390

6. Development of High-Temperature Membranes and Improved Cathode Catalysts, UTC Fuel Cells

395

7. High-Temperature Membranes, Case Western Reserve University . . . . . . . . . . . . . . . . . . . . . . 400

8. Bacterial Cellulose Membranes, Oak Ridge National Laboratory. . . . . . . . . . . . . . . . . . . . . . . 404

9. Nano-Particle Porous Oxide Electrolyte Membranes (POEMs) as Proton Exchange Membranes, 

University Of Wisconsin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408

10. Low-Platinum Catalysts for Oxygen Reduction at PEMFC Cathodes, Naval Research Laboratory

413

11. Low Platinum Loading Catalysts for Fuel Cells, Brookhaven National Laboratory . . . . . . . . . 418

12. Development of High-Performance, Low-Pt Cathodes Containing New Catalyst and Layer 

Structure, Superior MicroPowders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423

13. New Electrocatalysts for Fuel Cells, Lawrence Berkeley National Laboratory. . . . . . . . . . . . . 429

14. Electrodes for Polymer Electrolyte Membrane Fuel Cell Operation on Hydrogen/Air and 

Reformate/Air, Los Alamos National Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433

15. Nondestructive Study of the Water Transport Mechanism inside Operating PEM Fuel Cells Using 

Neutron Imaging Techniques, National Inst. for Standards and Testing . . . . . . . . . . . . . . . . . . 438

16. Direct Methanol Fuel Cells, Los Alamos National Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . 441

17. Development of Advanced Catalysts for Direct Methanol Fuel Cells, NASA Jet Propulsion 

Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447

18. Carbon Composite Bipolar Plates, Oak Ridge National Laboratory . . . . . . . . . . . . . . . . . . . . . 451

19. Cost-Effective Surface Modification for Metallic Bipolar Plates, Oak Ridge National Laboratory

454

20. Scale-Up of Carbon/Carbon Composite Bipolar Plates, Porvair Corporation . . . . . . . . . . . . . 458

21. Carbon Foam for Fuel Cell Humidification, Oak Ridge National Laboratory . . . . . . . . . . . . . 463

22. Carbon Monoxide Sensors for Reformate-Powered Fuel Cells, Los Alamos National Laboratory

468

23. Electrochemical Sensors for PEMFC Vehicles, Lawrence Livermore National Laboratory . . 473

24. Development of Sensors for Automotive Fuel Cell Systems, United Technologies Research Center

476

25. Design & Development of New Glass-Ceramic Proton Conducting Membranes, Iowa State 

University . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480

26. Fuel Cell System Durability, Los Alamos National Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . 485
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

vii

CONTENTS (Continued)

IV. Fuel Cells (Continued)

E. Air Management Subsystems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490

1. Turbocompressor for PEM Fuel Cells, Honeywell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490

2. Development and Testing of a High Efficiency Integrated Compressor/Expander based on 

Torroidal Intersecting Vane Machine Geometry, Mechanology, LLC . . . . . . . . . . . . . . . . . . . . . 494

3. Turbocompressor for Vehicular Fuel Cell Service, Meruit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 499

4. Motor Blower Technologies for Fuel Cell Automotive Power Systems, UTC Fuel Cells . 503

5. Hybrid Compressor/Expander Module, TIAX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508

F. Crosscutting Fuel Cell Analysis and Demonstration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513

1. Precious Metal Availability and Cost Analysis for PEMFC Commercialization, TIAX . . . . . . . 513

2. Assessment of Fuel Cell Auxiliary Power Systems for Onroad Transportation Applications, TIAX

517

3. Guidance for Transportation Technologies: Fuel Choice for Fuel Cell Vehicles, TIAX . . . . . . . 522

4. Fuel Cell R&D and Demonstration, Los Alamos National Laboratory . . . . . . . . . . . . . . . . . . . 526

5. Advanced Underground Vehicle Power and Control Fuel Cell Mine Locomotive, Vehicle Projects, 

LLC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530

V. Integrated Hydrogen and Fuel Cell Demonstration/Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535

A. System Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537

1. Analysis of Hydrogen Production Using Ammonia and Ammonia-Borane Complex for Fuel Cell 

Applications, Florida Solar Energy Center. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537

2. Well-to-Wheels Analysis of Energy and Emission Impacts of Fuel-Cell Vehicle Fuels, Argonne 

National Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543

3. Hydrogen and Fuel Cell Vehicle Evaluation, National Renewable Energy Laboratory . . . . . . . 547

4. Power Parks System Simulation, Sandia National Laboratory. . . . . . . . . . . . . . . . . . . . . . . . . . 550

5. Process Analysis Work for the DOE Hydrogen Program - 2001, National Renewable Energy 

Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 554

B. Integrated Hydrogen and Fuel Cell Demonstration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 558

1. Real-World Demonstration of Fuel Cell Vehicles and Refueling Technology, California Fuel Cell 

Partnership . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 558

2. Filling Up With Hydrogen 2000, Stuart Energy USA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 563

3. Hydrogen Reformer, Fuel Cell Power Plant, and Vehicle Refueling System, Air Products and 

Chemicals, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 567

VI. Safety and Codes & Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 571

A. Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573

1. Gallium Nitride Integrated Gas/Temperature Sensors for Fuel Cell System Monitoring for 

Hydrogen and Carbon Monoxide, Peterson Ridge LLC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573

2. Interfacial Stability of Thin Film H2 Sensors, National Renewable Laboratory . . . . . . . . . . . . 577

3. Micro-Machined Thin-Film H2 Gas Sensors, Advanced Technology Materials Inc. . . . . . . . . . 581
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

viii

CONTENTS (Continued)

VI. Safety and Codes & Standards (Continued)

B. Codes and Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585

1. H2 Infrastructure Activities Codes and Standards: Hydrogen Codes and Standards Outreach, 

National Hydrogen Association . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585

2. Codes and Standards Analysis, University of Miami . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 591

3. Hydrogen Codes and Standards, National Renewable Energy Laboratory . . . . . . . . . . . . . . . . 595

4. SAE Fuel Cell Codes and Standards Initiative, Society of Automotive Engineers. . . . . . . . . . . 598

VII.Conversion Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 603

A. Turbines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 605

1. Reduced Turbine Emissions Using H2-Enriched Fuels, Sandia National Laboratories . . . . . . 605

B. Internal Combustion Engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 609

1. Internal Combustion Engines Research and Development, Sandia National Laboratories. . 609

2. HCNG Heavy Duty Vehicle Prime Mover, NRG Tech . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 613

Acronyms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 619

Appendix A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 625

Primary Contact List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 637
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

1

I. INTRODUCTION

Developing Advanced Hydrogen and Fuel Cell Technologies for Transportation, 

and Stationary Power Systems

We are pleased to present the Fiscal Year (FY) 2002 Annual Progress Report 

for the Hydrogen, Fuel Cells, and Infrastructure Technologies Program. This new 

program office integrates activities in hydrogen production, storage, and delivery 

with transportation and stationary fuel cell activities. Under the Assistant 

Secretary for Energy Efficiency and Renewable Energy (EERE), the new Office of 

Hydrogen, Fuel Cells, and Infrastructure Technologies is responsible for research, 

development and demonstration of all aspects of hydrogen and fuel cells and was 

formed in response to a recommendation in the National Energy Policy to “focus 

research and development efforts ... on integrating current programs ... regarding 

hydrogen and fuel cells..." 

In January 2002, as a further step toward implementation of the National 

Energy Policy, Secretary of Energy Spencer Abraham announced formation of the 

FreedomCAR Partnership, an ambitious, 

cost-shared cooperative research and 

development partnership between the 

Department of Energy (DOE) and the U.S. 

Council for Automotive Research, the 

precompetitive research organization of 

Ford, General Motors (GM), and 

DaimlerChrysler. The CAR in 

FreedomCAR stands for Cooperative 

Automotive Research. And the 

“Freedom” principle is framed by:

• Freedom from foreign petroleum dependence; 

• Freedom from pollutant emissions;

• Freedom for Americans to drive where they want, when 

they want, in the vehicle of their choice; and

• Freedom to obtain fuel affordably and conveniently.

The long-term goal of the FreedomCAR Partnership is the 

achievement of vehicles and fuels that lead to a clean and 

sustainable energy future. Fuel cell vehicles running on 

renewable hydrogen offer a promising path toward achieving 

this vision. Thus, a major focus of FreedomCAR is the 

development of hydrogen and fuel cell technologies. The 

formation of FreedomCAR demonstrates the federal 

government's commitment to next generation transportation 

technologies including fuel cells and hydrogen. The 

FreedomCAR Partnership Plan can be downloaded from the 

internet at http://www.cartech.doe.gov.

Secretary Abraham announces FreedomCAR

President Bush and UTC Fuel Cells President 

William Miller discuss fuel cell technology
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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The U.S. Department of Energy has also initiated a National 

Hydrogen Vision and Roadmap process in response to 

recommendations made in the National Energy Policy. Energy 

Secretary Spencer Abraham stated, "The President's Plan directs us 

to explore the possibility of a hydrogen economy." The Vision 

Meeting, an important first step, took place November 15-16, 2001. 

The 53 business executives, Federal and State energy policy 

officials, and leaders of universities, environmental organizations, 

and National Laboratories who participated contributed to the 

development of the vision:

Hydrogen is America's clean energy choice. It is flexible, 

affordable, safe, domestically produced, used in all 

sectors of the economy, and in all regions of the country.

Building on the work of the Vision Meeting, more than 200 

participants representing hydrogen energy industries, academia, 

environmental organizations, federal and state government agencies, and 

National Laboratories met on April 2-3, 2002 for a National Hydrogen Energy 

Roadmap Workshop in Washington, DC. The purpose of the workshop was to 

identify the key activities that will have to take place to enable the vision to 

become reality. The intent was to identify the most important barriers and 

paths forward that should be addressed in order to achieve the Vision; the time 

frames for the top priority research and development and other efforts; and the 

respective roles of industry, government, universities, and National 

Laboratories in dealing with these issues. In his concluding remarks to the 

workshop participants, David Garman, Assistant Secretary for Energy 

Efficiency and Renewable Energy, stated: "There are two paths we need to 

follow: research and development, and public outreach to capture the 

imagination of the American people. This will be a long journey and process, 

and the Department of Energy will work with you as we move forward." The 

National Hydrogen Energy Roadmap Report is available on http://

www.eren.doe.gov/hydrogen.

This report provides an overview of the nature, objectives, and progress of the Program; examines the 

remaining technical barriers to commercialization of the technology; and highlights the Program’s future 

directions. While the primary purpose of this report is to document the progress made by the DOE Hydrogen, 

Fuel Cells, and Infrastructure Technologies Program during FY 2002 in overcoming the R&D barriers, it also 

highlights some of the major advances in fuel cell technology made through other private and public initiatives 

throughout the year. The reader is also referred to http://www.eren.doe.gov/hydrogen for additional 

information. 

Transportation Highlights

In October 2001, Ford set a national record for fuel cell endurance by 

running a P2000 car continuously for 24 hours. The vehicle traveled 

1,391 miles averaging 58 mph, including stops for refueling and driver 

changes. Average actual on-track speed was 65 mph. The P2000 uses an 

advanced lightweight Ford Research vehicle platform that offers interior 

space for 5 passengers while weighing only ~3,300 pounds. The P2000's 

Shown above is the breakdown of DOE 

FreedomCAR funding ($150 million) by 

technology area. Industry share is an 

additional 20-50%.

Ford P2000 Fuel Cell Vehicle
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

3

fuel cell system delivers 90 hp and accelerates the car from 0 to 60 in less than 14 seconds. The polymer 

electrolyte membrane fuel cells and electric drive powertrain were supplied by Ballard Power Systems. 

DaimlerChrysler’s NECAR 5 sedan completed the 

first transcontinental journey of a fuel cell powered 

vehicle in June 2002. The NECAR 5 is powered by a 

fuel cell engine designed by Ballard Power Systems and 

fueled by methanol. The 3,262-mile trip, which took 85 

hours of driving over 12 days, ended at the DOEsponsored Future Car Congress in Washington, D.C. in 

June, 2002. According to DaimlerChrysler, no 

components of the fuel cell engine had to be repaired 

during the journey. An electrical short caused by 

moisture delayed the trip for one day, and two belts, four 

fuel filters, and one water compartment had to be 

replaced. 

In January 2002, at the North American International 

Auto Show in Detroit, General Motors unveiled the 

Autonomy fuel cell concept car. The basic component of 

GM’s plan for a fuel cell vehicle is a so-called “skateboard” 

platform that would include both the fuel cells and the 

vehicle’s electronic powertrain. The platform would allow a 

variety of body types to be built and assembled to the chassis.

To accelerate the development of fuel cell vehicles, the California Fuel Cell Partnership (CaFCP) was 

established in Sacramento, CA, in November 2000 (see http://www.fuelcellpartnership.org). The CaFCP 2002 

technical achievements include: 

• operation of 16 CaFCP fuel cell powered vehicles, 

• installation of a methanol fuel station at the West Sacramento headquarters, and

• commencement of a second joint study examining hydrogen vehicle facility construction and use issues.

Technology Status and Challenges

Hydrogen Production

Hydrogen, like electricity, can be produced from many sources, 

including fossil fuels, renewable resources, and nuclear energy. The 

Department currently supports R&D on a number of different 

hydrogen production technologies, including biological-, biomass-, 

fossil-, nuclear-, and renewable-based processes. Future R&D will 

also address approaches for producing hydrogen utilizing waste 

heat from nuclear energy sources.

The FreedomCAR target for hydrogen production via natural 

gas reforming is presented in Table 1. Targets for hydrogen 

production, separation and purification, storage, and delivery are 

listed in Appendix A. Remaining technical challenges for hydrogen 

energy systems include:

DaimlerChrysler NECAR 5 and Jeep Commander Fuel 

Cell Vehicles

GM Autonomy Fuel Cell Car (left) and the 

“Skateboard” Platform (right)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

4

• Reducing the cost of hydrogen production from renewable resources and fossil feedstocks 

• Establishing “learning” hydrogen fuel infrastructure demonstrations to address technical and economic 

issues that will help refocus research 

• Developing standards of safe practice, codes, and product certification to enable commercial 

production of hydrogen-based systems for mobile and stationary applications

Hydrogen Storage 

The overarching technical challenge for hydrogen storage is how to store the necessary amount of 

hydrogen needed to fuel the vehicle for its required driving range (>300 miles), within the constraints of 

weight, volume, efficiency, and cost.

The Department is currently pursuing three approaches for on-board hydrogen storage: 1) physical 

storage, 2) reversible chemical storage, and 3) irreversible chemical storage. Physical storage involves the 

development of tanks for either compressed hydrogen gas or liquid hydrogen. Reversible chemical approaches 

store hydrogen in solid materials where the hydrogen can be released and refilled without physically removing 

the storage media from the vehicle. Potential reversible storage materials include metal hydrides and carbon 

materials such as carbon nanotubes. Irreversible chemical approaches release hydrogen via an on-board 

chemical reaction with the storage material. In this case, the storage media must be physically replaced with 

fresh material once it has become exhausted. The reaction of sodium borohydride with water is an example of 

this approach. 

Table 2 gives the DOE hydrogen storage system goals for the year 2005 and compares these goals to the 

state-of-the-art hydrogen storage technology – 5,000 psi tanks, which have been certified. Development of 

compressed hydrogen tanks at 10,000 psi is near completion; certification activities are in progress. Materials 

to enable low pressure hydrogen storage are the focus of DOE hydrogen storage activities. Other hydrogen 

storage targets are listed in Appendix A. 

Technology1 2002 Status 2010

Natural Gas Reforming $6.00/gge2 $1.50/gge3

1. A thorough analysis will be performed in FY 2003 to establish technical targets for biomass and other hydrogen 

production pathways. 

2. Status based on single, 215 kg/day unit. (gge=gasoline gallon equivalent)

3. Target based on projected cost for ~900 kg/day units, produced in volume of 100 units per year.

Table 1. Hydrogen Production Status and Targets

Characteristic 2002 Status2 2005 Goal

Weight Percent 5.2 6

Specific Energy (W-h/kg) 1745 2000

Energy Density (W-h/liter) 813 1100

Cost ($/kWh) 50 5

1. 2010 targets are under review by the FreedomCAR Hydrogen Storage Technical Team

2. Status is based on certified 5,000 psi hydrogen tanks; 10,000 psi tanks have been developed – certification activities 

are underway 

Table 2. Comparison of Current Status1 to 2005 Hydrogen Storage System Goals
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

5

Transportation Fuel Cells

Direct hydrogen PEM fuel cell systems are more technically mature and face fewer challenges than 

systems requiring an on-board fuel processor. Although the demonstrated performance and efficiency of direct 

hydrogen systems approach the anticipated goals, several issues remain. The primary barriers are lack of a 

refueling infrastructure and on-board hydrogen storage, cost, durability, size, and weight.

Remaining technical challenges for automotive fuel cell power systems include:

• Reducing component and system costs (including reducing precious metal requirements)

• Developing high-volume manufacturing capability

• Demonstrating component and system durability

• Reducing system start-up time, especially for gasoline-powered systems

• Developing high-efficiency air management subsystems

Technical and economic targets were developed for direct hydrogen transportation PEM fuel cell systems 

and they are indicated along with the status in Table 3, as well as in Appendix A. The targets and status of 

gasoline-fueled systems remain the same as in FY 2001. Note that the FreedomCAR fuel cell technical team is 

currently considering revisions to all technical targets.

Characteristic 2002 Status 2005 2010

Energy efficiency @ 25% of rated power (%) 59 60 60

Energy efficiency @ rated power (%) 50 50 50

Power density (W/L)

 excluding H2 storage 

 including H2 storage

400

140

500

150

650

220

Specific power (W/kg)

 excluding H2 storage

 including H2 storage

400

250

500

250

650

325

Cost (including H2 storage) ($/kW) 200 125 45

Transient response (time from 10% to 90% of rated power) 

(seconds)

321

Cold start-up time to maximum power (seconds)

 @ –20bC ambient temperature

 @+20bC ambient temperature

120

60

60

30

30

15

Emissions Zero Zero Zero

Durability (hours) 1000 2000 5000

Survivability (bC) -20 - 30 -40

Table 3. Comparison of Targets for 50 kWe (net) Integrated Fuel Cell Power Systems Operating on Direct Hydrogen 

to Current Status
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

6

Major Go/No-Go Decision Planned

DOE is pursuing a dual pathway to evaluate fuels for fuel cell vehicles. As an alternative to the direct 

hydrogen approach, the Program is pursuing development of on-board fuel processors to reform gasoline and 

alternative fuels such as methanol, ethanol, and natural gas to produce the required hydrogen. An advanced 

petroleum-based fuel, which is "gasoline-like," would be an interim “transition” strategy. It would be 

compatible with the existing refueling infrastructure and eliminate the hydrogen storage barrier. However, onboard fuel processing has been presenting serious technical and economic challenges which may not be 

overcome in the required “transition” timeframe. Consequently, DOE is deciding whether to continue onboard fuel processing R&D beyond the end of FY 2004. Identification of decision criteria (such as energy 

required for start-up) and metrics is in the early stages.

Stationary Fuel Cells

Because the buildings sector accounts for ~36% of the U.S. primary energy consumption and between 30% 

and 40% of all airborne emissions, DOE is developing high efficiency polymer electrolyte membrane (PEM) 

fuel cell power systems as an alternative power source to grid-based electricity for buildings. A successful 

stationary fuel cell program will not only save energy and reduce emissions, but its inherent flexibility will 

help address energy shortage issues through energy diversity. Industry cost-shared projects will cross-cut 

several technological areas addressing research needs in stationary fuel cell systems, fuel cells for back-up 

power, materials for high temperature membranes, fuel cell component durability, water and thermal 

management, fuel processing for stationary applications, platinum recycling, and non-precious metal catalysts.

Technical and economic challenges for natural gas-based stationary fuel cell R&D include:

• Improving energy efficiency

• Improving integrated system durability

• Reducing component and system cost

• Resolving interconnectivity issues with grid and developing codes/standards

• Developing fuel-cell systems with potential to meet cost-effective thermal energy needs for some or all 

of the building's heating/cooling requirements

In FY 2003, a study is planned to establish baseline performance and outyear targets for stationary PEM 

fuel cells for various market segments.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

7

Research, Development and Demonstration (R,D&D) Highlights

Researchers supporting the Hydrogen, Fuel Cells, and Infrastructure Technologies Program continued to 

make significant progress in meeting R,D&D challenges during FY 2002. The summaries that follow are 

selected highlights of the progress made under the program.

Biological Organisms Replace Expensive Nickel 

Catalysts for Hydrogen Production The National Renewable 

Energy Laboratory has successfully shown that a unique 

photosynthetic organism can replace nickel catalysts in the 

water-gas-shift reaction for hydrogen production from synthesis 

gas. These organisms are able to produce hydrogen from water 

while converting carbon monoxide to carbon dioxide. 

Industrially, this reaction is normally performed using 

expensive nickel catalysts and at high temperatures. To date, 

these organisms have been able to perform with industrial 

synthesis gas and with gas from a biomass gasification process 

development unit. The organisms are robust under a variety of 

conditions. Work is now progressing on improving reactor 

design and reaction rates.

SNL Develops Defect-Free Thin Film Membranes for Hydrogen Separation and Isolation 

Even small amounts of carbon monoxide or other 

contaminants can poison a fuel cell. Sandia National 

Laboratories (SNL) is working on developing gasselective thin film membranes to improve and lower the 

cost for hydrogen purification. Defect-free 

aluminosilicate and silicalite zeolite thin films 

supported on commercially available alpha and gamma 

alumina disk substrates were developed. In tests using 

SNL’s permeation unit, which can test both pure and 

mixed gases from room temperature to 250°C, excellent 

separation values for hydrogen were achieved.

University, Industry and Laboratory Team Completes Reactor Testing and Produces Hydrogen from 

Peanut Shells Clark Atlanta University, Georgia Institute of Technology, Scientific Carbons Inc., Enviro-Tech 

Enterprises Inc. and the National Renewable Energy Laboratory (NREL) have partnered to move NREL’s 

technology for the generation of hydrogen from biomass and agricultural residue into 

the commercial setting. This success marks the first application of a near-term 

economically viable option for renewable hydrogen production. During FY 2002, 

the team successfully tested a 1 kg per hour shift reactor on vapors from peanut shell 

pyrolysis, both at NREL and at the Scientific Carbons Inc. facility in Blakely, 

Georgia. The unit was also used to show that the fluidizable catalyst being developed 

by NREL in collaboration with CoorsTek in Golden, Colorado, is able to reform the 

pyrolysis vapors while maintaining its physical integrity. This technology is 

particularly interesting because it is applicable to all forms of biomass. This project 

is a showcase of the hydrogen economy vision that exemplifies stakeholder 

involvement throughout the energy chain (farmers, food processors, industrial 

commodity producers, energy/fuel consumers).

Hydrogen Production and Carbon Monoxide 

Uptake Rates vs. Total Call Mass

Cross section view by SEM 

of the micron thick Na/Al/Si 

ZSM-5 membrane on 

gamma-alumina substrate for 

hydrogen purification.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

8

QUANTUM Technologies Tanks Validated for 5,000 and 10,000 psi On-Board Hydrogen Storage 

The 5,000 and 10,000 psi tanks developed by QUANTUM 

Technologies have been validated to meet the requirements 

of DOT FMVSS304, NGV2-2000 (both modified for 

10,000 psi hydrogen) and draft E.I.H.P standard. The tanks 

were submitted to typical safety testing, including: Burst 

Tests (2.35 safety margin), Fatigue, Extreme Temperature, 

Hydrogen Cycling, Bonfire, Severe Drop Impact Test, Flaw 

Tolerance, Acid Environment, Gunfire Penetration, 

Accelerated Stress, Permeation and Material testing. These 

QUANTUM “TriShield” tanks achieve 6% hydrogen by 

weight, 1,050 W-h/L, and 2,000 W-h/kg, meeting the 

percent weight and specific energy goals and nearly 

meeting the energy density goal of 1,100 W-h/L. 

Significant cost reductions are possible with further 

optimization. QUANTUM is now working with several 

automotive manufacturers to incorporate these tanks into hydrogen fuel cell vehicles.

World’s First Hydrogen Station Co-Produces Fuel and Electricity A facility that will serve as a 

“learning” demonstration of hydrogen as a safe and clean energy alternative for vehicle refueling is under 

construction by Air Products and Chemicals, Inc., in partnership with Plug Power Inc. and the City of Las 

Vegas (CLV), Nevada. The facility includes small-scale, on-site hydrogen production technologies, a 

hydrogen/compressed natural gas blend refueling facility, and a 50-kW PEM fuel cell system which supplies 

electricity to the grid. The fueling station and power 

plant are co-located at the existing City of Las Vegas 

Fleet & Transportation Western Service Center. The 

CLV was given easement to public lands by the Bureau 

of Land Management, which also conducted the 

appropriate environmental analyses for the facility. All 

permits were approved and construction is nearly 

complete. Other partners include NRG Technologies in 

Reno, Nevada, who is retrofitting the 6 buses donated by 

the City of Las Vegas that will be refueled at this station, 

and the University of Las Vegas, who is modifying a bus 

to burn hydrogen in an internal combustion engine and 

to store the hydrogen in a compressed tank. 

Hydrogen Technologies for Public 

Transportation in California’s Coachella Valley The 

SunLine Services group continued to host what has 

been called the world’s most complex hydrogen 

demonstration project to date. Buses running on 

hydrogen and hydrogen/natural gas mixtures were used 

for public transport and filled at SunLine’s public 

access fueling island. Two different types of 

electrolyzers, one supplied by a photovoltaic grid and 

the other by a natural gas reformer, produced hydrogen 

on-site. A full training program, including a 

curriculum for the local community college, has been 

developed. More than 5,000 visitors a year from 

QUANTUM TriShieldTM Type IV Tank

Sunline Transit Clean Fuel 

Mall and Hydrogen Transit 

Bus Being Refueled
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

9

around the world have toured SunLine’s facilities. SunLine’s experience and leadership is instrumental in 

establishing a knowledge base and developing codes and standards for hydrogen production and use.

University of Miami Leads Hydrogen Safety Evaluation and Simulation Studies for Codes and 

Standards Development Using computer simulations and 

real-time safety studies, Dr. Michael Swain at the University 

of Miami evaluated the safety protocols at the California Fuel 

Cell Partnership (CaFCP) building in Sacramento, California. 

Two different hydrogen leak scenarios were used to evaluate 

building ventilation and potential ignition hazards, and to 

establish safety procedures in the event of a hydrogen leak. 

Dr. Swain also developed a simple method for visualizing the 

motion of gases from a hydrogen leak, which will be used to 

determine sensor placement for hydrogen leak detection. 

These and other tests being done at the University of Miami 

are being used by the International Code Council Ad Hoc 

Committee to develop codes and standards for the safe use of 

hydrogen.

Transportation Fueling Infrastructure Analysis Completed Longitude 122 West completed its analysis 

of transportation fueling infrastructure costs and environmental impacts, looking at refueling alternatives 

(gaseous or liquid hydrogen); vehicle configuration and fuel alternatives (various hydrogen storage and power 

plant selections, and alternative fuels, including methanol and gasoline); cost variations for electricity, natural 

gas and hydrogen with economic conditions and over international boundaries; and future costs of upstream 

infrastructure. The analysis showed that various options for hydrogen infrastructure are possible and that the 

least costly option may vary with location, local pricing of gas or electricity, and technology maturity. Nearterm options using hydrogen delivered from existing sources are quite feasible. The longer-term options 

include building new central production and distribution facilities. On-site generation requires development of 

commercial subsystems. The urgency of reduced local emissions can be met with hydrogen-fueled vehicles 

and clean hydrogen brought in by pipeline or produced by electrolysis. 

Porvair Scales Up Oak Ridge Bipolar Plate Process During FY 2002, Porvair Fuel Cell Technology 

scaled up PEM bipolar plate fabrication technology licensed from Oak Ridge National Laboratory. The 

process involves fabricating porous carbon pre-forms 

which are subsequently impregnated with carbon by a 

chemical vapor impregnation or deposition process to the 

desired density. The plates can be embossed with the flow 

field pattern to eliminate machining. Porvair has scaled 

up production to 30 plates per day and is designing a 

semi-continuous process for 300 plates per day. As 

shown in the accompanying table, DOE material 

properties have been met. Plates designed by UTC Fuel 

Cells have been delivered to them for a 20-cell stack.

Brookhaven National Laboratory Has Developed a Process for Low-Pt Electrodes Brookhaven 

National Laboratory has developed and demonstrated a new electrocatalyst structure and deposition process 

with higher mass-specific activity (amps/mole of Pt) for hydrogen oxidation and CO tolerance than 

commercial electrocatalysts with several times higher platinum loadings. The concept involves synthesis of 

electrocatalysts by spontaneous deposition of Pt on a Ru surface, resulting in a submonolayer of Pt on the Ru 

nanoparticles. Based on cell testing performed at Los Alamos National Laboratory, the Pt loading and Ru 

Porvair Carbon/Carbon BiPolar Plates
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

10

loading of the new anode catalyst structure are 0.06 g/

kW and 0.50 g/kW, respectively. The Pt loading is well 

below the DOE target of 0.2 g Pt/peak kW total for the 

MEA, and the Ru loading is at the level of the present 

state-of-the-art catalysts. Future work in this area 

includes replacement of the Ru with a non-precious 

metal such as tungsten to further reduce the precious 

metal loading and demonstration of the concept for 

oxygen reduction at the fuel cell cathode. Durability 

and scale-up issues will also be addressed.

3M Develops High-Performance MEAs This 3M 

project is directed toward demonstrating highperformance, matching PEM fuel cell components that 

can be manufactured by integrated pilot processes, 

using a patented nano-structured thin-film catalyst 

support system, and reducing precious metal loadings. 

Progress during FY 2002 includes: 

development of a new Pt ternary cathode 

catalyst that gives the same performance 

with one-half the amount of Pt, producing 

0.4 A/cm2

 at 0.8 V under 30/30 psig H2/air 

with 0.2 mg/cm2 total precious metal per 

MEA; identification of a non-precious 

metal replacement for Ru on the anode for 

reformate tolerance, which, with air bleed, 

gives equivalent performances within ± 10-

20 mV; integration of multiple process 

steps for generating the nanostructured 

catalyst support films into a single pass, dry 

web-coating, pilot plant process; and 

verification of the uniformity of the 

processed roll-goods. The accompanying 

figure shows the excellent uniformity of 7 statistically sampled MEAs from a 450-lineal yard roll-good.

SwRI Demonstrates Pilot Manufacturing of Low-Pt Electrodes During FY 2002, Southwest Research 

Institute (SwRI), in cooperation with W.L. Gore and Associates, a leading supplier of MEAs for PEM fuel 

cells, completed scale-up and demonstration of a high-volume pilot manufacturing process for electrode 

material, a crucial (and currently costly) element in the highvolume production of fuel cell MEAs. The key component of this 

process is a vacuum coating unit capable of producing large 

quantities of high-performance, ultra-low platinum (0.1 mg/cm2

total) per year and the potential for bringing MEA production costs 

below $10/kW. A pilot manufacturing facility was installed which 

has the capability of catalyzing more than 100,000 m2

 per year of 

electrode material on a 2-shift basis. Several thousand ft2 of 

electrode materials at 40 linear feet per minute have been 

manufactured and fabricated into MEAs, which were tested on 

reformate and neat hydrogen in single cells. The continuously-
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

11

produced MEAs compare favorably with baseline MEAs with much higher Pt loadings. Future work will 

focus on the durability of the low-Pt MEAs. 

McDermott Operates Integrated Gasoline Fuel Processor During a 100-hour test, McDermott 

Technology successfully demonstrated a large-scale, fully-integrated multi-fuel processor on gasoline to 

produce a fuel cell-quality gas containing 43% hydrogen. The 

fuel processor produces enough hydrogen for a 50-kW PEM fuel 

cell power plant, sufficient to provide propulsion power for a 

small vehicle or to supply hydrogen to a stationary fuel cell 

installation. The processor is based on a design which 

incorporates state-of-the-art autothermal reforming, liquid-phase 

desulfurization, and a medium-temperature shift reactor for CO 

clean-up to achieve compact size, simplified controls, and high 

efficiency. The system also includes a preferential oxidation 

(PrOx) unit supplied by Los Alamos National Laboratory and a 

steam generator based on microchannel heat exchanger 

technology developed by Pacific Northwest National Laboratory.

Caterpillar Operates PEM Fuel Cell stack on 

Ethanol Reformate Caterpillar, Nuvera Fuel Cells, 

and Williams Bio-Energy have teamed to develop and 

demonstrate a 15-kW ethanol-fueled PEM fuel cell 

system. The primary technical objectives of this project 

are to demonstrate performance, durability and 

reliability and to understand correlations and reduce 

gaps between stationary and transportation PEM fuel 

cell applications. Power module design specifications 

have been completed. The reformer has been tested for 

a short period of time (45 minutes) on ethanol at rated 

power, and 45- and 80-cell stacks have been 

successfully tested with output from the reformer. 

Programmatic Highlights

Hydrogen Storage Workshop On-board hydrogen storage is a “critical path” enabling technology 

because current technologies offer limited driving range and demand excessive cost, volume, and weight. A 

Hydrogen Storage Workshop (see http://www.eren.doe.gov/hydrogen/docs/2002storageworkshop.html) was 

held during FY2002 to discuss approaches to increasing the capacity and reducing the cost of hydrogen storage 

technologies. Sessions were held on carbon technologies, chemical storage, advanced/complex hydrides, and 

advanced concepts. Participants included representatives of industry, academia, and DOE/national 

Laboratories. As a result of the Workshop, a hydrogen storage solicitation is planned for FY2003.

High-Temperature Polymer Membrane Working Group It is desirable to operate PEM fuel cells at 

temperatures exceeding the currently typical 80°C. Operation at higher temperature would facilitate stack and 

system thermal management, increase CO tolerance, and improve electrode kinetics. A High-Temperature 

Polymer Membrane Working Group was established to address this challenging task and to coordinate 

industrial, government, and academic efforts on membrane design and synthesis, thermal stability, maintaining 

conditions beneficial to proton conduction in the polymeric medium, implementation of new “carrier” media to 

replace the function of water in Nafion, study of proton transfer dynamics, and understanding the fundamentals 

of the proton transfer and transport processes.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

12

The formation and processing of MEAs from any new polymers, including any critical additives, is also 

being addressed. The oxygen reduction reaction (ORR) activity within MEAs containing different additives or 

other mechanisms of proton transfer must be understood as well.

The Working Group meets biannually in conjunction with the Electrochemical Society Meetings, allowing 

us to assess progress and to communicate issues and needs to the High-Temperature-Membrane community at 

large.

Fuel Cells for Buildings and Stationary Applications A workshop was held with DOE and industry 

stakeholders on April 10-11, 2002 to identify the issues related to fuel cells for buildings and stationary 

applications (see http://www.eren.doe.gov/hydrogen/pdfs/stationary_fc_proceedings.pdf). A solicitation, 

“Cooperative Research, Development, and Demonstration for Fuel Cells for Stationary and Automotive 

Applications”, was issued (see http://www.energy.gov/HQPress/releases02/seppr/pr02193.htm) addressing the 

major issues raised during the workshop through DOE’s “Industry Interactive Procurement System” (IIPS) 

web page (http://e-center.doe.gov under the “HELP” section of the website – DE-SC02-02EE11137). The 

solicitation also includes topics that address cross-cutting barriers to both stationary and automotive fuel cells. 

Portable and Off-Road Fuel Cell Power Applications Portable power will likely be the first highvolume market for fuel cells because of their low power requirements and less-stringent cost target (~$5,000/

kW). The manufacturing capability that develops for portable power fuel cells will help accelerate 

commercialization of fuel cells for stationary power generation and transportation. A joint DOE/industry 

Portable Power Workshop was held in January 2002 (see http://www.eren.doe.gov/hydrogen/docs/

2002fcportablepowerworkshop.html). The focus of the Workshop was portable fuel cells for low-power (subwatt to 20-50W) applications such as consumer electronics and high-power (20W to 5kW) applications such as 

auxiliary power units (APUs) (1-10kW) for hotel and refrigeration loads for long-haul trucks and recreational 

vehicles. A solicitation, “Research, Development, and Integration of Energy Efficient Technologies in 

Portable Power and Off-Road Fuel Cell Applications” (see http://www.golden.doe.gov/

business%20opportunities/solicitations.html - DE-PS36-02GO92TBD) will be issued for R,D&D in proposed 

consumer electronics and auxiliary power unit fuel cell systems. The solicitation will also request proposals to 

assess technical issues and perform R&D to evaluate and demonstrate remedies specific to off-road fuel cell 

applications. 

Reports to Congress The United States Congress, in November of 2001, directed the DOE to submit two 

reports addressing the status of fuel cell technologies (see http://www.eren.doe.gov/RE/hydrogen.html. The 

first of these reports, to be issued in November of 2002, addressed the need for public/private partnerships to 

demonstrate the use of fuel cells in commercial scale applications. This report identified two public-private 

partnership programs, one on Stationary and Distributed Generation and one on Transportation and 

Infrastructure, which would be required to enable commercial-scale demonstration and to realize the benefits 

of fuel cell technologies.

The second report requires DOE to report on “the technical and economic barriers to the use of fuel cells in 

transportation, portable power, stationary and distributed generation applications.” The report is also expected 

to include “recommendations on program adjustments based on an assessment of the technical, economic and 

infrastructure requirements needed for the commercial use of fuel cells for stationary and transportation 

applications by 2012.” This second report is in the early draft stage.

Future Directions

Worldwide interest in hydrogen and fuel cell technologies remains very strong for a broad range of 

transportation, stationary, and portable power applications. The U.S. DOE remains committed to contributing 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

13

to this progress in a significant way by supporting R&D activities that address the most critical barriers to the 

introduction of commercially viable PEM fuel cell systems and supporting fuel infrastructure.

Recent new DOE projects de-emphasize fuel cell system integration and full-scale stack development 

because industry has the capability to carry these efforts forward. The DOE program will focus on addressing 

the most critical issues of cost, durability, and performance of materials, components, and enabling 

technologies. Substantial progress was made during 2002 toward meeting the technical targets for fuel cell and 

fueling systems for light-duty vehicles; however, significant technical and economic challenges remain before 

fuel cell vehicles and the supporting infrastructure will achieve significant market penetration. As we move 

forward, we will continue to work with our government and industry partners to address these challenges. In 

addition to the contracts with industry and academia, the DOE national laboratories will continue to provide 

valuable support to the Hydrogen, Fuel Cells, and Infrastructure Technologies Program during FY 2003 (see 

Table 4). Through these efforts and other related projects, researchers in the Program will continue to improve 

cost, durability, efficiency, and overall system performance, allowing us to move closer to the commercial 

availability of fuel cell vehicles.

Table 4. DOE national laboratory R&D in support of Hydrogen, Fuel Cells, 

and Infrastructure Technologies program. 

Laboratory R&D Focus 

Argonne National Laboratory Systems Analysis 

Fuel Processor Catalysis 

Fast-Start Fuel Processing 

Brookhaven National Laboratory Low-Pt Electrodes 

Lawrence Berkeley National Laboratory Electrocatalysts 

Lawrence Liverm ore National Sensors 

Hydrogen Storage 

Los Alam os National Laboratory Sensors 

Im proved Cathodes 

High-Temperature Mem branes 

Durability Studies 

Fuels Effects 

National Energy Technology Laboratory Fuel Processing

National Renewable Energy Laboratory Vehicle and Hydrogen Infrastructure Analyses

Hydrogen Production 

Hydrogen Storage 

Oak Ridge National Laboratory Stack Materials/Components 

Pacific Northwest National Laboratory Microchannel Fuel Processing 

Sandia National Laboratory Hydrogen Purification 

Hydrogen Storage 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

14

As mentioned earlier, EERE’s Hydrogen Program, Fuel Cells for Buildings Program, and Fuel Cells for 

Transportation Program were merged to form the Hydrogen, Fuel Cells and Infrastructure Program. The 

Program Office is organized as follows:

Programmatic responsibilities have been assigned as follows:

Hydrogen Production Team

Pete Devlin

(202) 586-4905

Peter.Devlin@ee.doe.gov

• Overall Hydrogen Production R&D

• FreedomCAR Energy Industry Expansion

Roxanne Danz

(202) 586-7260

Roxanne.Danz@ee.doe.gov

• Biological, Biomass, and other Renewable Hydrogen Production

Chris Bordeaux

(202) 586-3070

Christopher.Bordeaux@ee.doe.gov

• Integrated Power Parks

• Uninterruptible Power Systems

• H2 Infrastructure Validation

• California Fuel Cell Partnership

• International Outreach (non-IEA)

Matt Kauffman

(202) 586-5824

Matthew.Kauffman@ee.doe.gov

• Cross-cutting Analyses

• Electrolyzers

Arlene Anderson

(202) 586-3818

Arlene.Anderson@ee.doe.gov

• H2 Production: Natural Gas, Petroleum Feedstocks

• Coordinate with Fossil Energy on Coal-Based H2 Production

• 5-Year R,D&D Plan Development

• Platinum Mining & Recovery

Mark Paster

(202) 586-2821

Mark.Paster@ee.doe.gov

• Overall Feedstock Strategy for H2 production

• High Temperature Thermochemical and Electroysis H2 Production

• Hydrogen Delivery
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Hydrogen Storage Team

Lucito Cataquiz

(202) 586-0729

Lucito.Cataquiz@ee.doe.gov

• Support Service Contractor COTR

• Cost/Financial Status

• Pressurized Tanks & Hydrogen Compressors

JoAnn Milliken

(202) 586-2480

JoAnn.Milliken@ee.doe.gov

• Overall Hydrogen Storage

• Fuel Cell International Activities

• FreedomCAR Storage & Vehicle Interface Tech Team

Fuel Cell Team

Pat Davis

(202) 586-8061

Patrick.Davis@ee.doe.gov

• Overall Fuel Cell Systems

• FreedomCAR Fuel Cell Tech Team

• Compressors/Expanders

Donna Ho

(202) 586-8000

Donna.Ho@ee.doe.gov

• Transportation Fuel Cells

• CARAT Program

Valri Lightner

(202) 586-0937

Valri.Lightner@ee.doe.gov

• Fuel Processing

• MEA R&D

John Garbak

(202) 586-1723

John.Garbak@ee.doe.gov

• Fuel Cell Vehicle Demonstration

• Liaison with 21st Century Truck

• Fuel Cells for APUs

Kathi Epping

(202) 586-7425

Kathi.Epping@ee.doe.gov

• Stationary Fuel Cells

Nancy Garland

(202) 586-5673

Nancy.Garland@ee.doe.gov

• National Lab Fuel Cell R&D

• Sensors

• GATE Program

Cross-Cutting Functions

Sig Gronich

(202) 586-1623

Sigmund.Gronich@ee.doe.gov

• Overall Technology Validations for Transportation and Stationary 

Applications

Christy Cooper 

(202) 586-1885

christy.cooper@ee.doe.gov

• Education on Hydrogen and Fuel Cells

Neil Rossmeissl

(202) 586-8668

Neil.Rossmeissl@ee.doe.gov

• H2 Codes and Standards

• H2 Safety

• Hydrogen Technical Advisory Panel

• IEA H2 Agreement
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

16

The Office of Hydrogen, Fuel Cells and Infrastructure Technologies has established the following FY 2003 

priorities:

1. Develop an integrated 5-year R,D&D Plan to address challenges identified in the National Hydrogen 

Energy Roadmap.

2. Implement a “national” program in hydrogen storage that focuses on low pressure, solid-state materials.

3. Develop, with assistance of the National Academy of Sciences, a feedstock strategy for hydrogen 

production which can be used as a basis for cost effective implementation of hydrogen infrastructure.

4. Prepare an integrated DOE Hydrogen Plan to coordinate efforts among the Offices of Energy Efficiency 

and Renewable Energy, Fossil Energy, Nuclear Energy and Science.

5. Evaluate the feasibility and conduct planning for a fuel cell vehicle and hydrogen infrastructure test and 

evaluation program.

6. Engage the energy industry as formal partners in FreedomCAR.

7. Establish more comprehensive PEM stationary fuel cell activities. (Initiating new activities with a 

solicitation for fuel cell R,D&D, see graphic.)

8. Publish a national plan for safety, codes and standards.

9. Develop a hydrogen education “campaign” as recommended in the President’s National Energy Policy.

10. Establish closer relationships with states through EERE Regional Support Offices to execute hydrogen and 

fuel cell R,D&D.

The remainder of this report presents extended project abstracts that highlight progress achieved during FY 

2002 under the Hydrogen, Fuel Cells, and Infrastructure Technologies Program. The extended abstracts 

summarize both industry and national laboratory projects, providing the major results of the work being 

conducted to overcome the technical barriers associated with the development of hydrogen production, 

storage, and delivery and fuel cell power systems.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

17

We hope to see you at the next program review meeting to be held in Berkeley, California on May 19-22, 

2003.

Steven G. Chalk, Program Manager

Office of Hydrogen, Fuel Cells, and Infrastructure Technologies

Energy Efficiency and Renewable Energy

Left to Right: Front Row: Donna Ho, Patrick Davis, Steve Chalk, Mark Paster, John Garbak

Middle Row: Christy Cooper, JoAnn Milliken, Roxanne Danz, Sigmund Gronich, Lucito Cataquiz, 

Arlene Anderson, Nancy Garland, Kathi Epping, Valri Lightner, Chris Bordeaux

Back Row: Neil Rossmeissl, Tia Alexander, John Petrovic (LANL), Reeshemiah Schuler (CSMI), 

Peter Devlin, Matt Kauffman, Bill Cleary (ANL)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Section II. Hydrogen Production and Delivery
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

21

II.A Biological Processes

II.A.1 Biological Water Gas Shift Development 

Gary R. Vanzin, Sharon Smolinski, Karen Kronoveter, Pin-Ching Maness, Edward J. Wolfrum 

(Primary Contact), Andrew S. Watt, and Jie Huang

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401

(303) 384-7705, fax: (303) 384-6363, e-mail: ed_wolfum@nrel.gov

DOE Technology Development Manager: Roxanne Danz

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Objectives

• Study the overall biological CO shift pathway at the physiological, biochemical, and genetic levels.

• Improve the rates and durability of H2 production from CO by determining how CO regulates the 

overall water-gas shift (WGS) pathway by serving as an inducer, a substrate, and an inhibitor. 

• Elucidate the genetic system of the CO shift reaction to (1) identify the various components involved 

and (2) allow manipulation of gene expression.

• Develop bioreactors that will promote an economic biological WGS reaction.

• Design, construct, and operate a bioreactor capable of operating at elevated system pressures.

• Measure the specific CO shift kinetics of the photosynthetic bacterium Rubrivivax (Rx.) gelatinosus

CBS.

Approach

• Characterize the physiological and biochemical mechanisms in the CO shift reaction by which Rx. 

gelatinosus CBS produces H2 from CO. 

• Clone and characterize genes involved in the Rx. gelatinosus CBS CO shift pathway.

• Build on the understanding of the CO shift pathway, optimize the WGS process for maximum H2

production.

• Develop reactor models and economic analyses to guide the research and development efforts of the 

biological WGS process.

• Scale up the WGS bioreactor design based on laboratory data, reactor modeling results, and economic 

analyses.

Accomplishments

• Completed physiological/biochemical study of the CO shift reaction and determined that CO acts as an 

inducer of the CO shift reaction at the gene transcription level and that at least 10% (v/v) CO is 

required to maximally induce the H2 production activity.

• Identified several aspects of the CBS genome that will aid in the cloning of genes involved in H2

production. 

• Successfully operated trickle-bed bioreactors with volumes of 1L and 5L, and showed that the 

performance of the larger reactor could be predicted from the performance of the smaller one.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

22

• Operated the 1-L bioreactor on a synthesis gas stream derived from biomass gasification, and 

investigated a number of materials for use as reactor supports.

• Determined the specific CO shift rate of Rx. gelatinosus CBS.

• Operated a 100-mL pressurized bioshift reactor at system pressure of 10 atm. 

• Completed a "Work for Others" project with a refinery services company that demonstrated the ability 

of NREL-isolated microorganisms to effectively treat certain "real-world" refinery gas streams, and 

documented the attractive economics of the overall process. This work culminated in a National 

Renewable Energy Laboratory (NREL) Record of Invention (ROI).

Future Directions

• Determine if the CO shift reaction can serve as an energy-yielding step in darkness. If verified, this 

energy can be used to sustain cell growth and to induce new CO shift enzymes to support H2

production for a longer duration without the need for light input.

• Investigate the enzymes and proteins involved in the initial CO oxidation step - namely the CO 

dehydrogenase (CODH) enzyme, its electron acceptor and electron mediators - to further understand 

the biochemistry of the CO shift pathway.

• Construct a large-insert genomic library in a broad host range plasmid. This will facilitate the cloning 

of CO-shift related genes as well as be useful in complementation experiments when a CO-shift 

mutant is obtained.

• Continue efforts to overcome the technical hurdles involved in operating the pressurized 1-L volume 

WGS bioreactor. Key issues to be resolved include system pressure control, in-place reactor 

sterilization, media addition and removal, and pH/ORP monitoring at elevated pressures. 

• Once the bench scale system is optimized, design and construct a pilot-scale pressurized bioreactor at 

significantly increased scale.

• Continue to build on the specific rate measurement work completed, continuing experiments on the 

effect of trace levels of organic compounds on the specific CO shift rate of Rx. gelatinosus CBS.

• Determine how coproducts might affect the overall economics of biological hydrogen production, 

specifically on the co-production of single-cell protein (SCP).

• Continue work with industrial partners to investigate near-term applications for the biological water 

gas shift process.

Introduction

Microbial production of H2 has gained 

substantial interest in recent years due to the wide 

variety of substrates microbes can use to generate H2. 

These substrates can either be waste biomass or 

commercial waste streams containing organic 

compounds. Microbial H2 production therefore has 

the dual benefits of generating a clean fuel and 

reducing waste. However, due to its heterogenous 

nature, biomass utilization by microbes is extremely 

slow. Instead, biomass can be gasified via a 

thermochemical process to generate a homogeneous 

synthesis gas, which contains hydrogen, carbon 

monoxide and carbon dioxide. The water-gas shift 

reaction, in which carbon monoxide is oxidized to 

carbon dioxide, and simultaneously water is reduced 

to hydrogen, is used to produce hydrogen from 

synthesis gas. The photosynthetic bacterium 

Rubrivivax gelatinosus CBS is one of a small 

number of organisms that can perform this reaction at 

ambient temperatures. This biologically-mediated 

shift reaction may be a cost-effective technology for 

the production of hydrogen from syngas.

Approach

Biological Hydrogen from Fuel Gases

To fully utilize the CO shift reaction as a 

renewable energy resource, it is necessary to 

understand the mechanism of how Rx. gelatinosus
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

23

CBS produces H2 from CO. Carbon monoxide plays 

multiple roles in the microbial CO oxidation system, 

serving as a substrate, an inducer, and an inhibitor. 

In order to obtain optimal activity, we must 

understand how CO regulates the overall pathway, 

i.e., the effect and concentrations of CO on the 

maximal induction, synthesis, and maintenance of 

enzymatic activities in the CO pathway. 

Another approach to gain insight into the CO 

shift is to clone and characterize genes involved in 

the pathway. For example, gene discovery will help 

in the understanding of the rate-limiting step during 

H2 production, as well as how CO shift enzymes are 

produced and degraded.

Bioreactor Development for Biological Hydrogen 

Production

The overall goal of this part of the project is the 

scale-up of the low-temperature biological WGS 

reaction to provide a cost-effective technology for 

the conditioning of biomass-derived synthesis gas. 

Laboratory-scale data, reactor modeling results, and 

technoeconomic analyses are used to guide the 

development of the bioreactor and the biological 

WGS process. To date, these efforts indicate that 

favorable process economics are achievable if the 

WGS bioreactor can be operated at elevated 

pressures with improved volumetric mass transfer 

rates. The current approach is focused on examining 

the effect of reactor parameters on volumetric mass 

transfer rates, and designing and testing laboratoryscale bioreactors with higher system operating 

pressures. Once positive results are achieved in 

small-scale tests, a larger high-pressure reactor can 

be constructed to collect more detailed reactor data.

Results

Induction of CO Shift Activity by CO

A series of tests were conducted to determine if 

CO induces the CO-shift activity in Rx. gelatinosus

CBS. Within two hours after adding CO to the gas 

phase of CBS cultures previously incubated in the 

absence of CO, CO consumption and H2 production 

were detected (Figure 1). The addition of 

chloramphenicol (which inhibits new protein 

synthesis while exerting no effect on existing 

hydrogenase activity) along with the CO 

immediately stopped the appearance of the CO-shift 

activity for up to a seven-hour period (triangle), 

suggesting that CO acts as an inducer for the de novo

synthesis of both carbon monoxide dehydrogenase 

(CODH) and hydrogenase of the CO-shift pathway. 

Consequently, in order to maintain CO shift activity, 

CO must be present to ensure that new enzymes are 

constantly being synthesized.

To determine if an optimal or minimal level of 

CO is required for maximal induction of the CO shift 

activity, Rx. gelatinosus CBS was cultured in various 

amounts of CO, ranging from 0%-50% (v/v). Data 

from Figure 2 suggests that at least 10% CO has to 

present at all times to ensure the maximal induction 

of the CO shift pathway. 

Because CO facilitates the production of new CO 

shift enzymes, its constant presence is likely required 

to maintain steady-state levels of CO shift proteins. 

To verify this, two identical CBS cultures were 

Figure 1. Effects of CO and a Protein Synthesis 

Inhibitor Chloramphenicol (Choloram) on 

Inducing CO Shift Activity

Figure 2. Effect of CO Concentrations on the 

Induction of Various Levels of CO Shift 

Activity
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

24

prepared and fed 20% CO during inoculation. To the 

control culture, no CO was fed once it was consumed 

within 10 hours, and to a parallel culture CO (20%) 

was fed daily. Results from Figure 3 indicate that, 

over a period of five days, the culture receiving CO 

daily was able to maintain a more constant CO shift 

rate, between day two and day five, 56% higher than 

that of the control without daily CO feeding. 

Cloning the CO Shift Genes

To identify the genes involved in the CO shift 

pathway in Rx. gelatinosus CBS, a library of 

transposon mutants was created and then screened 

for CO shift activity. Mutants unable to either 

consume CO or produce H2 would suggest that the 

gene(s) responsible for that function has been 

interrupted with the transposon insertion. After 

screening approximately 2000 mutants, two lines that 

were unable to consume CO or produce H2 were 

identified. Biochemical analysis indicates that 

mutant GV1214 lacks the CODH activity, yet it still 

retains partial hydrogenase activity; mutant GV1762 

retains 32% of the CODH activity, yet its 

hydrogenase activity is abolished completely. 

Sequence analysis suggests that the mutations 

occurred in a CODH gene and hydrogenase large 

subunit gene, respectively.

During the mutagenesis process, several mutants 

unable to produce carotenoid, the photoprotective 

pigment responsible for scavenging oxygen radicals, 

were identified. Without the carotenoid pigment, 

these colonies will die when exposed to both high 

light and O2 simultaneously. Data from Figure 4 

show that when a G1 culture was bubbled with air, 

the bulk of the cells were killed completely within 

one minute of illumination (open square). Little 

impact was observed with a parallel control 

containing CBS wild-type cells (closed square). 

Based on the susceptibility of the pigmented mutant 

to photo-oxidative killing, CO shift mutant can be 

selected from a population of cells cultured in CO as 

the sole carbon substrate. 

Effect of Bioreactor Pressure and Inlet CO 

Concentration

Experiments were performed to investigate the 

effects of reactor pressure and carbon monoxide 

concentration on the volumetric productivity of 

trickle bed bioreactors. Figure 5 shows the apparent 

rate constant, kapp (a measure of reactor 

productivity), as a function of bioreactor operating 

pressure. As the system pressure is increased, the 

Figure 3. Effect of CO Feedings on Rates and 

Longevity of the CO Shift Reaction

Figure 4. Photo-Oxidative Killing of Rx. gelatinosus 

Figure 5. The effect of elevated operating pressure on 

the apparent bioshift rate constant kapp. At 

modest pressures, a significant increase in rate 

with pressure is seen. This effect appears to 

diminish at approximately 80 psia. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

25

apparent rate constant increases up to approximately 

80 pounds per square inch absolute (psia), after 

which no further increase in reactor productivity 

occurs. 

The effect of CO concentration on reactor 

performance was evaluated in a series of experiments 

in a 1-L bioreactor. The data in Figure 6 cover the 

range of CO inlet concentrations of 8% to 99%. The 

curve is a model fit using a previously developed 

reactor model (Wolfrum 2002). The data at low CO 

concentrations (triangle symbols) are believed to be 

unreliable because the measured concentration 

change is close to the repeatability of the analytical 

equipment (Agilent P200 gas chromatograph). The 

data in Figure 6 clearly indicate that the biologicallymediated CO-shift reaction is robust over a very wide 

range of inlet carbon monoxide concentrations; no 

poisoning of the microorganism occurred at high 

inlet CO concentrations.

Measurement of Specific H2 Production Rate

The overall rate of CO uptake and H2 production 

were measured at various cell densities.

Figure 7 shows a plot of hydrogen production 

and carbon monoxide uptake rates vs. the total cell 

mass for all experiments. When the total cell mass is 

less than approximately 0.012 g, there is a linear 

relationship between cell mass and H2 production 

and CO uptake. At higher cell mass values, the CO 

uptake and H2 production values do not appear to 

increase linearly with cell mass. This is an indication 

of bulk (gas-liquid) mass transfer limitations. The 

data in the linear region of the curves in Figure 7 

were used to calculate the specific CO uptake rate 

and H2 production rate. 

The specific rate of H2 production appears to be 

slightly higher than the specific CO uptake rate (0.80 

vs. 0.73 mmol/min/g [millimole/minute/gram]), 

although theoretical stoichiometry predicts that they 

should be equal. However, at the 95% confidence 

level, the two parameters are equal. This is 

supported by the value of the H2/CO ratio (1.07 ± 

0.14), which cannot be distinguished from unity at 

the 95% confidence level. 

Conclusions

• CO serves as an inducer for the CO shift 

reaction in Rx. gelatinosus CBS, and its 

constant presence is required to maintain this 

reaction both at a higher rate and for a longer 

duration.

• At least 10% CO has to be present at all 

times to ensure the maximal induction of the 

CO shift pathway in Rx. gelatinosus CBS.

• By identifying putative CO shift genes, 

researchers are beginning to understand, on 

the molecular level, how Rx. gelatinosus

CBS responds to CO and produces H2. 

• A line of carotenoidless pigmented mutants 

has been isolated and could be incorporated 

Figure 6. Effect of inlet CO concentration on CO 

conversion in a 1-L bioreactor. Curve is 

model prediction (Wolfrum 2002).

Figure 7. Hydrogen Production and Carbon 

Monoxide Uptake Rates vs. Total Cell 

Mass for Photosynthetic Bacterium 

Rhodocyclus gelatinosus CBS
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

26

in a photo-oxidative killing scheme to enrich 

for CO-shift mutants.

• Inlet CO concentration has little impact on 

the bioreactor conversion efficiency over the 

range 8%-99% CO (v/v%).

• Increasing the system pressure increased the 

bioreactor productivity up to approximately 

80 psia, after which no increase in 

productivity was seen. 

• The specific CO uptake rate was activity 

0.73 ± 0.10 mmol/min/g, while the specific 

H2 production rate was 0.80 ± 0.13 mmol/

min/g. These two rates cannot be 

distinguished from each other at the 95% 

confidence level.

FY 2002 Publications/Presentations

1. Maness, P.-C. and Weaver, P.F. "Evidence for 

Three Distinct Hydrogenase Activities in 

Rhodospirillum rubrum." Applied Microbiology 

and Biotechnology, 57, pp. 751-756 (2001).

2. Maness, P.-C., Smolinski, S., Dillon, A.C., Heben, 

M.J., and Weaver, P.F. "Characterization of the 

Oxygen Tolerance of a Hydrogenase Linked to a 

Carbon-Monoxide Oxidation Pathway in 

Rubrivivax gelatinosus." Applied and 

Environmental Microbiology, 68: 2633-2636 

(2002).

3. Maness, P.-C. and Weaver, P.F. "Hydrogen 

Production from a Carbon-Monoxide Oxidation 

Pathway in Rubrivivax gelatinosus." International 

Journal of Hydrogen Energy. In press (October 

2002).

4. Wolfrum, Edward J. and Watt Andrew S. 

"Bioreactor Design Studies for a HydrogenProducing Bacterium." Applied Biotechnology 

and Bioengineering, 98-100, pp. 611-625 (2002).

5. Maness, P.-C. "The Production of H2 from a COOxidation Reaction in the Photosynthetic 

Bacterium Rubrivivax gelatinosus." Lecture to the 

Graduate Program in Plant Physiology, Institute of 

Biological Chemistry, Washington State 

University (March 15, 2002) (Honorarium).

6. Wolfrum, E., Amos, W., and Hamel, B. "Method 

for the Recovery and Incremental Production of 

Hydrogen from Process Waste Streams in 

Refineries." (Record of Invention).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

27

II.A.2 Maximizing Photosynthetic Efficiencies and H2 Production in Microalgal 

Cultures

Tasios Melis (Primary Contact)

University of California at Berkeley

Plant & Microbial Biology

Berkeley, CA 94720-3102

(510) 642-8166, fax: (510) 642-4995, e-mail: melis@nature.berkeley.edu

DOE Technology Development Manager: Roxanne Danz

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Objectives 

• Develop genetically engineered microalgae with enhanced photosynthetic solar conversion 

efficiencies and biomass/hydrogen production capabilities under mass culture conditions. 

• Minimize absorption and wasteful dissipation of sunlight by the algae, a solution that requires 

reduction in the number of the chlorophyll (Chl) molecules in photosynthesis. 

• Clone genes that determine the size of the Chl antenna in the model green alga Chlamydomonas 

reinhardtii. These genes could then be over-expressed or down-regulated to improve green alga solar 

conversion efficiency and biomass/hydrogen production. 

• Create a library of genes conferring a 'truncated chlorophyll antenna size' in green algae.

Approach

• Apply DNA insertional mutagenesis and screening in the model green alga Chlamydomonas 

reinhardtii for the isolation of 'truncated Chl antenna' transformants. 

• Apply biochemical, genetic and molecular analyses of the transformant cells, followed by DNA 

sequencing to identify genes that confer a 'truncated Chl antenna size'. 

Accomplishments 

• DNA analysis of the 'truncated Chl antenna size' tla1 insertional transformant: Completed the DNA 

sequencing of the ARG7 insertion site in the tla1 strain. Obtained full-length genomic DNA, cDNA 

and protein amino acid sequences for the TLA1 gene. 

• Initiate tla1 mutant complementation studies: Successfully complemented the tla1 strain with plasmid 

carrying the ble selectable marker and the isolated TLA1 gene. Biochemical analyses are now under 

way to characterize the complemented strain. Initial results showed that the complemented strain has 

nearly wild type levels of Chl/cell and a low Chl a / Chl b ratio in its thylakoid membranes. The Tla1

protein sequence analysis and the recovery of wild type phenotype provide a strong indication that the 

TLA1 gene is a "Chl antenna size" regulatory gene. This is a first-time isolation and characterization of 

such a regulatory gene.

• Investigate mechanism of CAO (chlorophyll a oxygenase) gene expression: The CAO gene expression 

affects the biosynthesis and distribution of chlorophyll among the photosystems in green algae. The 

research proved that it is an important target for a truncated Chl antenna size in photosystem II (PSII). 

Beyond CAO, the work investigated the signal transduction pathway for the regulation of the Chl 

antenna size by irradiance. A novel molecular mechanism was discovered and analyzed.

• DNA insertional mutagenesis library: An additional 5,000 DNA insertional transformants were 

generated and screened by the Chl a/ Chl b ratio measurement. Among those, two putative "truncated 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

28

Chl antenna size" strains were identified. A biochemical and molecular analysis of these new 

transformants is now being undertaken.

• Solar conversion efficiency and H2 production tests in wild type and tla1 transformant: Scale-up tests 

were initiated under field conditions (in the University of California Berkeley [UCB] greenhouse) 

where photosynthetic productivity of wild type and tla1 strains is conducted under mass culture 

conditions. Preliminary measurements of biomass accumulation and gas production (so far oxygen) 

support the notion of a better performance for the tla1 versus the wild type strain.

Future Directions 

• Functional analysis of the TLA1 gene: Initiate a study of expression patterns for the TLA1 gene under 

different irradiance conditions. 

• Bring to a completion the tla1 mutant complementation studies: Complete the biochemical analyses of 

the complemented strain by providing a full molecular and biochemical characterization of its 

properties. 

• DNA insertional mutagenesis library: Proceed with the genetic, molecular and biochemical analysis of 

the two additional (recently isolated) putative "truncated Chl antenna size" strains that have been 

isolated. 

• Solar conversion efficiency and H2 production measurements in wild type and tla1 mutant: Continue 

with the scale-up measurements under field conditions (in the UCB greenhouse) to fully assess 

photosynthetic productivity and H2 production in wild type and tla1 strains.

Introduction 

Green algae growing under full sunlight, when 

photosynthetic productivity ought to be at a 

maximum, have disappointingly low solar 

conversion efficiencies. The reason for this 

inefficiency is that green algae have a genetic 

tendency to assemble large arrays of light absorbing 

chlorophyll antenna molecules in their photosystems 

[1]. At high solar intensities, the rate of photon 

absorption by the Chl antennae of the first few layers 

of cells in the mass culture far exceeds the rate at 

which photosynthesis can utilize them, resulting in 

dissipation and loss of the excess photons as 

fluorescence or heat. Up to 95% of absorbed photons 

could thus be wasted, reducing solar conversion 

efficiencies and cellular productivity to unacceptably 

low levels. In addition to the wasteful dissipation of 

excitation, and due to the high rate of photon 

absorption by the photosynthetic apparatus, cells at 

the surface of the mass culture are subject to severe 

photoinhibition of photosynthesis [2], a phenomenon 

that compounds losses in productivity. Moreover, 

cells deeper in the culture are deprived of much 

needed sunlight, as this is strongly attenuated due to 

filtering [1, 3, 4]. A genetic tendency of the algae to 

assemble large arrays of light absorbing chlorophyll 

antenna molecules in their photosystems is a survival 

strategy and a competitive advantage in the wild, 

where light is often limiting. Obviously, this property 

of the algae is detrimental to the yield and 

productivity in a mass culture.

The work aims to minimize the Chl antenna size 

of green algae and, thus, to maximize solar 

conversion efficiencies and the yield of biomass/

hydrogen production in mass culture. 

Approach 

A smaller, or truncated, chlorophyll antenna size 

in microalgae could alleviate the optical 

shortcomings associated with a fully pigmented Chl 

antenna, because it will minimize the overabsorption of bright incident sunlight by the 

photochemical apparatus of the algae. A truncated 

Chl antenna will diminish the over-absorption and 

wasteful dissipation of excitation energy by the cells, 

and it will also diminish photoinhibition of 

photosynthesis at the surface while permitting greater 

transmittance of light deeper into the culture. Such 

altered optical properties of the cells would result in 

much greater photosynthetic productivity and better 

solar conversion efficiency in the mass culture. 

Indeed, actual experiments [1, 5] showed that a 

smaller Chl antenna size results in a relatively higher 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

29

light intensity for the saturation of photosynthesis in 

individual cells but, concomitantly, in a 3-fold 

greater productivity of the mass culture. Thus, 

approaches by which to genetically truncate the Chl 

antenna size of photosynthesis in green algae merit 

serious consideration. 

The Chl antenna size of the photosystems is not 

constant. In general, low light intensity during 

growth promotes a large Chl antenna size. Growth 

under high light intensities elicits the assembly of a 

smaller Chl antenna size [6-11]. Such adjustments of 

the Chl antenna size in response to irradiance are a 

compensation reaction of the chloroplast, as they are 

inversely related to the incident intensity. This 

regulatory mechanism functions in all organisms of 

oxygenic and anoxygenic photosynthesis [7, 12, 13]. 

It is possible to genetically interfere with this 

regulatory mechanism through DNA insertional 

mutagenesis and transformation of the algae and to 

direct the chloroplast biosynthetic/assembly 

activities toward a permanently truncated Chl 

antenna size.

Results 

The foregoing suggests that, for purposes of 

biomass or H2-production under ambient sunlight 

conditions, it is important to identify genes that 

confer a truncated Chl antenna size in the model 

green alga Chlamydomonas reinhardtii. Once a 

library of such genes is at hand, over-expression or 

down-regulation of expression of these genes, as 

needed, can be applied to other green algae that 

might be suitable for commercial exploitation and 

H2-production. 

The chlorophyll a oxygenase (CAO) gene 

encodes a chloroplast enzyme that catalyzes the last 

step in the Chl biosynthetic pathway, namely the 

conversion of Chl a into Chl b. A mutant with 

inactivated CAO was unable to synthesize Chl b, 

thereby lacking this auxiliary light-harvesting 

pigment. The assembly, organization and function of 

the photosynthetic apparatus was comparatively 

investigated in wild type and a Chl b-less mutant of 

Chlamydomonas reinhardtii, generated by DNA 

insertional mutagenesis [14]. It was shown that lack 

of Chl b diminished the photosystem II (PSII) 

functional Chl antenna size from 230 Chl (a and b) to 

about 95 Chl a molecules [15]. However, the 

functional Chl antenna size of photosystem I (PSI) 

remained fairly constant at about 290 Chl molecules, 

independent of the presence of Chl b (Table 1). This 

work provided evidence to show that transformation 

of green algae can be used as a tool by which to 

interfere with the biosynthesis of specific pigments 

and, thus, to generate mutants exhibiting a 

permanently truncated Chl antenna size. In support 

of the role of CAO in the Chl antenna size of 

photosynthesis, further work [11] showed that CAO

gene expression is highly regulated in vivo according 

to the Chl antenna size needs of the organism. Thus, 

the CAO gene may be a target for a truncated Chl 

antenna size in PSII. 

Chlamydomonas reinhardtii double mutant 

npq2/lor1 lacks the β,ε-carotenoids lutein and 

loroxanthin as well as all β,β-epoxycarotenoids 

derived from zeaxanthin (e.g. violaxanthin and 

neoxanthin). Thus, the only carotenoids present in 

the thylakoid membranes of the npq2/lor1 cells are 

β-carotene and zeaxanthin. The effect of these 

mutations and the lack of specific xanthophylls on 

the Chl antenna size of the photosystems was 

investigated [16]. In cells of the mutant strain, the 

Chl antenna size of PSII was substantially smaller 

than that of the wild type (Table 1). In contrast, the 

Chl antenna size of PSI was not truncated in the 

mutant. This analysis showed that absence of lutein, 

violaxanthin and neoxanthin specifically caused a 

smaller functional Chl antenna size for PSII but not 

for that of PSI. Thus, xanthophyll-biosynthesis 

genes, such as lycopene ε-cyclase and zeaxanthin 

epoxidase may be targets for a truncated Chl antenna 

size in PSII. 

More recent DNA insertional mutagenesis and 

screening resulted in the isolation of a regulatory 

mutant, the phenotype of which was Chl deficiency 

and elevated Chl a /Chl b ratio [17]. This truncated 

light-harvesting Chl antenna (tla1) mutant apparently 

has a defect in the Chl antenna regulatory 

mechanism, the result of which is inability to 

produce a large Chl antenna size under any growth 

conditions. Table 1 shows that both the Chl antenna 

size of PSII and PSI were smaller in the tla1 strain. 

This work provided further evidence to show that 

transformation of green algae can also be used as a 

tool by which to genetically interfere with the 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

30

molecular mechanism for the regulation of the Chl 

antenna size in green algae (Kanakagiri, Polle and 

Melis, unpublished). 

The ultimate goal of our combined approaches is 

to develop customized strains of green algae which 

assemble only the minimum Chl antenna size of the 

PSII-core complex (37 Chl) and of the PSI-core 

complex (95 Chl molecules) (Table 1). 

Table 1. Photosystem Chl antenna size in wild 

type and three Chlamydomonas reinhardtii mutant 

strains. The cbs3 strain lacks Chl b and was isolated 

upon DNA insertional mutagenesis [15]. The npq2/

lor1 strain lacks all β,ε-carotenoids as well as the 

β,β-epoxycarotenoids. It contains zeaxanthin but 

lacks lutein, violaxanthin and neoxanthin from its 

thylakoid membranes [16]. The tla1 strain was 

isolated upon DNA insertional mutagenesis [17]. 

Note that the tla1 transformant has the smallest 

combined Chl antenna size of the three mutants 

described.

Notes:

Numbers show the Chl antenna size, i.e., the Chl (a and b) 

molecules specifically associated with each photosystem. 

1

Polle, Kanakagiri and Melis, unpublished.

Conclusions 

Identification of three genes that confer a 

truncated Chl antenna size in the photosynthetic 

apparatus is a significant development in the 

direction toward cost-effective commercialization of 

green algae for biomass and H2 production. Most 

promising in this respect is the cloning of the TLA1

regulatory gene. A complete genomic and cDNA 

sequence of TLA1 as well as the amino acid sequence 

of the Tla1 protein are currently at hand (Kanakagiri 

and Melis, manuscript in preparation). It should be 

noted that this is a first-time isolation and 

characterization of a "Chl antenna size" regulatory 

gene. The TLA1 gene may serve as a molecular tool 

in the elucidation of the function of the mechanism 

that regulates the Chl antenna size in photosynthesis. 

It may thus contribute to the identification of other 

genes that are important in this regulatory process. 

Further, TLA1 may serve in the truncation of the Chl 

antenna size in a variety of green algae and, 

potentially, in non-oxygenic photosynthetic bacteria. 

In conclusion, green algae with a truncated Chl 

antenna size are indispensable in efforts to 

substantially increase solar conversion efficiencies 

and the yield of biomass and H2 production in 

photobioreactors under mass culture conditions.

References 

1. Melis A, Neidhardt J and Benemann JR (1999) 

Dunaliella salina (Chlorophyta) with small 

chlorophyll antenna sizes exhibit higher 

photosynthetic productivities and photon use 

efficiencies than normally pigmented cells. J. 

appl. Phycol. 10: 515-525

2. Melis A (1999) Photosystem-II damage and repair 

cycle in chloroplasts. What modulates the rate of 

photodamage in vivo? Trends in Plant Science 4: 

130-135

3. Naus J and Melis A (1991) Changes of 

photosystem stoichiometry during cell growth in 

Dunaliella salina cultures. Plant Cell Physiol. 32: 

569-575

4. Neidhardt J, Benemann JR, Zhang L and Melis A 

(1998) Photosystem-II repair and chloroplast 

recovery from irradiance stress: relationship 

between chronic photoinhibition, light-harvesting 

chlorophyll antenna size and photosynthetic 

productivity in Dunaliella salina (green algae). 

Photosynth. Res. 56:175-184

5. Nakajima Y and Ueda R (1999) Improvement of 

microalgal photosynthetic productivity by 

reducing the content of light harvesting pigment. J 

Appl Phycol 11: 195-201

6. Melis A (1991) Dynamics of photosynthetic 

membrane composition and function. Biochim. 

Biophys. Acta (Reviews on Bioenergetics) 1058: 

87-106

Wild 

type

cbs3

(Chl 

b-less)

npq2/lor1

(Lut, Vio & 

Neo-less)

tla1 Goal

(minimum Chl 

antenna size)

Chl-PSII 230 90 125 1151 37

Chl-PSI 290 289 294 1601 95

 Table 1.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

31

7. Melis A (1996) Excitation energy transfer: 

functional and dynamic aspects of Lhc (cab) 

proteins. In, Oxygenic Photosynthesis: The Light 

Reactions" (DR Ort, CF Yocum, eds), Kluwer 

Academic Publishers, Dordrecht, The 

Netherlands, pp. 523-538

8. Maxwell DP, Falk S and Huner NPA (1995) 

Photosystem II excitation pressure and 

development of resistance to photoinhibition. 1. 

Light harvesting complex II abundance and 

zeaxanthin content in Chlorella vulgaris. Plant 

Physiol 107: 687-694

9. Huner NPA, Oquist G and Sarhan F (1998) 

Energy balance and acclimation to light and cold. 

Trends in Plant Science 3: 224-230

10. Escoubas JM, Lomas M, LaRoche J and 

Falkowski PG (1995) Light intensity regulation 

of cab gene transcription is signalled by the redox 

state of the plastoquinone pool. Proc. Nat. Acad. 

Sci. 92: 10237-10241

11. Masuda T, Polle JEW and Melis A (2002) 

Biosynthesis and distribution of chlorophyll 

among the photosystems during recovery of the 

green alga Dunaliella salina from irradiance 

stress. Plant Physiol. 128: 603-614

12. Webb MR and Melis A (1995) Chloroplast 

response in Dunaliella salina to irradiance stress. 

Effect on thylakoid membrane assembly and 

function. Plant Physiol. 107: 885-893

13. Tanaka A and Melis A (1997) Irradiancedependent changes in the size and composition of 

the chlorophyll a-b light-harvesting complex in 

the green alga Dunaliella salina. Plant Cell 

Physiol. 38: 17-24

14. Tanaka A, Ito H, Tanaka R, Tanaka N, Yoshida 

K and Okada K (1998) Chlorophyll a oxygenase 

(CAO) is involved in chlorophyll b formation 

from chlorophyll a. Proc Natl Acad Sci USA 95: 

12719-12723

15. Polle JEW, Benemann JR, Tanaka A and Melis A 

(2000) Photosynthetic apparatus organization and 

function in wild type and a Chl b-less mutant of 

Chlamydomonas reinhardtii. Dependence on 

carbon source. Planta 211: 335-344

16. Polle JEW, Niyogi KK and Melis A (2001) 

Absence of lutein, violaxanthin and neoxanthin 

affects the functional chlorophyll antenna size of 

photosystem-II but not that of photosystem-I in 

the green alga Chlamydomonas reinhardtii. Plant 

Cell Physiol. 42: 482-491

17. Polle JEW, Kanakagiri S, Benemann JR and 

Melis A (2001) Maximizing photosynthetic 

efficiencies and hydrogen production in 

microalga cultures. In, BioHydrogen II (J 

Miyake, T Matsunaga and A San Pietro, eds), 

Elsevier, Kidlington, Oxford, U.K., pp. 111-130

FY 2002 Publications/Presentations

1. Polle JEW, Niyogi KK and Melis A (2001) 

Absence of lutein, violaxanthin and neoxanthin 

affects the functional chlorophyll antenna size of 

photosystem-II but not that of photosystem-I in 

the green alga Chlamydomonas reinhardtii. Plant 

Cell Physiol. 42: 482-491

2. Polle JEW, Kanakagiri S, Benemann JR and 

Melis A (2001) Maximizing photosynthetic 

efficiencies and hydrogen production in microalga 

cultures. In, BioHydrogen II (J Miyake, T 

Matsunaga and A San Pietro, eds), Pergamon/

Elsevier Science, Kidlington, Oxford, U.K., pp. 

111-130.

3. Masuda T, Polle JEW and Melis A (2002) 

Biosynthesis and distribution of chlorophyll 

among the photosystems during recovery of the 

green alga Dunaliella salina from irradiance 

stress. Plant Physiol. 128: 603-614

4. Masuda T, Tanaka A and Melis A (2002) 

Irradiance-dependent adjustments in the 

Chlorophyll antenna size of Dunaliella salina are 

regulated by coordinate expression of Chlorophyll 

a Oxygenase (CAO) and Lhcb genes in shared 

signaling pathways. Plant Mol. Biol., in press

5. Polle JEW, Niyogi KK and Melis A (2001) 

Annual Meeting of the American Society of Plant 

Biologists. Providence, Rhode Island, July 21-25, 

2001. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

32

6. Masuda T, Tanaka A and Melis A (2001). Annual 

Meeting of the American Society of Plant 

Biologists. Providence, Rhode Island, July 21-25, 

2001.

7. Melis A, Polle JEW, Kanakagiri S and Masuda T 

(2001) International Photosynthesis Congress, 

Australia, Aug. 15-18, 2001. 

8. Melis A (2002) British Royal Society Meeting, 

London. March 13-15, 2002.

9. Melis A (2002) BioHydrogen 2002 (An 

International Conference Held in The 

Netherlands). April 21-24 2002. 

10. Polle JEW, Kanakagiri S, Jin E-S and Melis A 

(2002) BioHydrogen 2002 (An International 

Conference Held in The Netherlands). April 21-

24 2002. 

11. Kanakagiri S, Polle JEW and Melis A (2002) 

Tenth International Conference on the Cell & 

Molecular Biology of Chlamydomonas. 

University of British Columbia, Vancouver. 

June 11-16, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

33

II.A.3 Efficient Hydrogen Production Using Enzymes of the Pentose Phosphate 

Pathway

Barbara R. Evans (Primary Contact), Jonathan Woodward (Retired), Hugh M. O'Neill (University of 

Tennessee, Knoxville), Eugene Pinkhassik (University of Memphis), and John P. Getty, Jr.

Oak Ridge National Laboratory 

4500N Bethel Valley Road

Oak Ridge, TN 37831-6194

(865) 241-3185, fax: (865) 574-1275, e-mail: evansb@ornl.gov

DOE Technology Development Manager: Roxanne Danz

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Main Subcontractor: J.P. Getty Enterprise, Inc., Oak Ridge, Tennessee

Objectives 

• Cloning and expression of thermophilic pentose phosphate pathway enzymes

• Immobilization and stabilization of enzymes and cofactors for bioreactor development

• High stoichiometric yields of hydrogen from sugars derived from renewable resources using the 

optimized pentose phosphate pathway enzymes

Approach

• Isolate genes for thermophilic enzymes by polymerase chain reaction (PCR) and subclone into 

expression vectors for production in mesophilic host

• Employ and analyze immobilization methods for optimal performance

• Determine enzyme kinetics separately and in combination to optimize hydrogen production

Accomplishments 

• Demonstration of the production of hydrogen by combination of enzymes from different thermophiles 

• Isolation and subcloning of two key enzymes, glucose 6-phosphate dehydrogenase and 6-

phosphogluconate dehydrogenase, from the thermophile Thermotoga maritima

• Production of hydrogen by enzymes encapsulated in lipsomes

Future Directions 

• Isolate, clone, and express the remaining pentose phosphate pathway enzymes

• Demonstrate hydrogen production with thermophilic pentose phosphate pathway enzymes and 

compare with mesophilic counterparts

• Improve liposome encapsulation and investigate additional immobilization methods

Introduction

The sugar glucose is the monomeric unit of 

which the major biomass components starch and 

cellulose are made. The abundant disaccharide 

sucrose, composed of glucose and fructose, is 

another common source of glucose. Methods to 

hydrolyze these bioproducts to glucose have been 

studied intensively by the food and bioethanol 

industries. But direct microbial production of 

hydrogen from glucose is generally not very efficient 

and often produces undesirable side products such as 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

34

hydrogen sulfide. Utilization of isolated enzymes 

has been shown to increase the efficiency of 

hydrogen production. Two enzymes, glucose 

dehydrogenase and hydrogenase, can be coupled 

through the cofactor nicotinamide adenine 

dinucleotide phosphate (NADP) to produce 1 mol H2

per mol glucose (1, 2). By addition of the enzymes 

of the pentose phosphate pathway (Figure 1), a 

metabolic pathway found in all organisms, the yield 

can be increased to close to the theoretical value of 

12 mol H2/mol glucose. In this pathway, the cofactor 

NADP is reduced by the two enzymes glucose 6-

phosphate dehydrogenase and 6-phosphogluconate 

dehydrogenase, then used by hydrogenase for 

production of hydrogen gas (3). Utilization of the 

pentose phosphate pathway enzymes is currently 

limited by their expense and lack of long-term 

stability, as well as the instability and expense of the 

cofactor NADP. Development of cost-effective 

enzyme catalysts, cofactor stabilization, and 

bioreactor design is essential for practical application 

of this method for hydrogen generation from biomass 

components.

A popular method for obtaining stable 

biocatalysts is the utilization of enzymes originating 

from thermophiles, microorganisms that grow at high 

temperatures. Many of these enzymes can be 

conveniently produced from recombinant DNA 

constructs in mesophilic hosts such as Escherchia 

coli laboratory strains. The recombinant versions 

offer the advantages of simpler culture conditions, 

high yields, and simplified purification compared to 

production from the original thermophiles. 

However, some enzymes, such as hydrogenases, 

require certain special metal groups or other features 

and cannot be produced in common laboratory host 

bacteria. 

Utilizing specific DNA primers that flank the 

desired gene sequences, copying and amplification of 

target genes for cloning can be rapidly carried out 

using PCR. The cloning of thermophilic enzymes is 

simplified by the availability of the complete 

genomic sequences of thermophiles such as 

Methanococcus jannaschii (4) and Thermotoga 

maritima (5) as a result of the DOE Microbial 

Genome Program, as well as the availability of 

bacterial strains from the American Type Culture 

Collection. 

Approach

Enzyme and whole cell activities of the 

thermophile Thermotoga maritima were examined 

for comparison with and complementation of the 

recombinant enzymes and the Pyrococcus 

hydrogenase.

The target genes were determined based on the 

successful production of hydrogen using 

commercially available pentose phosphate pathway 

enzymes originating from mesophilic organisms such 

as yeast and rabbits. Based on the published 

genomic sequences of thermophiles, DNA primers 

are designed and synthesized for amplification of the 

target genes by PCR. The amplified genes are then 

cloned into an expression vector so they can be 

produced in laboratory host strains of Escherichia 

coli. These recombinant thermophilic enzymes will 

be tested for activity, then combined with the 

hydrogenase produced by the thermophile 

Pyrococcus furiosus (M. M. Adams, University of 

Figure 1. Production of Hydrogen from Glucose Using 

Pentose Phosphate Pathway Enzymes
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

35

Georgia) and the cofactor NADP for optimization of 

the production of hydrogen from glucose.Parallel to 

the cloning endeavor, methods of immobilization and 

stabilization, as well as cofactor recycling, are being 

investigated for suitability in a bioreactor for the 

production of hydrogen. Methods that are being 

examined include sol gel immobilization, NADP 

analogs, and liposome encapsulation. The formation 

of liposomes, small vesicles composed of lipid 

bilayers that enclose aqueous solutions, does not 

require covalent linking of enzymes and can easily 

entrap multiple enzymes and cofactors in one step. 

Results

The intrinsic production of hydrogen by 

Thermotoga whole cells and cell extracts was found 

to be low. The cell extracts produced hydrogen at a 

rate of 0.1 μmol/h. The key enzyme glucose 6-

phosphate dehydrogenase was detected in the cell 

extracts. Addition of Pyrococcus hydrogenase 

increased the rate of hydrogen production by the cell 

extract to 1.9 μmol/h. 

Primers were designed and used to clone the 

genes for the pentose phosphate pathway enzymes 

glucose 6-phosphate dehydrogenase and 6-

phosphogluconate dehydrogenase from genomic 

DNA prepared from T. maritima. Activity of the 

cloned enzymes was detected when the recombinant 

genes were expressed in E.coli.

Liposomes were prepared containing glucose 

dehydrogenase, hydrogenase, and the cofactor 

NADP+ encapsulated in lipid bilayers. The bilayers 

Figure 3. Glucose Transporter Mechanism

Figure 2. Liposomes as Nanobioreactors 

Figure 4. Production of Hydrogen from Glucose by 

Encapsulated Glucose Dehydrogenase, 

Hydrogenase, and NADP in Presence (+) or 

Absence of Glucose Transporter
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

36

are permeable to hydrogen gas but keep proteins and 

other water-soluble molecules inside the liposome, 

similar to natural cell membranes (Figure 2). The 

compound tertbutylphenyl boronic acid was 

incorporated into the liposomes to transport glucose 

across the lipid bilayer (Figure 3). Hydrogen 

production was demonstrated when this transporter 

was included in the liposomes with the two enzymes 

at an encapsulation efficiency of 1% (Figure 4). A 

modified procedure using dried, reconstituted lipid 

vesicles to encapsulate the enzymes increased the 

efficiency to 30-50%

Conclusions

The Thermotoga enzymes were demonstrated to 

be compatible with the Pyrococcus hydrogenase, 

indicating that the utilization of recombinant 

enzymes coupled with this hydrogenase will be 

successful. Without hydrogenase supplementation, 

Thermotoga whole cells and extracts produced 

hydrogen at a low rate. Cloning and expression of 

two of the pentose phosphate pathway enzymes from 

Thermotoga was accomplished. Liposome 

encapsulation was shown to be a promising method 

for immobilization of enzymes for the production of 

hydrogen. The enzymes and cofactor are kept inside 

the liposomes and are not diluted or lost, while 

hydrogen passes through the liposome membrane 

and is removed from the solution by the carrier gas. 

References 

1. Woodward, J., Mattingly, S. M., Danson, M., 

Hough, D., Ward, N., Adams, M. (1996) Nature 

Biotechnology 14, 872-874, "In vitro hydrogen 

production by glucose dehydrogenase and 

hydrogenase".

2. Woodward, J., Cordray, K. A., Edmonston, R. J., 

Blanco-Rivera, M., Mattingly, S. M., and Evans, 

B. R., "Enzymatic Hydrogen Production: 

Conversion of Renewable Resources for Energy 

Production", (2000) Energy & Fuels 14, 197-201.

3. Woodward, J., Orr, M., Cordray, K., Greenbaum, 

E. (2000) Nature 405, 1014-1015, "Enzymatic 

Production of Biohydrogen".

4. Bult, C. J., White, O., Olsen, G. L., Zhou, L., 

Fleischmann, R. D., Sutton, G. G., Blake, J. A., 

Fitzgerald, L. M., Clayton, R. A., Gocayne, J. D., 

Kerlavage, A. R., Dougherty, B. A., Tomb, J.-F., 

Adams, M. D., Reich, C. I., Overbeek, R., 

Kirkness, E. F., Weinstock, K. G., Merrick, J. M., 

Glodek, A., Scott, J. L., Geoghagen, N. S. M., 

Weidman, J. F., Fuhrman, J. L., Nguyen, D., 

Utterback, T. R., Kelley, J. M., Peterson, J. D., 

Sadow, P. W., Hanna, M. C., Cotton, M. D., 

Roberts, K. M., Hurst, M. A., Kaine, B. P., 

Borodovsky, M., Klenk, H.-P., Fraser, C. M., 

Smith, H. O., Woese, C. R., Ventner, J. C. (1996) 

Science 273, 1058-1073 (23 August), "Complete 

Genome Sequence of the Methanogenic Archeon, 

Methanococcus jannaschii".

5. Nelson, K. E., Clayton, R. A., Gill, S. R., Gwinn, 

M. L., Dodson, R. J., Haft, D. H., Hickey, E. K., 

Peterson, J. D., Nelson, W. C., Ketchum, K. A., 

McDonald, L., Utterback, T. R., Malek, J. A., 

Linher, K. D., Garrett, M. M., Stewart, A. M., 

Cotton, M. D., Pratt, M. S., Phillips, C. A., 

Richardson, D., Heidelberg, J., Sutton, G. G., 

Fleischmann, R. D., White, O., Salzberg, S. L., 

Smith, H. O., Venter, J. C. and Fraser, C. M. 

(1999) Nature 399(6734), 323-329, "Evidence for 

lateral gene transfer between Archaea and bacteria 

from genome sequence of Thermotoga maritima."

FY 2002 Publications/Presentations 

1. Woodward, J., Heyer, N. I., Getty, J. P., O'Neill, 

H. M., Pinkhassik, E., Evans, B. R. "Efficient 

Hydrogen Production Using Enzymes of the 

Pentose Phosphate Pathway". Proceedings of the 

Annual Review Meeting, U. S. Department of 

Energy Hydrogen Program, Golden, CO, May 6-

8, 2002.

2. O'Neill, H. M., Angley, C. V., Hemery, I., Evans, 

B. R., Dai, S., and Woodward, J., "Properties of 

carbohydrate-metabolizing enzymes immobilized 

in sol-gel beads: stabilization of invertase and -

glucosidase by Blue Dextran", (2002) Biotechnol. 

Lett. 24: 783-790.

3. Heyer, N. I., O'Neill, H. M., Gerike, U., 

Woodward, J., Danson, M. J., Hough, D. W. 

Extremophiles (2002) in press.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

37

Special Recognitions & Awards/Patents 

Issued 

1. Getty, J. P., Orr, M. T., Woodward, J. USPO 

6,395,252 (2002), "Method for the continuous 

production of hydrogen".
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

38

II.A.4 Biohydrogen Production from Renewable Organic Wastes

Shihwu Sung (Primary Contact), Dennis A. Bazylinski, and Lutgarde Raskin 

Dept. of Civil and Construction Engineering

Iowa State University, Ames IA 50011

(515) 294-3896, fax (515) 294-8216, e-mail: sung@iastate.edu

DOE Technology Development Manager: Roxanne Danz

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Objectives

• Develop different strategies for selective growth of hydrogen producing bacteria (e.g., heat selection 

and pH control) in a mixed culture environment.

• Apply nucleic acid based technique to identify and quantify the hydrogen-producing bacterial 

population in a complex microbial community background. 

• Optimize process to achieve sustainable hydrogen production in continuous flow bioreactors.

Approach

• Evaluate technical and practical feasibility of sustainable hydrogen production in continuous flow 

bioreactors. 

• Investigate the effect of heat treatment of sludge on hydrogen production rate through batch and 

continuous experiments. 

• Apply nucleic acid based techniques for microbial identification and quantification.

• Find the correlation between hydrogen yield and the Clostridium sp. in the continuous bioreactor.

Accomplishments

• Evaluated the effect of environmental factors on hydrogen production using mixed culture.

• Successfully enriched naturally available mixed seed to culture hydrogen producing bacteria. 

• Enhanced the hydrogen production through preheat treatment of seed inoculum at 70-90oC for 15 - 20 

minutes followed by repeated heat treatment of settled returned sludge.

• Found positive correlation of hydrogen production with Clostridium sp. in the continuous bioreactor.

Future Directions

• Develop pilot-scale hydrogen production demonstration project using real wastes.

• Evaluate the full-scale plant design.

• Prepare design manual with detail guidelines for biohydrogen production from organic wastes.

• "Identify and quantify the hydrogen-producing bacterial population in a complex microbial 

community background using nucleic acid based techniques.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

39

Introduction

As a sustainable energy supply with minimal or 

zero use of hydrocarbons, hydrogen is a promising 

alternative to fossil fuels. It is a clean and 

environmentally friendly fuel, which produces water 

instead of greenhouse gases when combusted. The 

waste streams from corn, soybean, and meat 

processing plants pose a major burden on the 

environment. Aerobic wastewater treatment of these 

wastes requires energy input to provide aeration, 

whereas anaerobic digestion processes can achieve 

the dual benefits of energy production in the form of 

hydrogen or methane, and waste stabilization. By 

using hardware similar to that used in industrial 

methane fermentation, the economics of hydrogen 

fermentation could be favorable due to its faster 

reaction rate. 

For global environmental considerations, 

production of hydrogen by biological reactions from 

renewable organic waste sources represents an 

important area of bioenergy production. However, 

the viability of biohydrogen production using mixed 

culture in a continuous mode has not yet been 

evaluated. This study evaluated the potential 

application of mixed culture to produce hydrogen 

and also examined two important operating 

strategies, heat treatment, and pH, control to achieve 

sustainable hydrogen production.

Approach

The first phase of this study involved the design 

and development of a completely mixed bioreactor 

for continuous hydrogen production using mixed 

culture. The experimental setup is shown in Figure 1. 

The bioreactor was equipped with mixer, pH control 

unit, external settling tank and heating chamber. 

Upon successful start-up, operation of the bioreactor 

was optimized to maximize hydrogen production. 

The process optimization included determination of 

optimum operating pH, temperature, and duration of 

heating of settled biomass, and COD loading rate. 

Detail microbial study is crucial to correlate 

hydrogen production to the microbial group 

involved. For this purpose, a nucleic acid based 

technique - terminal restriction fragment length 

polymorphism (T-RFLP) - was used to identify the 

abundant populations in the bioreactors in a complex 

microbial community background. 

Results

According to the batch test result in Figure 2, the 

pH of 5.5 was found optimum for hydrogen 

production without any detection of methane in the 

gas phase. This pH was therefore selected for all 

continuous phase research. Batch tests showed that 

heat treatment of seed inocula at 70-90oC for 15-20 

Figure 1. Experimental Setup of Continuous Bioreactor

Figure 2. Effect of pH on Hydrogen Production in 

Batch Studies
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

40

minutes enhanced the hydrogen production by more 

than five times with respect to the control (without 

heat treatment), as shown in Figure 3. Such an 

increase was likely due to more favorable conditions 

for spore-forming hydrogen producers by reducing 

nonspore-forming hydrogen consumers. An 

interesting observation was the occurrence of a lag 

phase during hydrogen production. Heat treatment 

could potentially damage the cells. Thus, the HRT 

should be longer than the lag time in the continuous 

operation so that hydrogen producers can adjust 

themselves to a new environment.

In the continuous operation, a substrate 

concentration of 20 g/L was chosen to improve 

hydrogen production because high substrate 

concentrations were favorable to hydrogen 

producers. The seed sludge was preheat-treated at 

100o

C for 15 minutes, whereas repeated heat 

treatment was applied only to returned sludge from 

reactor R1. After 10 days of operation (in steadystate), hydrogen production of reactor R1 was similar 

to that of reactor R2 but higher hydrogen content was 

maintained in reactor R1 (Figure 4). Methane was 

not detected in these two reactors. The average VFA 

concentrations were measured at 5,220 and 5,100 

mg/L as acetic acid for reactors R1 and R2, 

respectively. Approximately 92% and 93% of 

sucrose were converted into H2 and VFA in reactors 

R1 and R2, respectively. H2 yield (0.113 m3 H2/kg 

COD) of reactor R1 was higher than that (0.075 m3 

H2/kg COD) of R2 based on maximum values. 

Repeated heat treatment was, therefore, effective in 

selecting or even activating spore-forming hydrogenproducers.

Microbial studies conducted at University of 

Illinois Urbana Champaign showed that Clostridium

butyricum, C. beijerinckii, C. botulinum, C. 

putrificum and C. sporogenes were predominant in 

both reactors. Clostridia are obligate anaerobic 

acidogenic bacteria that can form spores 

(endospores) to protect themselves against 

unfavorable environmental conditions, such as high 

temperature, desiccation, radiation, or toxic 

chemicals; however, when favorable conditions 

return, they can germinate and become vegetative 

cells. Some of Clostridia's spores require heat 

treatment to increase the germination of spores.

Figure 3. Effect of Heat Treatment on Hydrogen 

Production in Batch Studies

Figure 4. Hydrogen Production Rate and Percentage 

of Hydrogen in Biogas for Continuous 

Anaerobic Reactor with (Reactor R1) and 

Without (Reactor R2) Repeated Heat 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

41

Conclusions

• Both initial heat treatment of the inoculum 

and repeated heat treatments of the biomass 

during operation promoted hydrogen 

production by eliminating non-spore forming 

hydrogen consuming microorganisms and by 

selecting for hydrogen producing, spore 

forming bacteria. 

• An operational pH of 5.5 was shown to be 

optimal for hydrogen production.

• Sustainable hydrogen production was 

possible with pH control and repeated heat 

treatment of settled sludge at 70-90oC for 

15-20 min.

• Terminal restriction fragment length 

polymorphism (T-RFLP) analysis showed 

that Clostridium and Bacillus species were 

the dominant populations in the bioreactors. 

• A positive correlation was observed between 

the total abundance of Clostridium species 

and hydrogen production during part of an 

operational run. 

Publications and Presentations

1. Duangmanee, T., Padmasiri, S., Simmons, J. J., 

Raskin, L. and Sung, S. (2002) Hydrogen 

production by anaerobic communities exposed to 

repeated heat treatment. Water Environment 

Federation 74th Conference, Chicago., Ilinois.

2. Duangmanee, T., Chyi, Y. and Sung, S. (2002) 

Biohydrogen production in mixed culture 

anaerobic fermentation. 14th World Hydrogen 

Energy Conference, Montreal, Canada.

3. Van Ginkel, S., Sung, S. and Lay, J. J. (2001) 

Biohydrogen production as a function of pH and 

substrate concentration. Environmental Science & 

Technology, 35:4726 - 4730.

4. Van Ginkel, S., Lay, J. J. and Sung, S. (2000) 

Biohydrogen production optimization using 

variable natural inocula. Proceedings of Water 

Environment Federation 73rd Annual Conference, 

Anaheim, California.

 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

42

II.A.5 Photobiological Algal H2 Production 

Task 1: Molecular Engineering of Algal H2 Production

Michael Seibert, Paul King, Liping Zhang, Lauren Mets, and Maria Ghirardi (Primary Contact)

Task 2: Cyclic Photobiological Algal H2 Production

Maria L. Ghirardi, Sergey Kosourov, Anatoly Tsygankov, Andrew Rubin, and Michael Seibert

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401

(303) 384-6312, (303) 384-6150 (fax), maria_ghirardi@nrel.gov

DOE Technology Development Manager: Roxanne Danz

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Objectives

Molecular Engineering of Algal H2 Production

• Study two cloned Chlamydomonas reinhardtii hydrogenases at the molecular biology, biochemical and 

structural level. 

• Use the information from these studies to design mutated genes with potentially higher tolerance to 

O2. 

Cyclic Photobiological Algal H2 Production

• Build a new photobioreactor system with monitoring and feeedback control capability for key 

biophysical and biochemical parameters and determine the effect of chosen parameters (pH, light 

intensity, temperature) on inactivation of O2 evolution and/or rates of H2 photoproduction by sulfurdepleted Chlamydomonas reinhardtii.

Approach

Molecular Engineering of Algal H2 Production

• Clone and sequence the [Fe]-hydrogenase genes (encoding for the enzymes that releaseH2 gas), hydA1

and hydA2, in C. reinhardtii. 

• Raise antibodies specific against each of the enzymes to investigate differences in the physiological 

role of the two cloned algal hydrogenases and to decide which enzyme to target for mutagenesis.

• Use the antibodies in detailed protein expression studies. 

• Characterize the differences between the purported amino acid sequences and structures of HydA1 and 

HydA2 to identify what specific regions of the protein to target for future mutagenesis in order to 

improve the O2-tolerance of the system. 

Cyclic Photobiological Algal H2 Production

• Evaluate the effects of pH, light intensity, and temperature on the inactivation of photosynthetic O2

evolution by sulfur-depleted algal cultures. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

43

• Build a photobioreactor with feedback control to monitor biophysical and biochemical culture 

parameters.

• Determine the effects of adding controlled amounts of sulfate during H2-production to maintain 

electron transport from H2O to the hydrogenase at higher levels.

Accomplishments

Molecular Engineering of Algal H2 Production

• Cloned and sequenced the hydA1 and hydA2 [Fe]-hydrogenase genes in C. reinhardtii. 

• Developed a new high-throughput screening procedure based on a DNA plasmid, constructed to study 

the expression of in vitro mutated hydrogenases introduced into wild-type algae. 

• Generated antibodies against oligopeptides specific to the HydA1 and HydA2 proteins to facilitate the 

expression studies. Heterologous expression of the two algal hydrogenases further confirmed the 

specificity of the antibodies.

• Completed biochemical studies of the physiological changes of C. reinhardtii upon anaerobic 

induction under photoheterotrophic and photoautotrophic conditions and correlated these results to the 

expression of the hydA1 and hydA2 transcripts. 

• Completed preliminary structural modeling studies of the proteins encoded by hydA1 and hydA2.

Cyclic Photobiological Algal H2 Production

• Evaluated the effects of pH, high light and/or high temperature on the inactivation of photosynthetic 

O2 evolution by sulfur-depleted algal cultures.

• Investigated the effects of adding controlled amounts of sulfate during H2-production to maintain 

electron transport from H2O to the hydrogenase at higher levels.

• Found that the residual PSII electron transport activity in sulfur-deprived cultures limits the rate of H2

photoproduction by the system.

• Developed the use of a fluorescence method to externally monitor the health of the cultures in the 

bioreactors and to determine when they will start to produce H2. 

Future Directions

Molecular Engineering of Algal H2 Production

• Continue to study mutant hydrogenase genes, differentiating between the roles of HydA1 and putative 

HydA2 in H2 photoproduction under different physiological conditions. These studies will determine 

which of the enzymes should be the focus of future mutagenesis efforts to generate O2-tolerant 

mutants. 

• Study the regulation of HydA2 expression using the antibody developed this year. Correlate expression 

studies of HydA2 using activity assays, antibodies, and nucleic acid hybridization techniques.

• Improve the frequency of C. reinhardtii transformation by electroporation in NREL’s laboratory.

• Generate mutant hydrogenase genes by either random or site-directed mutagenesis, based on 

information obtained from structural analyses. 

Cyclic Photobiological Algal H2 Production

• Complete a feasibility study on the operation of a new photobioreactor that produces H2 for longer 

periods of time as an alternative to significantly increasing H2-production rates.

• Design, construct, and test a photobioreactor with immobilized algal cells.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

44

• Identify and test physical and chemical variables to optimize the H2-production rates with the new 

photobioreactors.

• Eliminate the need for costly centrifugation as a means to change the growth medium from sulfurreplete to sulfur-depleted.

Introduction

Hydrogen metabolism, catalyzed by [Fe]-

hydrogenases in green algae, was first observed 60 

years ago in Scenedesmus obliquus. Since then, 

hydrogenase enzymes that either uptake or evolve H2

have been found in many green algae. Hydrogen 

production by green algae has significant advantages 

over other photobiological systems: ATP is not 

required, high theoretical efficiencies are possible, 

and water is used directly as the source of reductant 

without the need to produce biomass or to store 

intermediary carbon metabolites. Research is 

underway in several areas to maximize the hydrogen 

production capabilities of green algae: 

1. Molecular Engineering of Algal H2 Production. 

Algal H2 photoproduction is sensitive to O2, a coproduct of photosynthesis, and this sensitivity is 

one of the major factors currently limiting the use 

of algal systems for H2 production. One research 

goal is to engineer the metabolic pathways in the 

green alga, Chlamydomonas reinhardtii, involved 

in H2 photoproduction to decrease their O2

sensitivity and eventually lead to development of 

a mutant hydrogenase gene that produces H2 

under aerobic conditions.

2. Cyclic Photobiological Algal H2 Production.

Previous research has shown that removing 

sulfate from the algal growth medium partially 

inactivates the photosynthetic H2O-oxidizing 

activity of the cells and results in the 

establishment of anaerobic conditions in the 

culture. The resulting anaerobiosis leads to 

induction of the hydrogenase activity. This 

research effort is focused on further developing 

the sulfur-deprivation approach, elucidating the 

pathways involved in H2-production under sulfurdeprivation, and developing approaches to 

improve the H2-production yield of the process.

Approach

Molecular Engineering of Algal H2 Production

Mutagenesis can be used to decrease the O2

sensitivity of [Fe]-hydrogenases and thus lead 

eventually to a system that produces H2 under 

aerobic conditions. The first step in the process is to 

clone and sequence the [Fe]-hydrogenase genes 

(encoding for the enzymes that releases H2 gas), 

hydA1 and hydA2, in C. reinhardtii. In order to 

investigate differences in the physiological role of 

the two cloned algal hydrogenases, antibodies 

specific against each of the two enzymes have been 

raised and will be used for detailed protein 

expression studies. This information will help us to 

determine which enzyme to target for mutagenesis in 

order to improve the O2-tolerance of the system. 

Characterization of the differences between the 

purported amino acid sequences of HydA1 and 

HydA2, combined with structural modeling of the 

two enzymes, will be used to identify what specific 

regions of the protein to focus on in our mutagenesis 

studies, which will be done concomitantly with 

random error-prone PCR mutagenesis. 

Cyclic Photobiological Algal H2 Production

This work stems from past research that 

demonstrated the feasibility of using sulfur-deprived 

algal cultures to photoproduce H2 continuously over 

a number of days. In this case, the approach is to 

control the environment in the photobioreactor to 

maximize the H2-production activity of the system. 

This includes evaluating the effects of pH, light 

intensity, and temperature on the inactivation of 

photosynthetic O2 evolution by sulfur-depleted algal 

cultures. A photobioreactor with feedback control 

was built to support this effort. In situ fluorometry is 

also being developed as a method to externally 

monitor the physiological state of the H2-producing 

cultures. Finally, the effects of adding controlled 

amounts of sulfate during H2-production to maintain 

electron transport from H2O to the hydrogenase at 

higher levels are evaluated.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

45

Results

Molecular Engineering of Algal H2 Production

Two [Fe]-hydrogenase genes from C. reinhardtii, 

hydA1 and hydA2, have been cloned and sequenced. 

The hydA2 gene has a similar degree of homology to 

other [Fe]-hydrogenases as hydA1, and it contains all 

the motifs characteristic of other [Fe]-hydrogenases. 

Additional analysis shows that hydA2 is a distinct 

nuclear gene that is located on a different 

chromosome from hydA1 (see Figure 1A). Exposure 

of C. reinhardtii to anaerobic conditions is 

accompanied by the induction of hydrogenase 

activity. Figure 1B shows that the induced H2

photoproduction reaches steady-state levels after 

about 90 minutes of anaerobic treatment. The hydA1 

and hydA2 transcripts are induced almost equally 

under anaerobic conditions, when grown either 

photoheterotrophically (Fig. 1B) or 

photoautotrophically (not shown). Moreover, both 

transcripts are equally inactivated by exposure to O2

(not shown). 

Two oligopeptides containing sequences that are 

specifically found in either HydA1 or HydA2 were 

designed, coupled to a carrier protein and used as 

antigens to generate specific antibodies in rabbits. 

The specific antibody reaction to HydA1 and HydA2 

was characterized using cell extracts from E. coli, 

and demonstrates that the anti-HydA1 antibody 

shows very little cross-reaction with the HydA2 

protein and vice-versa. These antibodies are being 

tested against cell extracts from C. reinhardtii and 

will be used for detailed protein expression studies in 

the future. 

The predicted structures of HydA1 and of the 

putative HydA2 hydrogenase were generated by 

homology modeling of the purported amino acid 

sequences against the known structure of the [Fe]-

hydrogenase from the anaerobic bacterium, 

Clostridium pasteurianum (Cpl). The core regions of 

the HydA1 and HydA2 exhibit a very high degree of 

structural similarity with each other and with Cpl. 

Figure 2 shows a surface view of HydA1. Careful 

analyses of the model structures of the two algal 

hydrogenases will help to direct further efforts in the 

generation of O2-tolerant mutants for sustained H2

production under aerobic conditions. 

Cyclic Photobiological Algal H2 Production

Sustained production of H2 by green algae can be 

achieved by the reversible inactivation of 

photosynthetic H2O-oxidizing activity, catalyzed by 

Photosystem II (PSII). Past research has shown that 

the removal of sulfate from the growth medium can 

accomplish this inactivation. Current research efforts 

are focused on the elucidation of the pathways 

involved in H2-production under sulfur-deprivation 

Figure 1. (A) Southern blot analyses of PstI-digested C. 

reinhardtii DNA probed with, respectively, 

hydA1- or hydA2-specific DNA probes. The 

arrows indicate the location of the restriction 

digest fragments. (B) Results from Northern 

blot analyses of RNA isolated from cultures 

grown photoheterotrophically and then 

anaerobically-induced for different periods of 

time and probed with hydA1- or hydA2-

specific probes. The bars represent H2-

production activity measured concomitantly. 

Gels at the bottom show the original Northern 

blot data.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

46

and on approaches to improve the H2 production 

yield of the process. 

First, a pH titration of various metabolic 

activities during sulfur-deprivation was used to 

identify those favoring H2 production. The 

maximum yield and initial rates of H2 photoproduction by sulfur-deprived cultures were 

observed at pHs that favor the residual activity of 

PSII (Figure 3), strengthening previous observations 

that photosynthetic water oxidation is the main 

source of electrons for H2 production. At the 

equivalent optimal initial pH of 7.7, hydrogenase 

activity is close to its maximum rate. In contrast, 

starch and protein degradation peak at acidic pHs, 

and generate fermentation products (acetate, formate, 

and ethanol). If fermentation products are desired, 

the algal system is robust enough to shift its 

metabolism to a fermentative mode upon lowering 

the pH inside the photobioreactor. 

A second approach focused on the addition of 

limiting amounts of sulfate at different points during 

the process. When added at the start of anaerobiosis, 

a concentration of 5 μM sulfate will allow H2

photoproduction to start at the expected time and to 

proceed at rates similar to those of samples to which 

no sulfate was re-added. However, addition of 

sulfate at concentrations of 1 μM or higher 14 h after 

the start of H2 photoproduction will interrupt the 

process temporarily and result in lower final yields. 

These results show that it is possible to find a 

maximum concentration of sulfate that will not 

inactivate H2 photoproduction, and that this 

concentration is different depending on the time at 

which sulfate is added. These results open up the 

possibility of maintaining high PSII capacity during 

the H2-production phase by continuously supplying 

the medium with specific amounts of sulfate. 

To further understand factors that currently limit 

the rate of H2 photoproduction, PAM fluorometry 

measurements were used to externally monitor the in 

situ PSII photochemical activity of the algal culture 

inside the photobioreactor vessels. These results 

show that during the early stages of sulfur 

deprivation (O2-production and consumption 

phases), PSII photochemical activity gradually 

declines. However, at the time anaerobiosis is 

established, an additional, abrupt, and partially 

reversible down-regulation of PSII photochemical 

activity occurs, as shown in Figure 4. This drop 

begins at the exact time that the O2 concentration in 

the culture suspension reached zero. These changes 

in PSII activity are characterized by complex 

Figure 2. Surface model of HydA1. The red dot in the 

center of the structure represents the [2Fe2S] 

center of the catalytic H-cluster.

Figure 3. pH titrations of the amounts of starch and 

protein degraded, the amount of H2 produced, 

the maximum Chl a fluorescence yield (a 

measure of PSII capacity) and the in vitro

hydrogenase activity. As observed in the text, 

the pHs used in the titration of hydrogenase 

activity only were set to the actual values 

measured in vitro, and do not represent the 

initial pH at sulfur deprivation. In order to 

correlate them to the pH titrations of the other 

parameters, it is necessary to subtract 0.4 pH 

units from each value, which corresponds to 

the change in pH of the cultures from the start 

of sulfur deprivation to the early H2

photoproduction phase. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

47

dynamics during the course of cell adaptation to the 

nutrient stress. The redox state of the PQ pool has 

been identified as the primary factor in regulating the 

activity of PSII water-splitting capacity during all 

stages of sulfur deprivation. Thus, the redox potential 

of the PQ pool depends on the relationship between 

the rates of photosynthesis, chlororespiration, 

respiration, and H2 production. 

Conclusions

Molecular Engineering of Algal H2 Production

• Characterization of hydA2 confirmed that it is 

expressed at the mRNA level and is located on a 

different gene than hydA1. In addition, its 

expression is regulated by anaerobiosis. The 

hydA2 gene has a similar degree of homology to 

other [Fe]-hydrogenases as hydA1, and it contains all the motifs characteristic of these hydrogenases in algae.

• The hydA1 and hydA2 transcripts are induced 

almost equally under anaerobic conditions, and 

equally inactivated by exposure to O2. The level 

of both transcripts is further modulated by the 

growth condition of the culture prior to the 

anaerobic treatment.

• Modeled structures of HydA1 and HydA2 are 

very similar to each other and to the core structures of the [Fe]-hydrogenase from the anaerobic 

bacterium, Clostridium pasteurianum, for which 

there is a solved X-ray crystal structure. A gas 

channel from the surface to the catalytic center of 

the enzyme was identified and will direct further 

mutagenesis work.

Cyclic Photobiological Algal H2 Production

• H2 production can be optimized by controlling 

the pH of the medium at the start of sulfur deprivation.

• Different maximum amounts of sulfate can be readded to the system at different points of the sulfur-deprivation process without decreasing H2

production.

• Overall, the rates of H2-production in the system 

are limited by the rates of electron transport from 

the H2O-oxidizing complex to hydrogenase 

under anaerobic conditions. H2-production during sulfur-deprivation provides the means to reactivate residual photosynthetic electron transport capacity, which is rapidly down-regulated 

by the establishment of anaerobiosis. 

• The technique of PAM fluorescence is a practical 

and inexpensive means to externally monitor the 

start of H2 photoproduction by the cultures and 

could be further developed for use with future 

applied systems.

FY 2002 Publications/Presentations

Molecular Engineering of Algal H2 Production

1. Seibert, M., Flynn, T. and Ghirardi, M.L. (2001) 

"Strategies for Improving Oxygen Tolerance of 

Algal Hydrogen Production". In BioHydrogen II

(J. Miyake, T. Matsunaga, and A. San Pietro, 

Eds), Pergamon, Amsterdam, pp. 65-76 (2000, 

CD ROM 2000).

2. Forestier, M., Zhang, L., King, P., Plummer, S., 

Ahmann, D., Seibert, M., and Ghirardi, M. “The 

Cloning of Two Hydrogenase Genes from the 

Green Alga, C. reinhardtii”. Proceedings of the 

12th International Congress on Photosynthesis, 

18-23 August 2001, Brisbane, Australia, CSIRO 

Publishing, Melbourne, Australia. http://

www.publish.csiro.au/ps2001 (2001).

3. Zhang, L., King, P., Seibert, M. and Ghirardi, M.L. 

“Direct Evidence for Different Electron Transport 

Figure 4. Time course of physiological parameters and 

H2 production in C. reinhardtii cells during 

incubation under sulfur-deprived conditions. 

Ft

 (open squares), D∆F/Fm ́ (solid circles), Fm ́ 

(open triangles), dissolved oxygen (pO2, 

crosses), redox potential (Eh, asterisks) and 

H2 content (%) in the gas phase of the culture 

vessel (solid squares). Incubation in sulfurdeprived medium started at 0 h.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

48

Pathways Linked to H2 production in the green 

alga Chlamydomonas reinhardtii”. Abstracts of 

the 11th Western Photosynthesis Conference, 

January 3-6, 2002, Asilomar Conference Center, 

Pacific Grove, CA, p. 44.

4. Forestier, P., King, P., Posewitz, M., Schwarzer, S., 

Happe, T., Zhang, L., Ghirardi, M.L., and Seibert, 

M. “A Second Putative [Fe]-Hydrogenase Gene 

(hydA2) in C. reinhardtii is Also Expressed Under 

Anaerobic Conditions”. Submitted (2002).

5. Flynn, T., Ghirardi, M.L., and Seibert, M. 

“Accumulation of Multiple O2-Tolerant 

Phenotypes in H2-Producing Strains of C. 

reinhardtii by Sequential Application of Chemical 

Mutagenesis and Selection”. Int. J. Hydrogen 

Energy 27, 1421-1430.

6. Ghirardi, M. “The Cloning of Two Hydrogenase 

Genes from the Green Alga Chlamydomonas 

reinhardtii”. Invited plenary lecture at the 12th

International Congress on Photosynthesis, 18-23 

August 2001, Brisbane, Australia.

Cyclic Photobiological Algal H2 Production

1. Kosourov, S., Tsygankov, A., Ghirardi, M.L., and 

Seibert, M. “Sustained Hydrogen 

Photoproduction by Chlamydomonas 

reinhardtii—Effects of Sulfur Re-addition”. 

Proceedings of the 12th International Congress on 

Photosynthesis, 18-23 August 2001, Brisbane, 

Australia, CSIRO Publishing, Melbourne, 

Australia, (2001).

2. Kosourov, S., Ghirardi, M.L. and Seibert, S. 

“Influence of Extracellular pH on Hydrogen 

Photoproduction by Sulfur-Depleted 

Chlamydomonas reinhardtii Cultures”. Abstracts 

of the 11th Western Photosynthesis Conference, 

January 3-6, 2002, Asilomar Conference Center, 

Pacific Grove, CA, p. 33.

3. Antal , T. K., T. E. Krendeleva, T. V. 

Laurinavichene, V. V. Makarova, A. A. 

Tsygankov, M. Seibert, and A. B. Rubin (2001) 

"The Relationship between Photosystem 2 

Activity and Hydrogen Production in Sulfur 

Deprived Chlamydomonas reinhardtii Cells'" 

Doklady Akademii Nauk (Biochemistry and 

Biophysics) 381, 371-375.

4. Kosourov, S., Tsygankov, A., Seibert, M, and 

Ghirardi, M.L. “Sustained Hydrogen 

Photoproduction by Chlamydomonas 

reinhardtii—Effects of Culture Parameters”. 

Biotechnol. Bioeng. 78 p. 731-740 (2002).

5. Laurinavichene, T.V., Tolstygina, I.V., Galiulina, 

R.R., Ghirardi, M.L., Seibert, M., and Tsygankov, 

A. “Different Methods to Deprive 

Chlamydomonas reinhardtii Cultures of Sulfur for 

Subsequent Hydrogen Photoproduction”. Int. J. 

Hydrogen Energy 27, 1245-1249.

6. Tsygankov, A., Kosourov, S., Seibert, M., and 

Ghirardi, M.L. “Hydrogen Photoproduction under 

Continuous Illumination by Sulfur-Deprived, 

Synchronous Chlamydomonas reinhardtii

Cultures”. Int. J. Hydrogen Energy 27, 1239-

1244. 

7. Seibert, M. “Hydrogen Gas Production in 

Chlamydomonas—Effects of Sulfate Re-addition 

to Sulfur-Deprived Cultures,” Invited plenary 

lecture at the Biohydrogen Joint Workshop of 

COST Action 841 and IEA Annex 15, (September 

2002).

Special Recognitions & Awards/Patents 

Issued

Molecular Engineering of Algal H2 Production

1. Seibert, M., Flynn, T., and Benson, D. “Method for 

Rapid Biohydrogen Phenotypic Screening of 

Microorganisms Using a Chemochromic Sensor,” 

U.S. Patent No. 6,277,589.

2. Seibert, M., Flynn, T. and Benson, D. “Apparatus 

for Rapid Biohydrogen Phenotypic Screening of 

Microorganisms Using a Chemochromic Sensor,” 

U.S. Divisional Patent pending.

Cyclic Photobiological Algal H2 Production

1. Seibert, M., Makarova, A., Tsygankov, A., and 

Rubin, A.B. “A Fluorescence Technique for Online Monitoring of the Physiological State of 

Hydrogen-Producing Microorganisms,” Patent 

application submitted.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

49

II.B Biomass-Based

II.B.1 H2 Production by Catalytic Reforming of Pyrolysis Vapors

R.J. Evans (Primary Contact)

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401

(303) 384-6284, fax: (303) 384-6363, e-mail: bob_evans@nrel.gov

Task 1: Fluidizable Catalysts for Producing Hydrogen by Steam Reforming Biomass Pyrolysis 

Liquids, K. Magrini-Bair, S. Czernik, R. French, Y. Parent, M. Ritland, E. Chornet

Task 2: Production of Hydrogen from Post-Consumer Wastes, S. Czernik, R. French, C. Feik, E. 

Chornet

Task 3: Hydrogen from Biomass for Urban Transportation, Y.D. Yeboah, K.B. Bota, Z. Wang, M. 

Realff, D. Day, J. Howard, D. McGee

Task 4: Engineering Scale-Up of Renewable Hydrogen Production by Catalytic Steam Reforming of 

Peanut Shells Pyrolysis Products, R.J. Evans, S. Czernik, E. Chornet, C.J. Feik, R. French, S.D. 

Phillips 

DOE Technology Development Manager: Roxanne Danz

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Objectives

Fluidizable Catalysts for Producing Hydrogen by Steam Reforming Biomass Pyrolysis Liquids

• Formulate a fluidizable particulate catalyst for the production of hydrogen (H2) by reforming biomassderived pyrolysis oils. The catalyst support must be able to withstand reforming conditions for 

extended operation.

Production of Hydrogen from Post-Consumer Wastes

• Develop a robust thermo-catalytic process for producing hydrogen from readily available nonrecyclable post-consumer materials and residues, such as spent plastics, organic solid residues, and 

waste grease. 

• Demonstrate the feasibility of the production of hydrogen from synthetic polymers and from waste 

grease with a yield of 80% of the stoichiometric potential.

Hydrogen from Biomass for Urban Transportation

• Demonstrate process to produce hydrogen from peanut shells and other agricultural residues for use in 

an urban bus/transportation demonstration.

• Integrate a pilot-scale version of the pyrolyzer that is currently used to produce activated carbon from 

peanut shells with the pilot-scale catalytic steam reformer designed and constructed in Phase I.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

50

Engineering Scale-Up of Renewable Hydrogen Production by Catalytic Steam Reforming of Peanut Shells 

Pyrolysis Products

• Partner with interested parties to demonstrate that the thermochemical conversion of biomass to 

hydrogen is commercially viable over the next three years. 

• Scale up the National Renewable Energy Laboratory's (NREL's) thermochemical biomass-tohydrogen production process.

• Determine gas composition over the catalyst life cycle and compare the purity requirements needed for 

the shift reactors and pressure swing adsorption unit.

• Participate in Phase 2 testing work that will occur in Georgia at Scientific Carbon's activated carbon 

production facility.

Approach

Fluidizable Catalysts for Producing Hydrogen by Steam Reforming Biomass Pyrolysis Liquids

• Identify, refine, and optimize robust, available catalyst support materials.

• Formulate and evaluate multicomponent reforming catalysts made with the best supports.

Production of Hydrogen from Post-Consumer Wastes

• Identify and evaluate appropriate waste streams.

• Develop and refine the thermochemical processes (i.e., pyrolysis or partial oxidation followed by 

catalytic steam reforming) used to produce hydrogen from wastes.

Hydrogen from Biomass for Urban Transportation

• Develop decision models for selecting a feedstock, a process, and alternatives, and characterize the 

coproducts of the process.

• Design, construct, test, and integrate the pilot-scale pyrolyzer and the pilot-scale steam reformer, and 

begin long-term catalyst activity testing.

• Design a separation and storage system for hydrogen, and develop analytical systems for monitoring 

transportation system performance.

• Develop partnerships and collaborations for future bus/transportation demonstrations, the use of other 

feedstocks, and the development of new processes and markets for the co-products.

Engineering Scale-Up of Renewable Hydrogen Production by Catalytic Steam Reforming of Peanut Shells 

Pyrolysis Products

• In NREL's Thermochemical User's Facility (TCUF), scale up and shake down catalytic steam 

reforming process as derived from the bench-scale experimentation carried out at NREL to develop the 

process concept.

• Provide technical support for the shakedown of the pyrolyzer/reformer system in Georgia.

• Support the partnership development that will be necessary for the bus demonstration. Identify other 

biomass resources in the region that could be used to produce hydrogen.

Accomplishments

Fluidizable Catalysts for Producing Hydrogen by Steam Reforming Biomass Pyrolysis Liquids

• Tested 11 commercially-available spherical alumina catalyst supports to determine optimum particle 

size, surface area, and attrition resistance.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

51

• Prepared and evaluated several viable catalysts from the two alumina supports that showed the best 

performance in simulated reforming operations.

Production of Hydrogen from Post-Consumer Wastes

• Demonstrated a fluidized bed catalytic steam reforming process for the production of hydrogen from 

"trap grease".

• Studied pyrolysis/reforming of several types of common plastics using a micro-reactor interfaced with 

a molecular-beam mass spectrometer (MBMS).

• Designed a bench-scale fluidized bed pyrolysis reactor.

Hydrogen from Biomass for Urban Transportation

• Collected bio-oil and determined solubility parameters and physical property estimation methods for 

the components of the bio-oil product of peanut shell pyrolysis.

• Completed the design and construction of a pilot-scale (1/8th-scale) pyrolyzer. Began integration of 

the pyrolyzer with the reformer.

• Prepared the catalyst and feed samples for the pyrolyzer-reformer integration shakedown and longterm catalyst testing at Scientific Carbons Inc. 

• Acquired additional analytical instruments for determining and monitoring the composition of the 

pyrolyzer and reformer inlet and output streams.

• Developed partnerships with several institutions and organizations including the Federation of 

Southern Cooperatives (for feedstock/farmer training in future phases); Albany State University 

(summer student interns and community acceptability study); Dougherty County, City of Albany and 

Georgia's Water Gas & Light Commission (future bus/transportation demonstration). 

Engineering Scale-Up of Renewable Hydrogen Production by Catalytic Steam Reforming of Peanut Shells 

Pyrolysis Products

• Developed a new heater control system to protect the reactor from overheating in case of heater 

malfunction.

• Successfully operated the 30-cemtimeter (cm) catalytic steam reformer on methane and peanut shell 

pyrolysis products at NREL.

• Experiments with peanut shell pyrolysis vapor reforming duplicated the 5-cm bench-scale unit results 

with the aqueous fraction of wood pyrolysis oil. This is the first time whole pyrolysis vapors have been 

processed in the fluid bed reforming process.

• Developed a computer system to to ensure that the unit in Georgia can be monitored during operation 

and utilize the new control strategy to protect the reactor.

Future Directions

Fluidizable Catalysts for Producing Hydrogen by Steam Reforming Biomass Pyrolysis Liquids

• Produce attrition-resistant alumina supports and develop an appropriate "recipe" for adding promoters 

during support preparation.

• Develop a "recipe" for producing a broad range of robust promoted nickel (Ni) fluidization catalysts, 

focusing on adding stabilization agents (magnesium [Mg], manganese [Mn]) to Ni to improve 

reforming performance. 

• Provide the best catalysts to the Post-Consumer Waste Hydrogen Production project.

• Produce a pilot-scale quantity of catalyst for use in the scale-up evaluation for the Steam Reforming of 

Peanut Shell Pyrolysis Vapors project.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

52

Production of Hydrogen from Post-Consumer Wastes

• Demonstrate the process concept for producing hydrogen by pyrolysis and subsequent reforming of 

plastics and achieve 80% of the theoretically possible conversion of plastics to hydrogen.

• Construct and demonstrate a bench-scale two-step pyrolysis reforming system.

• Continue using the MBMS reactor system to quantitatively evaluate the process performance.

• Demonstrate the "trap grease"-to-hydrogen process in long-duration tests using the attrition-resistant 

catalysts. An alternative reactor option that uses a circulating bed to prepare 80 μm catalyst particles 

will also be considered.

• Analyze the catalyst used in "trap grease" reforming tests to determine if it was affected by possible 

contaminants in the feed.

Hydrogen from Biomass for Urban Transportation

• Perform liquid-liquid equilibrium experiments on representative bio-oil compounds and develop 

property estimation methods.

• Develop models and heuristic solution methods for the network of process steps to account for 

feedstock, location, process and the uncertainties of these factors.

• Complete integration and testing of the pyrolyzer, reformer, analytical instruments, and accessories, 

and begin long-term catalyst testing at Blakely, GA.

• Design pressure swing adsorption (PSA) separation and hydrogen storage systems for the produced 

hydrogen.

• Establish additional partnerships to prepare for the urban bus demonstration, identify alternative 

feedstocks, and develop new markets for the coproducts.

Engineering Scale-Up of Renewable Hydrogen Production by Catalytic Steam Reforming of Peanut Shells 

Pyrolysis Products

• Complete detailed analysis of the product over the catalyst life cycle.

• Continue to provide technical support for the shakedown testing in Georgia. The goal is 100 hours of 

operation.

• Recommend a design and implementation plan for the shift and separation steps for the Phase 3 

demonstration in Georgia in 2003.

Introduction

Fluidizable Catalysts for Producing Hydrogen by 

Steam Reforming Biomass Pyrolysis Liquid 

Bio-oil reforming requires a multi-functional 

catalyst which can (1) steam reform the oil organic 

components into carbon dioxide (CO2), carbon 

monoxide (CO) and H2; (2) shift the produced CO 

with steam to make more CO2 and H2; (3) gasify 

carbonaceous residues formed on the catalyst surface 

mostly from non-volatile bio-oil components; and (4) 

resist attrition. CoorsTek Ceramics produces 

spherical aluminas, with a range of physical 

properties, which could meet these requirements. 

Nickel-based catalysts, the most widely used shift 

catalysts, with potassium and magnesium as 

additives to aid coke and shift gasification and 

stabilize nickel crystals, respectively, are being 

evaluated to optimize catalyst performance.

Production of Hydrogen from Post-Consumer 

Wastes

At present, hydrogen is mostly produced by 

catalytic steam reforming of hydrocarbons: natural 

gas and naphtha. The goal of this research is to 

develop a technology for producing hydrogen from 

alternative resources, specifically from two types of 

waste post-consumer materials: plastics and "trap 

grease". The concept proposed for plastics is a twostage process: fast pyrolysis to convert polymers to a 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

53

gas/vapor stream of monomers and other lowmolecular weight compounds, followed by catalytic 

steam reforming of this gas to yield hydrogen and 

carbon oxides. "Trap grease", a waste material 

recovered from traps on sewer lines, does not require 

a depolymerization step and can be directly steam 

reformed to produce hydrogen. The challenge is to 

efficiently convert plastic polymers and the 

constitutive molecules of "trap grease" 

(predominantly free fatty acids and glycerides) to 

hydrogen at a cost similar to that for the existing 

natural gas-based technologies.

Hydrogen from Biomass for Urban Transportation

Clark Atlanta University has teamed with the 

National Renewable Energy Laboratory (NREL) and 

other partners in Georgia to develop and demonstrate 

a biomass-to-hydrogen process that will use peanut 

shells as a biomass feedstock for hydrogen 

production, and then use this hydrogen as a 

transportation fuel. Specifically, a pilot-scale reactor 

on site at Scientific Carbons Inc., a company in 

Blakely, Georgia, that produces activated carbon by 

pyrolysis of densified peanut shells, is being used to 

test the concept. The vapor by-products from the 

pyrolysis, which are currently used as fuel for steam 

generation, will be converted to hydrogen using 

NREL's catalytic steam reforming process. In the 

transportation demonstration, the hydrogen produced 

from peanut shells will be combined with 

compressed natural gas to raise its energy density and 

create a more viable transportation fuel. 

Engineering Scale-Up of Renewable Hydrogen 

Production by Catalytic Steam Reforming of Peanut 

Shells Pyrolysis Products

The steam reforming of biomass pyrolysis oil, 

when integrated with the production of high-value 

products, is a promising near-term approach to the 

production of renewable hydrogen. Based on benchscale work at NREL, a team from Georgia is utilizing 

the NREL TCUF and its staff to develop a 7 kg/hr 

reactor that will be operated at NREL this year before 

being run at the production site in Georgia on 

densified peanut shells. The application in Georgia 

is at a plant that makes activated carbon from peanut 

shells and has pyrolysis by-products available for 

conversion. The key technical goals for the 

shakedown at NREL are to ensure the safety of the 

reactor and obtain preliminary performance data on 

the catalyst, especially physical attrition and 

deactivation.

Approach

Fluidizable Catalysts for Producing Hydrogen by 

Steam Reforming Biomass Pyrolysis Liquids

The mechanical strength of the fluidized catalyst 

is a significant process issue that must be solved. To 

address this operational problem, a two-step 

approach was taken to (1) identify and develop 

economical and attrition resistant support materials 

that could withstand high-temperature fluidization, 

and (2) prepare reforming catalysts from the best 

supports. The catalysts, containing nickel oxide 

(NiO), manganese oxide (MgO) and/or potassium 

oxide (K2O), were then evaluated for attrition 

resistance and activity in a fluid bed system. 

Production of Hydrogen from Post-Consumer Wastes

To prove this process concept, a two-stage 

micro-scale reactor interfaced with a molecular-beam 

mass spectrometer was used to qualitatively evaluate 

several types of plastic. Samples of plastics were 

pyrolyzed in the bottom part of the reactor; then the 

created gases and vapors were steam reformed in a 

fixed bed of a commercial Ni catalyst located in the 

upper part of the reactor. The product gas was 

analyzed by mass spectroscopy. "Trap grease" was 

catalytically steam reformed in a 2"-diameter 

fluidized bed reactor using the same commercial 

nickel catalyst. Observed catalyst losses, and the 

resulting hydrogen conversion efficiency losses, 

highlight the need for either further process 

evaluation using a fluidizable attrition-resistant 

catalyst, or reconfiguring the bed to allow the use of 

existing commercial catalysts. 

Hydrogen from Biomass for Urban Transportation

In Phase 1 of this project, decision models for 

selecting a feedstock, a process, and alternatives 

were developed, and a 7 kg/hr fluidized-bed catalytic 

steam reformer system was designed and 

constructed. In Phase 2, the emphasis is on 

integrating and testing the pilot-scale pyrolyzer at 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

54

Scientific Carbon's activated carbon production 

facility with the pilot-scale reformer constructed and 

tested in Phase 1. In addition, Phase 2 will involve 

engineering research and pilot-scale process 

development studies in the use of peanut shells as 

feedstock for the pyrolysis-steam reforming process 

to produce hydrogen. The hydrogen produced in 

Phase 3 will be blended with CNG and used to power 

a bus in nearby Albany, Georgia. Partnershipbuilding and outreach play a key role in this 

collaborative project. 

Engineering Scale-Up of Renewable Hydrogen 

Production by Catalytic Steam Reforming of Peanut 

Shells Pyrolysis Products

The peanut shell-to-hydrogen concept is a 

modification of the biomass-to-hydrogen process that 

has been under development at NREL since 1993. 

This process concept was first characterized at the 

bench scale to determine the concept viability and to 

define key process parameters. Based on past results 

with the bench-scale fluid bed reactor, a pilot-scale 

unit was constructed and tested in NREL's 

Thermochemical User's Facility (TCUF). The 20-kg/

hr fluid bed pyrolysis unit at TCUF was used to feed 

the steam-reforming unit for the shakedown tests. 

The TCUF is designed to test new thermochemical 

process concepts by interfacing key unit operations 

in the existing TCUF facility. This approach 

minimizes risk and disruption by taking advantage of 

process control systems and analytical capabilities, 

which would not be available for shakedown or proof 

of concept in an industrial environment. By 

performing the initial system tests at NREL, the 

experience of the NREL researchers with the process 

and the analytical equipment of TCUF can be used to 

monitor and optimize the system performance. 

Results

Fluidizable Catalysts for Producing Hydrogen by 

Steam Reforming Biomass Pyrolysis Liquids

Eleven commercial catalysts were tested for 

attrition resistance under simulated reforming 

conditions. Two alumina supports supplied by 

CoorsTek Ceramics (90% and 99% alumina) showed 

the best combination of attrition resistance and 

surface area. In addition, they consist of alpha 

Figure 1. Reaction Gas Composition Data Versus 

Reaction Time for Catalysts 7-9 and CK11 NK
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

55

alumina, the desired support for reforming because 

of surface acid sites, which contribute to 

hydrocarbon cracking, and are readily available in 

the kg amounts required for testing. These materials 

were used to prepare several simple Ni-based 

catalysts to evaluate reforming and gasification 

activity with pyrolysis oil in the 2" fluidization 

reactor. 

The sample catalysts, prepared from CoorsTek 

supports, were evaluated by comparing their 

performance with that of the industrial catalyst, C-11 

NK. Preliminary evaluations (Catalysts 1-6) led to 

the development of Catalyst 7, which showed a 

slightly better short-term performance and a 20% 

improvement in the shift reaction when compared to 

C-11 NK. Catalyst 7 contained 1.8% Ni, 0.15% Mg, 

and 0.1% potassium (K), on 99% alumina with 0.2-

1.4 m2

/g surface area. Two additional catalysts 

(Catalysts 8 and 9), with varying amounts of Ni, Mg, 

and K, were prepared in an effort to establish the 

boundary compositions for the three-component, 

multifunctional catalyst. Figure 1 plots H2, CO, CO2, 

and CH4 concentration versus reaction time for 

Catalysts 7-9 and C-11 NK.

Production of Hydrogen from Post-Consumer Wastes

Pyrolysis and reforming of several types of 

common plastics (polyethylene, polypropylene, 

polyvinyl chloride, polyethylene terephthalate, 

polyurethane, and polycarbonate) were studied 

qualitatively, using a micro-reactor interfaced with a 

MBMS. Each type of plastic pyrolyzed at 550-750oC. 

This was followed by steam reforming of vapors in a 

fixed bed of C-11 NK catalyst at 750-800oC. The 

composition of the product gas (mass spectrum) was 

observed for different values of the steam-to-carbon 

ratio and space velocity that changed depending on 

the size of plastic samples. Preliminary tests showed 

that at process conditions similar to those used for 

reforming natural gas, polymers were almost 

completely converted to hydrogen and carbon 

oxides. 

"Trap grease" was also evaluated as a low-cost 

feedstock for hydrogen production, via catalytic 

steam reforming. The suitable process conditions are 

similar to those for natural gas reforming. At 850°C, 

using steam-to-carbon ratio 5, and with a space 

velocity of 1000 h-1, hydrogen was produced with a 

yield of 25 grams (g) per 100 g of grease during 135 

hours of continuous testing. This yield could be 

increased to over 28 g H2/100 g grease (85% of the 

stoichiometric potential) if CO were further 

converted by water-gas shift. At the end of the 

testing, this yield decreased to 16.4 g/100 g grease 

(48% of the stoichiometric potential), as shown in 

Figure 2. 

Hydrogen from Biomass for Urban Transportation

A schematic flow diagram of the biomass 

pyrolyzer-reformer designed and constructed for 

Phase 2 is shown in Figure 3. The pyrolyzer is 

designed to process up to 188 lbs (85 kg) per hour of 

pelletized biomass into char and pyrolytic off-gas. 

Figure 3. Schematic Flow Diagram of the Biomass 

Pyrolysis-Reformer Process

Figure 2. Yield of Hydrogen from Reforming "Trap 

Grease"; t=850°C, S/C=5, GC1 VHSV=970 

h-1
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

56

After carbon particulates are removed from the 

off-gas, it is heated to 700°C and then fed into the 

bottom of a steam reformer. Literature data and 

thermodynamic models were employed to evaluate a 

large number of organic solvents for the extraction of 

phenol from aqueous bio-oils. Propyl acetate and 

methyl isobutyl ketone (MIBK) were identified as 

good solvents as a result of this evaluation. These 

two solvents were used in extractions of bio-oil 

samples.

The hydrogen produced from peanut shells will 

be combined with compressed natural gas (CNG). 

This will require the development of a safe 

hydrogen-compressed natural gas storage system. 

Key design issues under evaluation include gas 

storage pressure, slow-fill versus fast-fill refueling 

stations, hydrogen/natural gas mixture, and materials 

of construction for storage cylinders. Given a target 

gas pressure of 3,600 psi and variable composition 

ranges from 75% to 85% CNG (i.e., 15% to 25% 

hydrogen), a tank volume of 1.78 cubic meters, 

diameter of 0.61 m, and length of 6.1 m is required. 

Due to the limitations placed on the system by the 

CNG distribution pipelines and the corrosive 

properties of hydrogen, the 80:20 mixture was 

selected.

Engineering Scale-Up of Renewable Hydrogen 

Production by Catalytic Steam Reforming of Peanut 

Shells Pyrolysis Products

A schematic and photograph of the pilot-scale 

catalytic fluid bed reformer are shown in Figure 4. 

The 30-cm catalytic steam reforming reactor was 

successfully operated on peanut pyrolysis vapor at a 

feed rate of 7 kg/hour of vapors. The results are in 

agreement with those obtained from the 5-cm benchscale reactor used for the reforming of the aqueous 

fraction of pyrolysis oil. Typical gas compositions at 

the outlet of the reformer are shown in Figure 5. 

These data show that the yield of hydrogen is 

approximately 90% of maximum. 

The fluid bed pyrolysis unit was fed at a 

maximum feed rate of 20 kg/hour of peanut shell 

pellets. Because peanut shells are high in lignin 

(32%) and protein (8%), the char yield was 

approximately 35%, which is higher than the yield 

from typical biomass. Vapor contact time was 

explored by varying the weight hourly space velocity 

(WHSV) (weight of feed/hr/weight of catalyst). A 

plot of H2 yield on an oil basis versus the inverse of 

WHSV is shown in Figure 6. A smaller WHSV 

represents more catalyst contact; therefore, plotting 

Figure 4. Catalytic Fluid Bed Steam Reforming Reactor
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

57

the inverse, which is proportional to contact time, 

presents a clearer picture of the effect of increasing 

catalyst contact. A 5% relative increase in H2 yield 

was noted at higher contact time.

Conclusions

Fluidizable Catalysts for Producing Hydrogen by 

Steam Reforming Biomass Pyrolysis Liquids

• Most of the alumina materials tested 

exhibited improved attrition resistance under 

steam reforming conditions compared to that 

of commercial fluidized reforming catalysts 

though surface areas are about an order of 

magnitude less. 

• The best support materials were CoorsTek 

90% and 99% alumina particles with surface 

areas of 0.2-1.4 m2/g. Attrition losses for the 

materials were less than 0.5 wt% per day. 

• Catalysts made from the CoorsTek supports 

and containing Ni, Mg, and K oxides exhibit 

increased shift/gasification activity and 

significantly improved reforming ability 

compared to the industrial material for the 

first 3 hours of reaction. From 20-23 hours, 

we observed a reduction in shift/gasification 

activity for the NREL and commercial 

catalysts. 

• While this new support/catalyst system 

works about as well as the commercial 

catalyst (C-11 NK), further optimization of 

support and catalyst composition may yield 

even more active and selective catalysts. 

Production of Hydrogen from Post-Consumer Wastes

• Qualitative tests for producing hydrogen by 

pyrolysis/reforming of plastics showed 

promising results. 

• NREL's fluidized bed catalytic steam 

reforming process for the production of 

hydrogen from "trap grease" also showed 

promising results in a bench-scale system. 

• The fluidized bed process performance 

significantly decreased after 135 hours of 

uninterrupted operation. This low 

conversion to hydrogen was most likely due 

to the catalyst losses by attrition and 

elutriation from the reactor, though some 

deactivation effects cannot be excluded at 

this time. 

Hydrogen from Biomass for Urban Transportation

• The project is ready to begin the shakedown 

and testing phase of the entire pyrolyzer/

reforming system at the Scientific Carbon 

facility in Blakely, Georgia. 

• The hydrogen storage system design is 

underway, and some of the system 

constraints have been identified.

• The partnership efforts are building interest 

in the project and helping to lay the 

groundwork for the future bus 

demonstration.

• Engineering Scale-Up of Renewable 

Hydrogen Production by Catalytic Steam 

Figure 5. Gas Composition from Reforming Peanut-Shell

Pyrolysis Vapors Figure 6. Variation in Estimated H2 Yield based on 

Contact Time (inverse WHSV is proportional 

to contact time)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

58

Reforming of Peanut Shells Pyrolysis 

Products

• The 30-cm catalytic steam reforming reactor 

was successfully operated on peanut shell 

pyrolysis vapor at a feed rate of 7 kg/hour of 

vapors.

• Experiments with peanut pyrolysis vapor 

reforming duplicated the results in a 5-cm 

bench-scale unit with the aqueous fraction of 

wood pyrolysis oil.

• The whole vapors from peanut shells, which 

have a unique composition, i.e., high levels 

of lignin and protein, can be successfully 

reformed. Over the time on stream tested to 

date, no significant deactivation of the 

catalyst was noted. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

59

II.B.2 Supercritical Water Partial Oxidation

Michael H. Spritzer (Primary Contact) and Glenn T. Hong

General Atomics

3550 General Atomics Court

San Diego, California 92121

(858) 455-2337, fax: (858) 455-4111, e-mail: michael.spritzer@gat.com

DOE Technology Development Manager: Roxanne Danz

(202) 586-7260, fax: (202) 586-9811, e- mail: Roxanne.Danz@ee.doe.gov

Main Subcontractor: General Atomics, San Diego, CA

Objectives 

• Show feasibility of supercritical water partial oxidation (SWPO) in pilot-scale preliminary testing.

• Develop improvements to SWPO hardware.

• Optimize SWPO operating parameters and hydrogen yields.

• Demonstrate an integrated SWPO pilot-scale system including hydrogen separation.

Approach 

• Test various feedstocks and reactor designs using existing General Atomics (GA) pilot plant.

• Identify suitable SWPO feedstocks.

• Identify improvements to reactor and system design.

• Implement and test improvements when possible.

Accomplishments 

• Showed basic feasibility of SWPO at a pilot scale.

• Established suitable operating conditions, e.g. reactor and preheat temperatures.

• Confirmed prior laboratory-scale results showing high hydrogen yields.

• Identified suitable feedstocks.

• Attained reliable pumping of thick feed slurries.

• Identified improvements to reactor design.

Future Directions 

• Update a Development Plan for commercializing SWPO (Phase I).

• Implement second-generation pilot-scale SWPO reactor (Phase II).

• Characterize SWPO operating parameters and hydrogen yields (Phase II).

• Demonstrate an integrated SWPO pilot-scale system including hydrogen separation (Phases III & IV).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

60

Introduction

General Atomics is developing Supercritical 

Water Partial Oxidation (SWPO) for the efficient and 

environmentally advantageous gasification of and 

hydrogen production from low-grade fuels such as 

biomass, municipal/solid waste (MSW) and highsulfur coal.

SWPO involves carrying out oxidative reactions 

in a supercritical water environment - akin to highpressure steam - in the presence of limited quantities 

of oxidant, typically pure oxygen or air. The key 

potential advantage of the SWPO process is the use 

of partial oxidation in-situ to rapidly heat the 

gasification medium, resulting in less char formation 

and improved hydrogen yield. Another major 

advantage is that the high-pressure, high-density 

aqueous environment is ideal for reacting and 

gasifying organics. The high water content of the 

medium should encourage formation of hydrogen 

and hydrogen-rich products and is highly compatible 

with high water content feeds such as biomass 

materials. By the same token, the high water content 

of the medium is effective for gasification of 

hydrogen-poor materials such as coal. The 

pressurized nature of the SWPO process naturally 

lends itself to the liquefaction and sequestration of 

carbon dioxide (CO2). The combination of high 

pressure and the cold sink available with a liquid 

oxygen oxidant enables ready liquefaction of CO2. It 

may then be recycled, injected for oil recovery or 

otherwise handled to reduce greenhouse effects.

Approach 

Figure 1 provides a representative process flow 

diagram for the gasification tests carried out. A 

number of different configurations were tested over 

the course of the project. The particular 

configuration shown is that used in conjunction with 

the "large" reactor vessel. This reactor has a volume 

of about 10 liters and at the flow rates tested provides 

a residence time of about 75 seconds at 650o

C 

operating temperature and about 60 seconds at 800oC 

operating temperature. Figures 2 through 4 show 

photographs of three skids comprising the SWPO 

system. 

Pressurized slurry (or water during startup and 

shutdown) is fed to the preheater, where it is 

preheated to a temperature of 250o

C, or other 

suitable temperature depending on the feed material. 

It was found during testing that slurry preheating had 

to be limited to avoid char formation and plugging of 

the preheater. In addition, the pumpable 

Figure 1. Process Flow Diagram for the SWPO System

Figure 2. SWPO System Feed Skid
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

61

concentration of biomass slurry was limited, for 

example to about 10-15 wt% for wood flour. Due to 

limited resources for advancing solutions to these 

limitations during the Phase I effort, it was decided to 

utilize a liquid fuel to help attain the desired reactor 

operating temperature. Thus, as shown in Figure 1, 

high-pressure auxiliary fuel (ethanol) and oxygen are 

combined with the preheated slurry at the reactor 

inlet. Oxidation of the organics results in a typical 

reactor temperature of 650°C. In the reactor, the feed 

is converted primarily to CO2, H2O, hydrogen gas 

(H2), methane (CH4) and CO. The liquid effluent is 

collected in a tank, while the gases are vented 

through the facility carbon filter and released to the 

atmosphere.

Table 1 provides a synopsis of the Phase I pilotscale testing carried out. Several runs with 

composted municipal solid waste (MSW) were 

carried out with a pipe reactor in the absence of 

oxidant, i.e., they were indirectly heated and did not 

utilize partial oxidation. The pipe reactor had an ID 

of 0.815 inches and a length of about 90 feet.

Table 1. Summary of Gasification Runs

Results 

The major results observed over the past year are 

as follows:

1. Using direct mixing with supercritical water for 

heat-up of a biomass slurry entering the reactor is 

problematic because a relatively large amount of 

supercritical water is required. This dilutes the 

biomass slurry and requires oxidation of most of 

the biomass to attain the desired final temperature 

of about 650o

C. Limited preheat and partial 

oxidation have been established as the preferred 

means of heat-up.

2. Significant effort was required to obtain reliable 

operation of a dual syringe pump for pumping 

thick slurries to high pressure. A number of 

improvements over the basic design were 

implemented, including magnetic sensing of the 

position of the driving pistons. The pump is now 

operating in highly reliable fashion.

Feed No. of 

Runs

Reactor 

Type

Run 

Conditions

40% corn starch 1 Small vessel 605°C

40% coal 2 Small vessel 530°C; 620°C

30-40% MSW compost 2 Small vessel 570°C

30-40% MSW compost 5 Pipe 620°C- 650°C

30% corn starch 1 Pipe 650°C, 300°C preheat

10% wood + 10% coal 2 Large vessel 800°C, 250°C

preheat, EtOH fuel2

10% wood 3 Large vessel 650°C, 250°C

preheat, EtOH fuel2

10% wood 3 Large vessel 800°C, 250°C

preheat, EtOH fuel2

10% corn starch 4 Large vessel 650°C, EtOH fuel2

40% corn starch 2 Large vessel 650°C, EtOH fuel2

15% wood 2 Large vessel 650°C, 250°C

preheat, EtOH fuel2

20% MSW compost 1 Large vessel 650°C, 250°C

preheat, EtOH fuel2

Notes:

1. All tests are at 3400 psi.

2. Ethanol (EtOH) is oxidized with approxiately stoichiometric oxygen in 

the reactor to bring the preheated stream up to the target reactor 

temperature.

Figure 3. SWPO System Pump Skid

Figure 4. SWPO System Reactor Skid
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

62

3. The maximum pumpable concentration of wood 

flour slurries is in the range of 10-15 wt% dry 

basis. The maximum pumpable concentration of 

composted MSW is in the range of 30 wt% dry 

basis. A mixture of 10 wt% wood plus 10 wt% 

coal is readily pumpable.

4. Preheat temperatures in excess of about 250oC are 

conducive to charring with many biomass feeds. 

Preheating is being limited to 250o

C.

5. A vessel reactor is preferable to a pipe reactor, 

allowing better temperature control and heat 

conservation and better ash and char handling.

6. Coal does not gasify well at 3400 psi and 

temperatures up to 800oC, but excellent oxidation 

has been achieved for coal at the same conditions.

7. Results for gasification of wood slurries have 

generally confirmed the high hydrogen yields 

reported in earlier laboratory testing at the 

University of Hawaii (UH). Table 2 compares the 

GA pilot scale results with UH’s results. In 

addition to some temperature and pressure 

differences as shown in the table, the UH tests 

utilized an activated carbon catalyst with external 

heating, while the GA tests utilized no catalyst 

and partial oxidation with ethanol fuel. Hydrogen 

yields (Table 2, last column) are similar for both 

sets of tests, and both show a significant takeup of 

hydrogen from the water to make gaseous 

products.

Table 2. Comparison of GA Pilot-Scale Tests with UH 

Lab-Scale Tests

Notes:

1. CMC is carboxymethyl cellulose suspension agent.

2. Average of 3 runs, some ethanol fuel present.

3. Activated carbon catalyst used.

Conclusions

A versatile pilot plant for exploring gasification 

in supercritical water has been established at the 

General Atomics' facility in San Diego. Preliminary 

testing of the SWPO process has found hydrogen 

yields of about 10 grams per 100 grams of feed, 

comparable to those found in prior laboratory-scale 

work carried out at UH. As in that prior work, a 

significant amount of the hydrogen found in the gas 

phase products is derived from the water/steam 

matrix. Potential improvements to the SWPO 

process include higher energy feed injector nozzles 

for the reactor to achieve better dispersion of the 

incoming feed, second-generation reactor designs 

with higher solids residence times, and means for 

feeding more concentrated slurries or dry feed.

 References 

1. Antal, M.J., Jr. and X. Xu, "Hydrogen Production 

by the Total, Catalytic, Supercritical Steam 

Reforming of Wood Sawdust", 216th American 

Chemical Society National Meeting, Boston, 

August 23, 1998.

2. Xu, X and M.J. Antal, "Gasification of Sewage 

Sludge and Organics in Supercritical Water", 

American Institute of Chemical Engineers Annual 

Meeting, Los Angeles, 1997.

FY 2002 Publications/Presentations 

1. Spritzer , M.H. and G.T. Hong, "Supercritical 

Water Partial Oxidation", Presented at the Annual 

Peer Review Meeting, USDOE Hydrogen 

Program, Golden, CO, May 2002.

2. Hong, G.T. and M.H. Spritzer, "Supercritical 

Water Partial Oxidation", 2002 Annual Report to 

USDOE Hydrogen Program, available at 

www.eren.doe.gov/hydrogen/docs/2002toc.html.

OrganizationFeed

T

°C 

P

psi

%

H2

%

CH4

%

C2

%

CO

%

CO2

g H/

100g

 feed

GA 9% wood + 

CMC1,2

650 3400 44 33 0.3 7 16 9.9

GA 9% wood + 

CMC1,2

800 3400 38 30 0.2 4 28 10.8

UH Ref. 1 10.4% corn starch3 650 4061 45 14 0.0 2 35 9.1

UH Ref. 1 5% wood + 

5.5% corn starch3

650 4061 34 23 0.2 3 45 8.2

UH Ref. 1 5% wood + 

5.6% corn starch3

650 4061 50 10 0.0 4 39 11.4

UH Ref. 1 5% wood + 6/1% 

corn starch3

650 4061 43 14 0.2 3 37 9.3

UH Ref. 2 11% wood + 

4.25% corn starch3

650 4061 57 6 NA 4 33 12.2
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

63

II.B.3 Biomass-Derived Hydrogen from a Thermally Ballasted Gasifier

Robert C. Brown (Primary Contact)

Center for Sustainable Environmental Technologies

Iowa State University

283 Metals Development Bldg.

Ames, IA 50011-3020

(515) 294-7934, fax: (515) 294-3091, e-mail: rcbrown@iastate.edu

DOE Technology Development Manager: Roxanne Danz

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Main Subcontractor: Iowa State University, Ames, Iowa

Objectives

• Determine whether switchgrass is a suitable fuel for the ballasted gasifier.

• Obtain time-resolved concentrations of important fuel components evolved.

• Identify process conditions that maximize the production of hydrogen (H2).

• Evaluate methods for removing contaminants from the producer gas.

• Evaluate methods for mediating the water-gas shift reaction in the product gas.

• Estimate the economics of H2 production from switchgrass.

Approach

• Prepare switchgrass fuel and feeder.

• Prepare 5-ton per day bubbling fluidized bed gasifier and a latent heat ballasting system.

• Prepare slipstream for upgrading producer gas.

• Prepare gas sampling and analysis system.

• Perform gasification trials.

• Perform cost estimate of the gasification system.

Accomplishments

• The 5-ton per day biomass gasifier has been modified to operate as a ballasted gasifier.

• The gas sampling system and a slipstream of the gasifier effluent have been prepared.

• The gas conditioning system has been designed and constructed.

• Analytical methods for measurement of trace contaminants (hydrogen sulfide [H2S], Ammonia [NH3], 

and hydrochloric acid [HCl]) have been established.

• Shakedown trials of the gasifier have been performed.

• Producer gas composition has been characterized for gasification of switchgrass.

• The steam reformer has been demonstrated to reduce total tar by 95% and condensable (heavy) tar by 

greater than 99%.

• The catalytic water-gas shift reactor has been demonstrated to reduce carbon monoxide (CO) to less 

than 0.5 %-vol.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

64

Future Directions

• Design and construct multi-contaminant control system based on sorbent injection. This system will 

remove particulate, sulfur, and halogen contaminants.

• Improve trace contaminant instrumentation. These improvements will give on-line capability for 

sulfur, NH3, and some tar species.

• Evaluate effectiveness of multi-contaminant control system.

• Evaluate additional catalysts for removal of tar and NH3 and enriching H2 content via water-gas shift 

reaction.

• Identify appropriate separation technology to purify H2.

• Perform thermal system and cost estimate analyses.

Introduction

The goal of this project is to optimize 

performance of an indirectly heated gasification 

system that converts switchgrass into H2-rich gas 

suitable for powering fuel cells. We have developed 

a thermally ballasted gasifier that uses a single 

reactor for both combustion and pyrolysis. Instead of 

spatially separating these processes, they are 

temporally isolated. The producer gas is diluted with 

neither nitrogen (N2) nor the products of combustion. 

The heat released during combustion at 850o

C is 

stored as latent heat in the form of molten salt sealed 

in tubes immersed in the fluidized bed. During the 

pyrolysis phase, which occurs at temperatures 

between 600 and 850oC, the reactor is fluidized with 

steam or recycled producer gas rather than air. Heat 

stored in the phase change material is released during 

this phase of the cycle to support the endothermic 

reactions of the pyrolysis stage.

Because air is not used during the gas-producing 

phase of the cycle, N2 does not dilute the product 

gas, resulting in relatively high concentrations of H2

and CO in the producer gas compared to 

conventional gasifiers. The CO, along with steam 

used to fluidize the reactor, can be shifted to 

additional H2 by the water-gas shift reaction.

Approach

The approach to this project is to employ a pilotscale (5-ton per day) gasifier to evaluate the 

thermally ballasted gasifier as a means for producing 

H2 from switchgrass. Gasification at the pilot scale 

is important for obtaining realistic process data, 

especially for calculating energy flows through the 

system and assessing the practicality of feeding 

switchgrass into the gasifier. A series of gasification 

trials are being performed to evaluate the effect of 

biomass feed rate (fixed steam rate) and the effect of 

biomass/steam rate (fixed biomass feed rate) on H2

production.

A slipstream from the gasifier will be used to 

evaluate gas cleaning and upgrading options during 

the first year of research. This slipstream will 

include a guard bed designed to remove H2S and HCl 

and some tar, a steam reformer designed to crack the 

remaining tar and decompose NH3, and hightemperature and low-temperature catalytic water-gas 

shift reactors to remove CO from the product gas and 

increase its H2 content. A series of gasification trials 

will be performed to evaluate the effectiveness of 

these four reactors in removing tar and contaminants, 

and shifting producer gas towards increased H2 and 

decreased CO.

Results

Most of the first year was consumed in 

constructing the experimental equipment required for 

the gasification system and the gas analysis system. 

The gasification system is illustrated schematically in 

Figure 1. The 5-ton per day bubbling fluidized bed 

gasifier was modified to operate as a ballasted 

gasifier. This entailed installation of the ballast 

system within the fluid bed reactor. The ballast 

system consists of 25.4 mm diameter stainless steel 

tubes 610 mm in length. Each of the ballast tubes 

was filled with 0.3 kg (0.66 lb) of Lithium Fluoride 

(LiF). An air pocket was left in each of the tubes to 

allow for expansion of the LiF. Forty-eight ballast 

tubes cover about 15% of the bed cross-sectional 

area. This represents a total latent heat storage 

capacity of 15,100 kJ.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

65

Several other modifications have been made to 

the gasifier system. An additional fuel hopper was 

added to the system to enable the use of multiple 

fuels. Both fuel hoppers were outfitted with load 

cells to accurately measure fuel flow into the 

gasification reactor. The moving bed granular filter, 

which will be evaluated for hot gas cleanup of 

particulate material in the producer gas, has been 

improved by the addition of a new auger system to 

remove dirty filter media from the bottom of the 

filter. The exhaust system, which was in poor repair, 

was replaced and upgraded to minimize the impacts 

of temperature on the system. Additionally, an 

automated high-temperature valve was installed to 

enable division of the pyrolytic gases from the 

combustion gases.

Figure 2 is a flow diagram of the gas sampling 

system and the slipstream used on the producer gas 

effluent. Producer gas is extracted at two locations in 

the producer gas effluent. The first sampling point is 

positioned just downstream of the gasifier to provide 

raw gas characterization. This sampling is 

performed isokinetically to obtain a representative 

particulate loading. The isokinetically-sampled gas 

passes through a Mott Hyline porous metal filter 

operated at 600oC to prevent condensation of tar. 

The gas then passes through a series of impingers 

containing varying combinations of dichloromethane 

(DCM) and glass beads. The impingers remove all 

condensable species, including tars and water. The 

Varian Micro-Gas Chromatograph draws a small 

portion of the sample stream in order to characterize 

the gas, specifically for H2, CO, carbon dioxide 

(CO2), N2, methane (CH4) and ethylene (C2H4). The 

remaining portion of the sample stream is passed 

through a total volumetric gas meter and exhausted to 

atmosphere.

The second extraction point is for the purpose of 

producing a slipstream of the gasifier effluent, which 

is used to evaluate an experimental gas conditioning 

system. A heated filter, similar to the one previously 

described, removes particulate matter, but gas is not 

sampled isokinetically, as is done in the first gas 

extraction location. After passing through the gas 

conditioning system, described in the next section, 

the producer gas passes through on-line gas analyzers 

that monitor CO, CO2, Oxygen (O2) and H2. The 

slipstream also provides a particulate-free gas for the 

quantification of trace contaminants such as H2S, 

HCl, hydrogen cyanide (HCN), and NH3.

Based upon previous work on the catalytic 

conversion of tars, new reactors have been designed 

and constructed. Improvements include the addition 

of standard flanges for better leakage control, 

upgraded reactor materials for improved 

characteristics in high-temperature environments, 

and welded joints in all areas inside the heated 

enclosures to vastly reduce leakage potential. Two 

more reactors were added for high-temperature and 

low-temperature H2 shift reaction purposes. Figure 3 

shows the current design for the gas conditioning 

system. The reactor bodies are made of 11⁄4 inch 

pipes constructed with Haynes 230 and premanufactured flanges made of 304 stainless steel. 

The 3/8 inch inlet and outlet pipes are constructed 

Figure 1. Schematic of the Gasifier System Figure 2. Overall Schematic of Gas Sampling System 

and Slipstream from Gasifier Effluent
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

66

with Haynes 230 material and have 3/8 inch stainless 

steel tube adapters welded to them. Each reactor has 

a volume of approximately 16.5 cubic inches (270 

cubic centimeters).

The trace contaminant sampling system draws a 

slipstream from the gas passing into the catalytic 

reactor system. This sample is drawn following the 

porous metal filter through which all of the gas 

passes. The slipstream progresses through a 

condensing coil to remove all tars. The flow is then 

split into two smaller streams. The first stream is 

passed through a nafion membrane to remove all 

moisture from the gas, and a sample is drawn with 

Draeger tubes to quantify H2S content. The second 

stream passes through bubblers plumbed in parallel 

to each other to simultaneously quantify HCl, HCN 

and NH3. Following sampling, these streams are 

exhausted to the atmosphere.

During the first year, most gasification trials 

were performed with the gasifier operated in 

conventional, air-blown mode. Experimental results 

included characterization of the gas obtained from 

gasification of switchgrass, preliminary evaluation of 

the performance of the steam reformer, and 

preliminary evaluation of the catalytic water-gas shift 

reactors.

Air-blown gasification of switchgrass produced 

tar loadings of 117 g/nM3

, which is within 10% of 

the tar loadings obtained from gasification of 

obsolete seed corn, the model fuel used in this test 

program. Particulate loadings from air-gasification 

of switchgrass were 19.3 g/nm3. The steam reformer 

was able to reduce total tar by 95% and condensable 

(heavy) tar by greater than 99%. The catalytic watergas shift reactor reduced CO to less than 0.5 %-vol.

Conclusions

Most of the first year was occupied in setting up 

the 5-ton per day pilot plant gasifier to operate in 

thermally ballasted mode and preparing the slip 

stream for gas conditioning studies.

Switchgrass was successfully gasified and shown 

to produce a gas with characteristics similar to 

producer gas from a model gasification fuel, namely 

obsolete seed corn.

The steam reformer was able to eliminate up to 

95% of heavy tars.

The water-gas shift reactors reduced CO in the 

producer gas to 0.5 %-vol.

FY 2002 Publications/Presentations

1. Cummer, K. and Brown, R. C., "Ancillary 

equipment for biomass gasification," accepted for 

publication in Biomass and Bioenergy, Fall 2001.

2. Pletka, R., Brown, R. C., and Smeenk, J., 

"Indirectly heated biomass gasification using a 

latent heat ballast. Part 1: Experimental 

evaluations," Biomass and Bioenergy 20, 297-

305, 2001.

3. Pletka, R., Brown, R. C., and Smeenk, J., 

"Indirectly heated biomass gasification using a 

latent heat ballast. Part 2: Computational model," 

Biomass and Bioenergy 20, 307-315, 2001.

4. Zhang, R., Brown, R. C., Suby, A., Cummer, K., 

"Catalytic cleaning of hot producer gas," Fifth 

International Biomass of the Americas 

Conference, Orlando, FL, September 17-21, 2001 

(conference cancelled because of national 

emergency).

5. Nunez, J. S., Cummer, K., Brown, R. C., Smeenk, 

J., "Use of a moving bed filter for cleanup of hot 

producer gas," Fifth International Biomass of the 

Figure 3. Gas Conditioning System
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

67

Americas Conference, Orlando, FL, September 

17-21, 2001 (conference cancelled because of 

national emergency).

6. Levin, D. B., Maness, P., Brown, R. C., 

"Integrated hydrogen energy system for power 

and transportation," Fifth International Biomass of 

the Americas Conference, Orlando, FL, 

September 17-21, 2001 (conference cancelled 

because of national emergency).

7. Cummer, K., Zhang, R., Suby, A., Norton, G., and 

Brown, R. C., "Improving prospects for 

gasification of wastes through gas conditioning: 

Tar removal," Renewable Energy and Organics 

Recycling Conference, Des Moines, IA, October 

29-31, 2001.

8. Nunez, J., Cummer, K., Suby, A., Dvorak, B., 

Smeenk, J., Brown, R. C., "Improving prospects 

for gasification of wastes through gas 

conditioning: Dust removal," Renewable Energy 

and Organics Recycling Conference, Des Moines, 

IA, October 29-31, 2001.

9. Méridaa, W., Levina, D. B., Manessb, P. C., and 

Brown, R. C., "Enhanced hydrogen production 

and CO removal from indirectly heated biomass 

gasification," 11th Canadian Hydrogen 

Conference, Victoria, British Columbia, Canada, 

June 17-20, 2001.

10.Young, B. L. and R. C. Brown, "Application of 

biomass gasification to Chinese markets," EcoInforma 2001, Argonne National Lab, Chicago, 

May 14-18, 2001.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

68

II.B.4 Techno-Economic Analysis of Hydrogen Production by Gasification of 

Biomass

Francis Lau (Primary Contact), Dave Bowen, Robert Zabransky

Gas Technology Institute

1700 South Mount Prospect Road

Des Plaines, Illinois 60018

 (847) 768-0592, fax: (847) 768-0600, e-mail: Francis.Lau@gastechnology.org

DOE Technology Development Manager: Peter Devlin

(202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

Main Subcontractors: Hawaii Natural Energy Institute, Honolulu, Hawaii, Electrical Power 

Research Institute, Palo Alto, California

Objectives 

• To determine the economics of hydrogen production by gasification of three biomass candidates: 

bagasse, switch grass, and nutshells.

• To optimize hydrogen production for transportation use.

• To identify the economic and technical barriers associated with biomass gasification.

Approach

• Develop a simulation to quantify hydrogen production.

• Determine the optimization of hydrogen by testing various cases through simulation.

• Analyze research and simulation results to determine technical and economic feasibility.

Accomplishments 

• Developed a model using a Hysis Simulation package.

• Explored the resource base for nutshells and bagasse to determine their availability.

• Gathered literature for an ultimate dry basis analysis of the feedstocks.

Future Directions 

• Develop a more detailed process flow schematic with a complete gas cleanup system.

• Perform laboratory testing on biomass feedstocks and analyze hydrogen production.

Introduction 

The future application of hydrogen as a nonpolluting fuel is dependent on the convergence of 

cost effective technologies for its manufacture, 

delivery, and end-use. DOE is actively pursuing 

research in all these areas to enable the private sector 

to demonstrate the technical viability of hydrogen 

technologies. Once viable from a technical 

viewpoint, commercial acceptance requires that these 

technologies demonstrate cost effectiveness in the 

marketplace. Key markets for hydrogen 

technologies are the transportation, stationary 

industrial, residential, and commercial energy 

markets. The prime mover targeted for hydrogen is 

fuel cell systems that are capable of very efficient 

and clean conversion of hydrogen to electricity, 

either with or without byproduct heat recovery.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

69

Approach 

The object of this project is to assess the cost of 

hydrogen production from three candidate biomass 

feedstocks and identify the barriers for 

commercialization of this technology. This is to be 

accomplished by first assessing the resource base. A 

process flow scheme will be developed for each 

feedstock that includes the following sections: feed 

preparation, followed by gasification or pyrolysis, a 

reforming section to reduce heavy hydrocarbons in 

the gas, a shift conversion process to maximize 

hydrogen production, and a gas purification process 

to provide gas meeting end-use specifications. The 

process design will then be used to perform an 

economic analysis to determine the cost of producing 

hydrogen. Throughout this effort, possible barriers to 

implementation of the technology will be identified, 

and a cost sensitivity analysis examining the major 

cost elements of the process will be performed. The 

resultant package will identify areas where targeted 

research will have the greatest benefits. The project 

will also identify the current influence of government 

incentive programs for biomass production and 

recommend changes that will further stimulate 

integration of biomass as an energy feedstock.

Results 

This project is still in the analysis phase to 

determine the economics of hydrogen production 

from biomass. A process flow sheet has been 

developed (see Figure 1) and a resource base for 

nutshells and bagasse has been analyzed. Nut 

production varies, as with any agricultural crop, due 

to changing climates and weather conditions. 

Generally, the production of nuts has increased over 

the past 10 years. Heating values for nutshells range 

from 7500 - 9000 BTU/lb on a dry basis. 

Bagasse is leftover material from the production 

of sugar cane. The majority of sugar cane production 

comes from Brazil, India, and China (the United 

States ranks tenth in world production of sugar cane). 

Data on world and major sugar cane producing 

countries can be seen in Figure 2. The majority 

(85%) of bagasse is used to meet the thermal 

demands of the processing factory. The remaining 

15% can be used for power generation needs. During 

the crushing season in Brazil, there would be roughly 

165 ton/day of bagasse fiber if a given factory 

operated at capacity. Based on this estimate, four 

plants have the ability to produce around 660 tons of 

bagasse per day for around 200 days per year, which 

would satisfy the needs of a small hydrogen 

production facility. The heating value of bagasse is 

around 7200 - 8000 BTU/lb on a dry basis.

Switchgrass is an energy crop being studied for 

its potential as a fuel source. Switchgrass is 

beneficial in that it has yet to be cultivated and 

therefore can potentially be grown in locations close 

to the gasifier and ultimately reduce hydrogen 

production costs by reducing transportation costs. 

Typical heating values for switchgrass range from 

7700 - 8200 BTU/lb on a dry basis.

Conclusions 

• Gasification technologies, in combination 

with advancements in hot gas cleanup 

technologies, allow for hydrogen production 

with little environmental impact.

Figure 1. Hysis Simulation Flow Sheet

Figure 3. Sugar Cane Production for the World, 

Brazil, India, and China (1992 - 2001)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

70

• Biomass can be used as a valuable and 

environmentally clean product, instead of a 

waste product, if used to produce hydrogen.

• Hydrogen production costs for transportation 

use will be significantly higher than current 

fossil fuel prices, but hydrogen from biomass 

has potential to become a competitive fuel 

with various government incentives and 

advances in technology.

• Hydrogen from biomass yielded production 

values ranging from 5.7 - 9.1 scf H2 / lb 

biomass during initial case studies (this is 

assuming that all the CO is shifted to H2).

• A typical hydrogen from biomass plant will 

be able to operate economically at around 

600 tons/day for bagasse. A plant producing 

hydrogen from nutshells will be significantly 

lower. Switchgrass has yet to be determined.

References 

1. Woodruff, J.G. 1979. Tree Nuts: Production, 

Processing, Products. AVI Publishing, Westport, 

CN. http://www.fao.org/waicent/faoinfo/

Economic/faodef/FDEF05E.HTM.

FY 2002 Publications/Presentations 

1. F. Lau, R. Zabransky, D. Bowen, C. Kinoshita, S. 

Turn, and E. Hughes. Techno-Economic 

Analysis of Hydrogen Production by Gasification 

of Biomass. Proceedings of the 2002 US DOE 

Hydrogen and Fuel Cells Annual Program / Lab 

R&D Review, May 6-10, 2002, Golden 

Colorado. http://erendev.nrel.gov/hydrogen/

pdfs/32405b5.pdf.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

71

II.C Fossil-Based

II.C.1 Production of Hydrogen by Superadiabatic Decomposition of Hydrogen 

Sulfide

Francis S. Lau (Primary Contact), Rachid B. Slimane, Remon J. Dihu, and Mark Khinkis

Gas Technology Institute

1700 S. Mt. Prospect Rd., Des Plaines, Illinois 60018

(847) 768-0592, fax: (847) 768-0600, e-mail: francis.lau@gastechnology.org

Jacques Bingue, Alexei Saveliev, Alexander Fridman, and Lawrence Kennedy

University of Illinois at Chicago, Chicago, IL 

DOE Technology Development Manager: Peter Devlin

(202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

Main Subcontractor: University of Illinois at Chicago, Chicago, IL 

Objectives

• Demonstrate the feasibility of the superadiabatic partial oxidation concept as a basis for developing an 

innovative process for production of economically viable quantities of hydrogen through the thermal, 

noncatalytic decomposition of hydrogen sulfide (H2S) in H2S-rich waste streams into hydrogen and 

elemental sulfur, without the input of additional energy (and no additional carbon dioxide [CO2] 

emissions).

• Outline a research and development strategy leading to the demonstration of an integrated process at 

an industrial site.

Approach

• Develop a numerical model for the superadiabatic H2S decomposition reactor. 

• Design, construct, and operate a bench-scale reactor system to demonstrate technical feasibility of the 

superadiabatic partial oxidation concept.

• Evaluate process economics and markets.

• Conduct thermodynamic and kinetic modeling studies to evaluate agreement between modeling 

predictions and experimental data, and to extend model applicability to conditions not tested 

experimentally.

Accomplishments

• Identified key process variables and optimum operating conditions, and developed reactor design 

guidelines.

• Prepared a design package for a bench-scale testing system.

• Performed preliminary confirmation of technical viability of the concept.

• Designed and constructed a state-of-the-art superadiabatic H2S decomposition reactor system to carry 

out a rigorous demonstration of the technical feasibility of the superadiabatic decomposition approach. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

72

Future Directions

• Determine the fate of feed gas impurities (i.e., CO2, methane [CH4], etc.) in the product gas, and their 

effect on reactor performance, especially with respect to hydrogen yield. 

• Evaluate several product/byproduct separation schemes to separate the unreacted H2S for recycle (to 

maximize the overall H2S conversion), the hydrogen product for purification, and the tail gas for 

cleanup. 

• Construct and operate a pilot-scale superadiabatic reactor system to provide for a more practical 

evaluation of the process and to develop large-scale plant data permitting more realistic engineering 

and economic analysis. 

• Construct an integrated superadiabatic H2S decomposition system for field-testing at an industrial site 

(e.g., refinery).

Introduction

In recent years, H2S has come to be regarded as a 

mineral from which two valuable products (hydrogen 

and sulfur) can be extracted.1

 Technology is well 

established for the recovery of the sulfur component, 

with the Claus process being the most prominent. 

Although this technology also produces a low-quality 

steam, it does not fully utilize the potential of H2S as 

a resource for hydrogen. Because of the significant 

amounts of H2S available worldwide, efforts have 

been made in recent years for the production of 

hydrogen, in addition to sulfur, from H2S through a 

number of approaches. It is widely recognized that 

the most direct process of converting H2S into 

hydrogen (H2) and sulfur is through thermal 

decomposition (catalytic or noncatalytic). However, 

because of energy considerations, this approach has 

been considered impractical at temperatures 

exceeding about 927o

C (1200K). In addition to 

being endothermic, the equilibrium of the thermal 

decomposition of H2S at these temperatures is 

relatively low, and the reaction does not proceed to 

an industrially important extent.2

 For example, 

based on thermodynamic equilibria, conversion of 

H2S into H2 is only about 20% at 1000o

C and 38% at 

1200o

C. Temperatures exceeding 1375oC are 

needed to drive the H2S decomposition reaction to 

conversions > 50%. 

Because of these limitations and other 

considerations, such as strict environmental 

regulations on sulfur emissions, any process for the 

recovery of hydrogen, in addition to sulfur, from H2S 

based on thermal decomposition or dissociation has 

to overcome a number of technical (and economical) 

hurdles. These include:

• Low yields even at high temperature 

(equilibrium limited)

• To maximize H2 production, it is necessary 

to recycle unreacted H2S

• Need to separate product gases

• Large recycle streams, unless conversion is 

reasonably high

• Rapid quenching of product gas may be 

necessary to block any recombination of H2

and S2 (decomposition reaction is reversible)

• Fate of impurities in feed gas has 

implications on emissions, tail-gas cleanup, 

and purity of the H2 product.

Due to the high energy demands for thermal 

dissociation, other approaches were evaluated where 

attempts were made to carry out the decomposition 

reaction with equilibrium shift, such as by 

preferential removal of reaction products by 

membranes and thermal diffusion columns. Despite 

the advances made in these areas, no method of 

hydrogen sulfide decomposition can be considered 

commercially feasible today.

Approach

Working with the University of Illinois at 

Chicago (UIC) and other industrial partners, 

including Universal Oil Products and BP Amoco, the 

Gas Technology Institute (GTI) has been developing 

an innovative process that promises to overcome the 

limitations of the noncatalytic thermal decomposition 

approach. In this process, operation at significantly 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

73

high temperatures is made possible and economical 

by oxidation of part of the H2S to provide the energy 

required for the decomposition reaction to proceed to 

a significant extent. Partial oxidation of H2S in the 

H2S-containing fuel gas is carried out in the presence 

of an inert, porous, high-capacity medium, and the 

intense heat exchange results in flame temperatures 

that significantly exceed the adiabatic flame 

temperature of the gas mixture. By coupling the 

partial oxidation of H2S in the porous medium with 

the H2S decomposition, temperatures as high as 

1400o

C (1673K) can be achieved economically 

within a reaction zone without the input of external 

energy, and therefore, no additional CO2 emissions. 

In this reaction zone, the self-sustaining conditions 

are very favorable for the decomposition reaction to 

proceed to an industrially significant extent, within a 

slowly propagating thermal wave (Figure 1). The 

superadiabatic partial oxidation concept is depicted 

in Figure 2 for a given set of operating conditions 

(i.e., 20% H2S in the feed gas, 12 cm/s gas velocity, 

etc.).3 It is clearly seen that in this case, for 

equivalence ratios > 1.5, the temperature achieved 

greatly exceeds the adiabatic temperature of the gas 

mixture. (Equivalence ratio is defined as the molar 

ratio of oxygen gas (O2) supplied to the O2 that is 

stoichiometrically required to burn all the H2S.) It is 

conceivable that higher temperatures than shown in 

Figure 2 can be achieved by manipulating the 

operating conditions.

GTI has envisioned a process (Figure 3) 

comprising the superadiabatic H2S decomposition 

reactor, product/byproduct separation schemes, 

hydrogen purification, and tail gas cleanup. Work 

has so far concentrated mainly on the superadiabatic 

reactor, and has comprised computational modeling 

and experimental studies to demonstrate the technical 

and economical feasibility of the superadiabatic H2S 

decomposition concept, using H2S-nitrogen (N2)-O2

gas mixtures.

Groundwork numerical modeling of the 

superadiabatic decomposition reactor has been 

performed, identifying key process parameters. 

These parameters include fuel gas composition (i.e., 

H2S-rich and H2S-lean), oxidant composition (air/

enriched air/oxygen), equivalence ratio, superficial 

gas velocity, feed gas temperature (pre-heating 

effect), and product gas quenching (to avoid 

Figure 1. Propagating Superadiabatic Partial Oxidation 

Wave

Figure 2. Partial Oxidation Temperature of H2S (Gas 

Velocity= 12 cm/s)

Figure 3. Conceptual Process Design for Hydrogen 

Production Based on the Superadiabatic 

Decomposition Concept
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

74

recombination of H2 and S2). Qualitative and 

quantitative determinations were made of the effects 

of these parameters, individually and in combination, 

on the performance of the superadiabatic 

decomposition reactor for production of hydrogen 

and elemental sulfur.4,5 

Collaborative experimental investigations by 

GTI and UIC researchers on the generation of 

hydrogen-rich gases from hydrocarbons via 

superadiabatic partial oxidation have shown the high 

potential and practicality of this approach. To carry 

out a rigorous process evaluation, GTI designed and 

constructed a state-of-the-art superadiabatic H2S 

decomposition reactor system (Figure 4). This 

reactor is currently being operated to demonstrate the 

technical feasibility of the superadiabatic 

decomposition process, to evaluate the agreement 

between modeling predictions and experimental 

results, and to reassess the economic potential of the 

process. 

Results

The major findings from the numerical modeling 

work appear to indicate that by optimizing the porous 

body reactor configuration, equivalence ratio, and 

gas velocity, the overall H2S decomposition in a 

single pass can be as high as 50%, with a conversion 

of H2S to the desirable product hydrogen (H2) 

reaching a level of 30%. It is estimated that the 

overall process performance can be substantially 

improved with respect to hydrogen production by 

membrane separation of product gases and 

recirculation of unreacted H2S. It is estimated that in 

4 to 5 passes nearly total H2S decomposition into 

sulfur can be realized, with recovery of 30-40% of 

the hydrogen component.

The optimum numerical modeling scenario 

indicates that, with feed gases entering the reactor at 

ambient temperature, a maximum temperature of 

1631 K (1394oC or 2541oF) can be achieved in the 

superadiabatic reactor, resulting in an overall H2S 

conversion of 50%, with a hydrogen (H2)/water 

(H2O) selectivity of 57/43 and an elemental sulfur 

(S2)/sulfur dioxide (SO2) selectivity of 99/1.

Preliminary experimental testing has shown that 

stable self-sustained flames could be generated using 

H2S-containing gases as a feedstock in the range of 

equivalence ratios from 2 to 5 with a hydrogen 

output at about 20%6

, as shown in Figure 5. The 

agreement between the groundwork experimental 

data developed to-date and modeling predictions is 

quite reasonable.

Figure 4. Overall Arrangement of GTI's NewlyConstructed Lab-scale H2S Superadiabatic 

Decomposition Reactor

Figure 5. Hydrogen Sulfide Conversions (Vg= 12 cm/s)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

75

The newly constructed superadiabatic H2S 

decomposition reactor system is currently being 

operated to develop a data package to provide 

evidence of the technical feasibility of the 

superadiabatic partial oxidation concept for the 

production of hydrogen (and elemental sulfur) from 

H2S. Successful tests have been made; a photo of the 

sulfur product, collected at the end of a typical test, is 

shown in Figure 6.

Conclusions

The superadiabatic partial oxidation concept 

appears to hold significant promise as a basis for 

developing a novel process for the production of lowcost hydrogen (and sulfur) by enhanced thermal 

decomposition of H2S in H2S-containing waste 

streams, without the input of external energy, and 

therefore, no additional CO2 emissions. The process 

has potential to utilize significant quantities of 

hydrogen that are currently being wasted as water 

vapor by conventional sulfur recovery processes 

(e.g., Claus). 

References

1. Zaman, J. and Chakma, A. "Production of 

Hydrogen and Sulfur from Hydrogen Sulfide," 

Fuel Processing Technology 41 (1995) 159-198.

2. Norman, J.H., "Hydrogen Production from In-Situ 

Partial Burning of H2S," U.S. Patent Number: 

4,481,181, 1984, Assigned to GA Technologies 

Inc., San Diego, CA.

3. Bingue, J.P., Saveliev, A.V., Fridman, A.A., and 

Kennedy, L.A., "Filtration Combustion of 

Hydrogen Sulfide," Proceedings of the 2000 

Technical Meeting of the Central State Section of 

the Combustion Institute.

4. Slimane, R.B., Lau, F.S., and Abbasian, J. 

"Production of Hydrogen by Superadiabatic 

Decomposition of Hydrogen Sulfide," Final 

Technical Report, DOE Contract No.: DE-FC36-

99GO10450, June 1, 1999 - September 30, 2000.

5. Slimane, R.B., Lau, F.S., and Abbasian, J., 

"Hydrogen Production by Superadiabatic 

Combustion of Hydrogen Sulfide," Proceedings of 

the 2000 U.S. DOE Hydrogen Program Review.

6. Bingue, J.P., Saveliev, A.V., Fridman, A.A., and 

Kennedy, L.A., Proceedings of the 2000 

Technical Meeting, The Central State Section of 

the Combustion Institute, Indianapolis, IN, pp. 

379-384, 2000.

FY 2002 Publications/Presentations

1. Slimane, R.B., Lau, F.S., et al. "Production of 

Hydrogen by Superadiabatic Decomposition of 

Hydrogen Sulfide," GTI Technical Progress 

Report for Contract No. DE-FC36-99GO10450, 

Submitted to DOE, June 2002.

2. Slimane, R.B., Lau, F.S., Dihu, R., Bingue, J.P., 

Saveliev, A.V., Fridman, A.A., and Kennedy, 

L.A., "Production of Hydrogen by Superadiabatic 

Decomposition of Hydrogen Sulfide," Paper 

presented and published in the 14th World 

Hydrogen Energy Conference, June 9-14, 2002, 

Montreal, Quebec, Canada.

3. Slimane, R.B., Lau, F.S., Dihu, R., "An 

Economical Process for the Utilization of H2S 

from Natural Gas Upgrading Operations," Paper 

to be presented at the Natural Gas Technologies -

What's New and What's Next Conference, Sept. 

29 - Oct. 2, 2002, Lake Buena Vista, Florida.

4. Bingue, J.P., Saveliev, A.V., Fridman, A.A., and 

Kennedy, L.A., "Hydrogen Production in UltraRich Filtration Combustion of Methane and 

Hydrogen Sulfide," International Journal of 

Hydrogen Energy, 27/6, 643-649, 2002. 

Figure 6. Sulfur Produced Through the Superadiabatic 

Decomposition of H2S
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

76

II.C.2 Thermal Dissociation of Methane Using a Solar-Coupled Aerosol Flow 

Reactor

Alan W. Weimer (Primary Contact)

Department of Chemical Engineering

University of Colorado

Boulder, CO 80309-0424

(303) 492-3759, fax: (303)492-434, e-mail: alan.weimer@colorado.edu

DOE Technology Development Manager: Peter Devlin

(202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

Main Subcontractor: National Renewable Energy Laboratory (NREL), Golden, CO

Objectives 

• Demonstrate a pilot scale solar-thermal transport tube reactor process to thermally dissociate methane 

to hydrogen (H2) and carbon black.

• Develop a fundamental understanding of the reaction kinetics and transport heat and mass transfer 

processes to allow plant design of a scaled-up process for economic evaluation.

• Carry out an economic and environmental evaluation of the process in order to assess viability and to 

identify fruitful research areas where success would significantly impact the economics.

• Involve as many students and interested companies as possible in the project, nurture their interaction, 

and facilitate communication among all parties (students, NREL, and nine companies) to provide a 

framework for successful project completion and learning.

Approach

• A pilot reactor system was designed, constructed, and interfaced to the NREL High-Flux-Solar 

Furnace (HFSF).

• The process was successfully started up and has been operating for six months; a matrix of statistically 

designed experiments has been carried out to obtain data for fundamental understanding and process 

plant design scale-up.

• The produced carbon black has been evaluated internally and by Chevron-Phillips, the industry liaison 

interested in potentially marketing the carbon black.

• Four teams of senior chemical engineering students supervised by teams of the industry liaisons 

carried out plant designs and economic evaluations for four process scenarios - centralized hydrogen 

plant, distributed hydrogen plant, co-generation (H2 and electricity) utility plant, and industrial semiconductor hydrogen plant.

Accomplishments 

• Demonstrated rapid methane dissociation exceeding 60% for residence times of 0.01 second at a 

temperature of 1900o

K (Kelvin) and without co-feeding carbon black.

• Demonstrated production of an amorphous (not graphitic), ash-free, fine sized (20 to 40 nanometer) 

carbon black powder suitable for tire production or conversion in a high-efficiency carbon conversion 

fuel cell [1] with no wall deposition in reactor.

• Demonstrated suitable materials of construction for a high-temperature solar-thermal process - reactor 

assembly constructed of exterior quartz and interior porous and solid graphite.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

77

• Demonstrated a highly efficient process that requires ~ 40 times less heliostat (sun capture surface) 

area than photovoltaic cells powering electrolyzers to produce H2.

• Carried out an economic assessment of the process indicating a 15% internal rate of return (IRR) for an 

out-the-gate hydrogen plant selling hydrogen at < $15/GJ (Giga-Joule).

• Over a three-year period, the project involved 26 undergraduate students, one Ph.D. student, one 

postdoctoral researcher, nine companies, and NREL.

Future Directions 

• This is the final year of a three-year project and no future research is planned. However, DOE is 

currently considering a process extension proposal to support a solar-thermal process to rapidly dry 

reform waste landfill gas to hydrogen and carbon black. Independent of the outcome of that proposal, 

the following issues need to be addressed:

• The produced carbon black needs to be supplied in a large enough quantity for testing by tire 

manufacturers. The Goodyear Tire & Rubber Company has agreed to evaluate the carbon black. 

Extended reactor operations should be carried out to supply the carbon black powder to Goodyear for 

testing.

• Efforts should be directed to study the impact of transient effects (clouds passing over, etc.) on the 

process, and process control systems for operating the reactor under such transient conditions should 

be developed.

• An economic evaluation should be carried out for a one-step solar-thermal process to supply hydrogenenriched natural gas (HCNG) for fleet vehicle fueling. In such a process, 35% H2 in natural gas (NG) 

can be achieved at only 21% conversion by stripping some carbon out of the NG. The alternative 

steam-reforming process (oxygen added in the form of water) requires complete processing (many 

steps) to pure H2 which is then blended with NG to obtain the desired composition.

• Methods should be evaluated for operating the solar-thermal process continuously to produce H2. Two 

such methods are (1) design and construction of a reactor capable of operating with an electrically 

heated supplementary source of power and (2) development of and integration of the solar-thermal 

process with a high efficiency carbon conversion fuel cell to supply electricity to an electrolyzer for 

splitting water. In both instances, H2 could be supplied off-sun. Development of a carbon conversion 

fuel cell would also provide a significant outlet (in addition to tire sales) for all of the carbon black that 

is produced while on-sun. The carbon black that is produced is a perfect feed for a carbon conversion 

fuel cell - fine sized, amorphous, and ash-free.

• Alternative H2 production processes using concentrated sunlight to drive rapid reactions should be 

investigated. These reactions include the reforming of high CO2 containing NG wells (i.e. 

"contaminated wells") that may be capped and not used, and waste landfill biogas that is currently 

being flared or simply burned to generate electricity.

Introduction 

Sunlight can be concentrated with mirrors and 

used to achieve ultra-high temperatures that are 

otherwise only achievable using electricity or nuclear 

power. The use of such renewable solar-thermal 

processing has significant potential in the desert 

southwest United States (AZ, CA, CO, NM, NV, and 

UT) for heating specialized chemical reactors to 

produce H2 from NG, biogas, or waste landfill gas. 

Since there is no energy conversion processing 

required (i.e. no efficiency losses to convert steam 

generated by combustion into electricity via a turbine 

or to convert sunlight to electricity via a photovoltaic 

cell and then use the electricity to split water by 

electrolysis), the sunlight is directly used to drive 

high temperature "brute force" chemical reactions - 

such as dissociation reactions - at high efficiency. 

Overall solar-thermal efficiencies approach 50%. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

78

With the ultra-high temperatures (~ 2000oK) 

achieved in the process, the chemical reaction rates 

are enormous and approximately 1000 times faster 

than rates achieved when operating at more 

conventional (~ 1000o

K) temperatures. The primary 

technical challenges for solar-thermal NG 

dissociation are related to (1) the ability to operate on 

an on/off mode with the sun, (2) the selection of 

suitable materials of construction and reactor design 

to achieve the ultra-high temperatures, (3) the ability 

to prevent carbon deposition on the inside wall of the 

reaction vessel, (4) the ability to heat and dissociate a 

gas that is transparent to radiation, and (5) the ability 

to operate continuously using supplementary energy 

or stored energy that is produced while on-sun.

In this project, a pilot scale solar-thermal reactor 

was constructed at the University of Colorado 

(Boulder, CO) and interfaced to the HFSF at NREL 

in nearby Golden, CO (see Figure 1). After 

experiments were done, the reactor was optimized. 

This was followed by significant experimentation to 

develop an understanding of the rate of reaction at 

ultra-high solar-thermal temperatures. Produced 

carbon black was evaluated for product quality (i.e. 

market price). A study was conducted to design a 

scaled-up plant for commercial processing (four 

scenarios), and profitability studies were carried out. 

Nine companies (BP, Chevron-Phillips, ChevronTexaco, Electric Power Research Institute, General 

Motors, Harper International, Pinnacle West, 

PlugPower, and Siemens) are involved in the process 

and attended at least one of the two team meetings 

that were held during the year. Eight of the 

companies attended the final project review. The 

companies have been instrumental in guiding the 

research. One Ph.D. student is responsible for the 

fundamental understanding of the process. One 

chemical engineering postdoctoral researcher has 

been responsible for the applied aspects of the 

process. Ten undergraduate chemical engineering 

students (~ 50% female and/or under-represented 

minorities) were involved in the 2002 process design 

and profitability analysis as part of the senior 

chemical engineering plant design and economics 

course. The process appears feasible and potentially 

economical.

 

Approach 

A vertical aerosol flow reactor was constructed 

and interfaced to the HFSF at NREL [2]. Argon 

flows in the annular region between the two tubes 

and provides an inert atmosphere that prevents 

oxidation of the graphite tube while preventing any 

decomposition products from depositing on the inner 

quartz wall. Feed methane gas flows downward 

through the graphite tube. The reactor was placed at 

the focal point of the primary concentrator that can 

deliver up to 10 kW (kilowatt) of power on-sun. A 

secondary concentrator enveloping the reactor allows 

temperatures greater than 2000o

K to be achieved.

The reactor is operated as a cold wall process 

because the beam is delivered directly on target. 

Figure 1. Schematic of Photo and HFSF at NREL, 

(Golden CO)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

79

The graphite and quartz design allows for on/off 

processing without thermal expansion or stress 

difficulties. The graphite reaction tube can be heated 

to reaction temperatures in a matter of seconds. A 

schematic of the reactor system and a photograph of 

the reactor that was taken after the system had been 

heated are shown in Figure 2. An overall pilot system 

schematic is shown in Figure 3.

Four process scenarios were considered for plant 

design/profitability studies and environmental 

impact: (1) a large scale plant where H2 is being sent 

to a pipeline and carbon black is being sold, (2) a 

distributed industrial plant to supply H2 to a semiconductor processing facility in AZ, (3) a medium 

sized distributed plant where H2 is used to fill fuel 

cell vehicles, and (4) a large scale utility cogeneration facility where H2 is being supplied to a 

pipeline and carbon black is being fed to a carbon 

conversion fuel cell to supply electricity to the grid.

Results 

The process has been operated at temperatures as 

high as 2100oK for high power levels (8.5 kW) and 

gas flows of 5 standard liters per minute (slpm). 

However, typical operating temperatures are in the 

range of 1700 to 1900oK. The effect of varying the 

annular flow rate was examined during experiments. 

It was found that an increase in the argon flow rate 

between the quartz and solid graphite tube of from 7 

to 10 slpm at high power levels had little effect on the 

gas phase temperature. A greater effect is seen at 

lower power levels, such as 2.5 kW. In general, the Figure 2. Solar-Thermal Aerosol Reactor (Top) 

Schematic, (Bottom) Installed

Figure 3. Schematic of Solar-Thermal Pilot Facility 

Interfaced to HFSF at NREL (Golden, CO)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

80

amount of gas flowed between the quartz tube and 

the outer solid graphite tube will be very small and 

only enough to prevent deposition of any volatiles 

along the inside quartz wall.

Various experiments were run to determine the 

effect of temperature and residence time on 

conversion. In all cases, pure methane was fed to the 

reactor. As can be seen in Figure 4, conversions 

exceeding 60% have been obtained at 2000o

K for 

residence times on the order of 0.01 second and with 

no co-fed carbon black to improve reactor heating. It 

should be noted that complete dissociation is 

expected at these temperatures and that the 

conversion was limited by heat transfer. Future 

experiments will include the co-feeding of fine 

carbon black particles to act as radiation absorbers 

for heating the gas. Math modeling has indicated 

that the co-feeding of carbon black particles has a 

substantial effect on the overall process throughput 

and reactor performance.

The quality of the carbon black powder (Figure 

6) product was evaluated as it impacts the overall 

economics of the process. A transmission electron 

photomicrograh (TEM) of a carbon black powder 

produced at a power level of 8.5 kW (~ 2000oK) 

indicates a primary particle size of between 20 and 

40 nanometers. In addition, the solar-thermally 

produced carbon black is compared to ShawiniganTM

carbon black (tradename of Chevron-Phillips Corp.), 

the high quality world standard specialty carbon 

black. A comparative TEM image indicates that the 

carbon particles being formed have a similar chainlike structure as compared to the ShawiniganTM

black. An X-ray diffraction pattern of the carbon 

black and the TEM indicate that the solar-thermally 

produced carbon black is amorphous and has similar 

or reduced crystallinity compared to the 

ShawiniganTM black..

The solar-thermal process (Figure 5) for coproducing hydrogen (1670 t/yr [tonnes/year]) and 

carbon black (5000 t/yr) has been conceptualized and 

costed (± 30%; percentage of delivered equipment 

cost). The 16.6 Mega-Watt thermal plant has been 

designed for the Phoenix, AZ (USA) area (0.38 solar 

capacity factor). Produced carbon black will be sold 

into the carbon black market (world market is 7.9 M 

metric tonnes (t)/yr), and produced hydrogen will be 

supplied to a hydrogen pipeline at a pressure of 2.2 

MPa. The plant will dissociate 7300 t/yr of natural 

gas (NG). The reactor is sized from the kinetics rate 

expression developed by Dahl et al [4]. 

The process has been simulated and priced using 

base cases from Spath and Amos [3] and appropriate 

scale factors. The selling price of H2 is determined 

to be $13.80/GJ to achieve a 15% IRR when carbon 

black is sold at $0.66/kg. For a carbon black selling 

price of $0.80/kg, the price of H2 to achieve the 15% 

IRR drops to $10/GJ. For a carbon black selling price 

of $1.10/kg, the price of the H2 to achieve the 15% 

IRR drops to $5/GJ. It is important to note that most 

specialty carbon blacks sell for between $2 and 

$3.50/kg. The world market for these specialty 

blacks is 0.6 mega-t/yr. Hence, the 5000 t carbon 

black/yr co-product plant described here is 0.8% of 

Figure 4. Experimental Dissociation Results (t = 0.01 to 

0.02 sec)

Figure 5. Solar-Thermal Co-product Plant for Hydrogen 

and Carbon Black
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

81

the world market for specialty blacks. The process 

has a 3rd year return on investment of 16% and a 

payback period of 6 years. 

For the process scenario discussed, the solarthermal process avoids 277 MJ fossil fuel and 13.9 

kg-equivalent CO2/kg H2 produced as compared to 

conventional steam-methane reforming and furnace 

black processing.

Conclusions 

The solar-thermal process is feasible: there are 

no technical show stoppers and there are no materials 

concerns. The fluid-wall reactor design allows 

continuous operation without inside wall deposition 

of carbon black. Reaction rates at the demonstrated 

ultra-high temperatures are enormous.

The solar-thermal process is environmentally 

friendly. The most environmentally friendly option 

is when selling carbon black into the tire carbon 

black market as the energy and pollution associated 

with normal carbon black production are avoided. If 

carbon is fed to a carbon conversion fuel cell, the 

total green house gas emissions are still ~ 60% of 

those of a steam reformer and the bulk of the released 

CO2 is in a pure form so it can be easily sequestered.

The process is potentially economical in the 

desert southwest United States. However, an outlet 

for the carbon black is an integral part of the overall 

economics. Compared to photovoltaic conversion 

and electrolysis of water to produce H2, the solarthermal process requires ~ 40 times less heliostat 

surface, and the heliostats are lower cost mirrors 

rather than expensive photovoltaic cells. The solarthermal process can produce HCNG at high rates in 

one step by efficiently and cleanly removing carbon 

from fed NG.

References 

1. Cooper JF, Cherepy N, Berry G, Pasternak A, 

Surles T, Steinberg, M. Direct carbon 

conversion: Application to the efficient 

conversion of fossil fuels to electricity. Report 

no. UCRL-JC-140629. Lawrence Livermore 

National Laboratory: Livermore, CA, October 

2000.

2. Lewandowski A. Performance characterization 

of the SERI high-flux solar furnace. Solar 

Energy Materials 1991; 24: 550-563.

3. Spath PL, Amos WA. Assessment of natural gas 

splitting with a concentrating solar reactor for 

hydrogen production, report no. NREL/TP-510-

31949. National Renewable Energy Laboratory: 

Golden, CO, April 2002.

Figure 6. Comparison of Solar-Thermal Carbon Black 

with Commercial High Quality Standard 

(Chevron-Phillips Shawinigan BlackTM)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

82

4. Dahl JK, Barocas VH, Clough DE, Weimer AW. 

Intrinsic kinetics for rapid decomposition of 

methane in an aerosol flow reactor. International 

Journal of Hydrogen Energy 2002; 27: 377-386.

FY 2002 Publications/Presentations 

1. Dahl, JK, Barocas, VH, Clough, DE, Weimer, 

AW, "Intrinsic kinetics for rapid decomposition 

of methane in an aerosol flow reactor," 

International Journal of Hydrogen Energy 2002; 

27: 377-386.

2. Dahl, JK, Tamburini, J, Weimer, AW, 

Lewandowski, A, Pitts, R, and Bingham, C, 

"Solar-thermal Processing of Methane to Produce 

Hydrogen and Syngas," Energy and Fuels, 15, 

1227-1232 (2001).

3. Buechler, KJ, "Synthesis of Hydrogen through 

Solar-thermal Decomposition of Natural Gas," 

paper presented at the 2001 Annual Meeting of 

the American Institute of Chemical Engineers, 

November 6, 2001 (Reno).

4. Weimer, AW, "Ushering in the Hydrogen 

Economy," paper presented at the Center of the 

American West Program "Energy in the West: 

What Every Westerner Should Know", June 22, 

2002 (Boulder).

5. Dahl, JK, "Solar-thermal Dissociation of 

Methane in an Aerosol Flow Reactor," paper 

presented at the Fourth World Congress on 

Particle Technology," Sydney, Australia, July 25, 

2002 (Boulder).

6. Weimer, AW, "Solar-thermal Process for Rapid 

Natural Gas Dissociation," presented to the 

Department of Chemical Engineering - Graduate 

Seminar, University of Maryland (October, 

2001).

7. Weimer, AW, "Rapid Process for the Benign 

Synthesis of Hydrogen," presented to the 

Department of Chemical Engineering - Graduate 

Seminar, Colorado School of Mines and 

Technology (November, 2001).

8. Weimer, AW, "Benign Hydrogen Synthesis Using 

Rapid Solar-thermal Processing of Natural Gas," 

paper presented at the 14th World Hydrogen 

Energy Conference, Montreal, Ontario, Canada 

(June 12, 2002).

9. Weimer, AW, "Distributed Hydrogen by Rapid 

Solar-thermal Dissociation of Methane," paper to 

be presented at the 224th American Chemical 

Society Meeting, Boston, MA (August 21, 2002).

10. Weimer, AW, "Rapid Solar-thermal Dissociation 

of Natural Gas," paper to be presented at the 11th 

International Symposium on Concentrated Solar 

Power and Chemical Energy Technologies, 

Zurich, Switzerland (September 5, 2002).

11. Dahl, JK, "Production of Hydrogen Using a 

Solar-thermal Fluid-wall Reactor," paper to be 

presented at the 2002 Annual Meeting of the 

American Institute of Chemical Engineers," 

Indianapolis, IN (November, 2002).

12. Weimer, AW and Lewandowski, S, "Thermal 

Dissociation of Methane Using a Solar-coupled 

Aerosol Flow Reactor," U.S. Department of 

Energy Hydrogen Program Review Presentation, 

Golden, CO (May 7, 2002).

FY 2002 Patent Applications 

1. "Solar-thermal Aerosol Flow Reaction Process," 

International PCT Application Number PCT/US 

01/15160 (filed February 12, 2002, priority date 

May 8, 2001).

2. "Solar-thermal Fluid-wall Reaction Processing," 

Provisional Patent Application filed March 7, 

2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

83

II.C.3 Thermocatalytic CO2-Free Production of Hydrogen From Hydrocarbon 

Fuels

Nazim Muradov (Primary Contact)

Florida Solar Energy Center

1679 Clearlake Road, Cocoa, Florida 32922

 (321) 638-1448, fax: (321) 638-1010, e-mail: muradov@fsec.ucf.edu

DOE Technology Development Manager: Peter Devlin

(202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

Objectives

• Develop an economically viable thermocatalytic process for production of hydrogen (H2) and valueadded carbon products from hydrocarbon fuels 

• Obviate the concurrent production of carbon monoxide/carbon dioxide (CO/CO2) byproducts and 

drastically reduce (preferably, eliminate) greenhouse gas emissions from the process

• Improve the process efficiency and reduce the cost of hydrogen production

Approach

• Investigate CO/CO2-free production of hydrogen and carbon products via efficient thermocatalytic 

decomposition of hydrocarbon feedstocks over carbon-based catalysts in an air/water-free 

environment

• Improve the process efficiency and sustainability via in-situ generation of catalytically active carbon 

particulates

• Design, fabricate and test a bench-scale thermocatalytic reactor for CO/CO2-free production of 

hydrogen-rich gas and carbon products

• Determine the effect of heavy hydrocarbons, moisture and sulfur compounds present in commercial 

hydrocarbon fuels on the process efficiency and the catalyst activity/stability

• Characterize carbon products of the process and evaluate their application areas and market value

Accomplishments

• Developed new approaches to improving the catalyst long-term stability and process sustainability

• Determined the effect of heavy hydrocarbons, moisture and H2S present in commercial hydrocarbon 

feedstocks on the process efficiency and the catalyst activity and stability

• Designed, fabricated and operated a bench scale thermocatalytic reactor (TCR); demonstrated CO/

CO2-free production of hydrogen-rich gas with H2 concentration up to 80 v.%

• Tested TCR in combination with a proton exchange membrane (PEM) fuel cell

• Analyzed carbon products of the process using a number of material characterization methods; 

assessed potential markets for carbon products (in collaboration with industry)

• Conducted techno-economic analysis of thermocatalytic decomposition of natural gas (in cooperation 

with the National Renewable Energy Laboratory [NREL])
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

84

Future Directions

• Fabricate and operate the scaled-up (up to 5 kW) multi-fuel thermocatalytic reactor coupled with a gas 

clean-up system using commercial hydrocarbon fuels. 

• Reduce the amount of greenhouse gas emissions via optimization of the thermocatalytic process and 

utilization of carbon materials produced in the process

• Increase the yield of high-value carbon products and reduce the cost of hydrogen production 

• Address safety and reliability issues related to the operation of the thermocatalytic reactor

• Evaluate new application areas for carbon products (with industrial partners)

Introduction

Thermocatalytic decomposition (TCD) of 

methane (CH4) results in the formation of hydrogen 

(H2) and elemental carbon:

CH4 S C + 2H2 ∆Ho

= 75.6 kJ/mol (CH4)

The energy input requirements for TCD are 

significantly less than that of steam methane 

reforming (37.8 and 63.3 kJ/mol H2, respectively). 

Due to the absence of oxidants (e.g., H2O and/or O2), 

no carbon oxides are formed in the reaction. The 

choice of an efficient and durable methane 

decomposition catalyst is vital for the development 

of a TCD process. Two major problems associated 

with existing catalysts relate to their rapid 

deactivation (due to carbon deposition) and coproduction of large amounts of CO2 during the 

catalyst regeneration step. The successful 

development of efficient and stable carbon-based 

catalysts for a methane decomposition process can 

solve both the catalyst deactivation and CO2

emission problems. 

Approach

The approach is based on thermocatalytic 

decomposition of hydrocarbon fuels over carbonbased catalysts in an air/water-free environment. 

The important feature of the process is that the 

reaction is catalyzed by carbon particulates produced 

in the process, so no external catalyst is required 

(except for the start-up operation). This results in the 

following advantages: (1) no CO/CO2 byproducts are 

generated during the hydrocarbon decomposition 

stage, (2) no catalyst regeneration is required, (3) the 

catalyst is resistant to sulfur poisoning, (4) several 

valuable forms of carbon can be produced in the 

process, (5) overall CO2 emissions could be 

drastically reduced (compared to conventional 

processes).

Results

Improvement in Catalyst Stability and Process 

Sustainability. The following new approaches to 

improving the catalyst long-term stability and the 

process sustainability have been developed: (i) the 

in-situ generation of catalytically active carbon 

species produced by co-decomposition of 

hydrocarbons, and (ii) activation of carbon catalysts 

via surface treatment with activating agents. The 

treatment of carbon particles with steam and CO2

(outside the pyrolysis zone) resulted in a significant 

increase in methane decomposition rate (Figure 1). 

Effect of Moisture and Sulfur on Methane 

Decomposition Rate. The presence of small amounts 

of moisture and H2S (<3 v.%) in the hydrocarbon 

feedstock is not detrimental to the process efficiency. 

However, these impurities result in contamination of 

hydrogen with carbon oxides and H2S, which could 

be removed from the product gas using methanation 

and H2S scrubbing steps, respectively. Figure 2 

demonstrates the removal of carbon oxides from 

hydrogen-rich gas via methanation reactions using 

Ru-catalyst. 

Fabrication and Testing of Thermocatalytic 

Reactor. A bench-scale thermocatalytic reactor 

(TCR) for CO/CO2-free production of hydrogen-rich 

gases was designed, fabricated and operated using 

methane or propane as feedstocks (Figure 3). The 

concentration of hydrogen in the hydrogencontaining gas reached up to 80 v.% (the balance 

methane). Since no carbon oxides were detected in 

the hydrogen gas, it was directly fed to a PEM fuel 

cell. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

85

Structural and Surface Characterization of 

Carbon Products. Carbon products of the process 

were analyzed by a number of material 

characterization techniques, including x-ray 

diffraction, scanning electron microscopy, Auger 

electron spectroscopy, x-ray photoelectron 

spectroscopy, and others. X-ray diffraction studies 

revealed an ordered graphite-like (or turbostratic) 

structure of carbon products (Figure 4). 

Techno-economic Evaluation of Hydrogen 

Production by Thermocatalytic Decomposition of 

Natural Gas. Techno-economic analysis of hydrogen 

production by thermocatalytic decomposition of 

natural gas was conducted in cooperation with 

Figure 1. Effect of Carbon Catalyst Activation on 

Methane Decomposition Rate at 850o

Figure 2. Removal of CO and CO2 from H2-CH4

Stream via Methanation Reaction at 350o

C 

Figure 3. Experimental Set-Up with TCR, PEM Fuel 

Cell, Fuel Tank, and Testing Equipment

Figure 4. X-ray Diffraction Spectra of Carbon 

Particles Produced by C3H8 Decomposition 

Over CB(BP2000)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

86

NREL. The hydrogen selling price varied in the 

range of $7-21/GJ (giga-Joule) depending on the cost 

of natural gas and carbon selling price.

Conclusions

New methods for improving the sustainability of 

the methane thermocatalytic decomposition process 

have been developed. Studies indicate that the 

presence of small amounts of moisture and H2S (<3 

v.%) in the hydrocarbon feedstock is not detrimental 

for the catalyst activity and process efficiency. This 

implies that commercial hydrocarbon fuels could 

potentially be employed as feedstocks for the 

process. A bench-scale thermocatalytic reactor was 

designed, fabricated and operated using methane and 

propane as feedstocks. The TCR produced 

hydrogen-rich gas free of CO/CO2 impurities; the 

gas was directly fed to PEM fuel cell. Material 

characterization studies indicated that depending on 

operational conditions, carbon could be produced in 

several valuable forms including turbostratic carbon, 

pyrolytic graphite, spherical carbon particles, or 

filamentous carbon. 

FY 2002 Publications/Presentations

1. Muradov, N. "Low-emission Fuel Reformers for 

Fuel Cell Applications", 14th World Hydrogen 

Energy Conference, Montreal, Canada, 2002.

2. Muradov, N. "Thermocatalytic CO2-free 

Production of Hydrogen from Hydrocarbon 

Fuels", DOE Annual Hydrogen Program Review 

Meeting, Golden, CO, 2002.

3. Muradov, N. and Schwitter, A. "Formation of 

Conical Carbon Structures on Vapor-grown 

Carbon Filaments", Nano Letters, v.2, 673 (2002).

4. Muradov, N. "Emission-free Fuel Reformers for 

Fuel Cell Applications", Fuel Cells, Science and 

Technology 2002, Amsterdam, Netherlands, 

2002.

5. Muradov, N. "Hydrogen via Methane 

Decomposition: an Application for 

Decarbonization of Fossil Fuels", Intern. Journal 

Hydrogen Energy, v.26, 1165 (2001).

6. Muradov, N. "Catalysis of Methane 

Decomposition over Elemental Carbon", Catalysis 

Communications, No.2, 89 (2001).

7. Muradov, N. "Thermocatalytic Production of 

Hydrogen via Pyrolysis of Hydrocarbon Fuels: 

from Methane to Residual Oil", Amer. Chem. 

Soc. Symposium: Energy for 21st Century: 

Hydrogen Energy, San Diego, 2001.

8. Muradov, N. "Thermocatalytic CO2-free 

Production of Hydrogen from Hydrocarbon 

Fuels", DOE Annual Hydrogen Program Review 

Meeting, Baltimore, MD, 2001.

Special Recognitions & Awards/Patents 

Issued

1. Muradov, N. U.S. Patent Application No. 60/

194,828 (2001) "Thermocatalytic Process for 

CO2-free Production of Hydrogen and Carbon 

from Hydrocarbons".

2. Muradov, N. U.S. Patent Application No. 60/

203,370 (2001) "Portable Hydrogen Generator". 

3. Muradov, N. U.S. Patent Application No. 60/

346,548 (2002) "A Method and Apparatus for 

Production of 3D Carbon Fibers". 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

87

II.C.4 Novel Catalytic Fuel Processing Using Micro-Channel Steam Reforming 

and Advanced Separations Technology

Patricia Irving (Primary Contact), Quentin Ming, Lloyd Allen, Todd Healey, and Andrew Lee

InnovaTek, Inc. 

350 Hills Street 

Richland, WA 99352

(509) 375-1093, fax: (509) 375-5183, e-mail: Irving@tekkie.com

DOE Technology Development Manager: Peter Devlin

(202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

Objectives 

The goal of this project is to produce pure hydrogen from infrastructure fuels using cost-competitive, 

highly efficient catalytic steam reforming and membrane separation technology. The following objectives 

are identified to achieve this goal.

• Optimize InnovaTek’s proprietary steam reforming catalyst composition and evaluate reforming 

conditions for diesel fuel and natural gas.

• Optimize the hydrogen-permeable membrane composition and operating procedures, and compare to 

water gas shift approach for CO clean-up.

• Develop efficient thermal management using microchannel heat exchangers and an internal burner.

• Integrate processes and components to achieve smallest size and most efficient thermal management.

Approach

• Conduct system analysis and design specification.

• Design and develop components.

• Test components.

• Design process configurations.

• Evaluate configurations with model simulation.

• Predict component and operational requirements with model simulation.

• Conduct iterative testing of integrated system.

Accomplishments 

• Developed process model and used output to help size system components and select range for 

operating conditions.

• Developed sulfur-tolerant steam reforming catalyst that reforms current hydrocarbon fuels without the 

need for prior sulfur removal. 

• Designed and tested advanced membrane technology that separates pure hydrogen from reformate, 

thereby enabling higher fuel cell power densities and eliminating potential for electrode poisoning.

• Utilized micro technology for reactor, heat exchanger, and fuel vaporizer to improve system efficiency 

through optimized thermal management and fluid dynamics.

• Completed a successful 500-hour demonstration of natural gas steam reforming and an 80-hour test of 

diesel fuel reforming.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

88

Future Directions 

• Scale up to at least 60 LPM hydrogen output – enough for a 5 kWe fuel cell.

• Complete micro-channel implementation.

• Automate start-up, operation, shut-down.

• Achieve more complete thermal integration.

• Focus on manufacturability, cost-reduction and high-volume production.

• Achieve full integration with at least one fuel cell model.

• Conduct thorough reliability testing.

• Incorporate enhanced controls – off-site monitoring, data mining, self-diagnostics.

• Complete documentation – drawings, bills of material, manufacturing routers.

• Prepare tooling – dies, molds, computer aided machining (CAM) programming etc.

• Obtain agency approval – Underwriters Laboratory, Canadian Standards Association, Consumer 

Electronics, etc.

Introduction 

To be marketable now, fuel cells need to use 

primary fuel sources from existing production and 

distribution networks – i.e. natural gas, gasoline, 

diesel or jet fuels. 

 Fossil fuel-powered fuel cells or refueling 

stations can form the bridge to a future when 

renewable resources power fuel cells. When 

compared to compressed hydrogen, reformed 

hydrocarbon fuels offer a significant cost advantage 

in the delivery of power. The high energy density of 

these fuels will also contribute to increased run times 

per unit of fuel consumed, and size and weight 

reductions associated with fuel storage. 

To meet this need, InnovaTek is integrating 

microreactor technology with advanced sulfurtolerant catalysts and hydrogen membrane 

technology to create a fuel processor for hydrogen 

generation from hydrocarbons. The ultimate goal of 

this 4-year cooperative project is the development of 

a catalytic reactor heated by the combustion of 

membrane by-products (raffinate) for production of 

clean hydrogen by steam reforming hydrocarbon 

fuels, including fuels that contain sulfur. Advanced 

membrane technology is being used to remove CO 

and CO2 from the reformate. The fuel processor 

being developed will provide a pure output stream of 

hydrogen that can be used without further 

purification for electrical generation by a PEM fuel 

cell. 

Approach 

Process simulation and analysis was performed 

for all possible system configurations to obtain an 

optimal system design and a complete mass and 

energy balance for every individual component of the 

system. These include flow rates, flow compositions, 

and temperatures for every stream in the system. The 

information provided a solid foundation for the 

design, fabrication, and testing of the reactor, heat 

exchangers, and combustor. The information will 

also guide us during the integration and 

demonstration of the complete system throughout the 

entire project period.

Proprietary components were designed and 

developed to achieve a technically superior fuel 

processor by solving specific problems related to 

several of the fundamental processes associated with 

fuel processing. These components will comprise a 

more efficient system that is sulfur tolerant and 

produces pure hydrogen while remaining compact 

and lightweight.

The individual components have been tested, and 

results of key tests are summarized below. The 

components are now being integrated into a benchtop system that will undergo additional testing, 

culminating in a prototype demonstration in late 

2002 that produces 12 LPM of pure hydrogen, 

enough to power a 1 kWe fuel cell.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

89

Results 

The design and optimization of a fuel processing 

system is complex because of the number of required 

components and functions (Figure 1). The first step 

in developing an optimal system design is evaluating 

different process configurations using process 

simulation. Another objective is to develop the 

specifications for the design of the components used 

in the system. Special attention is paid to thermal 

management and water management, two of the most 

technically challenging issues of effective system 

operation and integration. 

A system process model was developed and used 

to track mass and enthalpy flows. Estimates of molar 

flows of reforming products were determined by 

solving for equilibrium concentrations at given 

temperatures and pressures. Thermodynamic 

properties were used to determine heat transfer, 

water removal, and air and heat required to achieve 

energy balance in the reforming reactor. A nonlinear differential equation was used to determine 

membrane area for the desired hydrogen output at 

various temperatures and pressures. Model output 

helped determine the size of system components and 

select the range for operating conditions.

System components were designed, fabricated, 

tested, and optimized in an iterative process. Primary 

system components and their functions are listed in 

Table 1. Each component was tested, redesigned, 

and tested again until optimum geometries and 

formulations were determined. Then the components 

were integrated step by step and tested again. 

Complete system testing is now underway.

Initial tests were conducted to investigate the 

effect of reaction temperature on conversion and 

product gas composition using our proprietary 

catalyst ITC-3. Additional testing was conducted to 

optimize the catalyst for specific fuel types. After 

catalyst optimization, long-term tests for reforming 

natural gas were successfully conducted using 

InnovaTek’s proprietary catalyst ITC #1148 (Figure 

2). The hydrogen concentration in the reformate 

product was over 74% on a dry basis. CO and CO2

concentrations were about 19% and 6%, respectively. 

No methane was detected, indicating 100% 

conversion during the entire testing period. The test 

was continuously conducted for 341 hours at the 

same conditions with the catalyst showing very high 

and stable activity. The reactor temperature was then 

set to 800°C and the tests were continued for another 

100 hours with very stable performance. These 

results indicate that our catalyst composition has 

great potential for stable hydrogen generation from 

natural gas. 

An 80-hour test with ultra-low sulfur (~5 ppm) 

diesel, a developmental product obtained from 

Chevron Phillips Chemical, was also successfully 

completed (Figure 3). The use of this product permits 

Figure 1. Flow Diagram of Major Fuel Processor 

System Components

Component Function Product

catalytic 

reactor

catalytically reforms 

fossil fuels 

Reformate 

(H, CO2, CO)

catalyst catalyzes the 

reforming reaction

reformate

combustor burns raffinate to 

provide heat for the 

reforming reaction

Heat, CO2, 

H2O

fuel injector injects and mixes fuel 

and steam into the 

reactor

Vaporized 

steam/fuel 

mixture

heat 

exchangers

provides the proper 

temperature for each 

component

Warmer or 

cooler gas 

streams

H-permeable 

membrane

converts reformate to 

pure hydrogen and 

produces raffinate 

(membrane reject 

stream) for combustor

Pure 

hydrogen, 

raffinate (H, 

CO2, CO) 

Table 1. Primary Components of InnovaTek’s Fuel 

Processor
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

90

us to add controlled amounts of sulfur for testing 

sulfur tolerance. In an 8-hour test using this fuel with 

100 ppm sulfur added, the catalyst had a 100% 

conversion rate. These test results indicate that our 

ITC catalyst #1145 has very high catalytic activity 

and selectivity to hydrogen production and tolerates 

the presence of sulfur in the fuel.

A radial concept is used for the integration of the 

combustor and catalytic reactor where concentric 

functional chambers build outward from a central 

core (Figure 4). The innermost sections comprise the 

combustor unit, where air is carried to the interior 

and raffinate gas from the membrane penetrates 

through the wall to form a combustion flame along 

the inner wall of the reaction chamber. Preheated 

and mixed steam and fuel enter the reaction chamber 

and are catalytically converted to reformate. 

Reformate exits the reactor and is then sent to the 

membrane, where pure hydrogen is separated. 

Exhaust gas from the combustion chamber is carried 

back so that the hot gas passes over the outside of the 

reaction chamber, thereby providing uniform thermal 

conditions. This reactor, which is about 12 inches 

long, has a capacity for producing enough hydrogen 

for a 1 kWe fuel cell. It is currently being used for 

integrated system testing.

For purification of the reformate, hydrogenpermeable membranes were constructed using a flatplate design that encased ultra-thin metal foils that 

are permeable only to hydrogen (Figure 5). 

InnovaTek is investigating several formulations of 

metal for these membranes, including sulfur-tolerant 

membranes. We were successful in producing 

several membrane prototypes for a range of hydrogen 

production rates. Work on membrane optimization is 

continuing as we examine variables such as pressure, 

temperature, and sulfur content of the reformate. 

One important finding is that hydrogen permeation 

Figure 2. Steam Reforming of Natural Gas Using 

InnovaTek’s Proprietary Catalyst, ITC-1145

Figure 3. Steam Reforming of Low-Sulfur Diesel Fuel 

Using InnovaTek’s Proprietary Catalyst

Figure 4. Photo of InnovaTek’s Steam Reformer with 

Integrated Raffinate Combustor

Figure 5. Photo of InnovaTek’s Hydrogen-Permeable 

Membrane Component
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

91

rate is reduced and higher membrane temperatures 

are required for processing sulfur-containing fuels 

(Figure 6). The membrane component has been 

integrated with the catalytic reactor component and 

testing is underway.

Conclusions 

• A proprietary sulfur-tolerant catalyst developed 

by InnovaTek can reform natural gas, gasoline, 

and diesel fuels without need for prior sulfur 

removal, thereby greatly improving the prospects 

for commercialization of fuel cell technology.

• Advanced membrane technology for hydrogen 

separation produces nearly pure hydrogen output 

from reformate gas, enabling higher fuel cell 

power densities and eliminating potential for 

electrode poisoning.

• The use of micro technology for reactor, heat 

exchanger, and fuel vaporizer components 

improves system efficiency through optimized 

thermal management and fluid dynamics.

• The use of steam reforming and membrane purification combined with tight thermal integration 

can result in a highly efficient fuel processor that, 

when combined with a fuel cell, will produce at 

least twice the energy of a combustion engine for 

a given amount of fuel. 

FY 2002 Publications/Presentations 

1. Ming, Q., Healey, T., Allen, L., and Irving, P., 

“Steam Reforming of Hydrocarbon Fuels”. 

Catalysis Today, in press, 2002.

2. Irving, P., Allen, L., Herron, T., and Stephens, R., 

“Diesel Fuel Reforming with Advanced 

Separations Technology for the Production of 

Pure Hydrogen”. Proceedings of the 3rd

Department of Defense Logistic Fuel Reforming 

Conference. Panama City Beach, FL, August 

27-28, 2002.

3. Irving, P. “Fuel Processor for Generating Pure 

Hydrogen for Fuel Cells from Sulfur-Containing 

Fuels”. Proceedings of the 4th Annual 

Knowledge Foundation’s International 

Symposium, Small Fuel Cells 2002. Washington 

D.C., April 21-23, 2002. 

Special Recognitions & Awards/Patents 

Issued 

1. Hydrocarbon Fuel Reforming Catalyst and Use 

Thereof. U.S Non-Provisional Patent 

Application, Q. Ming, T. Healey, and P. Irving, 

pending.

Figure 6. Hydrogen Permeation Rate through 

InnovaTek’s S-Tolerant Membrane as a 

Function of Temperature and Sulfur Content
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

92

II.C.5 ITM Syngas and ITM H2: Engineering Development of Ceramic 

Membrane Reactor Systems for Converting Natural Gas to Hydrogen and 

Synthesis Gas for Liquid Transportation Fuels

Christopher M. Chen (Primary Contact), Michael F. Carolan, Steven W. Rynders

Air Products and Chemicals, Inc.

7201 Hamilton Boulevard

Allentown, PA 18195

 (610) 481-3315, fax: (610) 706-6586, e-mail: chencm@apci.com

DOE Technology Deveopment Manager: Arlene Anderson

(202) 586- 3818, fax: (202) 586- 9234, e-mail: Arlene.Anderson@ee.doe.gov

Main Subcontractor: Air Products and Chemicals, Inc., Allentown, PA; Ceramatec, Inc. Salt Lake 

City, UT; ChevronTexaco, Richmond, CA; Eltron Research Inc., Boulder, CO; McDermott Technology 

Inc., Alliance, OH; Norsk Hydro, Oslo, Norway; Pacific Northwest National Laboratory, Richland, 

WA; Pennslyvania State University, University Park, PA; University of Alaska Fairbanks, Fairbanks, 

AK; University of Pennsylvania, Philadelphia, PA

Objectives 

• Research, develop and demonstrate ion transport membrane (ITM) Syngas/ITM H2 ceramic membrane 

reactor system for the low-cost conversion of natural gas to hydrogen and synthesis gas

• Scale-up the ITM Syngas/ITM H2 reactor technology through three levels of pilot-scale testing and 

precommercial demonstration

• Obtain the technical, engineering, operating and economic data necessary for the final step to full 

commercialization of the ITM Syngas/ITM H2 technologies

Approach

• This project is in Phase 2 of three phases. The approach in Phase 2 includes:

• Task 2.1 Commercial Plant Economic Evaluation

• Task 2.2 Materials and Seals Development and Evaluation

• Task 2.3 ITM Syngas/ITM H2 Membrane and Module Design and Fabrication

• Task 2.4 Nominal 24 thousand standard cubic feet per day gas flowrate (MSCFD) ITM Syngas/ITM 

H2 Process Development Unit (PDU)

• Task 2.5 Nominal 330 MSCFD ITM Syngas/ITM H2 Subscale Engineering Prototype

Accomplishments 

• Process design and economic evaluation of a 760 million standard cubic feet per day gas flowrate 

(MMSCFD) H2 plant with CO2 separation to provide a carbon-free "clean fuel" showed the potential 

for over 30% capital cost savings in the syngas production step

• Multiple tests of lab-scale tubular membranes and seals each operated continuously for over 6 months 

at 250 psig and 825°C with good performance stability

• A number of sub-scale thin film membranes were tested for over 1200 hours; oxygen fluxes of over 10 

sccm/cm2 were recorded
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

93

• PDU module seals demonstrated good performance at 425 psig and 900°C under static conditions and 

pressure/thermal cycling conditions

• Pilot-scale membrane modules were fabricated for PDU tests

• The PDU reactor system was commissioned at high temperature and pressure with synthesis gas

• Initial scope definition of SEP project was completed with vendor quotes

• Design of full-scale membranes for SEP was completed

• SEP membrane fabrication development commenced with the fabrication of SEP membrane 

components

Future Directions 

• Evaluate the ITM Syngas/ITM H2 processes using PDU data

• Conduct long-term stability tests of tubular membranes and seals at high pressure

• Demonstrate performance of pilot-scale membrane modules in PDU

• Complete membrane module design and select catalysts for the SEP

• Commission the ceramic Production Development Facility and fabricate SEP membranes

• Design and fabricate the SEP reactor

Introduction 

Ion Transport Membranes (ITMs) are a 

revolutionary platform technology for producing 

hydrogen and synthesis gas for applications in power 

generation, transportation fuels, and chemicals. The 

ITM Syngas and ITM H2 processes provide a lowercost method for converting natural gas to hydrogen 

and synthesis gas by combining air separation and 

natural gas partial oxidation in a single-step ceramic 

membrane reactor, with the potential for capital cost 

savings of over 30%. If successful, this technology 

could be important to emerging hydrogen markets, 

such as hydrogen-based fuel cells for transportation 

and large-scale centralized hydrogen production 

facilities with CO2 capture.

The new technology utilizes non-porous ceramic 

ITM membranes, fabricated from multi-component 

metallic oxides that have both high electronic and 

oxygen ion conductivity at high temperatures 

(greater than approximately 700°C). In operation, 

oxygen from a hot air stream is reduced at one 

surface of the ITM membrane to oxygen ions, which 

diffuse through the membrane under a chemical 

potential gradient. At the opposite surface of the 

membrane, the oxygen partially oxidizes a prereformed mixture of hot natural gas and steam to 

form syngas, a mixture of hydrogen and carbon 

monoxide. The ratio of hydrogen to carbon 

monoxide is in part dependent upon the amount of 

steam. The membrane material must show long-term 

stability in reducing and oxidizing atmospheres, and 

long-term compatibility with any oxygen reduction 

and reforming catalysts that are in contact with its 

surface.

Approach 

The objective of this project is to research, 

develop and demonstrate a novel ceramic membrane 

reactor system for the low-cost conversion of natural 

gas to hydrogen and synthesis gas: the ITM Syngas/

ITM H2 processes. Through a 91⁄2 year, three-phase 

program, the ITM Syngas/ITM H2 technology will 

be developed and scaled up to obtain the technical, 

engineering, operating and economic data necessary 

for the final step to full commercialization of the 

hydrogen and syngas generation technologies. Phase 

2 of the program was initiated in FY2000 and will 

extend for 41⁄2 years. Process concepts and 

performance will be validated in two stages of scaleup in Phase 2: the Process Development Unit (PDU), 

which began operation in 2002, and the Subscale 

Engineering Prototype (SEP), which will begin 

operation in 2004.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

94

In Task 2.1, "Commercial Plant Economic 

Evaluation," advanced ITM Syngas/ITM H2

processes will be developed, and the economics of 

operation at the commercial plant scale will be 

evaluated based on the results of the Phase 2 

program. In Task 2.2, "Materials and Seals 

Development and Evaluation," membrane materials 

and seals will be tested at the laboratory scale under 

ITM Syngas/ITM H2 process conditions to obtain 

statistical performance and lifetime data. In Task 

2.3, "ITM Syngas Membrane and Module Design 

and Fabrication," membrane reactors will be 

designed for the ITM Syngas/ITM H2 processes at 

the PDU, SEP and commercial scales. Pilot-scale 

membrane modules will be fabricated for testing in 

the PDU. Fabrication of the membrane reactor 

modules will be scaled up in a Production 

Development Facility to supply the requirements of 

the SEP.

In Task 2.4, "Nominal 24 MSCFD ITM Syngas/

ITM H2 PDU," the components of the ITM Syngas/

ITM H2 technology will be demonstrated in a 

laboratory Process Development Unit (PDU). The 

PDU will operate at an equivalent of 24 MSCFD of 

syngas capacity, and will performance test pilot-scale 

planar membranes under commercial process 

conditions. In Task 2.5, "Nominal 330 MSCFD ITM 

Syngas/ITM H2 SEP, "a Sub-Scale Engineering 

Prototype (SEP) unit will be built to demonstrate the 

ITM Syngas/ITM H2 technology using full-size 

membranes in sub-scale modules. The SEP will 

demonstrate the operation of the ITM Syngas/ITM 

H2 processes at up to an equivalent of 330 MSCFD 

of syngas capacity.

Results 

As reported previously, preliminary process 

design and economic evaluation for ITM H2 in the 

"Distributed H2" target range of 0.1 to 1.0 MMSCFD 

H2 indicated the potential for up to 27% savings in 

production costs compared with trucked-in liquid 

hydrogen for 5000 psig fuel cell vehicle refueling 

applications. In addition, economic evaluation of the 

ITM Syngas process producing about 150 MMSCFD 

of a 2:1 mixture of hydrogen and carbon monoxide 

confirmed the potential for >33% capital cost savings 

compared with conventional technology based on an 

autothermal reformer and cryogenic oxygen supply.

In an evaluation of advanced process concepts, 

the ITM H2 process was developed for a large 

hydrogen production plant with CO2 removal, 

producing 760 MMSCFD of fuel-grade hydrogen at 

100 bar and 14,000 tonne/day of CO2 at 80 bar for 

sequestration. For this application, the ITM H2

process was compared to a conventional oxygenblown Autothermal Reformer (ATR) with a 

cryogenic air separation unit to supply oxygen. 

Economic evaluation of the ITM H2 process showed 

the potential for over 30% capital cost savings in the 

syngas generation process area and over 20% capital 

cost savings for the overall syngas/H2/CO2

production process. The ITM H2 process also has a 

higher thermal efficiency of 74% compared to 71% 

for the oxygen-blown ATR process. The hydrogen 

product is a "clean" fuel suitable for centralized 

power generation (approximately 1300 MW) and for 

distribution to local stationary or mobile 

applications, including fuel cells.

Tubular membranes and seal assemblies were 

tested in high-pressure, high-temperature lab-scale 

units under ITM Syngas and ITM H2 process 

conditions. In these tests, pre-reformed natural gas 

mixtures at process pressure were passed over the 

outer surface of the tubular membrane, while air at 

atmospheric pressure was fed to the inner surface of 

the tube. Multiple tests under ITM H2 conditions 

each operated continuously for over 6 months at 250 

psig and 825°C with good performance stability. The 

results of one of these six-month continuous tests are 

shown in Figure 1.

Figure 1. Six Month High Pressure Test of a Tubular 

Membrane
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

95

Sub-scale thin film membranes were also tested 

at atmospheric pressure for periods of over 1200 

hours. Tests of advanced catalyzed membranes 

demonstrated oxygen fluxes that approach the 

commercial flux target range, as shown in Figure 2.

Pilot-scale PDU planar membrane modules were 

fabricated, an example is shown in Figure 3. Air at 

low pressure is passed through the inner support 

passages (not shown) constructed within the planar 

membrane, while the pre-reformed methane mixture 

is passed at high pressure over the surfaces of the 

membrane module, where partial oxidation takes 

place to produce syngas.

Installation of the PDU system was completed, 

and the PDU reactor system and PDU membrane 

modules were commissioned at high temperature and 

pressure with a syngas mixture. The PDU integrates 

the various components of the ITM Syngas/ITM H2

reactor design and will be used to confirm the 

performance of the planar membrane modules and 

seals under commercial process conditions. The 

PDU reactor is shown in Figure 4.

The design of the full-scale membrane for the 

SEP was completed. SEP membrane fabrication 

development commenced with the fabrication of SEP 

membrane components. The rapid scale-up in in 

ceramic membranes is shown in Figure 5. Lab-scale 

membranes were developed in 1999-2000 in 

conjunction with initial materials development and 

were used to demonstrate oxygen separation 

performance. Pilot-scale membranes were 

developed in 2000-2001 and have a 40-fold increase 

in membrane area over the lab-scale membranes. 

The pilot-scale membranes are being used to 

demonstrate membrane performance at commercial 

process conditions in the PDU. Fabrication methods 

that were developed at the pilot scale are being 

scaled-up for full-size membranes. Full-size 

membranes are currently under development and 

have a 180-fold increase in membrane area over the 

lab-scale membranes.

Figure 2. Advanced Catalyzed Membranes Approach 

Commercial Flux Target

Figure 3. Process Development Unit Membrane Module

Figure 4. The ITM Syngas/ITM H2 Process 

Development Unit 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

96

Initial scope definition of the SEP project was 

completed. Preliminary process flow diagrams were 

developed, and vendor quotes were received for 

major equipment items. In addition, preliminary 

design of the ITM Syngas/ITM H2 SEP reactor was 

completed.

Conclusions 

Significant progress has been made to develop 

the ITM Syngas/ITM H2 technology. A database is 

being built up of performance data from several sixmonth long membrane tests. Membrane modules and 

seal assemblies have also been fabricated for testing 

in the PDU and ceramic fabrication scale-up is 

continuing the progression from lab-scale to full-size 

membranes. The PDU has been commissioned at 

high temperature and pressure. We continue to make 

excellent progress against the remaining technical 

challenges in the demonstration and scale-up of the 

ITM Syngas and ITM H2 technology.

FY 2002 Publications/Presentations 

1. C.M. Chen and P.N. Dyer, "Development of the 

ITM Syngas Process For GTL Conversion," 

American Chemical Society 222nd National 

Meeting, Ultra-Clean Transportation Fuels Symp., 

Chicago, IL, August 2001.

2. C.M. Chen, US DOE H2 Program Review, 

Golden CO, May 2002, "Engineering 

Development of Ceramic Membrane Reactor 

Systems for Converting Natural Gas to Hydrogen 

and Synthesis Gas for Liquid Transportation 

Fuels."

Patents Issued 

1. US Patent 6214066, S. Nataraj, S.L. Russek, 

"Synthesis Gas Production by Ion Transport 

Membranes," April 2001.

2. US Patent 6302402, S.W. Rynders, E. Minford, 

R.E. Tressler, D.M. Taylor, "Compliant High 

Temperature Seals for Dissimilar Materials," 

Figure 5. October 2001. Scale-up of ITM Syngas/ITM H2 Ceramic 

Membranes. (a) Lab-scale (b) Pilot-scale (c) 

Full-size
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

97

II.C.6 Integrated Ceramic Membrane System for Hydrogen Production

Raymond F. Drnevich (Primary Contact), Minish M. Shah

Praxair, Inc.

P.O. Box 44

Tonawanda, NY 14151-0044

(716) 879-2595, fax: (716) 879-7091, e-mail: ray_drnevich@praxair.com

DOE Technology Development Manager: Arlene Anderson

(202) 586-3818, fax: (202) 586-923, e-mail: Arlene.Anderson@ee.doe.gov

Main Subcontractor: Argonne National Laboratory, Argonne, IL

Objectives 

• Perform technoeconomic feasibility analysis of the integrated ceramic membrane system for hydrogen 

production.

• Define the development needed to prepare the concept for pilot testing and demonstration.

Approach

• Identify process options with potential for lower product costs. 

• Evaluate performance of various process options by simulations.

• Carry out experiments to assess the performance of ceramic proton conducting membranes.

• Estimate capital and product costs.

• Select the process option that is most likely to be commercially viable.

• Identify development issues for the selected process option and prepare a development program for 

Phase II.

Accomplishments 

• Two process options were identified: 1) Integrated oxygen transport membrane (OTM)-hydrogen 

transport membrane (HTM) reactor process that uses proton conducting ceramic membrane for 

hydrogen separation and 2) sequential OTM and HTM reactors process that uses a palladium (Pd) 

alloy based membranes for hydrogen separation. The efficiency hydrogen/methane (H2/CH4) of the 

sequential OTM and HTM reactor was higher at 79% (on higher heating value [HHV] basis) as 

compared to 76% for the integrated OTM-HTM reactor process.

• The hydrogen flux through the proton conducting membrane was much lower than for the flux 

required for commercial viability.

• The capital and product costs for the sequential reactor process were 10 - 12% lower than for the 

integrated reactor process.

• A process with sequential OTM and HTM reactors was selected for further development, and Pd alloy 

based membrane was identified as a major development item for Phase II efforts. 

Future Directions 

• Develop a composite membrane with a thin film of Pd alloy deposited on a porous support.

• Develop a suitable porous support with desired pore architecture for supporting a thin film of 

membrane and with necessary mechanical strength.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

98

• Screen Pd alloy compositions for resistance to syngas and thermal cycling.

• Prepare tubes of composite membranes.

• Test a bench-scale membrane reactor for carrying out shift conversion and hydrogen separation. 

Introduction 

Hydrogen is expected to play a vital role in the 

transportation sector for the fuel cell vehicles 

(FCVs). One of the crucial factors for the successful 

introduction of FCVs on the U.S. roadways is a lowcost supply of hydrogen. The demand for hydrogen 

at fueling stations for FCVs is projected to be less 

than 10,000 standard cubic feet per hour (scfh). To be 

competitive with gasoline, the cost of hydrogen 

delivered to a vehicle must be below $20/MMBtu. A 

key challenge in achieving this hydrogen price is to 

reduce the capital costs of an on-site plant. The 

approach taken in this project is to reduce capital 

costs by reducing the complexity of the process and 

thus reducing the equipment needed to generate 

hydrogen.

Approach 

Two process options were evaluated. In the first 

process option, both the OTM and the HTM were 

integrated into a single unit such that various 

processing steps (syngas generation, shift conversion 

and hydrogen purification) necessary for hydrogen 

production occur in a single reactor [1]. Since the 

OTM reactor operates at high temperatures (800 to 

1100oC), it is necessary to have the HTM operating 

at high temperatures. The ceramic proton conducting 

membranes can operate at temperatures up to 900o

C 

and they were considered as HTMs for this process 

option. (The Pd alloys are not suitable for high 

temperature operation.) In the second process option, 

OTM and HTM are placed in two separate reactors 

(Figure 1). By de-coupling these two membranes, the 

temperature constraint for the HTM is removed, and 

the HTM reactor can be operated at much lower 

temperatures (e.g. 300 to 600o

C) than the OTM 

reactor. The Pd alloy membranes were considered for 

this process option.

Air at low pressure (~25 pounds per square inch 

absolute [psia]) is passed to the retentate side of the 

OTM, and compressed natural gas (200 - 300 psia) 

and steam are passed to the permeate side of the 

OTM. Oxygen is transported across the OTM to the 

permeate side, where it reacts with natural gas to 

form syngas. A portion of natural gas also reacts with 

steam to form syngas. Additional hydrogen is formed 

by the water-gas shift reaction. The basic reactions 

involved in the process are:

CH4 + 1/2O2 CO + 2H2 (Partial Oxidation)

CH4 + H2O CO + 3H2 (Reforming)

 H2O + CO H2 + CO2 (Shift)

A catalyst is incorporated in the reactors to 

promote the reactions. The syngas from the OTM 

reactor is cooled and then fed to the retentate side of 

the HTM reactor. In the HTM reactor, the shift 

reaction and the hydrogen separation through the 

HTM take place. Hydrogen is transported to the 

permeate side of the HTM by the partial pressure 

difference driving force. Due to removal of hydrogen 

from the reaction zone, more hydrogen is formed by 

the shift reaction. As much hydrogen as possible is 

recovered from the reaction zone by transport 

through the HTM to the permeate side. Eventually, a 

partial pressure pinch between the reaction zone and 

the permeate side is reached, limiting the amount of 

hydrogen that can be recovered. A process model 

was developed for the process with sequential OTM 

and HTM reactors. The Hysys simulation was used 

to evaluate the performance of the process.

 Figure 1. Sequential OTM and HTM Reactor System
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

99

Results 

The overall efficiency of the plant is defined as 

follows:

H2 efficiency = (energy recovered in H2 (HHV) 

x 100)/(energy input in natural gas (HHV)).

Table 1 Summarizes utility consumption and the 

H2 efficiency for the sequential reactor process.

Table 1. Performance Summary of the Sequential 

Reactor Process

The H2 efficiency of the process with sequential 

reactors was estimated to be 79% (HHV). This 

compares with ~76% efficiency (HHV) for the 

process with the integrated OTM-HTM reactor. The 

higher efficiency for the process with sequential 

OTM and HTM reactors was due to lower 

temperature, which is favorable for shift reaction 

equilibrium.

The cost estimate developed for the process 

based on the integrated OTM-HTM reactor was used 

as a baseline cost, and the cost estimate for the 

process with the sequential reactors was developed 

by extrapolation. The hydrogen plant capacity was 

fixed at 1,000 scfh for the cost estimation. The 

capital costs for 2,000 and 5,000 scfh were estimated 

by using appropriate scale-up factors. For each 

capacity, costs were estimated for 10, 100, and 1,000 

plants built/year. After reviewing the results, it was 

clear that the plants with capacities of 1,000 and 

2,000 scfh will not be economically viable, because 

the cost of hydrogen from such plants is either 

comparable to or higher than the cost of liquid 

hydrogen. Therefore, the results for only 5,000 scfh 

plants are presented here.

The cost estimate presented last year for the 

integrated reactor process was reviewed and revised. 

The cost components with significant revisions were 

costs of reactor, instrumentation, natural gas and 

capital recovery. In addition, the costs related to 

contingency and safety were added. To estimate 

capital recovery costs, the method described in the 

Hydrogen Infrastructure Report [2] was used. The 

financial parameters listed in Table 2 were used. 

Table 2. Financial Parameters

 These parameters lead to capital-related charges 

of 23.5% of capital investment/year. In addition, the 

assumptions listed in Table 3 were made.

Table 3. Cost Estimation Assumptions

Figures 2 and 3 show the revised capital and 

product costs for the process with the integrated 

reactor. Figures 4 and 5 show capital and product 

costs for the process with the sequential reactors. The 

range in capital costs for any given point is due to the 

level of uncertainty in the cost estimate, especially in 

the costs of membrane reactors. 

Comparing the costs for the two process options, 

the capital costs for the sequential reactor process are 

~12% lower than the costs for the integrated reactor 

Hydrogen Capacity, scfh 1,000

Natrual Gas, scfh 404

Power, kW 4.6

Water, gpm 1.1

H2 Efficiency, %(HHV) 79%

15% after-tax rate of return

38% corporate tax rate

15-year plant life

0% inflation rate

Natural Gas $4/MMBtu (HHV)

Power $0.05/kWh

Water $0.01/1000 gal.

Maintenance and Replacement 3% of capital investment/yr

Capacity Utilization 80%

Figure 2. Capital Costs for the Integrated OTM-HTM 

Reactor Process
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

100

process. Several factors contributed to lower costs 

for the sequential reactor process. The complexity of 

the reactor design is significantly reduced when there 

are two separate membrane reactors. Operation of the 

HTM reactor at lower temperature makes it possible 

to use less expensive materials of construction. The 

OTM reactor still operates at a high temperature; 

however, its size is significantly smaller than the size 

of the integrated OTM-HTM reactor. Finally, the 

hydrogen flux through a Pd alloy membrane (which 

is used in the sequential reactor process) is much 

higher than the flux through a proton conducting 

ceramic membrane (which is used in the integrated 

reactor process). As a result, less membrane area is 

required, which in turn reduces the size and cost of 

the HTM reactor. 

The product hydrogen costs for the sequential 

reactor process were ~10% lower than the integrated 

reactor process. The cost of hydrogen production (at 

15 psia) ranged from $15 to $21/MMBtu (HHV) 

depending on the number of plants built per year. 

These numbers do not include the costs of 

compression, storage and dispensing. At low 

production volume (10 units/year), the cost of 

hydrogen will be $19 to $21/MMBtu (HHV). With 

mass production (1000 units/year), the cost of 

hydrogen will drop down to $15 to $17/MMBtu 

(HHV). The capital cost reduction at higher 

production volume results from the volume discounts 

for the equipment purchases and reduction in 

assembly costs due to experience in building multiple 

identical plants. 

Phase I indicated that the two-step reactor system 

with OTM reactor followed by integrated HTM shift 

reactor is the preferred approach for an economical 

hydrogen production system. Significant efforts are 

required in two areas for successful 

commercialization: development of cost-effective 

HTM and development of mass production approach 

to reduce capital costs. We are proposing a program 

with the emphasis on advancing the hydrogen 

separation technology. Any effort related to mass 

Figure 3. Product Costs for the Integrated OTM-HTM 

Reactor Process Figure 4. Capital Costs for the Sequential OTM and 

HTM Reactors Process

Figure 5. Product Costs for the Sequential OTM and 

HTM Reactors Process
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

101

production will be undertaken when the market for 

FCVs is more clearly visible. 

The experimental work on the proton conducting 

materials based HTMs indicate that the hydrogen 

flux is not sufficient for commercial viability in the 

foreseeable future. Therefore, we have decided to 

focus on the Pd alloy based HTMs for further 

development efforts. The basis for the future work is 

the technology established by Research Triangle 

Institute to deposit thin, uniform, defect-free, Pd 

alloy membrane layer on the ceramic substrate and 

Praxair's ceramic membrane manufacturing 

technology.

Phase II of the program is expected to last three 

years, and it will be divided into two parts. The first 

part of Phase II will focus on developing a 

commercially viable HTM and will last two years. 

We expect to develop HTM and its sub-components 

during the first year and test a bench-scale membrane 

reactor (containing multiple membrane elements) 

with shift conversion in the subsequent year. The 

second part of Phase II will involve testing of critical 

balance of plant components such as OTM reactor, 

steam generator and high temperature heat 

exchangers.

Conclusions 

The efficiency of the sequential reactor process 

is estimated to be 79% (HHV). The sequential OTM 

and HTM reactors process with the HTM reactor 

operating at lower temperature will result in lower 

hydrogen costs compared to the integrated OTMHTM reactor process. The cost of hydrogen is 

estimated to range from $15 to $21/MMBtu (HHV) 

depending on the number of hydrogen plants built 

per year. The projected hydrogen costs from the 

proposed system are lower than the competing 

supply options, such as electrolysis and liquid 

hydrogen. 

A Phase II plan has been defined. The sequential 

reactor process has been selected as a preferred 

process option. The first objective of Phase II is to 

develop a low-cost HTM (based on Pd alloy) with 

high hydrogen flux and tolerance for syngas 

components and thermal cycling. The next task will 

be to design and test a bench-scale membrane reactor 

to carry out shift conversion and hydrogen 

separation. Finally, other critical components such as 

OTM reactor, steam generator and high temperature 

heat exchangers will be tested.

References 

1. Shah, M. M., Drnevich, R. F., Balachandran, U., 

Dorris, S. E. and Lee, T. H. 2001. 

"Technoeconomic Feasibility Analysis of 

Hydrogen Production by Integrated Ceramic 

Membrane System for Hydrogen Production", in 

the Proceedings of the DOE's 2001 Annual 

Hydrogen Review Meeting.

2. Thomas, C. E., James, B. D., Kuhn, I. F. Jr., 

Lomax, F. D., and Baum, G. N. 1997. Hydrogen 

Infrastructure Report, DOE Report No. DOE/CE/

50389-504.

FY 2002 Publications/Presentations 

1. Shah, M. M. and Drnevich, R. F., 2002. 

"Integrated Ceramic Membrane System for 

Hydrogen Production", Final Report Prepared for 

the DOE.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

102

II.C.7 Low Cost Hydrogen Production Platform

Timothy M. Aaron (Primary Contact)

Praxair, Inc.

P.O. Box 44

Tonawanda, NY 14151-0044

(716) 879-2615, fax: (716) 879-7567, e-mail: tim_aaron@praxair.com

DOE Technology Development Manager: Arlene Anderson

(202) 586-3818, fax: (202) 586-9234, e-mail: Arlene.Anderson.ee.doe.gov

Main Subcontractors: Praxair, Inc., Tonawanda, NY; Boothroyd Dewhurst Inc., Wakefield, RI; 

Diversified Manufacturing Inc., Lockport, NY

Objectives 

• Define process/equipment concepts and develop preliminary design suitable for mass production of a 

small on-site hydrogen systems.

• Perform a technoeconomic study for an on-site hydrogen production system for the transportation and 

industrial market (1,000 to 5,000 standard cubic feet per hour [scfh]).

• Develop business cases regarding the viability of the development project.

• Define the system in sufficient detail to develop a Phase II plan for the prototyping and system detail 

modeling of the major components.

Approach

• Use existing steam methane reformer (SMR) and purification process technologies as the base for the 

system.

• Develop design parameters for the system including natural gas, water and product specifications and 

pressures as well as setting goals for the mechanical details such as system footprint, shipping 

parameters and system setup time.

• Investigate current on-site hydrogen plant designs and develop component and overall cost 

breakdowns of the systems.

• Use design for manufacturing and assembly (DFMA) principles from the early stages of the design 

effort.

• Design the system with high volume manufacturing as an up-front design parameter.

• Select the system option that is most likely to be commercially viable when produced in high quantity 

production runs.

• Identify development issues for the selected design option and prepare a development plan for Phase 

II.

Accomplishments 

• Design parameters for the system have been determined.

• A detailed review of current on-site options was completed, and a cost percentage breakdown of 

individual plant components has been developed. This information was then used to set goals for the 

overall system and component cost and design.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

103

• Multiple process models of various reformer and purification options have been developed. These 

models served as a baseline to create the mechanical designs of the system.

• Three high potential conceptual designs were selected for further development. The selection process 

included design evaluations by the subcontractors.

Future Directions 

• Complete the evaluation of the three current design concepts. Select highest potential concept(s) or 

combination of concepts for further development.

• Refine and optimize the selected concept(s) using DFMA techniques.

• Develop scale of economy analysis for the selected system design(s).

• Complete the techno-economic study for the system, including business model and competitive 

assessment.

• Develop plan for Phase II of project. Determine components requiring prototyping and/or advanced 

modeling/simulation in Phase II.

Introduction 

Hydrogen is expected to play a vital role in the 

transportation sector with fuel cell vehicles (FCVs). 

A source of low cost hydrogen will be vital to the 

successful transition to a hydrogen based 

transportation economy and a key challenge to this 

goal is to reduce the overall cost for the small scale 

on-site generation of hydrogen. Praxair is an 

industry leader in the design, development and 

operation of hydrogen production facilities and is 

applying this extensive knowledge base, as well as 

advanced mass production, design and tooling 

experience provided by the subcontractors, to this 

development effort.

The overall goal of the Low Cost Hydrogen 

Production Platform (LCHPP) cooperative 

agreement is to develop an on-site hydrogen 

generation system, based on existing steam methane 

reformer technology, which will significantly lower 

the overall cost to produce hydrogen at low volumes. 

Praxair has, as partners in this project, BoothroydDewhurst Inc. (BDI) and Diversified Manufacturing 

Inc. (DMI). BDI has expertise in the area of DFMA, 

and they have worked extensively with the 

automotive industry to lower the overall cost of 

production for mass produced systems. DMI is a 

design and fabrication facility with extensive 

experience in the areas of high temperature 

component design for both new designs and 

refurbishments, tooling design and manufacturing 

processes.

Approach 

The requirement for industrial on-site hydrogen 

plants has typically been larger volumes than that of 

the LCHPP project. Achieving a competitive, lower 

volume plant offering has dictated the need to 

modularize plant components and streamline the 

installation and start-up process. The cost target of 

the LCHPP project is significantly lower than any 

previous goal set for the industrial market and to 

approach this goal, further integration, scale of 

economies and design optimization will need to be 

implemented. Rather than designing a system from a 

block flow process engineering approach, the system 

will be designed from the ground floor using DFMA 

techniques as well as a very high level of system 

integration. The system will also be designed for 

mass production and will therefore require the 

development of tooling and fixtures to aid in the 

assembly process. It will not be possible to build 0 - 

10 of these units and approach the DOE cost goal. 

The economic viability of the system will only be 

achieved in large volume production runs.

The LCHPP project is structured in 3 distinct 

phases. Phase I is the engineering study and 

feasibility phase, which is scheduled to be completed 

in October 2002. A business plan and economic 

model will be developed as part of Phase I and will 

be updated as required during Phases II and III. 

Phase II is the system detail design, tooling 

development and prototype phase and is currently 

scheduled to begin in December 2002. Phase III is 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

104

the final phase where a demonstration unit will be 

developed and tested. The tooling required for the 

mass production of the system will also be developed 

in Phase III. Phase III is currently scheduled to begin 

in September 2004 and last for 1.5 years.

The process used for this project will be a SMR 

with a pressure swing adsorption (PSA) or membrane 

based purification system. The project does not 

include the hydrogen compression, storage or 

distribution system required for the high-pressure 

filling of FCVs. A process diagram of the system is 

shown in Figure 1.

Results 

Praxair previously developed what was then 

considered to be a small on-site hydrogen plant for 

the industrial market in the mid 1990s. The system 

capacity ranges from 12,000 to 30,000 scfh (340 to 

850 Nm3/hr) and generates hydrogen using a SMR 

with a PSA purification system. The system, 

although it has multiple skids requiring field 

assembly, demonstrates some of the potential 

positive effects of packaging all components on skids 

and limiting the field installed items to a few 

miscellaneous components. The installation cost 

percentage of the overall capital was less than one 

half of that of the larger systems, and the system was 

installed in less than 4 weeks. This is a significant 

improvement over the large plant approach, but the 

goals for the LCHPP will require additional 

installation and start-up cost reductions. The Praxair 

on-site hydrogen generating system (HGS) is shown 

in Figures 2 and 3.

Although the HGS system has been a success in 

the industrial market, with the system being over 

97% reliable, the goals for the LCHPP project 

require a step change. The LCHPP will be 

approximately one-sixth the capacity, about one-fifth 

the footprint, and will lower the hydrogen product to 

about one-half that of the HGS system.

A detailed analysis of existing SMR based onsite hydrogen plants, including the HGS system 

detailed above, has been completed. The object of 

this analysis was to evaluate the current design 

methodology related to industrial on-site hydrogen 

plants. A cost matrix detailing the individual 

component costs as well as the project and operating 

costs associated with the plants was created. The 

data was collected from over 15 on-site hydrogen 

supply systems currently operated by Praxair. The 

Figure 1. Low Cost Hydrogen Production Platform 

(LCHPP) Process Diagram

Figure 2. Praxair HGS On-Site Supply System 

Figure 3. Praxair HGS On-Site Supply System 

(Seymour, Indiana)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

105

systems analyzed ranged from 10 to 100 times the 

capacity required in accordance with this project. 

Data from the analysis indicates that SMR hydrogen 

plants are typically custom designed with very low 

levels of integration. A significant percentage of the 

capital is required for the installation of the plant. 

The analysis also confirmed that typically over 50% 

of the installed capital cost is related to the reformer 

and shift components. With the cost matrix 

component breakdown, the areas of highest potential 

cost savings were clearly identified.

Results to date also include the development of 

detailed process models of SMR and purification 

systems. These models served as the baseline for the 

development of the mechanical design concepts. 

Options such as high/low pressure reforming, natural 

gas/syngas compression, PSA/membrane 

purification and various levels of thermal/process 

integration were modeled.

After the initial development of the process flow 

models, the mechanical design phase of the project 

began. As a result of the existing technology 

assessment discussed above, significant initial effort 

was placed in the cost reduction of the reformer and 

shift portion of the system. Initially, 6 mechanical 

design concepts were developed and evaluated. 

After discussions with the subcontractors, the six 

initial concepts were narrowed down to the three 

highest potential concepts. The three conceptual 

design options are currently being evaluated from the 

following three perspectives: 1) Praxair is developing 

3D mechanical models as well as detailed process 

models of the various options, 2) DMI is reviewing 

the designs regarding manufacturability, single unit 

cost and higher quantity manufacturing costs, and 3) 

BDI is reviewing the options from a part count and 

system mechanical design optimization approach. 

Both a preliminary manufacturing cost summary of 

each concept for a single unit and the potential for 

cost savings in a mass production operation are being 

developed. At the conclusion of the preliminary 

analysis, the concepts will be narrowed down to the 

one (or possibly two) highest potential concept(s).

The purification system is also currently being 

evaluated. A PSA-based purification system appears 

to be the clear overall economic choice. Praxair has 

extensive experience in the area of PSA development 

and has developed advanced PSA cycles and system 

designs that will lower the overall cost of this 

component.

Conclusions 

Development of a cost effective hydrogen supply 

infrastructure is a major issue facing the use of 

hydrogen in FCVs. Design-optimized, integrated 

small scale systems are likely to play an important 

role in the development of that infrastructure. The 

low cost hydrogen production platform project 

should lead to a cost effective SMR based system 

that can be an economical source of hydrogen for 

retail fueling stations. A report summarizing the 

findings of Phase I, as well as recommendations for 

Phase II will be developed at the end of Phase I of the 

agreement.

FY 2002 Publications/Presentations 

1. Aaron, T. M., 2002. "Low Cost Hydrogen 

Production Platform", Presentation given to the 

DOE at the annual review meeting in Golden, CO, 

May 6-10, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

106

II.C.8 Effects of Fuel Constituents on Fuel Processor Catalysts

John P. Kopasz (Primary Contact), Dan Applegate, Laura Miller, Shabbir Ahmed

Argonne National laboratory

9700 S. Cass Ave

Argonne, IL 60439

(630) 252-7531, fax: (630) 972-4405, e-mail: Kopasz@cmt.anl.gov

DOE Technology Development Managers: 

Peter Devlin: (202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Identify the effects of major constituents, additives, and impurities in petroleum-based fuels on 

reformer performance

• Evaluate the effects of fuel constituents and impurities on catalyst stability

• Collaborate with major oil companies for development of future fuels for fuel cells

Approach

• Investigate autothermal reforming of fuels and fuel constituents in microreactor

• Rate performance based on byproduct formation, catalyst deactivation, and dependence of hydrogen 

yield and conversion 

• Test blends of fuel components to establish a composition/performance relationship matrix; compare 

results with those for pure components

• Use long-term (>1000 h) tests to determine effects on catalyst stability, poisoning and long-term 

degradation

Accomplishments

• Completed short-term testing of refinery blends from three oil companies and determined that fuels 

low in aromatic and naphthenic components can be reformed over a wider range of operating 

conditions.

• Completed short-term testing of paraffinic-aromatic and paraffinic-naphthenic blends and determined 

that aromatic and naphthenic components decrease the rate at which paraffinic species are reformed

• Determined effects of amine additives on reforming behavior

• Studied effect of composition on water requirements and water balance issues in fuel reformer-fuel cell 

systems

• Completed long-term tests on monolithic catalysts

Future Directions

• Investigate long-term effects of additives (e.g., detergents, antioxidants) and impurities

• Continue investigating reforming of blended fuels; determine composition/performance relationships 

from results

• Investigate differences in fuel reforming with different catalysts

• Make recommendations for fuel cell fuels
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

107

Introduction

On-board reforming of petroleum-based fuels, 

such as gasoline, may help ease the introduction of 

fuel cell vehicles to the marketplace. Although 

gasoline can be reformed, some constituents and 

impurities may have detrimental effects on the fuel 

processing catalysts, which may lead to 

compromised performance and decreased fuel 

conversion efficiency. In order to identify which 

constituents are beneficial and which are detrimental 

to the reformer, we have begun to test various 

components of gasoline and blends of gasoline 

streams under autothermal reforming conditions. 

Prior work focused on the autothermal reforming 

of some of the major components of gasoline. We 

investigated the autothermal reforming of iso-octane, 

n-octane, octane, trimethylbenzene, toluene, 

methylcyclohexane, and methylcyclopentane. These 

chemicals represent the branched paraffins, straight 

chain paraffins, olefins, aromatics, and cyclic 

paraffins present in gasoline. We observed that 

trimethylbenzene required more severe reforming 

conditions than the other components.1 The current 

work focuses on the effects of blends of components 

and on the effects of additives. Blends are being 

investigated to determine if the presence of some 

components can affect the reforming of others. 

Approach

Fuel blends were obtained from three major oil 

companies. The blends were formulated to provide 

fuels with compositions of interest to the refineries. 

Reforming of the fuel blends was performed under 

constant O2:C and H2O:C ratios (0.42 and 1.4) on 

identical catalysts to allow for comparisons of the 

different fuels. Short-term (<20 h) tests were 

performed in a reactor containing ~2 g of catalyst. 

The fuel and water were vaporized, then mixed and 

sent to the reactor where oxygen was added. Four 

sampling ports allowed for testing at various 

positions (and space velocities) in the catalyst bed. A 

small portion (<1%) of the gas stream was diverted 

through one of these ports to the residual gas 

analyzer for analysis. The remainder of the gas 

stream continued through the reactor bed to the exit 

stream. Batch sampling was performed at the reactor 

exit.

Long-term (>1000 h) tests were performed in a 

separate reactor equipped with a solid-state on-line 

hydrogen sensor and infrared carbon monoxide and 

carbon dioxide detectors. Batch sampling was 

performed at the exit stream. This system allowed us 

to determine the durability of the autothermal 

reforming catalyst and to determine if there are any 

long-term problems (poisoning, coking) caused by 

the fuel components. 

Results

 Tests on the fuel blends indicate that fuels that 

are high in naphthenic components have a narrow 

window of operating conditions in which they 

provide good hydrogen yields. Figure 1 shows the 

dependence of hydrogen yield on naphthenic content 

for reforming at a GHSV of 30,000h-1 at 650, 700, 

750 and 800°C. Increasing the naphthene content 

from 0 to 5% has very little effect; however, when 

the naphthene content is increased to 20%, hydrogen 

yield drops off substantially. To better understand 

the effects of naphthenes, we investigated the 

reforming of a binary mixture of isooctane and 20% 

methylcyclohexane. The partial pressures of 

cyclohexane, methylcyclohexane, and benzene, 

normalized to the partial pressure of a helium internal 

standard, are plotted as a function of the inverse of 

the space velocity in Figure 2. The inverse of the 

GHSV is proportional to the residence time in the 

reactor. At short residence times methylcyclohexane 

and cyclohexane (formed by removing a methyl 

group from methylcyclohexane) dehydrogenated to 

form aromatics. The aromatics then behaved as they 

did in the refinery blends with high aromatic content 

and the isooctane-xylene mixtures,2

 and decreased 

Figure 1. Effect of naphthene content on the hydrogen 

yield from reforming refinery blends.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

108

the rate of reforming of the paraffin. In addition, the 

dehydrogenation reaction is endothermic. This 

reduces the temperature at the front of the reactor and 

further decreases the reaction kinetics relative to 

those for pure isooctane. 

Experiments were performed on solutions of 

isooctane with n-secbutylamine, a surrogate for 

isobutyleneamine detergents. The addition of nsecbutylamine decreased the hydrogen yield at 

temperatures below 750°C (see Figure 3). A closer 

investigation of the product gas revealed that, similar 

to the case for aromatics, the amine additive 

decreased the rate at which isooctane is reformed 

(Figure 4). However, with n-secbutylamine the 

effect is seen at much lower concentrations. A 

concern with amine additives is that they may form 

ammonia, which is a poison for PEM fuel cells at sub 

ppm levels. No ammonia was observed in the 

reforming of isooctane-n-secbutylamine solutions of 

50 ppm n-secbutylamine. For solutions with 500 

wppm n-secbutylamine, no ammonia was observed 

when the reforming was performed at 800°C; 

however, trace amounts (<250 ppb) were observed 

when the reformer was operated at 650°C. When the 

amine concentration was 1000 wppm, ammonia was 

observed in the product gas at levels of 1 ppm when 

the reactor was at 800°C and 1.5 ppm when the 

reactor was at 650°C. 

These results indicate that species that adsorb 

more strongly to the metal centers in the catalyst tend 

to decrease the rate at which the paraffinic species in 

the fuel are reformed. This is similar to results 

reported in combustion literature, where species such 

as aromatics have been observed to decrease the 

combustion of paraffins in a mixed stream.3,4 It also 

suggests that other additives and impurities that have 

strong adsorption to platinum will decrease the rate 

of reforming.

Water Balance Issues

Where fuel cell systems use on-board fuel 

processing of available fuels, the fuel processor 

requires high-purity water. For transportation 

applications, the process water must be recovered 

from the fuel cell system exhaust gas. For such 

Figure 2. Methylcyclohexane, cyclohexane, and 

benzene content in the product gas from 

reforming isooctane+20%methylcyclohexane, 

showing conversion of cyclohexanes to 

benzene.

Figure 3. Effect of n-secbutyl amine on the hydrogen 

yield from reforming isooctane.

Figure 4. Effect of n-secbutylamine on the rate of 

disappearance of paraffinic species during 

isooctane reforming.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

109

applications, it is critically important that the fuel cell 

system be a net water-producing device. A variety of 

environmental conditions (e.g., temperature, 

pressure), fuel cell system design, and operating 

conditions determine whether the fuel cell system is 

water-producing or water-consuming. The fuel 

composition can also have a significant effect. We 

have performed calculations determining the water 

balance for an ambient pressure system with onboard reforming and water recovery, assuming fuel 

feed rates of 1 gmol/min. In the reformer the steamto-carbon ratio is 1.5, and oxygen flow rates are 

adjusted to provide a temperature rise in the reactor 

of 200°C. For the condenser, we have assumed a 

design ambient temperature of 35°C (95°F) and an 

approach temperature of 11.1°C (20°F), leading to an 

exhaust gas temperature of 46.1°C (115°F). In the 

fuel cell we are assuming 80% fuel utilization and 

40% oxygen utilization. Calculations for several 

different fuels are shown in Table 1. Methane is a net 

water producer under these conditions, while 

trimethylbenzene leads to a water deficit of 81 ml/

min. In order to achieve water balance for 

trimethylbenzene under these conditions, the exhaust 

gas temperature would need to be lowered to 36.6°C 

(97°F), just 1.6°C above the ambient design 

temperature. Alternatively, the pressure can be 

increased. For trimethylbenzene, a pressure of 1.7 

atm is needed to achieve water balance, while for 

isooctane a pressure of 1.2 atm is sufficient. 

Conclusions

These tests indicate that the fuel composition can 

have a large impact on reformer performance. Some 

fuel components can affect how other components 

are reformed. Species that adsorb more strongly to 

the metal centers in the catalyst, such as aromatics, 

tend to decrease the rate at which paraffinic species 

in the fuel reform. This is similar to results reported 

in combustion literature, where species such as 

aromatics have been observed to decrease the 

combustion of paraffins in a mixed stream.3,4 This 

work also indicates that the fuel composition will 

have an impact on the water balance issues for the 

system. Fuels high in aromatics will need more 

aggressive conditions to be able to maintain a water 

balance. Future work will be directed towards 

understanding the interactions between the different 

types of components in multicomponent fuels.

References

1. J. P. Kopasz, S. Ahmed, M. Krumpelt, and P. 

Devlin, SAE Technical Paper Series 20001-01-

1915, 2001.

2. J.P. Kopasz, D. Applegate, X. Wang, L. Miller, S. 

Ahmed, “Effects of Fuel Constituents on Fuel 

Processor Catalysts”, 2001 Annual Progress 

Report, Fuels for Advanced CIDI Engines and 

Fuel Cells, U.S. Department of Energy, Office of 

Transportation Technologies, Washington D.C.

3. J. J. Spivey, Ind. Eng. Chem. Res. 1987, 26,2165-

2180.

4. A. Barresi and G. Baldi, Ind. Eng. Chem. Res. 

1994,33,2964-2974.

FY 2002 Publications/Presentations

1. Reforming Petroleum Based Fuels for Fuel Cell 

Vehicles: Composition-Performance 

Relationships, J. P. Kopasz, L. E. Miller, S. 

Ahmed, P. Devlin, and M. Pacheco, presented at 

2002 Future Car Congress, Arlington, VA, June 3-

5, 2002. SAE Technical Paper Series, 2002-01-

1885, 2002.

2. Water Balance in Fuel Cells Systems, J. P. 

Kopasz, S. Ahmed, R. Kumar, M. Krumpelt, 

presented at 10th AIChE Spring National 

Meeting, New Orleans, LA, March 10-14, 2002.

3. Autothermal Reforming of New Gasoline for Fuel 

Cell Applications, J. P. Kopasz, M.A. Pacheco, S. 

Ahmed, X. Wang, M.A. Marquez, presented at the 

Fuel Net water 

produced,

ml/min

Exhaust temperature for 

water balance, °C (°F)

Gasoline -38 42.0 (107)

Isooctane -33 43.2 (109)

Trimethylbenzene-81 36.6 (97)

Methane +5 49.2 (120)

Table 1. Fuel Calculations
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

110

7th Grove Fuel Cell Symposium, Westminster, 

London, UK, Sept. 11-13, 2001.

4. Reformability of Fuels and Fuel Constituents, J. P. 

Kopasz, presented at the IEA Annex XV 

Advanced Fuel Cell Meeting, Lucerne, 

Switzerland, July 1-2, 2001.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

111

II.C.9 Separation Membrane Development

Kit Heung (Primary Contact)

Westinghouse Savannah River Technology Center

773-A, Savannah River Site

Aiken, South Carolina

(803) 725-3161, fax: (803) 725-2756, e-mail: leung.heung@srs.gov

DOE Technology Development Manager: Peter Devlin

(202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

Objectives 

• Produce a sol-gel encapsulated metal hydride packing material that will absorb hyrogen selectively, 

not break down to fines, and tolerate reactive impurities.

• Evaluate selected packing material for hydogen separation in a small-scale column.

Approach

• Develop formulations and procedures to make silica encapsulated metal hydride composite material.

• Test selected samples in a laboratory scale separation column for hydrogen separation from feed 

streams of different compositions.

Accomplishments 

• Produced hundred-gram size samples with three different procedures.

• Designed and installed an apparatus for gas separation tests.

• Conducted hydrogen separation from a nitrogen stream on two samples.

Future Directions 

• Modify procedure to produce improved composite material to achieve required performance and 

reduce cost.

• Conduct hydrogen separation tests with feeds containing reactive impurities such as CO.

• Conduct cost analysis.

Introduction 

For a hydrogen economy to become a reality, 

hydrogen production will have to be greatly 

increased from what it is today. According to U.S. 

DOE 1994 fuel use numbers, U.S. household 

transportation fuel use is a hydrogen equivalent of 

0.55 billion lb/day. This is about 6 times the total 

U.S. hydrogen use of 0.1 billion lb/day today. Where 

will all the hydrogen come from? A definitive answer 

to this question is not yet known. One probable 

answer may be that hydrogen must come from 

multiple sources. These sources will include 

renewable (solar, wind, hydro, biomass, etc.) and 

non-renewable (fossil, nuclear, etc.) feedstocks. One 

sure thing is that hydrogen will have to be recovered 

from all kinds of gas streams. Many of the gas 

streams will contain low levels of hydrogen and 

undesirable impurities. Today's hydrogen recovery 

processes include the most commonly used pressure 

swing adsorption process, the cryogenic process, and 

the membrane process. Their use with low 

concentration feeds and high recovery are not 

efficient. A new hydrogen recovery process is still 

needed. This work is targeted at a new hydrogen 

recovery process that will be suited for hydrogen 

recovery from low hydrogen concentration gas 

streams.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

112

Approach 

When hydrogen content in a feed stream is high 

(more than about 50%), it is efficient to purify the 

hydrogen by adsorbing the impurities. This is the 

principle of the pressure swing adsorption process. 

When the hydrogen concentration is low (less than 

about 50%), it is more efficient to absorb the 

hydrogen from the feed stream. However, a practical 

absorbent for hydrogen is not yet available. Metal 

hydrides are a promising candidate because they 

absorb hydrogen reversibly at moderate conditions. 

One example is LaNi4.25Al0.75:

2 LaNi4.25Al0.75 + 5 H2 u 2 LaNi4.25Al0.75H5

Each bulk liter of this material can absorb up to 

18 moles of hydrogen reversibly. The hydrogen can 

be absorbed and desorbed by changing the hydrogen 

pressure, the temperature or both. This group of 

materials would have been well suited for hydrogen 

recovery from low concentration streams if not for 

two practical problems. Metal hydrides in general 

break down to fines after repeated hydrogen 

absorption and desorption. The fines are in the 

micron range that makes them very difficult to use in 

separation columns. Metal hydrides are sensitive to 

reactive impurities like oxygen and carbon 

monoxide. Levels at hundredths of a fraction can 

render them inactive toward hydrogen. Past efforts to 

deal with these problems can be represented by the 

works of Sandrock et al [1] and Suda et al [2].

In this work metal hydride particles are 

encapsulated in a porous silica matrix to form a 

composite material. The composite is then broken 

into granules of desired size for packing separation 

columns. Each granule is a matrix of porous silica 

with metal hydride particles uniformly distributed in 

it. The porous matrix is strong so that hydrogen 

absorption and desorption of the metal hydride 

particles does not cause breakage. The porosity of the 

matrix permits hydrogen to reach the metal hydride 

particles but prevents the larger size impurity 

molecules from penetrating. The composite granules 

can therefore withstand hydrogen absorption/

desorption without generating fines and can tolerate 

reactive impurities.

Results 

The fabrication of encapsulated metal hydride 

involves 3 main steps: 1) break the metal hydride to 

fine particles and stabilize the fines for handling in 

open air; 2) encapsulate the metal hydride particles in 

silica with the sol-gel method; 3) treat the composite 

with heat to obtain desired strength and porosity. 

Micrographs of a typical encapsulated sample are 

shown in Figure 1.

 Figure 1. Silica Encapsulated Metal Hydride
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

113

Samples of encapsulated LaNi4.25Al0.75 were 

tested for hydrogen absorption in a gas manifold with 

hydrogen from a known volume. The results showed 

that the encapsulated sample was easier to activate 

than the non-encapsulated metal hydride. The 

hydrogen absorption capacity of the encapsulated 

metal hydride did not change significantly. The 

encapsulated sample also retained its activity better 

than the non-encapsulated sample after exposure to 

air. After repeated absorption/desorption cycles, the 

granules did not generate fines as metal hydride did. 

A laboratory scale separation apparatus was set 

up for testing the hydrogen separation properties of 

encapsulated metal hydride samples. The apparatus 

consists of a gas manifold, a packed column and a 

thermal conductivity detector (TCD). The gas 

manifold comprises supplies of hydrogen, nitrogen, 

methane, carbon dioxide and carbon monoxide. Mass 

flow controllers are used to generate gaseous 

mixtures to feed the separation column. The column 

is a U-shape 3⁄4-inch diameter, 6-inch long stainless 

steel tube, packed with encapsulated metal hydride 

granules. On the outlet side of the column, a 

pressure-regulating valve keeps the pressure in the 

column constant. A side stream is directed to the 

TCD for measuring the hydrogen concentration. A 

top-open furnace and a water bath are use to heat or 

cool the column when needed. 

A typical test involves a hydrogen absorption 

step and a regeneration step. In the absorption step, 

hydrogen and carrier gases at target rates are joined 

to form a feed stream to enter the column. The 

hydrogen is absorbed and the carrier gas is left 

passing through the column. As the absorption 

capacity of the packing material at the inlet end is 

saturated gradually, an absorption front is developed 

in the column. The absorption front is an inverse-S 

shaped concentration profile of hydrogen in the gas 

phase. This absorption front exits the column when 

the packing material is completely saturated. The 

hydrogen concentration measured by the TCD will 

show the absorption front to be an S-shaped curve of 

hydrogen concentration versus time. This curve is 

often called the breakthrough curve. The actual shape 

of the breakthrough curve is an indication of the 

kinetics of hydrogen absorption of the packing 

material. A steep rise of the curve indicates favorable 

kinetics for hydrogen separation. Hydrogen 

absorption by metal hydride is an exothermic 

reaction. A thermocouple located in the column can 

measure the temperature peak indicating the location 

of the absorption front at a given time. A typical 

breakthrough curve and temperature peak is shown in 

Figure 2. This kind of data may be used to compare 

separation efficiencies and to design separation 

columns.

The efficiency of hydrogen removal can be 

shown by the difference in the amounts of hydrogen 

entering the column and the amounts of hydrogen 

leaving the column as a function of time. For a 

typical run, the results show that about 95% of the 

hydrogen entering the column is absorbed 

continuously until the column is saturated, see Figure 

3.

Figure 2. Breakthrough Curve of Hydrogen Absorption 

by Encapsulated Metal Hydride Packed 

Figure 3. Hydrogen Removal from a Flowing Stream is 

about 95%.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

114

For typical regeneration, the column is purged 

with nitrogen and is heated up to about 100oC at the 

same time. The hydrogen concentration at the exit 

stream is measured by the TCD. From this 

concentration data the partial pressure of the 

hydrogen can be calculated. The data in Figure 4 

show that about half of the hydrogen can be 

recovered at 800 torr, and more than 95% can be 

recovered at 100 torr.

Conclusions 

Metal hydride powders can be encapsulated in a 

porous silica matrix using a sol-gel method. The 

encapsulated metal hydride retains its hydrogen 

absorption property with increased resistance to 

reactive impurities. Granules of encapsulated 

composite can withstand hydrogen absorption/

desorption cycles without producing fines. This 

makes them applicable in packed separation 

columns. Hydrogen recovery from a nitrogen stream 

has been demonstrated in a laboratory column with 

the encapsulated metal hydride. Hydrogen recovery 

from other gas streams such as methane, carbon 

dioxide and that containing carbon monoxide has 

been planned and will be tested. Encapsulated metal 

hydride is suited for hydrogen recovery from low 

concentration streams which will be needed in a 

hydrogen economy. 

References 

1. J. J. Sheridan III et al, Journal of the LessCommon Metals, 89 (1983) 447-455.

2. X.-L. Wang et al, Journal of Alloys and 

Compounds, 231 (1995) 860-864.

FY 2002 Publications/Presentations 

1. Paper titled "Hydrogen Separation Using 

Encapsulated Metal Hydride" presented in 14th 

World Hydrogen Energy Conference, June 9th13th, 2002.

Special Recognitions & Awards/Patents 

Issued 

1. US patent number 6,262,328 issued.

Figure 4. Hydrogen Recovery from the Column
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

115

II.C.10 Defect-Free Thin Film Membranes For H2 Separation and Isolation 

Tina M. Nenoff (Primary Contact)

Sandia National Laboratories

PO Box 5800, MS 0755

Albuquerque, NM 87185-0755

(505) 844-0340, fax: (505) 844-0968, e-mail: tmnenof@sandia.gov

DOE Technology Development Manager: Peter Devlin

(202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

Objectives 

• Synthesize defect-free thin film zeolite membranes for H2 isolation and purification, and use as water 

management membranes in proton exchange membranes (PEMs).

• Replace existing expensive and fragile Pt catalysts.

• Test the separations of light gases (pure and mixtures) through the membranes.

• Demonstrate effective light gas separations and commericalization potential of zeolite membranes.

Approach

• Synthesize defect-free thin film zeolite membranes and microporous bulk phases for future membrane 

applications.

• Model/simulate permeation of light gases through various frameworks/pores for optimized 

performance.

• Analyze flux and permeation of gases through membranes on unique in-house permeation unit.

• Validate modeling/simulation with actual permeation data to optimize membranes synthesized.

Accomplishments 

• Synthesized defect-free zeolite membranes with different selectivities for various gas molecules; 

selectivity based upon a combination of molecular sieving through the pores and adsorption of the 

various composition frameworks.

• Designed and built a unique in-house permeation unit that can test both disk and tube membranes, with 

multiple pure or mixed gases, in a temperature range of 25-500°C.

• Analyzed selectivities of pure gases through various membranes; aluminosilicate (Al/Si) membranes 

are highly selective for hydrogen (H2); all silica membranes are selective for carbon dioxide (CO2).

• The Sandia aluminosilicate zeolite membranes have fluxes on the order of 10-6 mole/mole per meter 

squared Pascal secont (flux unit) (m2Pa sec) and pure gas separations of H2/N2 > 61, H2/CO2 >80, H2/

CH4 =7, CH4/CO2 >11. H2 (hydrogen), N2 (diatomic nitrogen),CO2 (carbon dioxide), CH4 (methane).

Future Directions 

• Synthesize and characterize of thin films and bulk novel microporous phases including of Al/Si zeolite 

thin films doped and/or ion exchanged with other elements, unsupported aluminosilicate zeolite 

membranes, and silicotitanate phases.

• Synthesize membranes on (commerically viable) oxide-coated porous stainless steel supports.

• Model separation values by molecular dynamics calculations for pure and mixed light gases 

interacting with differing zeolite type membranes (ie., comparing ZSM-5 to ZSM-22).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

116

• Perform permeation and flux studies of pure and mixed gases through membranes (H2, CO, CO2, CH4, 

N2, and sulfur hexafluoride [SF6]).

• Build a partnership with a membrane company. Initiate an agreement for product development with an 

industrial partner.

Introduction 

There is a great need for robust, defect-free, 

highly selective molecular sieve (zeolite) thin film 

membranes for light gas molecule separation ratios in 

hydrogen fuel production from CH4 or H2O sources. 

In particular, we are interested in (1) separating and 

isolating H2 from H2O and CH4, CO, CO2, diatomic 

oxygen (O2,) and N2 gases; (2) water management in 

PEMs, and (3) as replacing for expensive Pt catalysts 

needed for PEMs. Current hydrogen separation 

membranes are based on Pd alloys or on chemically 

and mechanically unstable organic polymer 

membranes. The use of molecular sieves brings a 

chemically and mechanically stable inorganic matrix 

to the membrane. The crystalline frameworks have 

"tunable" pores that are capable of size exclusion 

separations. The frameworks are made of inorganic 

oxides (e.g., silicates, aluminosilicates, phosphates) 

that bring different charge and electrostatic attraction 

forces to the separation media. The result is 

materials with high separation abilities plus inherent 

thermal stability over 600°C and chemical stability. 

Furthermore, the pore sizes and shapes are defined 

crystallographically (<1Å deviation) which allows 

for size exclusion of very similarly sized molecules. 

In comparison, organic polymer membranes are 

successful based on diffusion separations, not size 

exclusion. We envision positive results from this 

project in the near term with hydrocarbon fuels, and 

long term with biomass fuels.

Approach 

The approach for this program is the 

development of defect-free thin film zeolite 

membranes and new bulk microporous phases for the 

selective separation of light gases. The development 

of these membranes includes synthesis, modeling/

simulation, permeation studies and validation for 

separation and isolation of H2. The permeation of 

pure and mixed gases through membranes is studied 

at room temperature and 80°C. The modeling and 

simulation work helps determine improved pore size 

and composition for sieving. The validation involves 

comparing modeling/simulation data with actual 

permeation values to determine needed improve 

upon the membranes synthesized.

Previous work at Sandia has successfully shown 

the ability to grow defect-free aluminosilicate and 

phosphate-based molecular sieve membranes. The 

focus now is on the enhancement and optimization of 

the type of molecular sieve for separation, the 

methodology of film growth, and the type of supports 

upon which to grow membranes (and remain 

commercially viable). We are studying 

aluminosilicate frameworks and metal doped 

frameworks to better determine the relationship 

between adsorption, sieving and then permeation. To 

study the effect and prerferability of support types, 

we are studying and comparing unsupported film 

growth versus film growth on ceramic supports. We 

are also beginning studies on newly available 

ceramic coated stainless steel supports (allowing for 

phase match on the ceramic, with the durability of 

stainless steel). With all materials synthesized, we 

perform characterization in-house to better 

understand structure-permeability relationships. 

These include X-ray diffraction, thermal analyses, 

elemental analysis and permeation studies. Our inhouse permeation unit is capable of fitting both disk 

and tubular membrane supports, either of ceramic 

oxide or stainless steel materials. This unique unit 

can be run from room temperature to elevated 

temperatures (< 500°C), though we only plan to run 

as high as 80°C. The unit also contains a residual gas 

analyzer, enabling us to monitor and identify ratios 

of the permeate mixtures. We also are able to 

leverage end sealant technology patented through 

Sandia. The gases we plan to test for this project 

include H2, helium (He), CH4, CO, CO2, CH4, O2, 

N2, and SF6, plus mixtures of these gases.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

117

Results 

In the area of thin film membranes we have 

successfully synthesized micron thick 

aluminosilicate zeolite membranes on alumina disks 

(see Figure 1). Our permeation testing (see Figure 2) 

of the material shows that these membranes are 

defect-free. Defect free is denoted by permeation 

selectivity due to size exclusion by molecular sieving 

through the zeolite pores, and not through crystalline 

defect sites, pin holes, or crystallite mismatches 

(pores of this zeolite are 5.5 Å). Molecules used for 

this test are He (kinetic diameter = 2.6 Å) and SF6

(kinetic diameter = 5.5 Å). Pure gas studies are run 

at room temperature. The only consistent problem 

has been that membranes have grown on both sides 

of the disk support, even when seeding occurs on one 

side. As a result, flux through the membrane/support 

is slightly diminished from what it would be with 

only one side membranes.

Once the membrane is determined to be defectfree, testing on pure gases vital to the steam 

reforming cycle for natural gas to hydrogen fuels can 

begin. Pure gas data presented in Table 1 show the 

results achieved by our membranes, and compares 

them to literature values [1,2]. Most importantly, the 

Sandia aluminosilicate zeolite membranes have flux 

values superior to those observed elsewhere. In 

particular, the Sandia membranes have fluxes on the 

order of 10-6 mole/(m2Pa sec) and separations of H2/

N2 > 61, H2/CO2 >80, H2/CH4 =7, CH4/CO2 >11 

(see Table 1) [3]. Also, the all-silica zeolite 

membranes have superior CO2 separation from 

smaller light gases (such as H2) [3,4]. Though not 

completely understood, these results indicate that we 

can tune the membrane materials to have selectivity 

for various light gases. This is even more valuable as 

it is with crystalline inorganic zeolite membranes that 

are chemically, thermally and mechanically robust 

and stable. In comparison to Pd alloy films, the 

zeolite membranes perform well. According to the 

literature [5], Pd on alumina had relative ratios of 

light gas separations of H2/N2 = 110 at elevated 

temperature of 350°C. The flux was also low (2 x 

10-7 mole/m2Pa sec). Furthermore, we have 

synthesized defect-free aluminosilicate zeolite thin 

films supported on commercially available oxide 

coated stainless-steel supports (SS316); industry 

needs stainless steel to make membranes an 

economically viable technology. 

Another avenue of research is bulk novel 

molecular sieve materials, with the goal of "tuning" 

pore sizes to molecular sieving needs. In this arena, 

we have successfully synthesized many new phases, 

Figure 1. Cross Section View by Scanning Electron 

Microscope of the Micron Thick Zeolite 

Membrane on Gamma-Alumina Substrate

Table 1. Permeation Values for Pure Gases at Room 

Temperature
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

118

a number of which are promising for light gas 

separations. In particular, we have a novel 

crystalline 12-ring microporous 

fluorogallophosphate material. [6] Its pore sizes are 

the in range for light gas separations, as shown in 

Figure 3. We are now attempting to synthesize this as 

a thin film membrane.

Conclusions 

There is a great need for robust, defect-free, 

highly selective molecular sieve (zeolite) thin film 

membranes for light gas molecule separations in 

hydrogen fuel production from CH4 or H2O sources. 

They contain an inherent chemical, thermal and 

mechanical stability not found in conventional 

membrane materials. Our goal is to utilize those 

zeolitic qualities in membranes for the separation of 

light gases, and to eventually partner with industry to 

commercialize the membranes. To date, we have 

successfully:

• Demonstrated (through synthesis, 

characterization and permeation testing) both 

the ability to synthesize defect-free zeolitic 

membranes and use them as size selective 

gas separation membranes;

• Built and operated our in-house light gas 

permeation unit;

• Synthesized membranes on commercially 

available disks (this is in addition to 

successes we have had in synthesizing 

zeolitic membranes to tubular supports [7]); 

• Synthesized a number of new microporous 

bulk phases, including the novel 12-ring 

fluorogallophosphate; and

• Work continues in the synthesis of these 

novel materials as thin film membranes.

References 

1. Tavolaro, A.; Julbe, A.; Guizard, C.; Basile, A.; 

Cot, L.; Drioli, E. "Synthesis and characterization 

of a mordenite membrane on an Al2O3 tubular 

support". J. Mater. Chem. 2000, 10, 1131.

2. Lai, R.; Gavalas, G. R. "ZSM-5 membrane 

synthesis with organic-free mixtures". 

Microporous and Mesoporous Materials, 2000, 

38, 239.

3. Nenoff, T. M.; Bonhomme, F. "Defect-free thin 

film membranes for Hydrogen separation and 

isolation". 14th World Hydrogen Energy 

Conference Proceedings, Montreal, Canada, 2002, 

in press.

4. Bonhomme, F.; Nenoff, T. M. "Defect-free 

zeolite membranes for CO2 separations". 

Figure 2. Sandia Permeation Unit for Light Gases 

(including CO), Pure and Mixed (the 

equipment diagram) 

Figure 3. 3D Framework of 12-ring Gallo 

Fluorophosphate Microporous Phase
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

119

Microporous and Mesoporous Materials, 2002, in 

preparation.

5. Chou, K. S.; Wang, S. M. "Studies on the 

preparation of Pd/alumina/porous stainless steel 

membranes for hydrogen separation". J. Chinese 

Inst. Chem. Eng., 2000, 31, 499.

6. Bonhomme, F., Thoma, S. G., Rodriguez, M. A., 

Nenoff, T. M. "Ga4(PO4)4F·N2C7H11· 0.5H2O, A 

3D Open Framework with 12-member Pores and 

"bowl-shaped" Building Units". Chem. Mater., 

2001, 13(6), 2112.

7. Thoma, S. G.; Nenoff, T. M. "A New Method for 

Synthesizing Defect-Free Thin Film Membranes: 

Composite Zeolite/Sol-gel Membranes". SD6222, US Patent Submission, 2000.

FY 2002 Publications/Presentations 

1. Nenoff, T. M.; Bonhomme, F. "Defect-free thin 

film membranes for Hydrogen separation and 

isolation". 14th World Hydrogen Energy 

Conference Proceedings, Montreal, Canada, 2002, 

in press.

2. Bonhomme, F.; Thoma, S. T.; Nenoff, T. M. 

"Two ammonium templated gallophosphates: 

Synthesis and structure determination from 

powder diffraction data of 2D and 3D-GAPON". 

Micro. & Meso. Materials, 2002, 53, 87.

3. Bonhomme, F.; Thoma, S. G., Rodriguez; M. A.; 

Nenoff, T. M. "Ga4(PO4)4F·N2C7H11· 0.5H2O, A 

3D Open Framework with 12-member Pores and 

"bowl-shaped" Building Units". Chem. Mater., 

2001, 13(6), 2112.

4. Bonhomme, F.; Thoma, S. G.; Rodriguez; M. A., 

Nenoff, T. M. "Piperazine templated 3D 

flurogallophosphate: Synthesis and 

characterization of Ga5(PO4)5F4-2[N2C4H12]". 

Micro. & Mesoporous Materials, 2001, 47(2-3), 

185.

5. Bonhomme, F.; Thoma; S. G., Nyman; M., 

Rodriguez; M. A., Nenoff, T. M. "Synthesis and 

Crystal Structure of Guanidinium 

Tetrafluoro(trans-) dipyridinechromate(III), 

[CrF4(C5H5N)2]

-

CN3H6

+". J. Fluorine Chem., 

2001, 108, 73.

6. Mitchell, M. C.; Autry, J. D.; Nenoff, T. M. 

"Molecular Dynamics Simulations of Binary 

Mixtures of Methane and Hydrogen in Zeolite A 

and a Novel Zinc Phosphate". Mole. Physics, 

2001, 99(22), 1831.

7. Bonhomme, F.; Thoma, S. G.; Nenoff, T. M. "A 

linear DABCO templated fluorogallophosphate: 

Synthesis and Characterization of 

Ga(PO4H)2F·[N2C6H14]". J. Mater. Chem. 2001, 

11(10), 2559.

8. T. M. Nenoff, F. Bonhomme, "Defect-Free Thin 

Film Membranes for H2 Separation and 

Isolation", 14th World Hydrogen Energy 

Conference, Montreal, Canada, June 10, 2002.

Special Recognitions & Awards/Patents 

Issued 

1. T.M. Nenoff; F. Bonhomme; "Zeolite Membranes 

with High CO2 Selectivity". US Patent submitted 

to Sandia National Laboratories, August 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

120

II.C.11 DFMA Cost Estimates of Fuel-Cell/Reformer Systems at Low/Medium/

High Production Rates

Brian D. James (Primary Contact), Gregory D. Ariff, Reed C. Kuhn

Directed Technologies, Inc.

3601 Wilson Blvd., Suite 650

Arlington, VA 22201

(703) 243-3383, fax: (703) 243-2724, e-mail: Brian_James@DirectedTechnologies.com

DOE Technology Development Manager: Sigmund Gronich

(202) 586-1623, fax: (202) 586-5860, e-mail: Sigmund.Gronich@ee.doe.gov

ANL Technical Advisor: Walter Podolski

(630) 252-7558, fax: (630) 972-4430, email: podolski@cmt.anl.gov

Objectives

• Develop realistic and internally consistent detailed designs for automotive gasoline fuel processors and 

direct hydrogen PEM fuel cell systems based on current-year technology.

• Apply Design for Manufacture and Assembly (DFMA) design and costing techniques to compare 

system designs at low, medium, and high annual production rates.

Approach

• Update design and cost estimate for baseline 0.7 V/cell peak-power reformer/fuel cell system.

• Develop detailed designs for three additional 50 kWnet PEM fuel cell systems: 0.6 V/cell reformer 

system, 0.7 V/cell direct hydrogen system, 0.6 V/cell direct hydrogen system.

• Apply DFMA techniques to assess manufacturing methods and costs for each system for comparison 

to baseline.

Accomplishments

• Completed detailed baseline design and thermodynamic modeling.

• Performed annual update to cost estimates of baseline system with more detailed estimates of 

peripheral components.

• Completed cost estimates of additional reformer and direct hydrogen systems for comparison to 

baseline.

Future Directions

• Update baseline reformer and fuel cell cost estimates to reflect advances in technology and additional 

manufacturing and design improvements. Conduct a series of in-depth trade studies on selected issues 

to assess pathways to lower cost systems.

Introduction

Directed Technologies Inc. (DTI) has performed 

a DFMA-style cost estimation for an onboard 

gasoline reformer and fuel cell system at several 

annual production volumes. The DFMA technique is 

a rigorous design/redesign and cost estimation 

methodology developed by Boothroyd and 

Dewhurst1 and adapted by DTI. In a previous 

report2

, DTI analyzed the cost of a 50 kWnet baseline 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

121

system. The current report presents refined costs for 

the baseline system as well as comparisons to an 

alternate reformer/fuel cell system and two direct 

hydrogen fuel cell systems.

Approach

The contract statement of work defines four tasks 

to be completed by DTI. Having completed and 

reported the results for Task 1 and Task 2, our efforts 

are currently focused on Tasks 3 and 4. In Task 1, 

DTI specified the basic layout of the system and 

operating conditions. In Task 2, DFMA was used to 

identify the low-cost design and production methods 

and provide estimated material, manufacturing, and 

assembly costs. These results were reported in the 

“Fuel Cells for Transportation 2001 Annual Progress 

Report”. Task 3 consists of annual updates and 

refinements of the system cost to reflect changing 

technology and new information. In Task 4, a variety 

of trade-off studies will be used to elaborate on basic 

system architecture and operating modes.

For this report, the DFMA methodology was 

applied to refine costs for the baseline 0.7 V/cell 

reformer/fuel cell system at production rates of 500, 

10,000, 30,000, and 500,000 units per year. 

Additionally, three other systems were analyzed for 

comparison to the baseline: a gasoline reformer/fuel 

cell system operating at 0.6 V/cell (at peak power), a 

direct hydrogen system operating at 0.7 V/cell, and a 

direct hydrogen system operating at 0.6 V/cell. Each 

system is designed to provide 50 kW of net electrical 

power. The bills of materials for reformer/fuel cell 

systems and direct hydrogen systems are shown in 

Table 1. Items specifically not included in this 

analysis are the Traction Inverter Module, the main 

automotive electric motor, and any peak-power or 

load-leveling battery system.

Results

Reformer/fuel cell system definition

Figure 1 shows the system schematic for a 

gasoline reformer/fuel cell system. The drawing 

applies to both the 0.7 V/cell and 0.6 V/cell systems, 

which only differ dimensionally. In these systems, 

California reformulated gasoline is pumped from the 

fuel tank and injected into the integrated autothermal 

Subsystem Reformer/FC Direct hydrogen 

Fuel Loop

Fuel tank assembly Compressed H2 tank

High-pressure fuel pump H2 recirculation ejector

High-pressure fuel 

injector

H2 intank solenoid & 

PRD

Fuel Cell 

Stacks

MEA and bipolar plate MEA and bipolar plate

Endplates and brackets Endplates and brackets

Air Loop

Air compressor/

expander

Air compressor/

expander

Air mass flow sensors Air mass flow sensor

Air throttle body Air humidifier

Air humidifier

Water 

Loop

Water pump & reservoir Water pump & reservoir

Knock-out drum, 

condensers

Knock-out drum, 

condensers

High-pressure rail 

system

High-pressure rail 

system

Water deionization filter Water deionization filter

Coolant 

Loop

Pump, motor, controller Pump, motor, controller

Radiator assembly Radiator assembly

Thermostat, bypass 

valve

Thermostat, bypass 

valve

Controls

Electronic engine 

controller

Electronic engine 

controllers

CO sensors

Misc./

Balance of 

Plant

Start-up battery Start-up battery

Electrical Electrical

System mounting System mounting

Misc. Misc.

Integrated 

ATR 

Assembly

Autothermal reactor N/A

Water gas shift reactors

Sulfur removal

Water boiler

Reformate 

Loop

PrOx unit N/A

Air control solenoid

Catalytic burner

Condenser

Table 1. Bill of Materials for Gasoline Reformer and 

Direct Hydrogen Fuel Cell Systems

Figure 1. Gasoline Reformer/Fuel Cell System 

Schematic
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

122

reformer (ATR) assembly (which includes an ATR 

section, high and low temperature water-gas shift 

sections, and sulfur removal bed) where it is mixed 

with air and steam to generate a hydrogen-rich 

reformate stream. This gas stream is then sent to the 

preferential oxidation reactor (PrOx) to convert water 

and carbon monoxide to additional hydrogen and 

carbon dioxide. After the remaining water is 

condensed for removal, the reformate enters the PEM 

fuel cell where the hydrogen reacts with oxygen from 

air to generate electricity and heat. The unreacted 

fuel and air streams are mixed and burned in a 

catalytic burner and expanded in an exhaust gas 

expander to derive power for the air compressor.

The fuel cell system has four stacks containing 

110 cells each. Table 2 provides details of each stack 

and its parameters. Because the reformate contains 

small amounts of carbon monoxide (<50 ppm) which 

can poison the platinum membrane catalyst, the 

catalyst loadings are significantly higher than for 

direct hydrogen systems (0.7 g/cm2

 versus 0.15 g/

cm2). The fuel cell performance is further hindered 

by the dilution of hydrogen due to the CO2 and N2 in 

the reformate stream, resulting in lower power 

densities (higher membrane areas).

Direct Hydrogen system definition

Figure 2 shows the system schematic for a direct 

hydrogen reformer/fuel cell system. Compressed 

hydrogen is stored in a carbon-fiber wrapped 

composite vessel at pressures up to 340 atm. It is fed 

through a control valve to the fuel cell at 2 atm, 

where it reacts with oxygen from air to generate 

electricity and heat. Unreacted hydrogen is 

Peak Power Conditions 0.7 V/cell ATR 

(baseline) 0.6 V/cell ATR

0.7 V/cell

Direct H2

0.6 V/cell

Direct H2

Gross Power (kW) 55 56 56 57

Net Power (kW) 50 50 50 50

Cell Voltage (V) 0.7 0.6 0.7 0.6

Current Density (mA/cm2) 400 650 600 1076

Nom. Operating Pressure (atm) 2.2 2.2 2.2 2.2

Power Density (mW/cm2) 280 390 420 646

No. of strands 1 1 1 1

No. of stacks/strand 4 4 4 4

No. of cells/stack 110 110 110 110

Total active membrane area (m2) 19.64 14.36 13.33 8.83

Active area/cell (cm2) 446 326 303 201

Peak voltage (@ 0.92 V/cell) (V) 405 405 405 405

Min. voltage (@ peak power) (V) 308 264 308 264

Max current (@ peak power) (A) 178.6 212.1 181.8 215.9

Catalyst loading

 Cathode (mg/cm2) 0.3 Pt 0.3 Pt 0.10 Pt 0.10 Pt

 Anode (mg/cm2

)

0.4 Pt

0.2 Ru

0.4 Pt

0.2 Ru 0.05 Pt 0.05 Pt

Stack efficiency* 41.5% 35.1% 51.1% 43.1%

Onboard System efficiency* 33.4% 28.2% 51.1% 43.1%

* Stack efficieny is the electrical power output of the fuel cell stack divided by the lower heating value (LHV) per unit time of 

hydrogen entering the stack. System efficiency is the net electrical power of the system divided by the LHV per unit time of the fuel 

feed (gasoline for reformer system, hydrogen for direct hydrogen system).

Table 2. Operating Parameters for ATR and Direct H2 Fuel Cell Systems
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

123

recirculated to prevent loss of hydrogen from the 

system, while the oxygen-depleted air stream is 

exhausted.

Like the reformer systems, four PEM fuel cell 

stacks of 110 cells each are used. These stacks are 

smaller and have lower catalyst loading than those 

for the reformer systems because the hydrogen is 

99.99% pure, containing less than 10 ppm carbon 

monoxide. Stack parameters for the direct hydrogen 

systems are compared to those for the reformer 

systems in Table 2.

Cost estimates

Cost estimates for each system at each of the four 

production levels are the sum of materials, 

manufacturing, and assembly costs, as well as a 

manufacturer’s markup and a 10% cost contingency 

(as is standard automotive cost estimation practice). 

As might be expected, cost of the finished system 

decreases with increasing production volume.

Figure 3 shows the cost of each of the four 

systems at four different production volumes. The 

reformer/fuel cell system designed for peak power at 

0.6 V/cell offers some cost reductions compared to 

the baseline, but both direct hydrogen fuel cell 

systems are significantly less expensive than either of 

the reformer/fuel cell systems. This cost reduction is 

primarily due to the decreased size and cost of the 

fuel cell stack, as can be seen in Figure 4. The 

reformate loop and ATR are also eliminated in the 

direct hydrogen systems, but the fuel loop bears the 

cost of the fiber-wrapped composite tank for 

compressed hydrogen.

In all four systems studied and at all production 

rates, the fuel cell stack accounts for more than half 

of the total system cost. The cost of the stack is 

dominated by the membrane electrode assembly 

(MEA), as shown in Figure 5 for the 0.7 V/cell 

reformate fuel cell. The membrane material and 

catalyst account for roughly 85% of the MEA cost in 

the reformate systems and 62-76% in the direct 

hydrogen systems (low-high production volumes).

Differences in cost between the updated baseline 

system reflected in this report and preliminary costs 

Figure 2. Direct Hydrogen Fuel Cell System Schematic

Figure 3. Power System Cost vs. Production Rate for 

ATR and Direct Hydrogen Systems (50 kW)

Figure 4. Comparison of 0.7 V/cell ATR and Direct H2

System Costs (50 kW)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

124

from the previous report are the result of the more 

rigorous and thorough cost methodology performed 

in the past year. The updated costs, however, result 

in only a 3-4% change in total system cost for all 

production rates. 

Conclusions

Capital costs for fuel cell power systems vary 

with production rates, peak power voltage 

conditions, and hydrogen source (reformate vs. 

direct). As with most manufactured products, the 

cost of materials, manufacturing, and assembly 

decrease with increasing annual production volumes. 

Designing the fuel cell stack to operate at lower 

voltages at peak power (0.6 V/cell vs. 0.7 V/cell) 

offers capital cost savings at the expense of system 

efficiency.

Power systems for hydrogen fuel cell vehicles 

are costly, with approximately half the cost coming 

from the fuel cell stacks. Because the MEA accounts 

for sixty to ninety percent of the stack cost, the cost 

of the entire power system is highly dependent on the 

total membrane area of the system. Due to the low 

hydrogen quality of the fuel stream in reformate/fuel 

cell systems, the membrane area and catalyst 

loadings in such systems significantly exceed those 

in direct hydrogen systems, driving up the cost of the 

power system. This cost difference is true at all 

production levels, from initial introduction of fuel 

cell vehicles through full public acceptance. Overall 

system costs range from $105/kW to $243/kW for 

the 0.6 V/cell direct hydrogen system and $221/kW 

to $472/kW for the 0.6 V/cell reformate system. 

Comparable systems operating at 0.7 V/cell cost 

approximately 12% to 22% more than the 0.6 V/cell 

versions.

References

1. Boothroyd, G., Dewhurst, P., and Knight, W. 

Product Design for Manufacture and 

Assembly, Second Edition. Marcel Dekker, 

Inc. New York, 2002.

2. James, B., Thomas, C.E., Ho, J., and Lomax, F. 

“DFMA Cost Estimates of Fuel-Cell/Reformer 

Systems at Low/Medium/High Production 

Rates” in Fuel Cells for Transportation: 2001 

Annual Progress Report. U.S. Department of 

Energy, Office of Advanced Automotive 

Technology. Washington, D.C., 2001.

Presentations

1. This work was presented by Brian D. James at 

the SAE Future Car Congress in Washington, 

D.C. on June 7, 2002.

Figure 5. Cost Breakdown for Fuel Cell Stacks in 0.7 

V/cell ATR System (50 kW)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

125

II.D Electrolytic Processes

II.D.1 Photoelectrochemical Systems for Hydrogen Production

Ken Varner, Scott Warren, J.A. Turner (Primary Contact)

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401

(303) 275-4270, fax: (303) 275-3033, e-mail: john_turner@nrel.gov

DOE Technology Development Manager: Roxanne Danz 

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Objectives

• Identify and characterize possible semiconductor materials that have appropriate bandgaps and are 

stable in aqueous solutions.

• Study multi-junction semiconductor systems for higher efficiency water splitting.

• Develop techniques for the preparation of transparent catalytic coatings and their application to 

semiconductor surfaces.

• Identify environmental factors (i.e., pH, ionic strength, solution composition, etc.) that affect the 

energetics of the semiconductor, the properties of the catalysts, and the stability of the semiconductor.

• Develop techniques for the energetic control of the semiconductor electrolyte interphase.

Approach

• Identify new semiconductor materials with bandgaps in the ideal range.

• Catalyze the surfaces and engineer the bandedges of the identified semiconductor materials as 

required.

• Determine if existing photovoltaic (PV) device structures could be easily modified to effect the direct 

splitting of water.

Accomplishments

• Work on the stability and efficiency characteristics of amorphous silicon structures for direct water 

splitting systems clearly showed that it is feasible to utilize amorphous silicon devices in direct contact 

with aqueous electrolytes without additional protective coatings.

• Work on the study of gallium indium nitride materials for water splitting showed that if the bandgap 

can be reduced, these materials have very promising bandedge energetics and stabilities.

• Studies of bandedge engineering of gallium indium phosphide (p-GaInP2) have shown that the 

bandedges can be controlled within a small range of pHs.

Future Directions

• Continue to evaluate samples of new semiconducting materials with appropriate bandgaps.

• Continue to design and test additional multi-junction systems (CuGaInSSe, GaPN, and GaInN 

materials, and a-Si triple junction systems) for possible photoelectrochemical water splitting.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

126

• Study the stability of semiconductor 

materials and coatings for protection against 

corrosion.

• Develop techniques for controlling the 

semiconductor energetics so that the 

bandedges are matched for water splitting, 

and identify factors that influence the 

catalysts of hydrogen and oxygen.

Introduction

The goal of this research is to develop a stable, 

cost-effective, photoelectrochemical (PEC)-based 

system that will split water upon illumination, 

producing hydrogen and oxygen directly, using 

sunlight as the only energy input. Past work has 

shown that PEC hydrogen producing devices can 

have an efficiency 30% higher than separated PV 

electrolysis devices, and analysis work has shown 

that the cost of PEC hydrogen can be lower than 

PVelectrolysis. For direct photoelectrochemical 

decomposition of water to occur, the following 

conditions must be met:

• The semiconductor system must generate 

sufficient voltage to split water.

• The energetic of the semiconductor must 

overlap those of the hydrogen and oxygen 

redox reactions.

• The semiconductor system must be stable in 

aqueous electrolytes.

• The charge transfer from the surface of the 

semiconductor must be fast enough to 

prevent corrosion and reduce energy losses 

due to overvoltage.

In developing PEC hydrogen systems that will 

meet these requirements, research efforts are focused 

in two areas: (1) chemical modification of the 

semiconductor electrode surface material to improve 

system energetics, and (2) evaluation of triplejunction amorphous silicon structures as low-cost 

thin-film water splitting systems.

Approach

Surface Modification of Semiconductor Material

Gallium indium phosphide (p-GaInP2) is a 

semiconducting material that meets the bandgap 

energy criteria, but does not meet the bandedge 

overlap criteria required for PEC hydrogen 

production. This electrode also accumulates 

photogenerated charges at its surface, contributing to 

surface corrosion and bandedge migration away from 

the desired electrode energetics. In this research, pGaInP2 surfaces were modified by adsorption of 

metallated porphyrins and transition metals with the 

aim of moving bandedge energies and catalyzing 

interfacial charge transfer for PEC hydrogen 

generation.

Characterization of Triple-Junction Amorphous 

Silicon Systems

Low-cost solid state multi-junction systems, 

based on triple-junction amorphous silicon (a-Si) 

solar cells, have voltages sufficient for water 

splitting, and the cells can be tailored to produce 

voltages matched to the energetic requirements of the 

water splitting reaction. In this research, efforts 

focused on characterization of various a-Si triple 

junction samples. These samples underwent currentvoltage tests, corrosion measurements, and metal-ion 

catalyst treatments. Because of the instability of a-Si 

in an aqueous environment, research efforts included 

evaluation of a surface coating of amorphous silicon 

carbide (a-SiC) to stabilize and protect the system. 

The a-SiC samples were tested for their effect on the 

overall efficiency of water splitting and their 

effectiveness in protecting the underlying 

semiconducting material from corrosion.

Results

Surface Modification of Semiconductor Material

After initial characterization of the p-GaInP2

electrode material, seven different porphyrin 

treatments were evaluated for their ability to modify 

the surface of the p-GaInP2 electrode. All of the 

porphyrins show a statistically significant shift in flat 

band potential, with the ruthenated porphyrins 

showing the greatest shift. The bandedges shifted 

into overlap conditions about 20% of the time with 

ruthenium octaethyl porphyrin carbonyl RuOEP CO. 

The variability observed in the flat band potential 

was attributed to the porphyrin application method 

and/or the age of the electrode, both of which affect 

the amount of porphyrin on the p-GaInP2 surface. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

127

When combining the RuOEP CO with a 

transition metal, such as ruthenium or platinum, the 

bandedge shift increases up to 0.48 electron volts 

(eV) in the positive direction. These combination 

treatments allowed overlap of the water redox 

potentials to occur in the dark. The effect of pH on 

the flat band potential of an untreated electrode and 

an electrode treated with RuOEP CO in combination 

with transition metals is 

shown in Figure 1. The largest shifts in flat band 

potential occurred at a pH of 4. Adding platinum or 

ruthenium to the porphyrin also significantly 

improves the charge transfer catalysis properties 

under light irradiation up to a photocurrent of 1 mA/

cm2, as shown in Figure 2. Despite the improved 

placement of bandedges, no significant change in the 

two-electrode current-voltage curve was perceptible. 

In addition, differences in open circuit cell potential 

between modified and unmodified systems were not 

statistically significant.

Characterization of Triple-Junction Amorphous 

Silicon Systems

In order to evaluate the effectiveness of a-SiC as 

a protective layer on a triple-junction a-Si device, 

triple-junction a-Si devices, both with and without aSiC deposited on the surface, were exposed to 

chemically aggressive basic (1 molar [M] potassium 

hydroxide [KOH]) and acidic (1 M sulfuric acid) 

solutions. Current density measurements showed that 

the a-SiC coating provided some protection in the 

basic solution, but in acid, no noticeable difference 

occurred between the protected and non-protected 

samples. This suggests that a-SiC may not be 

necessary to protect the device, especially when the 

electrolyte solution is acidic.

Figure 1. The effect of pH on the flat band potential of 

an untreated electrode and an electrode treated 

with both ruthenium chloride (RuCl3) and 

RuOEP CO. Dip-coating an untreated 

electrode with RuCl3 and then dropevaporating RuOEP CO vastly improves 

charge catalysis properties up to a 

photocurrent of 1 mA/cm2

. Testing is in a 4 

pH buffer. The most substantial shift in flat 

band potential occurs at pH 4, hence the 

testing at that pH.

Figure 2. Charge transfer catalysis of various 

treatments. Testing performed in pH 4 buffer.

Figure 3. Comparison of the photocurrent for coated 

and uncoated samples in acid.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

128

However, as shown in Figure 3, in some cases, 

the a-SiC actually decreases the current density as 

compared to an unprotected sample. Because the aSiC is deposited on the surface of the electrode, its 

physical and optical properties must be optimized to 

work with the a-Si triple junction it is designed to 

protect. Researchers determined that for a-SiC to be 

effective in this device without hindering the 

photocurrent, bandgaps in the 2.5 eV range and 

higher would be ideal. In addition to the light, 

electrons must also be able to move through the aSiC to effect water splitting. Because it has a finite 

thickness, there will be some resistance associated 

with it. The resistance of a-SiC samples ranged from 

0.8-1.0 ohm (Ù). At 15 milliamps per centimeters 

squared mA/cm2

 (typical photocurrent values), a 1 Ù 

resistance causes a 15 millivolts (mV) decrease in 

voltage, which would drop the current and 

corresponding hydrogen production by a factor of 

2.5. Much additional work needs to be done to 

optimize this material before it can be used as a 

protective coating, including increasing the a-SiC’s 

bandgap and decreasing the resistance, or possibly 

integrating the top cell in the device with a-Si and aSiC.

Conclusions

• The surface of p-GaInP2 can be modified by 

adsorption of metallated porphyrins and 

transition metals, resulting in improved 

energetics and catalysis for PEC water 

splitting.

• It is feasible to utilize amorphous silicon 

devices in direct contact with aqueous 

electrolytes without an additional protective 

coating.

• The combination of an optimized protective 

coating and an inherent underlying stability 

in the semiconductor material itself can lead 

to an extended lifetime in operation, because 

a breach in the protective layer would not be 

fatal to the device.

• Continued work with Energy Conversion 

Devices, Inc. to optimize the triple junction 

for increased efficiency and to tune the top 

layer for optimum stability is clearly 

indicated.

FY 2002 Publications/Presentations

1. Breach, J.D., Al-Thani, H., McCray, S., Collins, 

R.T., and Turner, J.A. “Bandgaps and Lattice 

Parameters of 0.9 ìm thick InxGa1-xN Films for 

0<x<0.140,” Journal of Applied Physics, 91 

(May 1, 2002).

2. Aroutiounian, V.M., Arakelyan, V.M., 

Shahnazaryan, G.E., Stepanyan, G.M., Turner, 

J.A., and Khaselev, O. “Investigation of Ceramic 

Photoelectrodes Fe2O3<Ta> For Solar Energy 

Photoelectrochemical Converter,” International 

Journal of Hydrogen Energy, 27, pp. 33-38 

(January 2002).

3. Sebastian, P.J., Mathews, N.R., Pattabi, X., and 

Turner, J.A. “Photoelectrochemical 

Characterization of SiC,” International Journal of 

Hydrogen Energy, 26, p. 123 (2001).

4. Turner, John A. “Renewable Energy: Generation, 

Storage, and Utilization,” in Carbon 

Management: Implications for R&D in the 

Chemical Sciences Technology: A Workshop 

Report to the Chemical Sciences Roundtable, 

National Academy Press (2001).

5. Mathew, X., Bansal, A., Turner, J.A., Mathews, 

N.R., and Sebastion, P.J. “Photoelectrochemical 

Characterization of Surface Modified CdTe for 

Hydrogen Production,” submitted to 

International Journal on New Materials for 

Electrochemical Systems.

6. Fernández, A.M. and Turner, J.A. “Preparation 

and Photocharacterization of Cu-Sb-Se Films 

Prepared by Electrodeposition,” submitted to 

Solar Energy Materials and Solar Cells.

7. The Energy Council's 2001 State Trends in 

Energy and the Environment, entitled "Long 

Term Research on Solar Production of 

Hydrogen", June 30, 2001.

8. American Chemical Society meeting in Chicago, 

IL entitled "Renewable Energy: Sustainable 

Energy for all Future Generations", August 26, 

2001.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

129

9. General Motors Corporation, entitled 

"Renewable Energy, Hydrogen, and Direct 

Water-Splitting Systems", September 17, 2001.

10. Chemistry Department of the Colorado School of 

Mines entitled "Photoelectrochemical Direct 

Water Splitting Systems", October 4, 2001.

11. North Carolina State University entitled 

"Photoelectrochemical Systems for Hydrogen 

Production via Direct Water Splitting", October 

30, 2001. 

12. Lecture on basic fuel cell technology and 

operation at the ICBO/SBCCI Conference in 

Greensboro, NC, November 1, 2001.

13. National Academy of Sciences/National 

Research Council Workshop on Carbon 

Management, entitled "Renewable Energy: 

Generation, Storage and Utilization", January 8, 

2002.

14. The USDOE Hydrogen Program's first Quarterly 

Program Performance and Results Briefing, for 

upper DOE management entitled "Advances in 

Photoelectrochemical Hydrogen Production 

Technologies", February 20, 2002.

15. American Institute of Chemical Engineers' 

Spring meeting, in a session on climate change, 

entitled "The Renewable Energy and Hydrogen 

Infrastructure", March 12, 2002.

16. American Physical Society's Spring meeting, in a 

session on climate change, entitled "Renewable 

Energy: Energy Security and Sustainability", 

March 19, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

130

II.D.2 Photoelectrochemical Hydrogen Production

Eric L. Miller (Primary Contact), Richard E. Rocheleau

Hawaii Natural Energy Institute, University of Hawaii, Manoa

1680 East-West Road, POST 116

Honolulu, HI 96822

(808) 988-5337, fax: (808) 956-2336, e-mail: ericm@hawaii.edu

DOE Technology Development Manager: Roxanne Danz

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Main Subcontractor: University of Toledo, Toledo, OH

Objectives 

• To develop high efficiency, cost-effective photoelectrochemical processes for the production of 

hydrogen.

• To engineer stable multi-junction photoelectrodes based on low-cost materials [such as stainless steel 

(SS) foil, amorphous silicon/germanium (a-Si:Ge), copper-indium-gallium-diselenide (CIGS), iron 

oxide (Fe2O3), etc.] that match energy requirements for efficient hydrogen production.

• To design, fabricate and test optimized photoelectrodes suitable for eventual commercial-scale use. 

Approach

• Develop multi-junction a-Si:Ge and CIGS photovoltaic structures incorporating additional catalyst and 

protective thin film layers for use as hydrogen photoelectrodes. 

• Establish industry and university partners to accelerate development of advanced thin-film materials 

and devices for photoelectrode use.

• Upgrade in-house fabrication facilities for advanced materials and devices. 

• Adapt integrated electronic/optical/electrochemical models for analysis of advanced a-Si:Ge and CIGS 

photoelectrode configurations, including "hybrid" devices combining solid-state and 

photoelectrochemical junctions. 

• To design, fabricate and test prototype photoelectrode systems for efficiency and stability. 

Accomplishments 

• Maintained present and established new university and industrial partnerships for developing 

advanced a-Si:Ge and CIGS materials and devices. 

• Upgraded University of Hawaii (UH) in-house a-Si:Ge and CIGS deposition systems.

• Demonstrated 12% efficiency in in-house fabricated CIGS solar cells (2" x 4").

• Established partnerships for development of Fe2O3, WO3 and TiO2 for use in hybrid photoelectrode 

designs.

• Adapted models for hybrid photoelectrode analysis.

• Performed initial modeling of hybrid photoelectrodes using published data for nano-structured Fe2O3, 

WO3 and TiO2 films.

• Selected Fe2O3 for initial hybrid photoelectrodes based on model results.

• Initiated program to develop Fe2O3 in-house, and with Duquesne University.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

131

• Completed an evaluation of a-Si:Ge devices deposited on various metal-foil substrates for determining 

optimal yield (with the University of Toledo).

• Fabricated initial set of multi-junction a-Si:Ge devices for use in preliminary hybrid photoelectrode 

tests (with the University of Toledo).

Future Directions 

• Complete fabrication and testing of initial hybrid photoelectrode prototypes.

• Identify materials and design issues needed for improving hybrid photoelectrode performance.

• Continue cooperative partnerships with research organizations to further develop optimized a-Si:Ge, 

CIGS, Fe2O3, WO3 and TiO2 materials.

• Design, fabricate and evaluate optimized multi-junction a-Si:Ge hybrid photoelectrodes.

• Design higher-efficiency hybrid photoelectrodes using advanced CIGS tandem configurations.

Introduction 

In recent years under the sponsorship of the U.S. 

Department of Energy (DOE), the Thin Films 

Laboratory at the Hawaii Natural Energy Institute of 

the University of Hawaii (UH) has been developing 

high-efficiency, potentially low-cost, 

photoelectrochemical (PEC) systems to produce 

hydrogen directly from water using sunlight as the 

energy source. The main thrust of the PEC systems 

research at UH has been the development of 

integrated multi-junction photoelectrodes, 

comprising semiconductor, catalytic, and protective 

thinfilms deposited on inexpensive substrates (such 

as stainless steel), for solar hydrogen production [1].

Figure 1a shows sunlight shining on photoactive 

regions of a generic photoelectrode, producing 

electric current to drive the hydrogen and oxygen 

evolution reactions at opposite surfaces. In the 

conceptual design for a large-scale reactor shown in 

Figure 1b, arrays of photoelectrodes are arranged in 

tubular reactors, and electrolyte is circulated to 

extract the high-purity hydrogen and oxygen gases 

produced, which are separated using membranes (as 

shown in Figure 1c). In order to meet the DOE's 

goals, the photoelectrode system must be low-cost 

and must be capable of operating stably in corrosive 

aqueous electrolyte environments with solar-tohydrogen (STH) conversion efficiencies greater than 

10%.

Approach 

Numerous approaches involving a variety of 

semiconductors have been explored for hydrogen 

photoelectrolysis since the early 1980s, but none 

Figure 1. (a) Integrated planar photoelectrode for H2

production; (b) Conceptual design of largescale reactor; (c) Photoelectrode installed in 

collection tubes with separating membrane
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

132

have successfully met both efficiency and stability 

goals. A photoelectrode design approach developed 

at UH incorporates multi-junction thin-film 

photoconvertors for high voltage along with thin-film 

catalyst and protective layers for stability. This 

research approach has relied on continued use of 

integrated models for photoelectrode design; 

establishment of industry and university partners 

with materials expertise and fabrication capabilities; 

and fabrication and evaluation of photoelectrode test 

structures for photoactivity and stability. 

Examples of photoelectrode designs developed 

using this approach are shown in Figure 2, including 

(a) monolithically-stacked amorphous silicon/

germanium (a-Si:Ge), and (b) side-by-side stacked 

copper-indium-gallium-diselenide (CIGS) 

encapsulated triple-junction devices [2]. An 

important recent advance has been the design of a 

"hybrid" photoelectrode structure, shown in Figure 

2c, combining solid-state multi-junctions with stable, 

photoactive semiconductor outer layers. Significant 

advantages of this hybrid design include elimination 

of lateral current collection, simplification of device 

geometry for ease of fabrication, and improved 

stability based on the thick, seamless outer oxide 

layer. Development of high performance hybrid 

photoelectrode structures using low-cost materials 

such as a-Si:Ge, CIGS and photoactive nanostructured iron oxide (Fe2O3) is currently the primary 

focus of our work. 

Results 

To date, significant progress has been made in 

the advancement of a-Si:Ge and CIGS materials and 

devices for use in photoelectrode applications, and in 

the initial development of hybrid photoelectrode 

designs. Important industry and academic 

partnerships have been established, in-house 

materials fabrication facilities have been 

significantly upgraded, and integrated models have 

been adapted for the design of prototype hybrid 

photoelectrode structures.

This past year, while maintaining close ties with 

the Institute for Energy Conversion (IEC) at the 

University of Delaware, who have recently reported 

progress in several key areas of CIGS research 

(including deposition of high-performance cells onto 

lightweight polyamide substrates [3]), and with the 

University of Toledo, who has reported photovoltaic 

efficiencies approaching 13% in multi-junction aSi:Ge devices [4], we've also established a critical 

industry partnership with Daystar Technologies, 

whose principal scientist has reported record 

efficiencies approaching 19% in thin-film CIGS 

devices [5]. Another important new partnership 

established this year has been with Dr. Shahed Khan 

at Duquesne University, who has demonstrated 

nanostructured Fe2O3 films with good photoactivity 

deposited by spray pyrolysis [6], and who has been 

enthusiastic to participate in our hybrid 

photoelectrode research. 

Partly with the help of our industry and 

university partners, we have successfully completed 

Figure 2. Encapsulated triple-junction photoelectrodes 

using (a) a-Si:Ge; (b) CIGS; and (c) basic 

structure of a hybrid solid-state/

photoelectrochemical photoelectrode

Note: HER = hydrogen evolution reaction

 OER = oxygen evolution reaction
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

133

important upgrades of our in-house materials 

fabrication equipment. The upgraded plasmaenhanced chemical vapor deposition (PECVD) 

system for a-Si:Ge films now includes a pulsed 

plasma generator for improved material properties. 

The upgraded CIGS system, pictured in Figures 3a 

and 3b, produces device-quality films over 

approximately a 4" x 4" area. A significant 

achievement has been the in-house fabrication of 

CIGS photovoltaic devices onto 2" x 4" metal foil 

substrates (completed device shown in Figure 3c) 

with efficiencies exceeding 12%.

Also this year, we adapted our integrated 

electronic/optical/electrochemical models for the 

analysis of hybrid photoelectrode systems. Hybrid 

modeling using published data for nano-structured 

Fe2O3, WO3 and TiO2 films was performed, and 

based on this analysis (which utilizes current-voltage 

and quantum-efficiency film characteristics, as 

shown in Figure 4 for iron oxide films), Fe2O3 was 

selected for the initial hybrid prototypes. As a result, 

we initiated an Fe2O3 film development program 

focusing on the spray-pyrolysis material fabricated at 

Duquesne University and on sputter-deposited 

material fabricated in-house at UH. Preliminary 

hydrogen-reaction activity and surface morphology 

Figure 3. (a) CIGS deposition system at UH; (b) 

Interior view; (c) Completed CIGS PV device

Figure 4. Hybrid design based on (a) Photocurrent 

response and (b) QE of nanostructured Fe2O3

films
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

134

data for various iron-oxide films is shown in Figure 

5.

Efforts are currently underway to fabricate and 

test prototype a-Si:Ge/Fe2O3 hybrid devices. With 

the University of Toledo, we completed an 

evaluation of a-Si:Ge device yield on different metalfoil substrates, and a series of multi-junction devices 

Figure 5. (a) OER overpotentials in sputtered 

Fe2O3; (b) scanning electron 

microscopy (SEM) of sputtered 

Fe2O3; (c) SEM of photoactive 

spray-deposited Fe2O3

Figure 6. Photoelectrode testing jig for monitoring 

current under different biases: (a) Cross 

section of design; (b) Implementation with 

prototype hybrid photoelectrodes
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

135

for use in hybrid photoelectrode experiments was 

deposited on the highest-yield foil. The test jig 

shown in Figure 6 was designed and fabricated to 

facilitate evaluation of hybrid photoelectrode 

performance.

Conclusions 

With this year's work, we have continued our 

emphasis on developing high-performance multijunction hydrogen photoelectrodes based on low cost 

semiconductor and catalyst films. Significant 

progress was made in the advancement of amorphous 

silicon/germanium and copper-indium-galliumdiselenide materials for solid-state photojunctions, 

and great strides were made in the research and 

development of the 'hybrid' photoelectrode concept, 

including important initial work on nanostructured 

wide-bandgap semiconductor films for the 

photoelectrochemical interface. As a result of 

preliminary research and modeling efforts, iron oxide 

was selected as the most promising material for 

incorporation into first prototype hybrid devices. 

Development efforts to optimize Fe2O3 films, to 

design a-Si:Ge tandems with the correct optical and 

electronic properties, and to fabricate and evaluate 

test-structures combing the materials are currently 

underway. The conceptual design for higher 

efficiency hybrid devices using novel tandem CIGS 

configurations (in place of the a-Si:Ge tandems) with 

Fe2O3 outer layers is also under development.

References 

1. Rocheleau, R., Miller, E., and Misra, A. 1998. 

"High-Efficiency Photoelectrochemical Hydrogen 

Production Using Multijunction Amorphous 

Silicon Photoelectrodes". Energy and Fuels 12:3-

10.

2. Miller, E., Rocheleau, R. and Deng, X. 2002. 

"Design Considerations for a Hybrid Amorphous 

Silicon/Photoelectrochemical Multijunction Cell 

for Hydrogen Production" International Journal of 

Hydrogen Energy in press.

3. Hanket, G. et al. 2002. "Pilot-scale Manufacture 

of Cu(InGa)Se2 Films on a Flexible Polymer 

Substrate", In Proceedings of the 29th IEEE 

Photovoltaics Specialists Conference, New 

Orleans, LA: IEEE.

4. Wang, W., et al. 2001. "Triple-Junction a-SiBased Solar Cells with All Absorber Layers 

Deposited at the Edge of a-Si to μc-Si Transition." 

<http://www.physics.utoledo.edu/~dengx/

ref3.pdf>.

5. Tuttle, J., et al. 1995. "Thin-Film Cu(In,Ga)Se2

Materials and Devices: A Versatile Material for 

Flat Plate and Concentrator Photovoltaic 

Applications." Society of Photo-Optical 

Instrumentation Engineers, 2531:194-200.

6. Khan, S. U. M. and Akikusa, J. 1999. 

"Photoelectrochemical Splitting of Water at 

Nanocrystalline n-Fe2O3 Thin-film Electrodes, 

Journal of Physical Chemistry B, 1999, 103: 

7184-7189.

 FY 2002 Publications/Presentations 

1. International Conference on Advanced Materials 

(ICAM 2001): Invited Lecture on Hybrid 

Photoelectrode Design.

2. "Design Considerations for a Hybrid Amorphous 

Silicon/Photoelectrochemical Multijunction Cell 

for Hydrogen Production" (in press: International 

Journal of Hydrogen Energy).

3. "Evaluation of RF-Sputtered Indium-Tin Oxide 

Films for Photoelectrochemical Applications" 

(submitted to the Journal of the Electrochemical 

Society).

Special Recognitions & Awards/Patents 

Issued 

1. Patent Disclosure: "Hybrid Solid-State/

Electrochemical Photoelectrode for Hydrogen 

Production".
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

136

II.D.3 Photoelectrochemical Hydrogen Production Using New Combinatorial 

Chemistry Derived Materials

Eric W. McFarland (Primary Contact), Sung Hyeon Baeck, Kyoung-Shin Choi, Anna Ivanovskaya, 

Thomas F. Jaramillo

Department of Chemical Engineering

University of California, Santa Barbara, CA 93106-5080

(805) 893-4343, fax: (805) 893-4732, e-mail: mcfar@engineering.ucsb.edu

DOE Technology Development Manager: Roxanne Danz 

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Main Subcontractor: University of California, Santa Barbara, CA

Objectives 

• Design and construct a versatile automated system and methodologies for automated electrochemical 

synthesis of combinatorial libraries of mixed metal oxides

• Define electrosynthetic routes amenable to the automated electrochemical deposition system for 

synthesizing for doped and mixed metal 

• Develop an automated high-throughput photoelectrochemical screening system 

• Create and screen libraries of materials

• Complete the development of a chemo-optical detection system based on optical sensing of the 

reduction of tungsten oxide as a high-throughput screening system for monitoring hydrogen 

production

• Begin exploratory synthesis and screening of new metal-oxide systems and begin to examine 

composition-structure-function relationships 

• Design and synthesize libraries of potential patterned metal oxides using diverse types of structure 

directing agents under a variety of deposition conditions 

Approach

• Create synthesis and screening systems for rapid automated combinatorial synthesis of materials 

suitable for photoelectrochemical hydrogen production 

• Develop chemical synthesis routes amenable to automated high-throughput experimentation

• Utilize the automated synthesis systems to create libraries of potential hydrogen photocatalysts

• Rapidly screen libraries for potential materials with high photoelectrocatalytic activity

• Synthesize in conventional manner selected materials for detailed analysis

Accomplishments 

• Designed and built several prototype systems for electrosynthetic deposition of metal oxides, including 

both parallel and automated serial systems

• Developed direct cathodic routes to oxides of several metals including tungsten (W), nickel (Ni), 

niobium (Nb), titanium (Ti), Fe, copper (Cu), colbalt (Co), molybdenum (Mo), and zinc (Zn) by 

stabilization with several ligand types, and preliminary studies with libraries which have shown 

general trends
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

137

• Completed our chemo-optical high throughput screening system and demonstrated the first thin film 

results with zinc oxide (ZnO)

• Preliminary work on electrosynthesis of mesoporous tungsten trioxide (WO3) and titanium dioxide 

(TiO2) films from a peroxo-stabilized electrolyte using ionic surfactants has at last shown definitive 

evidence of highly structured materials (July 2002)

• From libraries of pulsed electrodeposited platinum (Pt) doped WO3, whereby a new means of creating 

nanoparticles has been developed. The nanoparticles show high activity for methanol oxidation 

without the poisoning problems of Pt

Future Directions 

• Explore the composition-function relationships of dopants in ZnO hosts

• Investigate metal oxide libraries for electrocatalytic hydrogen production and expand our highthroughput screening to include relative electrocatalytic overpotential as a routine screen

• Develop a high-throughput optical screening system to measure the effective bandgap of metal oxides 

in libraries

• Synthesize and screen model libraries optically for bandgap as a primary screen and create secondary 

libraries of compositions

• Investigate library designs for synthesis of semiconductor heterostructures utilizing two-photon 

absorption processes

• Continue and expand investigations of nanoporous materials with emphasis on the ZnO, WO3 and 

TiO2 hosts.

Introduction 

The overall project objective is the development 

and application of combinatorial methods to discover 

an efficient, practical, and economically sensible 

material for photoelectrochemical production of 

hydrogen from water and sunlight. We will 

introduce a shift in the research paradigm from the 

present method of conventional serial chemical 

research to a combinatorial approach featuring a 

systematic and deliberate high-speed exploration of 

the composition-structure-property relationship of 

new metal-oxide based solid-state materials to 

discover new and useful energy producing materials 

as well as better understand the fundamental 

mechanisms and composition-structure functional 

relationships of these materials.

Approach

Our studies have focused on the development of 

automated chemical synthesis and screening systems, 

then on the preparation and analysis of diverse 

photoelectrochemical libraries of metal-oxides with 

semiconducting and other properties suitable for 

photoelectrocatalysis. Diversity has included: 1) 

variations in composition (by variable doping, 

electrochemical synthesis conditions, and surface 

redox catalysts) and 2) variations in structure (by 

deliberate and diverse ionic and non-ionic templating 

agents, synthesis conditions, and doping). The 

libraries are screened directly for hydrogen 

production using a two-dimensional chemo-optical 

sensor array. 

Results

Specific Aim 1

Automated electrochemical synthesis routes are 

used to create libraries of mixed metal oxides, and 

we have designed and constructed the necessary 

apparatus and developed the detailed methodology to 

do so. Figure 1 schematically illustrates how our 

synthesis systems operate. 

Combinatorial methods only make sense when 

very large numbers of different materials are made 

and screened quickly. Compositional diversity 

across a library is obtained by varying the 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

138

electrochemical deposition conditions of time, 

voltage, current, surfactant additives and electrolyte. 

In the parallel system, the substrate (which is a 

common working electrode) has individual 

electrochemical cells isolated from each other by 

virtue of a perforated polypropylene block that is 

sealed to the substrate with an array of o-rings. This 

provides for different synthesis conditions at each 

library position; each cell constitutes an individual 

two-electrode system and is filled with a 

compositionally unique electrolyte. Clearly, 

synthesis speed is the advantage in a parallel scheme 

since all depositions occur simultaneously. In the 

rapid serial system, a complete three-electrode probe 

is scanned over the surface of the library substrate by 

an automated, computer-controlled set of x-y-z 

stages. The probe contains an o-ring at the bottom 

which forms a seal at the substrate. Electrolyte of 

choice flows into the cell by a computer-controlled 

pump, and a highly controlled deposition is 

conducted at each location by a potentiostat/

galvanostat. Several material systems have exhibited 

extraordinary sensitivity to deposition voltage. 

Specific Aim 2

We have developed new electrochemical 

synthesis routes and extended existing ones to create 

routes amenable to our automated synthesis system 

for the generation of mixed metal oxides. 

A number of metal hydroxides have been 

deposited by cathodic reduction. Metal oxides 

(WO3, MoO3, TiO2, ZnO, Fe2O3, Co3O4...) can be 

produced from the metal hydroxide by thermal 

annealing. In some cases, metal (Ni, Zn, Mn . . .) can 

be deposited by cathodic reduction and, after thermal 

annealing or electroanodization, a metal oxide can be 

obtained. We have also used electrochemical 

anodization for the synthesis of Al2O3 to roughen the 

surface and create a porous base material [13]. Our 

approach has been to stabilize the metal cations with 

ligands to allow for direct metal oxide deposition and 

the co-deposition of dopant cations. Several ligands 

we have used include hydrogen peroxide, citric acid, 

lactic acid, and acetic acid. WO3, TiO2, Nb2O5, and 

MoO3 have been cathodically deposited from metalperoxo solution. We have found that mixed metal 

oxides, such as WO3-MoO3, and WO3-TiO2 can be 

synthesized by mixing metal peroxo electrolytes. Pt 

or Ru doped tungsten oxide has been directly 

deposited under cathodic conditions in the presence 

of hydrogen peroxide, and diversity has been 

achieved by changing the concentration of the 

dopants in the electrolyte solution or by varying 

deposition potential. We have also stabilized the 

Figure 1. Schematic illustration of combinatorial 

synthesis by electrochemicaldeposition. The 

parallel approach is faster, but the rapid serial 

methodoffers greater control for each 

deposition.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

139

metal cations in basic media using a complexing 

agent such as citric and lactic acid. 

Specific Aim 3

We have developed two major systems for 

automated high-throughput photoelectrochemical 

screening designed to measure electrochemical and 

photoelectrochemical responses of combinatorially 

prepared photocatalyst libraries. The system in its 

electrochemical screening configuration allows for 

measuring cyclic voltammograms (I-V curves) and 

Mott-Schottky plots, which reveal flatband potential 

and sample dopant concentrations. The system is 

modular in nature - easy to set up for the experiment 

of interest by connecting the appropriate 

programmable source/measure devices: potentiostat, 

digital multimeter, data acquisition board, impedance 

analyzer and lock-in amplifier. This configuration 

allows for varying electrolytes for different samples 

by filling the wells of a perforated polypropylene 

block with a programmable pipette.

Specific Aim 4

We created a pair of libraries of WO3 doped with 

different transition metals (at a variety of doping 

densities) with the aim of improving upon the 

photocatalytic activity of pure WO3. The first library 

design is shown in Figure 2(a). The library 

incorporates Pt, Ru, Ni, Co, Cu, and Zn as dopants 

within polycrystalline WO3. The materials were 

each co-deposited with WO3 electrochemically from 

a mixture of 50 mM metal chloride solution and a Wperoxo solution. Altering the metal-chloride 

concentrations in the electrolyte, from 0% to 50% 

allowed for variation of doping concentrations within 

the deposited films. Figure 2(b) shows the 

relationship between doping density in the deposited 

film versus the concentration in the electrolyte for Pt 

and Ni as determined by Electron Dispersive X-Ray 

(EDX). Figure 3(a) illustrates the zero-bias 

photocurrent for the library members, and Figure 

3(b) shows a cyclic voltammogram taken of the pure 

WO3 film. We expect several photocurrent trends 

from this library. First of all, Ni has been shown to 

be an excellent absorber of visible light when doped 

into large band-gap oxide hosts, such as WO3, so we 

expect an increase in photocurrent from that row. 

Similarly, we would expect better photocurrent from 

Pt and Ru dopants, since Pt is an excellent reduction 

catalyst and RuO2 is a well-known oxidation catalyst. 

Figure 3(a) shows that, indeed, Ni doping increased 

photocurrent significantly compared to pure WO3, 

with a maximum photocurrent achieved for 10% Ni. 

Pt and Ru dopants show a different trend. 

Seemingly, a greater doping concentration of either 

element decreases the photoactivity of WO3. 

Figure. 2. Metal-doped WO3 binary library. (a) Library 

design: variation indoping density is achieved 

by varying dopant concentration in 

theelectrolyte. (b) Relationship between 

dopant concentration in thedeposited film 

versus dopant concentration in the electrolyte.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Specific Aim 5

We have engineered a high-throughput screening 

system for monitoring H2 production based on a 

chemo-optical H2 sensor [14-16]. This colorimetric 

sensor utilizes a Pd/WO3 bilayer, whereby molecular 

H2 dissociates on the Pd surface and diffuses as 

atomic hydrogen to reduce WO3 to a tungsten 

bronze, HyWO3-x. The reduced tungsten oxide is 

photometrically distinct from WO3 due to a 

decreased index of refraction. The reduction is 

reversible and the sensor can be regenerated in O2. 

Details are presented in our published papers.

Specific Aim 6

A library consisting of a 45-member (5 x 9 array) 

WO3-MoO3 mixed binary oxide library, with 

diversity achieved by variations in deposition voltage 

and Mo concentration in the electrolyte was 

synthesized. The concentration of Mo was varied 

Figure 3. High-throughput photocurrent screening of 

the WO3 library at zero bias.(a) Photocurrent 

trends in the library. (b) Cyclic 

voltammogram of pure WO3 (0.2 cm2) under 

chopped illumination from a 150 W Xe lamp 

(2.3 mW/cm2

).

Figure 4. (a) EDS measured atomic ratio of Mo to W in 

films as a function of Mo concentration in 

electrolyte. (b) Photocurrents in 0.1 M sodium 

acetatesolution at zero bias(=)and 1 V bias(<) 

for WO3-MoO3 mixed oxides as a function of 

Mo concentration in electrolyte.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

141

from 0 to 100 mol% and all films were deposited for 

10 minutes. After deposition, the library was 

calcined at 450o

C for 4 hours in air.

The film compositions were determined by EDX 

for fifth row (prepared from 50% W- 50% Mo 

mixture) and fourth column (electrodeposited at -1.0 

V). As expected, with increasing concentration of 

molybdenum in solution, the atomic fraction of 

molybdenum in the film increased (Figure 4(a)). 

However, the atomic ratio was independent of 

deposition voltage (-0.2 ~ -1.5 V, not shown). A 

trend in photoresponse as a function of molybdenum 

concentration in electrolyte was clearly observed. 

Figure 4(b) shows photocurrent at 0 and +1 V bias 

for the WO3-MoO3 mixed oxide. The photoresponse 

increased and reached a maximum when 50% Mo 

and 50% W concentration in electrolyte was used, 

and then decreased as concentration of Mo in 

electrolyte increased. In the cases where MoO3

concentration was below 10% or above 90%, there is 

no enhancement of photoactivity compared to either 

pure WO3 or pure MoO3. Interestingly, in the range 

of 20 ~ 80% MoO3, an increase of photoactivity was 

observed.

Nano-particulate tungsten oxide films were also 

synthesized by pulsed electrodeposition in libraries. 

Particle sizes between 45 ~ 330 nm were achieved by 

varying pulse duration from 5 ms to 500 ms. Films 

prepared by continuous electrodeposition had an 

average particle size of approximately 375 nm. As 

the pulse time decreased, particle size decreased as 

well. For a 5 msec pulsed deposition, the average 

particle size was approximately 45 nm. We checked 

the particle size with respect to deposition time (30 

sec to 30 min, that is 3,000 to 180,000 pulses) and 

found that particle size was independent of total 

number of pulses; the total number of pulses seemed 

to affect only film thickness and not the final particle 

size. 

We discovered that metal oxides (WO3, MoO3, 

TiO2, Nb2O5) can be synthesized from peroxostabilized solution onto Cu foil by electroless 

deposition. The deposition rate was found to be 

strongly dependent on temperature, electrolyte 

concentration, and deposition time. As-synthesized 

films were amorphous and showed weak p-type 

photocurrent due to the formation of Cu2O on the 

surface of Cu foil. After calcination at 450oC, metal 

oxide films were found to be crystalline. A 27-

member (3 x 9 array) WO3-MoO3 mixed oxide 

library was prepared by electroless deposition on Cu 

foil, with diversity achieved by variations in 

deposition time and Mo concentration in electrolyte. 

Specific Aim 7

In addition to our effort of finding better 

performance photocatalysts by tuning the 

composition of the films, we have been developing a 

general method for the production of high surface 

area nanostructured films by utilizing 

electrochemically driven self-assembly of surfactants 

at solid-liquid interfaces. We combined potentialcontrolled surface assembly with an 

electrodeposition process to fabricate nanostructured 

films. We have successfully electrodeposited 

mesoporous platinum and zinc oxide films by 

controlling deposition potentials and electrolyte 

compositions. The nanostructures of these films 

have been confirmed by transmission electron 

microscopy (TEM). The hexagonal structure of the 

Pt films, with the pores perpendicular to the substrate 

and the lamellar structure of ZnO, with the normal 

direction of the layers parallel to the substrate, are 

expected to allow facile access of the guest 

molecules and analytes to the pores and interlayers. 

The electrocatalytic properties of mesoporous Pt 

films, towards methanol oxidation were measured in 

order to confirm the increased effective surface areas 

and to evaluate a potentially important application of 

these films (i.e. direct methanol fuel cell 

applications). 

Conclusions

Our work during the first 9 months of this project 

has focused on the development of combinatorial 

methods to rapidly synthesize and high-throughput 

screen mixed metal oxides, and on using these 

systems to begin to investigate new materials for 

photocatalytic hydrogen production. We have 

designed and constructed much of the combinatorial 

infrastructure (automated parallel and rapid serial 

synthesis and screening systems), and we have 

developed synthesis routes (based on 

electrochemistry) amenable to our combinatorial 

instruments. Rapid synthesis and functional 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

142

screening of mixed metal oxides of W, Cu, Ti, and Fe 

hosts has been demonstrated, and new 

electrosynthetic routes to W-Mo-oxide and 

nanoporous WO3 have been developed. Recent data 

from Wx(Mo,Ni,Pt)yOz, Cux(ZnyNiy)Oz and 

Fex(Ti)yOz show (reserved) promise as improved 

materials. 

References

1. Gaffron, H and Rubin, J., J. Gen. Physiol., 26, 

219 (1942).

2. Fujishima, A. and Honda, K, Nature, 238, 37 

(1972).

3. Herriman, A. and West, M. A., editors, 

"Photogeneration of Hydrogen", Royal 

Institution Symposium, Academic Press (1982).

4. Domen, K., Kondo, J. N., Hara, M., and Takata, 

T., Bull. Chem. Soc. Jpn., 73, 1307 (2000).

5. Gratzel, M. A., "Energy Resources through 

Photochemistry and Catalysis", Academic Press, 

New York (1983).

6. Hanak, J. J., J. Mater. Sci., 5, 964 (1970).

7. Hanak, J. J., Gittleman, J. I., Pellicane, J. P., and 

Bozowski, S., Phys. Lett., 30(3), 210 (1969).

8. Danielson, E., Golden, J. H., McFarland, E. W., 

Reaves, C. M., Weinberg, W. H., and Wu, X. D., 

Nature, 389, 944 (1997).

9. Danielson, E., Devenney, M., Giaquinta, D. M., 

Golden, J. H., Haushalter, R. C., McFarland, 10. 

E. W., Poojary, D. M., Reaves, C. M., Weinberg, 

W. H., and Wu, X. D., Science, 279, 837 (1998).

10. Therese G. H. A. and Kamath, P. V., Chem. 

Mater., 12, 1195 (2000).

11. Meulenkamp, E. A., J. Electrochem. Soc., 144, 

1664 (1997).

12. Hutchins, M. G., Kamel, N. A., El-Kardy, W., 

Ramadan, A. A., and Abdel-Hady, K., Phys. Stat. 

Sol. A ,175, 991(1999).

13. Brandli, C., Jaramillo, T. F., Ivanovskaya, A., 

and McFarland, E. W., Electrochimica Acta, 47, 

553 (2001).

14. Ito, K. and Ohgami, T., Appl. Phys. Lett., 60, 938 

(1992).

15. Ito, K. and Kubo, T., Proceedings of the 4th 

Sensor Symposium, Tokyo, 153 (1984).

16. Tamura, H., Hashimoto, Y., and Ito, K., Solid 

State Phenom., 51-52, 429 (1996).

17. Shen, P., Chi, N., and Chan. K. Y., J. Mater. 

Chem., 1, 697 (2000).

18. Burgess, I., Jeffrey, C. A., Cai, X., Szymanski, 

G., Galus, Z., and Lipkowski, J., Langmuir, 15, 

2607 (1999).

FY 2002 Publications/Presentations

1. S.H. Baeck, T.F. Jaramillo, C. Brandli, and E. 

McFarland, "Combinatorial Electrochemical 

Synthesis and Characterization of Tungsten-based 

Mixed Metal Oxides", J. Combi. Chemistry, 

(accepted and in press 2002).

2. S.H. Baeck, T.F. Jaramillo, G.D. Stucky, and E. 

McFarland, "Controlled Electrodeposition of 

Nanoparticulate Tungsten Oxide", Nano Letters, 

(accepted and in press 2002).

3. S.H. Baeck and E.W. McFarland, "Combinatorial 

Electrochemical Synthesis and Characterization of 

Tungsten-Molybdenum Mixed Oxides", 

Korean.J.Chem.Eng., (accepted and in Press 

2002).

4. S.H. Baeck, T.F. Jaramillo, and E. McFarland, 

"Influence of Composition and Morphology on 

Photo and Electrocatalytic Activity of 

Electrodeposited Pt/WO3", 224th National ACS 

Conference Proceedings, Boston, MA (2002).

5. Invited Seminar October 2001 "Combinatorial 

Methods of New Materials Discovery For 

Photocatalytic Hydrogen Production: A Long 

Way to a Million Million Watts", Department of 

Nuclear Engineering, MIT.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

143

6. Invited Talk November 2001 "Combinatorial 

Electrosynthesis and Photoelectrocatalytic 

Screening of New Materials for Hydrogen 

Photosynthesis", AICHE Annual Meeting, Reno, 

Nevada.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

144

II.D.4 Combinatorial Discovery of Photocatalysts for Hydrogen Production

Brent MacQueen (Primary Contact), Al Hirschon, Ted Mill, Mike Coggiola

SRI International

333 Ravenswood Ave

Menlo Park, CA 94025

(650) 859-5286, fax: (650) 859-4321, e-mail: brent.macqueen@sri.com

DOE Technology Development Manager: Roxanne Danz 

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Objectives 

• Develop a high throughput system for evaluating photocatalytic materials for hydrogen production

• Develop a methodology to produce a database of photocatalytic materials

• Discover new photoactive materials capable of producing hydrogen using solar radiation

Approach

• Construct automated high throughput testing equipment to evaluate physical properties and measure 

solar hydrogen production of photoelectrochemical systems

• Evaluate the effectiveness of nanosized materials for hydrogen generation from water using visible 

light

• Develop database useful for all researchers

Accomplishments 

• Built and calibrated a light source for use as a solar simulator

• Built and tested a 4-cell reactor with pressure transducers for measuring hydrogen production from 

photocatalysts

• Modified and programmed a Gilson sampler for pressure transducer activated automated analysis of 

hydrogen production

• Synthesized and screened semiconductor materials, including nanosized titanium dioxide (TiO2) 

materials, for water splitting using visible light

• Designed and constructing a 25-cell combinatorial reactor for screening photocatalysts for hydrogen 

production

Future Directions 

• Develop a prototype multi-cell reactor for high throughput evaluation of the electrochemistry of 

photocatalytic materials

• Optimize the high throughput tools for discovery of water splitting catalysts

• Evaluate new nanoparticle materials synthesized as candidate photocatalysts

• Design and synthesize new materials which can produce hydrogen using visible light based on 

experimental results
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

145

Introduction 

The conversion of the dominant energy source 

from one that is petroleum-based to one based on 

hydrogen will have a profound effect on the 

reduction of greenhouse gases being emitted by 

current technologies. Furthermore, if the hydrogen is 

generated from a non-carbon containing feedstock, 

such as water, using an energy source that is not 

carbon-based, such as solar radiation, the reduction 

in emitted gases will be enhanced even further. The 

key hurdle to overcome the obstacles to such a 

technology, photolytic generation of hydrogen from 

water, is a materials related issue and can be solved 

by the discovery of materials with the appropriate 

energetics and stability upon solar irradiation. A key 

aspect of this project is that it incorporates a 

nanoparticulate semiconductor producer, NanoGram, 

with a research institute, SRI International, with the 

required capabilities to be successful in this very 

important endeavor. The combination of NanoGram's 

synthetic process, which is scalable to Kg/hour 

quantities, with SRI's high throughput screening 

capabilities has the potential to make breakthrough 

discoveries with respect to the photolytic generation 

of hydrogen from water.

The goal of this effort is to develop more 

efficient ways to discover photocatalysts for the 

economical and environmentally sound production of 

hydrogen by splitting water with sunlight. SRI is 

developing combinatorial tools to identify new 

semiconductor compositions, surface 

modification(s), and experimental conditions that 

lead to efficient hydrogen production with visible 

light. Our specific objective in Year 1 of this effort 

has been to develop and validate a combinatorial 

workstation that can be used to rapidly screen an 

array of materials in terms of electrochemical 

properties and photocatalysis. To that end we have 

constructed a combinatorial system consisting of a 

simulated sunlight source, a multi-cell reactor with 

pressure and sampling capabilities and a 

programmed sample handler.

Approach

We are using a combinatorial approach to 

discover new photocatalytic materials, which can 

generate hydrogen using visible light. By first 

constructing combinatorial tools to quickly screen for 

effective photocatalysts, we can then investigate new 

materials as photocatalysts, including 

nanoparticulate semiconductors prepared by 

NanoGram, Corp., with whom we are collaborating 

on this project. Our approach is divided into three 

tasks as follows:

In Task 1 we are developing tools for 

combinatorial evaluation of the photoelectrochemical 

properties of semiconductors relevant to 

photogeneration of hydrogen. The objective of Task 

1 is to develop plug and play components that will 

allow the rapid screening to find photocatalysts that 

generate hydrogen efficiently with visible light. 

The goal of Task 2 is to synthesize photocatalysts 

for combinatorial screening for rapid hydrogen 

generation. We plan to use a rational design for 

materials synthesis that leverages the particle 

fabrication capabilities of our partner in this project, 

NanoGram, Corp, with SRI's chemistry and 

engineering capabilities. Systems level investigation 

will include modified commercial materials as well 

as new materials such as nanophase powders 

produced by NanoGram with various particle sizes, 

phases, and dopant levels using their proprietary 

synthetic process.

The goals of Task 3 are to identify photocatalysts 

that merit further investigation as evidenced by the 

combinatorial screen results and to begin a 

systematic evaluation of the materials identified in 

Task 2 using the tools developed in Task 1. 

Results

We have modified a 1 kW Oriel xenon light 

source to provide an 8 inch illuminated circle with 

light between 300 and 1,000 nm to simulate sunlight 

for our prototype device. We have measured the light 

intensity distribution in the circle so that we can 

correct for effects of non-uniformity in the light field 

on the performance of photocatalysts. 

We have developed two modular designs for the 

combinatorial screening of photocatalysts. One 

design focuses on hydrogen production from 

particles suspended in water and the other measures 

the electrochemical properties of monolithic (solid) 

substrates. The latter design provides a more detailed 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

146

analysis of the physical properties of the 

photocatalysts as a result of electrical (ohmic) 

contact to the measuring system, while the former 

design allows for rapid screening of particle 

dispersions to find active catalysts to be investigated 

in detail. 

A 4-cell prototype of the particle suspension 

analysis design has been constructed (Figure 1). 

Individual cells are illuminated from the bottom, and 

each cell has a septum port and a micropressure 

transducer to detect evolution of gaseous products 

(i.e. H2/O2). A Gilson X-Y sampler (Figure 2) was 

programmed for autosampling based on the response 

of the micropressure transducers. The sampler injects 

the gas into a gas analyzer to determine how much 

hydrogen and oxygen were formed from any catalyst. 

Figure 3 shows typical data obtained during the 

course of a photolysis experiment. We are building a 

larger prototype with 25 cells, which has advantages 

in ease of assembly suitable for combinatorial use. 

The design of this multi-cell reactor is illustrated in 

Figure 4. A three-electrode system will be used for 

Figure 1. 4-cell Prototype of Photolysis Product 

Analysis Module

Figure 2. Gilson Autosampler and 4-cell Analysis 

Module

Figure 3. Pressure Transducer Output from 4-cell 

Module

Figure 4. Design of 25-cell Analysis Module Currently 

Under Construction
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

147

electrochemical measurements on monolithic 

materials. This module is attached to a common top 

that can be inserted onto the cell system designed for 

the particulate analysis (Figure 5). Thus, 

electrochemical properties of active semiconductor 

catalysts can be measured by switching the top plate 

of the analysis module. 

The particle synthesis is progressing with the use 

of NanoGram's proprietary laser pyrolysis 

nanoparticulate synthesis technology (Figure 6).

Conclusions

We have made a great deal of progress in 

assembling the components necessary to conduct 

high throughput screening of materials for 

photocatalytic generation of hydrogen from water. 

This includes building a solar simulator, assembling 

and modifying the sample collection and sample 

analysis equipment, and designing, constructing 

analysis cells. When completed our equipment will 

allow us to facilitate the discovery of new 

photocatalysts able to produce hydrogen using solar 

radiation. 

Special Recognitions & Awards/Patents 

Issued

Invention disclosure on quick release top plate 

design in progress.

Figure 5. Design of Electrode Assembly Used for 

Electrochemical Analysis Module

Figure 6. NanoGram Synthesis Workstation with 

Insert ShowingLaser Pyrolysis Reaction Zone
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

148

II.D.5 Low Cost, High Efficiency Reversible Fuel Cell Systems

Christopher Milliken (Primary Contact), Dr. Robert Ruhl

Technology Management, Inc.

9718 Lake Shore Blvd.

Cleveland, OH 44108

(440) 995-9500, fax: (440) 720-4527, e-mail: milliken@stratos.net

DOE Technology Development Manager: Sigmund Gronich

(202) 586-1623, fax: (202) 586-5860, e-mail: Sigmund.Gronich@ee.doe.gov

Main Subcontractor: Technology Management, Inc., Cleveland, OH

Objectives 

• Improve performance of reversible stacks (capable of operating in both fuel cell and electrolysis 

modes) by reducing area specific resistance, rate of degradation, and seal leakage.

• Demonstrate an integrated fuel cell hot subassembly opeating with a stack of about 50 reversible type 

cells operating on natural gas.

• Evaluate the economic impact of the reversible solid oxide fuel cell /solid oxide electrolyzer system 

and consider applications where a competitive advantage may be achieved.

Approach

• Evaluate alternate materials and geometric factors to reduce cell resistance.

• Reduce operating temperature to improve life and performance.

• Design and fabricate an integrated test station capable of testing reversible stacks (nominally 50 cells).

Accomplishments 

• Optimized cell geometry by modeling the stack and system.

• Designed, fabricated, and evaluated performance of reversible stack over a range of temperatures and 

operating conditions.

• Demonstrated stable operation for >1200 hours in small reversible stacks at acceptable efficiency.

• Completed preliminary economic analysis and identified applications where reversible electolyzer/fuel 

cell systems may have a competitive advantage.

Future Directions 

• Design, fabricate, and commission an integrated test system.

• Scale up fabrication to produce 50 cell stacks using standardized processes.

• Complete evaluation of alternate materials for improved life and performance.

Introduction 

The Technology Management, Inc. (TMI) 

reversible (fuel cell - electrolyzer) system employs a 

high temperature solid-oxide based electrochemical 

process to produce either electricity from common 

hydrocarbon fuels (e.g., natural gas, propane, and 

bio-derived fuel) or hydrogen from supplied 

electricity. In electrolyzer mode, the reversible 

system uses electricity and thermal energy to convert 

pure water into fuel (hydrogen and oxygen). TMI's 

reversible system uses the waste thermal energy 

produced during electricity generation mode to 

achieve high system efficiency during electrolysis 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

149

mode, ultimately lowering product life cycle costs 

for the combined system. To further increase system 

efficiency, TMI has implemented a 'passive' (cell) 

system design which reduces the number and 

complexity of the balance of plant components.

 During the current phase of the program, TMI 

has demonstrated reversible cells and stacks which 

met many of the performance targets including 

reversible efficiency and life. Several conditions 

were evaluated to understand the sensitivity of 

performance on operating variables such as 

temperature and current density. The highest 

reversible efficiency (DCVolts-Out / DCVoltage-In) 

measured was 90.8% at 925°C and 50 mA/cm2

. A 

five cell stack was operated at < 2% / 1000 hours 

voltage degradation in fuel cell mode for over 1200 

hours. Data from this work was used to expand 

economic and engineering studies completed earlier. 

An outcome of this was the concept for a system 

capable of delivering 5000 pounds per square inch 

(psi) pure hydrogen (e.g., needed for vehicle uses) in 

addition to electric power and recovered usable heat. 

The proposed systems would be configured in 

redundant modules to ensure high reliability and 

could be sized for either residential or commercial 

applications (including "power parks") being fed by 

electric power (renewable or low-cost grid) and/or 

fuel (fossil or biomass-derived).

Approach 

Reversible stacks goals require negligible gas 

leakage rates, low polarization voltages, stable 

microstructures, and reproducible fabrication 

techniques to meet the goals. Low gas leakage rates 

have been demonstrated in limited tests that will 

continue. The DOE has suggested an alternate 

sealing technology that may be applicable if it can be 

adapted.[i] Low polarization voltages will be sought 

by optimizing the electrode microstructure and by 

continuing to improve the separator interface. 

Microstructure stability will be addressed through 

materials and processing improvements. 

Reproducible fabrication will be achieved through 

the following: enhanced inspection techniques, data 

analysis, and mechanized production methods. 

Finally, the design of the hot subassembly will be 

based on proven engineering designs developed by 

TMI over the past 10 years.

Figure 1. Reversible Testing of Cells
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

150

Results

Cell Component Development

The goal of the cell testing task was to validate 

the passive mode of operation and characterize 

performance. Temperature and gas phase 

concentration gradients are of particular interest 

because the processes are driven by gaseous 

diffusion.

Evolutionary improvements and modifications 

were made to existing TMI materials specifications, 

fabrication methods, and cell dimensions to 

accommodate this design. Minor modifications of 

standard TMI fabrication procedures were sufficient 

to produce thicker fuel + oxygen electrodes. Larger 

diameter, thicker seals were made using methods 

from internally funded programs. Fifty-percent 

thinner electrolytes were procured and used in some 

of the trials.

Figure 1 shows data from cells operated with a 

65% hydrogen/35% steam mixture at two different 

temperatures. Operation was primarily in 

electrolysis mode with daily intervals in fuel cell 

mode. The mixture choice of fuel composition 

corresponds to the approximate midpoint in oxygen 

potential in a complete system as shown in the 

second part (b) of the figure. Characterization at 

extreme conditions was not considered during this 

phase.

The lack of offsets or slope changes near zero 

current indicates that no significant activation 

polarization exists in these cells (in marked contrast 

to proton exchange membrane [PEM] cells). The plot 

also shows that practical electrolysis current densities 

(100-200 mA/cm2

) required electrolysis voltages 

under 1.1 Volts --- far lower than PEM electrolyzers 

(which typically operate near 1.9 Volts) -- thus 

enabling higher electrolysis efficiencies when using 

TMI's solid oxide cells. Trends were consistent for 

similar materials and construction. The most likely 

sources of variability were fabrication quality and 

processing parameters. Because of the short program 

duration, fabrication condition optimization could 

not be explored. Finding an optimal set of 

fabrication conditions is essential for reproducible 

results.

Reversible cell efficiency is the ratio of fuel cell 

to electrolysis voltage at the same cell current and 

hydrogen/steam feed. It is a measure of the 

maximum possible energy storage efficiency for a 

reversible system using the cell (system efficiencies 

will be lower than cell efficiencies). The highest 

reversible cell efficiency observed was 90.8% (at 

925°C and 50 mA/cm2).

Engineering Studies

A modular system design producing both 

electricity and hydrogen was studied in the context of 

several assumptions. In this concept, AC power 

could be produced for local needs with possible sale 

of surplus power to the grid. High pressure (e.g., 

5000 psi) pure hydrogen could also be produced for 

later use in vehicles after temporary storage in 

adjacent tanks. Hot water would be produced as a 

useful byproduct when operating from natural gas 

fuel augmented by renewable electricity where 

applicable. The exhaust would be extremely clean, 

and CO2 emissions would be minimized during 

operation due to the high efficiency of the system.

Individual module sizes considered ranged from 

1 to 30 kW. For each kilowatt of capacity, a module 

could either produce up to 1.0 AC kilowatt or up to 

12.1 standard cubic feet per hour (scfh) of hydrogen 

(enough to power fuel cell cars for 21,200 miles per 

year) or a combination of electricity and hydrogen. 

The fuel cell subsystem would operate at 

atmospheric pressure, and the electrolysis subsystem 

would operate up to 5000 psi. Batteries could provide 

high power when needed for load-following, and 

surges would only require a small energy storage 

capacity. Mechanical auxiliary devices include a 

high-pressure water pump and compact heat 

exchangers. Complete systems assembled from two 

or more identical modules would have the added 

benefits of redundancy and ease of service. In 

multiples, overall system capacities could range from 

an individual residence to large vehicle filling 

stations or "power parks". Energy storage capacity 

can be supplanted by producing hydrogen at steadystate for later use in vehicles, thereby eliminating 

"round trips" and increasing overall efficiency. 

For some special applications, an electrolyzeronly module could be sufficient, operating on DC 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

151

input power plus water and delivering high pressure 

pure hydrogen. Such a module would have much 

lower installed cost than the above but the same DC 

to hydrogen efficiency given in Table 1.

Conclusions 

The project has met or exceeded all technical 

objectives (as revised by DOE Hydrogen Program 

management) on budget and on time. Experimental 

results have been promising. The economic / 

engineering studies indicate the potential for 

reversible systems to set new standards of 

performance, achieving lower cost of H2 production, 

lower pollution levels, and potentially serving as an 

enabling technology for hydrogen fuel cells. At the 

system level, a demonstration reactor of sufficient 

size to demonstrate technology proof-of-concept will 

be designed, built, and operated. The design of the 

hot subassembly will be advanced based upon 

engineering designs developed by TMI over the past 

10 years and will include the understandings from the 

work presented above and learning from advanced 

stack development.

References 

1. Private communication with Neil Rossmeissl, 

Hydrogen Technology Development Manager, 

Office of Power Delivery Systems, December 

2000

FY 2002 Publications/Presentations 

1. Hydrogen/Fuel Cells for Transportation/Fuels for 

Fuel Cells, DOE 2002 Annual Meeting, Denver 

Colorado, May 6-10, 2002. 

Operating 

Mode

Electrical 

Efficiency at 

60% Output

Electrical 

Efficiency at 

100% 

Output

Energy 

Efficiengy

Renewable 

DC to AC

96% 96%

Natural Gas to 

AC

72% 65% 97%

Renewable 

DC to

 Hydrogen

95% 95%

Natural Gas to 

Hydrogen

83% 75% 97%

Table 1. Projected Efficiencies for Several Systems
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

152

II.D.6 High-Efficiency Steam Electrolyzer

Ai-Quoc Pham (Primary Contact), Ervin See, David Lenz and Robert Glass

Lawrence Livermore National Laboratory

P.O. Box 808, L-350

Livermore, CA 94551

(925) 423-339, fax: (925) 422-6892, e-mail: pham2@llnl.gov

DOE Technology Development Manager: Sigmund Gronich

(202) 586-1623, fax: (202) 586-5860, e-mail: Sigmund.Gronich@ee.doe.gov

Objectives

• Develop a novel steam electrolysis approach for highly efficient hydrogen production.

• Demonstrate the concept of using natural gas as anode depolarizer to reduce the electrical energy 

consumption.

• Develop the materials, processes and engineering designs for the natural-gas-assisted steam 

electrolyzer (NGASE).

• Build and demonstrate prototype electrolyzers.

Approach

• Investigate the depolarizing effect of natural gas using disk type samples.

• Evaluate new materials for the electrolyzer anode and cathode.

• Study the effect of microstructure on electrode performance.

• Develop low cost electrolyzer tube fabrication processes.

• Develop ceramic-to-metal seal for easy gas manifolding.

• Design tubular electrolyzer stack for high-pressure operation.

• Build and test several electrolyzer prototypes.

Accomplishments 

• Demonstrated feasibility of using methane to reduce the electrical energy consumption in hightemperature steam electrolyzer.

• Developed high performance anode and cathode. 

• Developed a low-cost but highly reliable thin-film coating technique.

• Explored various tube fabrication techniques, including cold isostatic pressing and low-pressure 

injection molding.

• Demonstrated a metal-to-ceramic seal that withstands 150 psi pressure differential.

• Built the first electrolyzer stack capable of producing 700 sccm hydrogen.

Future Directions 

• Develop better tube-to-tube series connections for high voltage, low current operation.

• Study the long-term stability of the electrodes.

• Design and build 1 and 3 kW electrolyzer stacks.

• Work with our industrial partner to do system integration.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Introduction 

Currently, most hydrogen demand is met by 

hydrogen production from fossil fuels, i.e., by steam 

reforming of natural gas and by coal-gasification. It 

is unlikely that the same approach can be used for 

producing and delivering hydrogen for a hydrogenbased transportation system because of the absence 

of an adequate hydrogen distribution infrastructure. 

Hydrogen produced on-site would be much more 

attractive and would require less costly initial 

investments. Unfortunately, distributed hydrogen 

production using small-scale conventional steam 

reforming is not a viable option because of the high 

cost and low efficiency of the reactors at small 

scales. More interesting approaches, such as autothermal reforming, micro-channel steam reforming, 

as well as partial oxidation processes, are currently 

being pursued. However, these approaches are fairly 

complex, involving several additional steps, such as 

high-temperature shift, low-temperature shift, and 

preferential oxidation or hydrogen gas separation.

Hydrogen can be produced from water using the 

simple electrolysis reaction. Because of the 

modularity of the electrolyzer, electrolysis can be 

done at large central plants, at a refueling station, or 

even at home. However, water electrolysis has not 

had a significant commercial impact because of the 

high electrical energy consumption and the resulting 

high cost. Furthermore, using the grid electricity that 

is produced by burning coal and natural gas will 

result in high greenhouse gas emissions, which 

would defeat the purpose of the hydrogen program.

In the near-term, fossil fuels will still be a major 

source for hydrogen production. The challenge is to 

make the production efficient and suitable for a 

distributed generation scenario. The purpose of this 

project is to develop a system that has the simplicity 

of conventional electrolysis while being compatible 

with the existing fuel infrastructure and having high 

efficiency with respect to primary energy, and thus 

having low greenhouse gas emissions.

Approach

Our approach to decrease the electrical energy 

input requirements for electrolysis is to use natural 

gas as an anode depolarizer. This approach 

essentially replaces one unit of electricity by one 

equivalent energy unit of natural gas at one-fourth 

the cost. There are two possible modes of operation. 

In the total oxidation mode, i.e. when methane is just 

used to reduce the electrochemical potential 

difference across the two sides of the electrolyzer 

membrane, the system does not require any gas 

separation and has the potential to produce pure 

hydrogen at high pressures. In the partial oxidation 

mode, methane is converted to hydrogen and carbon 

monoxide, which is subsequently converted to 

hydrogen via the water-gas shift reaction. We 

choose to focus our current efforts on the 

development of a system operating in the total 

oxidation mode because of its simplicity. Using an 

appropriate system design, it is possible to 

electrochemically compress hydrogen in-situ, thus 

eliminating the need for an expensive hydrogen 

compressor.

Results 

We have demonstrated the proof-of-concept of 

the NGASE approach using single cells. A voltage 

reduction of 1 V was observed when methane was 

used in the anode side. The electricity consumption 

was estimated to be about one order of magnitude 

lower than in conventional electrolyzers. Using thin 

film and novel catalyst materials, we subsequently 

demonstrated very high performance, up to 1 A/cm2

at only 0.5 V at 700°C. At 900°C, cell current 

density was as high as 2.4 A/cm2. For electrolyzer 

stack development, we selected the tubular approach 

since tubular structures have good mechanical 

integrity (relative to planar designs) while enabling 

operation at high pressure differentials.

During FY02, we continued to improve the tube 

performance by improving the tube microstructure. 

Figure 1 shows the current-voltage characteristics for 

various electrolyzer tubes as compared to disk data. 

We have evaluated several ceramic tube 

fabrication techniques. The cold isostatic approach 

turned out to be inadequate for the present purpose 

because of the difficulties to incorporate sufficient 

porosity in the structure. A low pressure injection 

molding technique was successfully developed to 

fabricate green tubes with lengths up to sixteen 

inches (Figure 2).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Although the tubular design reduces significantly 

the issues typically encountered with sealing, there is 

still a need to seal the two ends of the tubes in order 

to avoid potential CO contamination and to enable 

operation with a pressure differential across the tube. 

We successfully developed a metal-to-ceramic seal 

that is leak-free up to 150 psi pressure differential 

(Figure 3). 

Four electrolyzer tubes were assembled in 

parallel to form a prototype stack (Figure 4). When 

operated at 750°C, the stack produces 700 sccm 

hydrogen standard temperature and pressure. The 

stack performance was somewhat lower than what 

was expected from single tube results. The 

difference could come from the resistive loss in the 

cables because of very high current in the stack. This 

observation suggests that a series design with lower 

current and higher voltage is more desirable. A new 

stack design is being developed.

Conclusions

The electricity required for steam electrolysis 

can be reduced significantly if natural gas is used as 

anode depolarizer. The efficiency of the NGASE 

was estimated to be between 60 to 75%, depending 

on the current density. That number is significantly 

higher than the typical 40% efficiency for 

conventional electrolysis using average grid 

electricity. 

Figure 1. Current-Voltage Curves of Various 

Electrolyzer Tubes and of Single Disk

Figure 2. An Injection-Molded Electrolyzer Tube

Figure 3. Metal-to-Ceramic Seal

Figure 4. A 4-tube Electrolyzer Stack Prototype
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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We have demonstrated the concept and have 

developed the materials and initial system design. 

The development of the first electrolyzer stack 

prototype indicated that a number of issues remain to 

be improved. Most important of all are the long-term 

stability and the electrical connection between tubes.

FY 2002 Publications/Presentations 

1. DOE Annual Program Review for 2002, May 8, 

2002, Denver, CO
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

156

II.D.7 Enabling Science for Advanced Ceramic Membrane Electrolyzers 

Fernando Garzon (Primary Contact), Rangachary Mukundan, and Eric Brosha

Los Alamos National Laboratory 

MS D429, MST-11 Group

Los Alamos, New Mexico, 87545

(505) 667-6643, fax: (505) 665-4292, e-mail: garzon@lanl.gov

DOE Technology Development Manager: Sigmund Gronich

(202) 586-1623, fax: (202) 586-5860, e-mail: Sigmund.Gronich@ee.doe.gov

Main Subcontractor: Los Alamos National Laboratory, Los Alamos, New Mexico

Objectives 

• Evaluate proton-conducting ceramic membranes for use in electrolyzers.

• Fabricate dense ceramics of cerates and zirconates and measure the bulk hydrogen conductivity using 

AC impedance spectroscopy and DC conductivity measurements; demonstrate water electrolysis using 

these materials.

• Synthesize electrode materials for electrolysis and characterize their polarization behavior using 

electrochemical methods.

Approach

• Synthesize cerate and zirconate proton-conducting oxides from the component oxides.

• Evaluate the structure and composition of the cerate and zirconate ceramics using X-ray diffraction 

and X-ray fluorescence techniques.

• Characterize the bulk hydrogen conductivity of the sintered proton-conducting ceramics using AC 

impedance spectroscopy and DC conductivity measurements.

• Obtain tubes of the proton-conducting ceramics and apply electrodes to these proton-conducting tubes.

• Design an experimental setup to demonstrate water electrolysis and hydrogen generation.

• Optimize electrode materials for electrolysis and characterize their polarization behavior using 

electrochemical methods.

Accomplishments 

• Synthesized SrCe0.95Yb0.05O3-x and SrZr0.9Y0.1O3-x proton-conducting oxides.

• Confirmed the orthorhombic crystal structure of the proton-conducting oxides using X-ray diffraction. 

The lattice parameters of the proton-conducting oxides were also measured.

• The composition of the oxides was verified using X-ray fluorescence.

• Dense sintered proton-conducting ceramics were prepared, and their electrical conductivity was 

characterized using AC impedance spectroscopy and DC conductivity measurements.

• Tubes of the proton-conducting ceramic SrCe0.95Yb0.05O3-x were obtained from TYK Ceramics, and 

platinum electrodes were applied to the inner and outer sides of these tubes.

• An experimental setup to demonstrate water electrolysis and hydrogen generation has been designed 

by modifying a furnace to fit the electrolyzer tubes and by using an HP 5890 Series II chromatograph 

to analyze the evolved gases.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

157

Future Directions 

• The hydrogen evolution from the SrCe0.95Yb0.05O3-x tubes will be characterized under various 

conditions of temperature, water vapor and oxygen partial pressure.

• The polarization due to the platinum electrodes will be evaluated using AC impedance techniques.

• Alternative oxide electrodes to replace the platinum electrode will be prepared and evaluated.

Introduction 

Efficient and economical electrolysis of water to 

hydrogen and oxygen gases is of great importance to 

renewable hydrogen energy programs. Combined 

fuel cell/electrolyzer systems offer the potential for 

efficient energy storage and conversion. 

Unfortunately, low-cost and low-maintenance 

electrolyzer technologies are not commercially 

available. Current alkaline and polymer membrane 

based electrolysis systems suffer from the following 

disadvantages:

• The hydrogen product gas is saturated with 

water vapor; the gas must be dried before the 

hydrogen can be stored in a hydride bed.

• Both technologies require high loadings of 

precious metal catalysts to reduce the 

overpotential losses.

• Neither technology is amenable to highpressure operation. It is very difficult to 

pressurize wet alkaline electrolyte cells. 

Polymer membrane cells allow high 

crossover rates of gases across the 

membranes at elevated pressures.

• Long-term stability and contamination is a 

problem with both alkaline and polymer 

membrane electrolysis electrolytes. Alkaline 

electrolytes adsorb carbon dioxide readily 

and form carbonates. Polymer membrane 

systems must use very pure de-ionized water 

or they will accumulate cations that displace 

protons and increase the cell resistance over 

time.

A promising alternative to liquid and polymer 

membrane electrolytes is a proton conducting 

ceramic solid electrolyte technology. These materials 

offer a number of potential advantages over current 

systems:

• The ceramic electrolyzers are solid-state 

devices with no polymer or liquid electrolyte 

to contaminate, and they are well suited to 

operate at elevated pressures.

• The devices should operate with steam 

without expensive cation removal/carbon 

dioxide pretreatment.

• The ceramic cells operate at temperatures 

from 450-800°C and thus at a lower 

thermodynamic potential than the lowtemperature systems.

• The elevated operating temperatures enable 

the use of non-precious metal electrodes, and 

electrode reaction kinetics may also be faster 

at these elevated temperatures.

• Temperatures in this range are directly 

compatible with solar furnace operating 

temperatures, offering potentially attractive 

integrated hybrid electrical/hydrogen 

generation systems.

 Finally, this technology is intrinsically different 

from the other solid-state technology using zirconiabased oxygen ion electrolyzers in that the transported 

(separated) species is hydrogen rather than oxygen. 

The zirconia oxide ion systems produce a wet 

hydrogen product stream. The proton conducting 

ceramic electrolyte does not suffer from this 

disadvantage and produces a dry hydrogen stream 

with no further purification needed. The electrolysis 

of water vapor on oxygen ion and proton conducting 

ceramics is illustrated in Figure 1. We propose to 

demonstrate the feasibility of water electrolysis using 

solid-state electrochemical cells based on proton ion 

conducting solid electrolytes.

Approach

The principal goal of this project is to 

demonstrate electrolysis technology using ceramic 

electrochemical cells based on solid oxide proton 

conductors. Los Alamos National Laboratory 

(LANL) has experience in solid-state bulk and thin 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

158

film materials synthesis and characterization 

capability. We will synthesize and characterize 

electrolyte and electrode materials and fabricate test 

cell apparatus. Characterization methods available in 

the Electronic and Electrochemical Materials and 

Devices Group include X-ray diffraction, thermo 

gravimetric analysis, energy dispersive X-ray 

analysis, scanning electron microscopy and AC 

impedance and DC cyclic voltammetry 

electrochemical methods.

Recently, a number of perovskite structure 

ceramic proton separation membranes have been 

developed and reported by Iwahara et. al. [1]. These 

materials exhibit good stability, high ionic transport 

rates for protons and also operate in the 600-900°C 

temperature range which is optimal for insitu 

 Figure 1. Schematic Illustration of Water 

Electrolysis on an Oxygen Ion Conducting 

Electrolyte (top) and a Hydrogen Ion 

Conducting Electrolyte (bottom).

Figure 2. Polyhedral representation of the 

(Sr,Ba)(Zr,Ce)(B)3+O3-y perovskites where 

(B)3+ designates a trivalent substituted cation. 

The (Sr,Ba) occupy the A site; (Zr,Ce)(B)3+

occupy the B center positions of the 

octahedrally coordinated oxygen.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

159

catalysis reactions. The materials are also of great 

value for high temperature fuel cell technologies, 

isotope separation systems, sensor applications and 

heterogeneous catalysis [2,3].

The proton conducting materials are rare earth 

cerate and zirconate ABO3 formula oxides, e.g. 

(Sr,Ba) (Zr,Ce)(B)3+O3-y, where (B)3+ is a three 

valent yttium or lanthanide cation. The crystal 

structures of all of these materials are typically 

orthorhombic distortions of the cubic perovskite 

structure due to a tilt of the oxygen coordinated 

octahedra as illustrated in Figure 2. The perovskite 

materials contain oxygen ion vacancies introduced 

by the (B)3+ substituting for four valent zirconium or 

cerium. Exposing these materials to steam at 

elevated temperatures causes water to hydrolyze and 

fill the vacancies with oxygen and two mobile 

protons. 

Since these first reports, Iwahara and other 

investigators have studied the conductivities (both 

ionic and electronic), conduction mechanism, 

deuterium isotope effect, and thermodynamic 

stability of these materials. The motivation for most 

of this work derives from the desire to utilize these 

materials for high temperature, hydrogen-fueled 

solid oxide fuel cells. In a reverse operation mode, if 

metal or metal oxide electrodes are deposited onto a 

dense pellet of this material and heated to 

temperature T, the application of an electric potential 

to the electrodes will cause a hydrogen partial 

pressure difference across the pellet according to the 

Nernst equation:

where F is Faraday's constant and z is the number of 

electrons transferred upon oxidation and reduction. 

For example, at 500°C the application of 1.5 V 

would produce a hydrogen partial pressure difference 

across a pellet on the order of 1020. These 

differences in hydrogen activity are high enough to 

decompose water at elevated temperatures.

The Sr and Ba-doped cerate electrolytes exhibit 

the highest proton conductivities; however, recent 

reports question the thermodynamic stabilities of the 

Ba compounds at intermediate temperatures and in 

the presence of high partial pressures of CO2 and 

H2O. It is unclear whether this will present a 

problem for electrolysis applications; therefore, we 

will evaluate the thermodynamic stability of these 

materials and study the stability of potential 

substitute candidates. 

Results

Consequently, we are in the startup phase of our 

program. Our first task was to identify candidate 

perovskite oxide materials with high protonic 

conductivities. We have identified ytterbium doped 

strontium cerate and yttrium doped strontium 

zirconate materials as possible electrolyte materials. 

Barium cerate perovskites exhibit higher protonic 

conductivity, but the reactivity with carbon dioxide 

would require pretreatment of the steam.

We have designed and assembled a high 

temperature AC impedance system for measurement 

of protonic conductivities. Our measurements of 

candidate ceramic protonic conductivities indicate 

that the electrolyte resistance in thin membrane form 

should not impose a large internal resistance (IR) loss 

on the electrolysis cell. However, ceramics 

processing also plays an important role in 

determining the conductivities of these materials. 

Figure 3 displays the conductivities of three 

Sr0.95Yb0.05CeO3-x samples made using differing 

starting powders and sintering schedules.

∆V RT

zF

------ P′H2

PH2 = ln-----------

Figure 3. The Conductivities of Three 

Sr0.95Yb0.05CeO3-x Ceramic Samples 

Produced Using Differing Ceramic 

Processing Methods
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

160

We have identified and contracted a ceramics 

supplier, TYK Corporation, to fabricate electrolyte 

tubes for prototype electrolyzer research studies. 

The supplier has successfully manufactured and 

delivered closed end electrolyzer membrane tubes to 

LANL. The composition of the tubes is 

SrCe0.95Yb0.05O2.975, and the tubes are 200 mm in 

length with an inner diameter of 12 mm and an outer 

diameter of 15 mm. Although the membrane 

thickness of 1.5mm could lead to significant IR 

losses (20-30 Ω cm2

 specific resistance), these tubes 

are ideally suited for the evaluation of these protonconducting membranes as electrolyzers. Figure 4 is a 

photograph of a recently manufactured electrolyzer 

tube.

Platinum electrodes have been painted on an 

electrolyzer tube, and an experimental setup has been 

designed and built to evaluate the hydrogen 

permeation. The electrolyzer tube is placed in a 

modified Lindberg/BlueM furnace, and the gases are 

fed into an HP 5890 Series II gas chromatograph for 

analysis.

Conclusions

• Sr0.95Yb0.05CeO3-x has been selected as the 

first protonic conductor to be evaluated as an 

electrolyzer membrane.

• The conductivity of the ceramics reveals that 

thin films (<100 μm) of this material should 

be suitable for the manufacture of a practical 

electrolyzer.

• Tubes of the Sr0.95Yb0.05CeO3-x ceramic 

have been obtained and will be evaluated 

with the experimental setup that has been 

designed and built.

References 

1. H. Iwahara, T. Esaka, H. Uchida and N. Maeda, 

Solid State Ionics, 3/4, 359 (1981)

2. A. S. Nowick and A. V. Vaysleyb, Solid State 

Ionics, 97, 17 (1997)

3. R. Mukundan, E.L. Brosha, S. A. Birdsell, A. L. 

Costello, F. H. Garzon, and R.S. Willms, Journal 

of the Electrochemical Society, 146, no.6, 2184-

7(1999)

FY 2002 Publications/Presentations

1.Applications of Proton Conducting Perovskites, 

Rangachary Mukundan, Eric L. Brosha, and 

Fernando H. Garzon, A symposium in Honor of 

the 65th Birthday of Professor Wayne L. Worrell, 

PV 2002-5, pp. 142-147 (2002) The 

Electrochemical Society Inc.

Figure 4. Ceramic Electrolyte Tube of 

SrCe0.95Yb0.05O2.975 Custom Fabricated for 

LANL by TYK Corporporation
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

161

II.D.8 Hydrogen Production Through Electrolysis

Robert J. Friedland (Primary Contact), A. John Speranza

Proton Energy Systems, Inc.

10 Technology Drive

Wallingford, CT 06492

(203) 678-2000, fax: (203) 949-8078, e-mail: rob.friedland@protonenergy.com

DOE Technology Development Manager: Sigmund Gronich

(202) 586-1623, fax: (202) 586-5860, e-mail: Sigmund.Gronich@ee.doe.gov

Objectives 

• Reduce the cost of proton exchange membrane (PEM) electrolysis to levels of $1250/kW for 10,000 

standard cubic feet per day (scfd) at production levels of 10,000 units per year.

• Reduce the cost of smaller units (1,000 scfd) of $2500/kW in production volumes of 10,000 units per 

year.

• Evolve the use of PEM electrolysis as an energy storage device to enable renewable energy technology 

as a sustainable source of electricity.

Approach

• Validate the design and cost reductions for the hydrogen oxygen generator (HOGEN7) 40 generator 

control board and advance that design into the more complicated controls of the HOGEN7 380 

hydrogen generator. 

• Design a cell stack compression scheme that reduces the material and labor cost associated with the 

manufacture of the cell stack.

• Investigate low cost power conversion options for use across the line of hydrogen generators.

• Test a renewables interface to a HOGEN7 40 generator and collect data to understand how the system 

interacts with the renewable (photovoltaic- or wind-powered) device.

Accomplishments 

• Completed the validation of the HOGEN7 40 generator control board and the design specification for 

the HOGEN7 380 hydrogen generator control board. Savings of at least $3,500 of material and 40 

hours of labor were removed from the HOGEN7 40 generator.

• Reduced the number of parts in the cell stack compression from 1344 to 15, assembly time from 75 

minutes to 5 minutes, and overall volume by over 30%.

• Determined that a non-isolated power converter with minimal energy storage can get to between 

$.033-$.05/watt for the generators.

• Developed a 5 kW converter for photovoltaic (PV) and wind systems and tested the converter at 

Northern Power Systems. 

Future Directions 

• Validate the design of the control board for the HOGEN7 380 generator.

• Analyze additional power electronics options for the HOGEN7 380 generator.

• Conduct additional testing using a PV array coupled to a HOGEN7 40 generator.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

162

Introduction

Proton's goal is to drive the cost of PEM 

electrolysis to levels of $1250 per kilowatt for 10,000 

scfd and $2500 per kilowatt for 1,000 scfd of 

hydrogen gas output. Both of these costs assume a 

manufacturing volume of 10,000 units per year, and 

the cost per kilowatt is based on electrical power into 

the electrolyzer. In addition, this project will evolve 

the use of PEM electrolysis as an energy storage 

device to enable renewable energy technology as a 

sustainable energy source. 

For this past fiscal year, Proton has focused on 

several aspects associated with these cost reduction 

efforts. First, all of the previous cost reductions on 

the HOGEN7 40 generator (see Figure 1) needed to 

be fully validated by testing to show they would meet 

the technical requirements of the product and support 

the customer and market requirements. Second, the 

control board on the HOGEN7 40 was to be 

advanced into the HOGEN7 380 generator product 

(see Figure 2). Third, investigation work was to be 

conducted on power supply options for the HOGEN7

380 generator based on some of the work on the 

HOGEN7 40 generator, but advanced to incorporate 

the higher power levels required on the larger units. 

Fourth, cell stack cost reduction activities on 

compression hardware was to be advanced and cost 

traded with traditional spring washer approaches. 

Finally, data was to be collected on renewable power 

inputs using power conditioning equipment 

developed by the project.

Approach

The HOGEN7 40 generator was chosen as the 

model for cost reduction for two reasons. First, the 

smaller size of the HOGEN7 40 generator made cost 

reduction activities and hardware purchases less 

costly, and thus enabled a larger scope of effort and 

impact on return. Second, advances are scalable. In 

other words, improvements and cost reductions made 

on the HOGEN7 40 generator can be scaled to the 

larger HOGEN7 380 generators with less financial 

and project related risk. The specifics of this 

approach were outlined in the Technical Paper 

submitted for that year’s annual review2.

The cost reduction effort targeted the electrical 

controls and mechanical systems that were common 

across the range of hydrogen generators and would 

need to be used for future products involving 

renewable energy technologies. The control board 

design and development done in this project yielded 

significant reductions in both material and labor 

costs. In addition, mechanical system 

Figure 1. HOGEN7 40 Hydrogen Generator

Figure 2. HOGEN7 380 Hydrogen Generator
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

163

simplifications, plumbing and fitting reductions and 

part substitutions also played a large role in the cost 

reduction effort for both labor and material. These 

modifications coupled with new technology 

developments like a power interface for renewable 

energy input successfully moved the HOGEN7 40 

generator product towards renewable energy utility. 

By the end of FY2001 many of these design 

improvements and cost reductions had been 

developed but not fully validated3. 

Results

Cell Stack Compression

This task was to study the cost and performance 

differences of changing the methodology of 

compressing the electrolysis cell stack from a large 

number of spring washers (see Figure 3) to a fewer 

number of larger spring washers (see Figure 4). This 

change has yielded some impressive results. 

Changing to the large diameter spring reduces the 

assembly time of the washers from 75 minutes to 5 

minutes, and reduces the parts count from 1344 

pieces to 15. From a manufacturing standpoint, these 

are very impressive reductions that also have a 

tremendous impact on quality and consistency of 

assembly. Each of the smaller springs needs to be 

oriented in a certain way and with a certain ordering 

configuration on each rod. This complicated 

assembly is prone to mistakes that cause rework and 

could possibly jeopardize the sealing integrity of the 

cell stack.

Control System Cost Reduction

The HOGEN7 40 generator control board design 

represents a significant cost reduction to the overall 

electrolyzer control system. The material cost for the 

control system has been reduced from over $3,500 to 

less than $300 with a 40 hours to one hour reduction 

in labor (see Figures 5 and 6). This year's effort was 

focused on validating the design changes that were 

made to cost reduce the electrolyzer control system 

Figure 3. Current Cell Stack Compression 

Configuration

Figure 4. Improved Cell Stack Compression 

Configuration
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

164

in order to insure that the integrity and reliability of 

the product was not compromised. The control board 

was developed beyond the prototype stage and 

underwent extensive design validation testing prior 

to production release. Validation of the control board 

included Highly Accelerated Life Testing (HALT), 

which exposed the board to environmental extremes 

in order to identify hardware limitations. The results 

of the HALT testing were fed back into the design 

process to further enhance the robustness of the 

control board design. Validation testing also included 

agency safety/EMC testing and equivalent 

certifications for Underwriters Laboratory, CSA, and 

CE. The control board also underwent operational 

testing to insure that the electrolyzer operated within 

design specifications through all modes of operation. 

The cost reduction efforts on the HOGEN7 380 

generator control system have resulted in a greater 

than 90% control system cost reduction. The fact that 

the HOGEN7 380 generator control board was 

developed off of the HOGEN7 40 generator control 

board design and was able to maintain the same basic 

architecture and function has resulted in a much more 

dramatic hardware cost reduction. The current 

HOGEN7 380 generator control system costs in 

excess of $10,000. The projected cost of the 

production control board in modest volumes is less 

than $500. The validated HOGEN7 40 generator 

control board was used as the base platform for the 

HOGEN7 380 generator control board.

 The HOGEN7 380 generator control board 

specification was drafted and a prototype board was 

delivered for functional testing early this year. The 

prototype board was then incorporated into an 

electrolyzer system to verify the design and test the 

basic functionality of the cost-reduced system. Basic 

design verification testing was completed, and the 

board design was modified to incorporate the 

changes that resulted from the verification testing. 

The beta board will be delivered this year and 

undergo extensive validation testing 

HOGEN7 380 Generator Fluid Management Cost 

Reduction

Following the same strategy as was used on the 

control board development, a tremendous amount of 

cost reduction has been realized on the HOGEN7 380 

generator fluids system with a minimal amount of 

reengineering. The components that were developed 

for the HOGEN7 40 generator were used as the 

platform for further cost reductions on the HOGEN7

380 generator. The development efforts on gas 

drying for the HOGEN7 380 generator have resulted 

in a low-cost pressure swing absorption dryer that 

can be manufactured in low quantities for under 

$4,000 compared to the previous design that was 

Figure 5. Current Discreet Electrical Component 

Layout

Figure 6. New Control Board Design
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

165

over $8,000. In higher volumes the cost of this dryer 

will be well under $2,000.

Power Conversion Cost Reduction

One of the first efforts that needed to occur, for 

the power conversion cost reduction to be successful, 

was a cell stack electrical characterization study. 

This task helped to understand the electrolysis cell 

stack as a power load. 

Utility Grid Converter

With the cell stack characterization complete, a 

feasibility study and paper design based on a power 

electronics cost reduction effort for the HOGEN7 40 

hydrogen generator was conducted. It was 

concluded that the high cost of power conversion of 

these units is due mainly to two factors: buying an 

"off-the-shelf" design that is not optimized for the 

electrolysis application and providing galvanic 

isolation to the electrolysis cell. The study 

concluded that a non-isolated power converter with 

minimal energy storage has the potential to achieve 

$.033/watt for the HOGEN7 40 generator and $.05/

watt for the HOGEN7 380 generator.

Based on the initial results of the feasibility 

study, the design and development of a cost reduced 

power electronics package appears feasible. The 

path to the lowest cost for power electronics is in a 

design that is optimized for the electrolysis process, 

and the best approach to accomplish this is to 

develop the design "In House" or in cooperation/

collaboration with a third party. 

Presently, the HOGEN7 40 generator power 

electronics costs $0.30/watt and delivers DC power 

at an average efficiency of 85%. The feasibility study 

identifies a design path with the ability to reduce the 

cost of power electronics to less than $0.10/watt and 

an average efficiency of 94%.

Renewable Energy Interface Converter

Sustainable Energy Technologies (SET) was 

contracted to develop an interface converter with the 

capability to accept a power input from a 

photovoltaic or wind source. SET delivered two 5 

kW photovoltaic interface converters that were tested 

by Northern Power Systems in Waitsfield, Vermont 

and found to meet the basic specifications of the 

design. SET also delivered an interface converter that 

was capable of accepting a wind turbine input, but 

due to the inability to interface directly to a wind 

turbine the converter was never tested beyond the 

basic power test. One of the PV converters has been 

delivered to the Illinois Institute of Technology for 

integration into a renewable energy system utilizing 

one of Proton's HOGEN7 40 hydrogen generators.

Conclusions

A sustainable energy system utilizing renewable 

energy technology must have the fundamental 

capability of storing excess renewable energy when it 

is available so it can be utilized on demand. 

Renewable energy technology is inherently 

intermittent based on the fundamental fact that the 

wind does not always blow and the sun does not 

always shine. Electrolyzer technology has great 

promise for helping to bridge the gap and make 

electricity available twenty-four hours a day, seven 

days a week. Proton's hydrogen generators also 

follow the load extremely well and can respond 

virtually instantaneously to fluctuations in power 

levels from the renewable energy device. However, 

the cost challenges associated with electrolysis must 

be overcome. This project has made tangible 

progress on reducing cost through various design 

initiatives and bringing those designs forward into 

products

References 

1. Friedland, R., Smith, W., Speranza, A., January 

2000. Integrated Renewable Hydrogen Utility 

System, Phase I Final Technical Report and 

Market Assessment PES-T-99014.

2. Friedland, R., May 2000. Integrated Renewable 

Hydrogen Utility System, Phase II Technical 

Paper for Annual Technical Peer Review.

3. Friedland, R., Speranza, A., May 2001. Hydrogen 

Production Through Electrolysis, Phase II 

Technical Paper for Annual Technical Peer 

Review.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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II.E Hydrogen Fueling Systems and Infrastructure

II.E.1 Development of a Turnkey Commercial Hydrogen Fueling Station

David E. Guro (Primary Contact)

Air Products and Chemicals, Inc.

7201 Hamilton Blvd.

Allentown, PA 18195-1501

(610) 481-4625, fax: (610) 481-4260, e-mail: gurode@apci.com

DOE Technology Development Manager: Arlene Anderson 

(202) 586-3818; fax (202) 586-9234, e-mail: Arlene.Anderson@ee.doe.gov

ANL Technical Advisor: William Swift

(630) 252-5964, fax: (630) 972-4473, e-mail: swift@cmt.anl.gov

Subcontractors: H2Gen Innovations, Inc., Alexandria, Virginia; Pennsylvania State University, 

University Park, Pennsylvania; QuestAir Technologies Inc. (under negotiation), Burnaby, British 

Columbia, Canada 

Objective

Demonstrate the potential for an economically viable stand-alone, fully integrated hydrogen (H2) fueling 

station based upon the reforming of natural gas by striving to:

• Develop a cost-effective solution to the reforming of natural gas to produce a reformate stream;

• Develop an efficient, cost-effective means to purify the hydrogen-rich reformate to pure hydrogen 

employing pressure swing adsorption (PSA) technology;

• Develop an optimum system to compress, store, meter, and dispense hydrogen into vehicles;

• Efficiently integrate the process steps mentioned above into a safe, user-friendly, cost-effective fueling 

station;

• Demonstrate the operation of the fueling station at Penn State University;

• Maintain safety as the top priority in the fueling station design and operation; and

• Obtain adequate operational data to provide the basis for future commercial H2 fueling stations.

Approach

This nine-quarter project is being managed in three phases, with Stage Gate reviews between each phase. 

These phases overlap in time in order to make efficient use of resources and minimize costs.

• In Phase 1, conceptual design and preliminary cost evaluations for each major sub-system in the 

fueling station will be completed.

• In Phase 2, sub-system R&D will be performed to test the concepts put forth in Phase 1. Technical 

viability and fueling station costs will be validated.

• Phase 3 will include fabrication, installation, and testing of the full-scale H2 generator and dispenser at 

Penn State University. This H2 fueling station will be designed to deliver 50 nm3/hr H2.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

167

Accomplishments

• Kicked off development work on the novel reforming system.

• Began the process and cost study of the various reforming options available.

• Initiated the H2 PSA development program at Air Products and Chemicals, Inc. (APCI) and the 

engineering services study at QuestAir.

• Built a prototype H2 PSA system to be installed for testing at an Air Products H2 production facility.

• Started engineering work on the compression and dispensing systems. 

• Equipped a laboratory to test H2 flow meters for use within the dispenser.

Future Directions

In the near term, the development team will conclude the Phase 1 work and hold a Stage Gate review 

meeting with DOE management. Then, work on all aspects of Phase 2 will commence, followed by Phase 

3. The expected schedule for these Phases is outlined in the table below:

Task Date

Phase 1 Pre-Contract Technical Development Oct 2001 – March 2002

Cooperative Agreement Award 29 March 2002

Phase 1 Conceptual Design and Economic Evaluation April 2002 – June 2002

Phase 2 Subsystem Development July 2002 – March 2003

Phase 3 System Deployment April 2003 – December 2003

Phase 3 System Deployment – Operation & Testing January 2004 – June 2004

Introduction

The transition to hydrogen as a fuel source 

presents several challenges. One of the major 

hurdles is the cost-effective production of hydrogen 

in small quantities. In the early demonstration phase, 

hydrogen can be provided by bulk distribution of 

liquid or compressed gas from central production 

plants; however, the next phase to fostering the 

hydrogen economy will likely require onsite 

generation to institute a pervasive infrastructure. 

Providing inexpensive hydrogen at a fleet operator’s 

garage or local fueling station is a key step toward 

enabling commercialization of direct hydrogen fuel 

cell vehicles (FCVs). The objective of this project is 

to develop a comprehensive, turnkey, stand-alone 

hydrogen fueling station for FCVs with state-of-theart technology that is cost-competitive with current 

hydrocarbon fuels. Such a station will promote the 

advent of the hydrogen fuel economy for buses, fleet 

vehicles, and ultimately personal vehicles.

Approach

The development efforts are expected to build on 

preliminary work accomplished by the major 

partners. Air Products, as the overall project 

manager, is responsible for the total system 

integration and final development of the installed 

equipment. As the system integrator, Air Products 

will ensure that the system is fully optimized and that 

all of the individual components are compatible to 

deliver the lowest cost H2 fuel. This nine-quarter 

project is being managed in three phases, with Stage 

Gate reviews between each phase. 

During Phase 1 of the program, subsystem 

conceptual designs will be formulated and costed. 

Options will be developed and compared for the 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

168

reformer system, PSA system, compression, storage, 

and dispenser. Air Products will work with H2Gen 

to develop and to evaluate the applicability of a novel 

convective steam methane reforming (SMR) based 

reforming system. At the end of Phase 1, we will 

confirm the preliminary feasibility of cost targets via 

an initial, pre-developmental definition of scope and 

execution costs and will identify the partners for 

further development of components.

In Phase 2, the most promising subsystem 

designs assessed and selected in Phase 1 will be 

further developed. Lab testing of certain components 

will be carried out. Recommendations for the 

optimal fueling station components will be made. 

Air Products engineers, working with the selected 

reforming partner, will optimize the design of the 

reformer and PSA systems, and build and test 

components of the systems in laboratories. Air 

Products will be directly responsible for the design of 

the dispenser, which will be tested in a shop prior to 

installation on site. Finally, Air Products will act as 

the system integrator to pull together the various 

pieces into a comprehensive turnkey unit and to 

minimize the total cost of delivered H2.

During Phase 3, scale-up and detailed 

engineering design of all equipment will be 

completed. The engineered system will be analyzed 

for Design for Manufacture and Assembly (DFMA), 

and the assembled system will include 

instrumentation for data collection and provisions for 

remote monitoring of operation. Fabrication of all 

equipment and installation at Penn State University 

will follow. The fueling station will be started up 

and put into operation, beginning with 6 months of 

operation and testing. Finally, the cost of H2

delivered from the installed fueling station will be 

validated, taking into account the impact of massproducing components.

Results

As shown in Figure 1, hydrogen can be delivered 

for use at a refueling station in several ways. It can 

be piped to the station via a pipeline, delivered in 

cryogenic liquid form and then vaporized, delivered 

in compressed gaseous form and stored in on-site 

tanks, generated on-site via reforming of 

hydrocarbon feedstocks such as natural gas, or 

produced via electrolysis of water with power input. 

The scope of this program is to develop the route 

highlighted with the bold arrows in Figure 1 S the 

reforming of natural gas followed by H2 purification 

with PSA technology. Subsequently, the high purity 

H2 will be compressed and stored prior to final 

dispensing into the H2 vehicles.

Also highlighted in Figure 1 next to each process 

unit operation is the development partner responsible 

to contribute to the development or engineering of 

that piece of equipment. The development team 

began work addressing the technical challenges in 

October 2001. Below is a summary of progress to 

date:

Regarding aggreements and contracts, the 

cooperative agreement between DOE and APCI was 

signed on 29 March 2002. Subsequently, the 

subcontract with H2Gen was signed for development 

of the reformer. The subcontract with QuestAir is in 

review for supply of an improved H2 PSA purifier 

design, and the subcontract with Penn State 

University has been completed for siting of the 

fueling station.

In the reforming area, H2Gen development work 

kicked off in October 2001. Catalyst 

characterization work has begun, and the first 

prototype reformer is being built. Components have 

been tested, and the burners have been sized and 

tested in the lab. In addition, APCI began its 

engineering study in April 2002 to update the 

comparison of autothermal reforming (ATR), partial 

oxidation (POX), and SMR technologies to 

Figure 1. Hydrogen Fueling Station
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

169

determine the optimum route to small-scale H2

production. This kicked off the “Phase 1” portion of 

the development program. 

As part of this Phase 1 study, APCI prepared and 

sent out a Request For Quotation (RFQ) for the 

reforming system to several reformer vendors. 

Included in the RFQ were companies offering SMR, 

ATR, and catalyst systems.

The development of a H2 PSA at APCI began in 

October 2001. Adsorbent development has 

commenced and step-out approaches to achieving 

compact PSA designs have been identified. PSA 

cycle development work is underway to fully utilize 

the adsorbents’ capabilities. Laboratory experiments 

are underway. Additionally, development of new 

PSA valves, vessels, and other mechanical 

components has been initiated; testing plans have 

been formulated; and laboratories are being equipped 

for component testing. To hasten the introduction of 

some of these new concepts, APCI completed 

detailed design of a prototype H2 PSA unit to be 

evaluated at one of APCI’s H2 production facilities. 

The data collected on this PSA unit will serve to 

verify several of the significant technical “step-outs” 

being taken in the new PSA design being developed 

by the APCI team. Fabrication of this PSA skid was 

completed in early June, and the system is being 

installed on site. Finally, in anticipation of an 

engineering services sub-contract, QuestAir began 

work to improve their HyQuestor H2 purifier in 

October 2001. Their preliminary design and cost 

summaries are nearing completion.

APCI’s compression, storage, and dispensing 

development work began in October 2001. To date, 

APCI has completed the preliminary engineering 

work to determine the optimum configuration and 

selection of components for the H2 dispenser. Also, 

laboratory equipment to test H2 flow meters for use 

in the dispenser has been purchased and is being 

installed.

APCI has completed the initial conceptual 

process flow diagram (PFD) for the integrated 

fueling station. This will serve as the basis for 

engineering discussions related to the Penn State 

fueling station. To date, process specifications for all 

major components in the fueling station have been 

issued. Regarding utilities, APCI has defined a 

natural gas specification based on North American 

averages, has defined a potable water specification, 

and has identified Penn State’s specific natural gas 

and potable water specifications for use as the design 

basis for the system to be placed there.

Conclusions / Future Directions

Work has begun on this aggressive project to 

determine the viability of a commercial turnkey H2

fueling station. Initial conclusions will be 

communicated at the completion of the Phase 1 tasks 

and will be included in the Phase 1 report.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

170

II.E.2 Autothermal Cyclic Reforming Based Fueling System

Ravi V. Kumar (Primary Contact), George N. Kastanas, Shawn Barge, Vladimir Zamansky, and 

Randy Seeker

GE Energy and Environmental Research Corporation

General Electric Co.

18 Mason

Irvine, CA 92618

(949) 859-8851 ext. 159, fax: (949) 859-3194, e-mail: Ravi.Kumar@ps.ge.com

DOE Technology Development Manager: Sigmund Gronich

(202) 586-1623, fax: (202) 586-5860, e-mail: Sigmund.Gronich@ee.doe.gov

ANL Technical Advisor: Thomas G. Benjamin

(630) 252-1632, fax: (630) 252-1632, e-mail: Benjamin@cmt.anl.gov

Subcontractors: Praxair and BP

Objectives

• Design, fabricate, and install a reliable and safe H2 refueling system, based on autothermal cyclic 

reforming (ACR), that is capable of producing at least 40 kg/day of H2 (450 std m3 per day of H2), 

which is sufficient for refueling at least 1 bus or 8 cars per day.

• The current target cost for generation and refueling of hydrogen is $19.2/GJ of hydrogen for a 900 kg/

day of H2 (10,000 std m3 per day of H2) system, based on the lower heating value (LHV) of hydrogen. 

The future target cost is expected to decrease to $17.2/GJ by 2005 and $16.2/GJ by 2010.

Approach

• Phase I (2002): Complete the design of the integrated system and assess the technical and economic 

feasibility of the design.

• Phase II (2003-4): Perform subsystem development. 

• Phase III (2004-5): Demonstrate the fully integrated system.

Accomplishments 

• An optimal process configuration was selected, process flow diagrams were developed and 

efficiencies were calculated.

• In collaboration with another ongoing DOE project, “Fuel Processing Based on ACR for Stationary 

PEM Fuel Cells” (contract No. DE-FC02-97EE50488), the component design of a fuel processor has 

been completed and the system is being fabricated. The fabrication is expected to be complete by July 

2002.

• A detailed safety assessment including personnel hazard analysis (PHA), hazardous operations 

(HAZOP) and failure mode and effects analysis (FMEA) has been performed.

• An economic analysis for the hydrogen refueling station is being performed. Based on information 

from the literature, the cost of each subsystem of the refueling station was expressed as a function of 

the quantity manufactured and the hydrogen capacity. Preliminary estimates were made for cost of H2.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

171

Future Directions: 

• Complete the system design.

• Complete the economic analysis.

• Develop a plan for Phase II.

Introduction

Autothermal Cyclic Reforming (ACR) is a GE 

patented technology for converting hydrocarbons to a 

hydrogen-rich stream. The ACR process operates in 

a three-step cycle that involves steam reforming the 

fuel on a nickel catalyst (reforming step), heating the 

catalyst bed through oxidizing the nickel catalyst to 

nickel oxide (air regeneration step), and finally 

reducing the catalyst to its original metal state (fuel 

regeneration step). The heat required for the 

endothermic reforming reaction is provided during 

the exothermic oxidation of nickel to nickel oxide. 

Approach

A system design is being developed for the 

integrated hydrogen refueling system, and the 

technical and economic feasibility of the design is 

being assessed. The developmental activities and test 

work that are needed to both validate the design and 

identify a viable business model for 

commercialization, within the capital cost target, will 

be completed during the remaining part of Phase I 

(2002).

During Phase II (2003-4), the critical 

components and subsystems will be developed and 

tested to achieve the performance goals.

During Phase III (2004-5), the integrated H2

refueling station will be fabricated, installed and 

operated. GE will develop the reformer and integrate 

the full system. Praxair will develop the pressure 

swing adsorption (PSA) unit, the H2 compressor, and 

the H2 storage tanks. BP will analyze the refueling 

logistics and safety.

Results

Process Analysis

A preliminary process analysis of the fuel 

processor, which includes the reformer, shift reactor

and PSA unit, has been completed. The major 

subsystems of the hydrogen refueling station are 

shown in Figure 1, and they are: 1) autothermal 

cyclic reformer and PSA unit, 2) hydrogen 

compressor, 3) hydrogen storage system, and 4) 

hydrogen dispenser. 

The efficiency of the fuel processor is defined as 

the ratio of the lower heating value (LHV) of the 

hydrogen produced to the LHV of the fuel consumed 

by the fuel processor. The major factors affecting the 

efficiency are: 1) the conversion in the reformer and 

shift reactors, 2) the recovery of hydrogen in the 

PSA, 3) the recovery of the process heat, and 4) the 

minimization of heat losses and parasitic 

requirements in compressors. 

Several heat exchanger and compressor 

configurations were considered, since the thermal 

integration of the system has a significant impact on 

the efficiency. An optimal process configuration was 

selected, and the process flow diagrams were 

developed. As shown in Table 1, the efficiency of 

the optimal configuration is 75.2%. Compressor 

calculations showed that electricity required was 

Figure 1. Major Subsystems of a Hydrogen Refueling 

Station
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

172

around 1% of the LHV of the fuel. The operating 

conditions for the PSA are 7.9 bar (100 psig) and 

50_

C with 80% hydrogen recovery.

Fabrication of Integrated Fuel Processor

In coordination with another ongoing DOE 

project, “Fuel Processing Based on ACR for 

Stationary PEM Fuel Cells” (contract No. DE-FC02-

97EE50488), the component design, fabrication and 

installation of the fuel processor have been 

completed (see Figure 2). The system can produce 90 

kg of H2 per day (127 kW on a LHV basis). The 

component design will be modified for hydrogen 

refueling applications, based on input from Praxair 

on integration of the PSA. 

Safety Analysis and Permitting

A detailed safety assessment including personnel 

hazard analysis (PHA), hazardous operations 

(HAZOP) and failure mode and effects analysis 

(FMEA) has been performed. The assessment will be 

expanded to ensure that the system is compliant with 

all applicable building, fire and electrical codes. 

Economic Analysis

Based on a literature search, the capital cost for 

each major subsystem was estimated and then 

expressed as a function of the quantity manufactured 

and the hydrogen capacity of the refueling station. 

Cost models available in the literature for the 

hydrogen compressor, dispenser and storage 

subsystems have fairly good agreement. However, 

there is disagreement among various cost models for 

reformers. In general, small capacity reformers with 

optimized thermal integration are expected to cost 

less than conventional steam methane reformers. 

Table 2 shows the information available in the 

literature1-4 for capital costs of the reformer 

(excluding the PSA), hydrogen compressor, storage 

tanks and dispenser island scaled to a hydrogen 

capacity of 10,000 std m3 per day (900 kg of H2 per 

day or 1249 kW of H2 on a LHV basis). Scaling 

factors were applied to determine the costs of the 

units as the manufactured quantities increase. The 

relationships between hydrogen capacity and 

subsystem capital cost are also shown in Table 2. 

The projected preliminary estimate for the cost 

of a commercial hydrogen generation system based 

on ACR excluding cost of compression, storage and 

dispensing is presented in Table 3. The system 

capacity is 900 kg/day of H2 (10,000 std m3 per day 

of H2), which can refuel 300 vehicles per day. 

The cost of hydrogen was estimated by 

considering the capital costs, capital recovery factor, 

the operating expenses of the refueling station, the 

cost of utilities (fuel and electricity), and the cost of 

catalysts. The natural gas cost was assumed to be $5/

GJ on a higher heating value (HHV) basis, and the 

electricity cost was assumed to be 7¢/kWhr. The 

efficiency of the system (75% on a LHV basis) was 

used to determine the required amount of natural gas. 

A capacity factor of 90% for plant utilization was 

used. The capital recovery factor was determined as 

13.1%, assuming 10% interest rate over 15 years. 

The cost of H2 generation was estimated to be $16.0/

GJ. This preliminary cost analysis did not consider 

the cost reduction due to mass production, and did 

not consider the cost of hydrogen compression, 

storage and dispensing. These costs are currently 

being analyzed. 

H2 Recovery in PSA 80%

Electricity Consumed / LHV of fuel 1%

Mol H2 Produced / Mol Fuel Fed 2.50

Efficiency= LHV of H2 Produced / 

LHV Fuel Fed

75.2%

Table 1. Efficiency for the Optimal ACR Fuel Processor 

Configuration

Figure 2. Prototype ACR Fuel Processor
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

173

Capital Cost 10 

Stations

100 

Stations

1,000 

Stations

10,000 

Stations

Fuel Processor (not 

including PSA)

.88*106*(Kg/hr*9.5*10-3)

0.7 

@10 units

$424,716 $115,799

H2 Compressor 1341*(Kg/hr)+20896

@1,000 units

$141,506 $70,753

H2 Storage Tanks 7708.8*(Kg/hr)+228

@10 units

$286,835 $200,784

H2 Dispenser Island 850+1327.56*(Kg/hr) 

@10,000 units

$439,043 $149,484 $50,208

Table 2. Capital cost for refueling station subsystems as a function of the manufactured quantities. The delivered 

hydrogen capacity is 67 kg/day.

REFORMER H2 GENERATION CAPACITY 1249 LHV kW

CAPITAL INVESTMENT

Total Plant Cost (TPC) $992,162

Allowance for Funds During Construction (AFDC) 6.3% of TPC $62,506

Total Plant Investment (TPI) $1,054,668

Royalty Allowance 2.6% of TPI $27,421

Inventory Capital 0.8% of TPI $8,437

Total Capital Requirement (TCR) $1,090,527

LEVELIZED CAPITAL CARRYING CHARGES (ANNUAL BASIS)

Capital Recovery Factor 13.1% of TCR $143,376

OPERATING AND MAINTENANCE COSTS (ANNUAL BASIS)

Operating Labor 1.0% of TCR $10,905

Maintenance Labor 0.9% of TCR $9,815

Maintenance Material 1.2% of TCR $13,086

Administrative and Support Labor 0.5% of TCR $5,453

Total Operation and Maintenance $39,259

SYSTEM EFFICINECY 80% (HHV)

SYSTEM EFFICIENCY 75% (LHV)

FUEL & ELECTRICITY COSTS (ANNUAL BASIS)

Natural Gas Feed 55,150.0 MMBtu/year

Natural Gas cost per year $5.3 per MMBtu HHV

Natural Gas cost per year $5.0 per GJ HHV $292,295

Electricity Required/HHV of Fuel 4.4%

Electricity Required 711,155.5 kW-hr

Electricity Unit Cost 7 cents/kW-hr $49,781

Catalysts $83,787

Total Cost of Fuel & Electricity & Catalysts, accounting for capacity factor $383,276

NET REVENUE REQUIRED (ANNUAL BASIS) $565,911

HYDROGEN GENERATED GJ/day (LHV) 107.89

CAPACITY FACTOR 90%

COST OF HYDROGEN $/GJ (LHV) $16.0

COST OF HYDROGEN $/kg $1.93

Table 3. Estimation of cost of hydrogen generation for a one-of-a-kind 900 kg/day of H2 system (10,000 std m3 per day 

of H2; excludes cost of compression, storage and dispensing; does not consider mass production)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

174

Conclusions 

The thermal integration of the system has a 

significant impact on the fuel conversion efficiency 

of the hydrogen production system. An optimal 

process configuration that generates the process 

steam with minimum parasitic losses was selected, 

and the fuel conversion efficiency on an LHV basis 

was estimated to be 75.2%. Compressor calculations 

showed that electricity required was around 1% of 

the LHV of the fuel. 

The preliminary analysis indicates that for a 900 

kg/day of H2 (10,000 std m3 per day of H2) one-of-akind commercial system, the cost of H2 generation is 

$1.93/kg ($16.0/GJ) excluding the costs of hydrogen 

purification, compression, storage and dispensing. 

Mass production is expected to reduce the cost of 

hydrogen significantly. 

 References

1. J.M. Ogden, T. Kreutz, S. Kartha, L. Iwan, 

“Hydrogen Energy Systems Studies”, Final 

Technical Report submitted to NREL, Contract # 

DE-FG04-94AL85803, August 13 1996.

2. C.E. Thomas, J.P. Barbour, B.D. James, 

“Analysis of Utility Hydrogen Systems @ 

Hydrogen Airport Ground Support Equipment”, 

from the Proceedings of the 1999 DOE 

Hydrogen Program Review.

3. C.E. Thomas, J.P. Reardon, F.D. Lomax Jr., J. 

Pinyan, I.F. Kuhn Jr., “Distributed Hydrogen 

Fueling Systems Analysis”, from the Proceedings 

of the 2001 DOE Hydrogen Program Review.

4. J.M. Ogden, “Developing an Infrastructure for 

Hydrogen Vehicles: A Southern California Case 

Study”, International Journal of Hydrogen 

Energy, 24 (1999) 709-730.

5. K. M. Guthrie, "Process Plant Estimating 

Evaluation and Control", 1974.

6. J.M. Ogden, “Data for Conventional Steam 

Reformers (Source Prospects for Building a H2

Energy Infrastructure )”, Annu. Rev. Energy 

Environ., 24 (1999) 227-279

2002 Publications and Presentations:

1. R.V. Kumar, “Autothermal Cyclic Reforming 

Based Hydrogen Refueling System”, IEA 

Annexe XV Fuel Cells for Transportation 

Meeting, 2002, Sacramento, California.

2. R.V. Kumar, G. Kastanas, S. Barge, V. 

Zamansky, R. Seeker, “Autothermal Cyclic 

Reforming Based Hydrogen Refueling System”, 

DOE Annual Hydrogen Program Review, 2002, 

Golden, Colorado.

3. R.V. Kumar, G. Kastanas, P. Kulkarni, C. 

Moorefield, S. Barge, V. Zamansky, R. Seeker, 

“Hydrogen Energy Park Based on Autothermal 

Cyclic Reforming”, Fuel Cell Seminar, 2002, 

Palm Springs, California.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

175

II.E.3 Development of a Natural Gas to Hydrogen Fuel Station

William E. Liss, Mark Richards

Gas Technology Institute

1700 S. Mount Prospect Road

Des Plaines, IL 60018

William E. Liss: (847) 768-0753, fax: (847) 768-0501, e-mail: william.liss@gastechnology.org

Mark Richards: (847) 768-0530, fax: (847) 768-0501, e-mail: mark.richards@gastechnology.org

DOE Technology Development Manager: Peter Devlin

(202) 586-8012, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

ANL Technical Advisor: Thomas Benjamin

(630) 252-1632, fax: (630) 252-4176, e-mail: Benjamin@cmt.anl.gov

Subcontractor: FuelMaker Corporation

Objectives

• Develop cost-competitive technology for high-pressure, hydrogen-based fueling systems. 

• Design a fast-fill natural gas-to-hydrogen fueling system with 40-60 kg/day delivery capacity that 

meets the DOE goal of providing hydrogen at a cost of $2.50/kg or less.

Approach

• Use innovative, compact natural gas steam reforming system and appliance-quality hydrogen 

compressor technologies.

• Undertake system design and analysis to find pathways for meeting cost and performance targets.

• Conduct development and lab testing to confirm subsystem operation.

• Integrate system and incorporate controls.

• Conduct lab and field testing to validate system performance and reliability.

Accomplishments

• Developed comprehensive model for analyzing hydrogen fueling station costs, including capital, 

operating, and maintenance cost elements. Included Monte Carlo techniques to account for 

uncertainty and variability in cost drivers. 

• Prepared and presented paper on hydrogen fueling system economics to World Hydrogen Energy 

Conference.

• Constructed a state-of-the-art high-pressure hydrogen testing environmental chamber. System 

contains a full-size hydrogen three-bank storage cascade that can be run from –45oC to 85oC.

• Developed a first-principle model for understanding the fast-fill behavior of hydrogen and the effects 

of temperature rise on cylinder fill performance.

Future Directions

• Complete design phase, including revised estimates of system capital, operating, and maintenance 

costs.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

176

• Begin work to document the fast-fill behavior of hydrogen over a range of temperatures and starting 

and ending conditions using cylinders of different construction.

• Begin long-term testing to evaluate and confirm the ability of various advanced materials to provide 

greater durability under dry gas conditions.

Introduction

A key barrier to expanded fuel cell vehicle use is 

fueling infrastructure. Along with onboard liquid 

hydrocarbon fuel reformers, a parallel DOE strategy 

is development of cost-competitive technology based 

on high-pressure, hydrogen-based fueling systems 

and on-board hydrogen storage. This project builds 

on experience gained with compressed natural gas 

coupled with targeted research on natural gas-tohydrogen reformation processes and innovative 

strategies to meet hydrogen fuel quality requirements 

(water, carbon dioxide, and carbon monoxide levels). 

An additional core effort is development of a 

hydrogen dispenser with an advanced filling 

algorithm that will permit accurate and complete 

filling of compressed hydrogen vehicles under a 

range of conditions. 

These advanced subsystems – reforming, fuel 

cleanup, compression, storage, and dispensing – will 

be incorporated into an integrated and costcompetitive small natural gas-to-hydrogen fueling 

station that will support hydrogen fueling 

infrastructure development and expansion. 

The specific goal is a fast-fill natural gas-tohydrogen fueling system with 40-60 kg/day delivery 

capacity. DOE goals include providing hydrogen at 

costs of $2.50/kg or less.

Approach

This project is based on leveraging developments 

at GTI in the stationary PEM fuel cell and 

compressed natural gas vehicle market sectors. GTI 

has been developing high-efficiency steam methane 

reformers for stationary fuel cells, including design 

approaches to achieve compact size, reduced cost, 

and simplified control and operation. Modification 

of this reformer—as a hydrogen generator with 

advanced controls—will comprise a core element of 

this system.

In addition, GTI is building upon its experience 

with high-pressure natural gas fueling systems and 

working with key partners to develop hydrogencapable and compatible versions of our fueling 

products—including compressors, dispensers, and 

cascade storage vessels. GTI sees this strategy of 

product line extension as a near-term pathway for 

achieving cost reduction and product availability to 

support early establishment of a hydrogen fueling 

infrastructure. 

In this regard, GTI is working with FuelMaker 

Corporation to develop a high-pressure hydrogen 

version of their vehicle refueling appliance (VRA). 

The FuelMaker VRA is a high-quality appliance-like 

compression unit that is completely oil free—an 

important consideration for contaminant sensitive 

PEM fuel cell stacks. 

The project approach includes three phases: 1) 

Design, 2) Development and Lab Testing, and 3) 

Field Testing. Through these progressive phases, 

GTI anticipates having a proven small natural gas-tohydrogen fueling system that can support the 

development and expansion of a distributed 

hydrogen fueling infrastructure.

Results

The project began in February 2002, with a focus 

on subsystem and system design. 

GTI has developed a comprehensive model for 

hydrogen fueling systems that takes into account all 

capital, operating, and maintenance cost elements. 

The model can also be used to assess the effects of 

factors such as grants and tax incentives. The output, 

among other dimensions, is the levelized cost for 

hydrogen.

GTI currently sees capital and energy costs 

(including the cost of natural gas consumed in the 

steam reformer and electricity for compression) as 

the dominant cost factors (see Figure 1). The cost of 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

177

“processed gas”—that is, the gas reformed into 

hydrogen—is less than 20% of the cost of 

production. 

Monte Carlo techniques were used to account for 

uncertainty and variability in individual cost 

elements—a facet of the nascent nature of this 

technology. Figure 2 shows the model results for 

expected cost. Levelized hydrogen costs are 

estimated at around $3.70/kg. Further work will be 

undertaken during the design phase to review these 

cost factors and revise the model.

GTI is also developing analytical and empirical 

information on the filling behavior of hydrogen 

under fast-fill conditions. Work has shown that 

hydrogen experiences a significant temperature rise 

under these conditions. GTI has developed a firstprinciple model called CHARGE H2 that can be used 

as a predictive tool for this phenomenon. Figure 3 

shows early results in comparing this model with 

empirical data. In this testing, a Dynetek carbonwrapped, aluminum lined hydrogen cylinder rated at 

345 bar (5000 psig) was “fast filled” in a period of 

less than 60 seconds. This cylinder had an internal 

water volume of 34 liters. At 345 bar, this implies a 

total hydrogen storage capacity of about 0.75 kg for 

this cylinder.

Of note is the nearly 55oC in situ gas temperature 

rise during cylinder filling. While some heat transfer 

from the gas phase to the cylinder liner occurs, the 

short duration of the fill process limits the amount of 

heat that can be dissipated. Longer fill times—for 

example, 3 to 5 minutes—may somewhat increase 

the amount of heat transferred. Preliminary 

indications show the initial cylinder internal heat 

transfer coefficient may be as high as 6 to 8 times 

greater than for natural gas.

The temperature rise phenomenon seen in 

hydrogen as well as natural gas reduces gas density 

and energy content and ultimately can result in 

reduced vehicle driving range. GTI will conduct 

comprehensive testing under a variety of conditions 

and using cylinders of differing construction to 

document this behavior and compare the resulting 

data with its CHARGE H2 model. To counteract this 

effect, GTI will develop a hydrogen dispenser control 

algorithm to more accurately fill cylinders and 

Figure 1. Hydrogen Station Costs

Figure 2. Hydrogen Fuel Station Cost Distribution

Figure 3. Hydrogen Fast Fill Data and Model
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

178

provide underfill compensation that largely offsets 

this phenomenon. 

To conduct this unique hydrogen testing, GTI has 

constructed a state-of-the-art high-pressure hydrogen 

environmental chamber. This system contains a fullsize hydrogen three-bank storage cascade that can be 

run from –45oC to 85oC (see Figure 4). The chamber 

is fully instrumented and connected to a high-speed 

data acquisition system. Fast-fill hydrogen tests will 

be run over a wide range of temperature and pressure 

conditions using cylinders constructed with steel, 

aluminum, and plastic liners.

Conclusions

Work was begun on this program in February 

2002. Preliminary indications are that a natural gas 

to hydrogen fueling system with reduced cost 

capabilities is possible. Achieving the stated cost 

targets of $2.50/kg will be a challenge.

The strategy of leveraging developments in PEM 

reformers for stationary applications and compressed 

natural gas vehicle technology appears to be a 

promising pathway for leveraging technology, 

experience, and market channels.

References

1. Richards, M. and Liss, W., “Reformer-based 

Hydrogen Fueling Station Economics.” World 

Hydrogen Energy Conference, June 11, 2002.

Figure 4. GTI Hydrogen Testing Environmental 

Chamber
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

179

II.E.4 Distributed Hydrogen Fueling Systems Analysis: Cost and Performance 

Comparison of Stationary Hydrogen Fueling Appliances

Brian D. James (Primary Contact), Duane B. Myers, Gregory D. Ariff, John S. Lettow, C.E. (Sandy) 

Thomas, & Reed C. Kuhn

Directed Technologies

3601 Wilson Blvd., Suite 650

Arlington, Virginia 22201

(703) 243-3383, fax: (703) 243-2724, e-mail: Brian_James@DirectedTechnologies.com

DOE Technology Development Manager: Sigmund Gronich

(202) 586-1623, fax: (202) 586-5860, e-mail: Sigmund.Gronich@ee.doe.gov 

Objectives 

• Quantify the costs of hydrogen fueling appliances (HFAs) using two natural gas reforming 

technologies (autothermal reforming versus steam methane reforming) and two gas cleanup 

technologies (pressure swing adsorption versus metal membrane gas separation) to provide on-site 

hydrogen for a community of 183 hydrogen fuel cell vehicles (FCVs) (equivalent to 20 refuelings per 

day or a capacity of 115 kilograms (kg) of hydrogen (H2) per day (with a 69% capacity factor).

• Estimate the cost of hydrogen using each combination of technologies.

• Estimate the cost reductions from scaling the least expensive technology to a larger unit providing 160 

fuel cell vehicle refuelings per day. 

Approach

• Design the chemical process, physical implementation, and manufacture and assembly methods for 

each of the four HFA technology combinations, produced in quantities of 250 units/year.

• Use Design for Manufacture and Assembly (DFMA) cost analysis techniques to estimate the capital 

costs of each HFA design.

• Apply discounted cash flow analysis to determine a cost per kilogram of hydrogen.

• Use common chemical engineering scale-up factors to scale-up the design producing lowest-cost 

hydrogen by 8x.

Accomplishments 

• Designed complete 115 kg/day capacity HFA systems for low-cost hydrogen from four combinations 

of reforming-cleanup technologies: steam methane reforming (SMR) with pressure swing adsorption 

(PSA), autothermal reforming (ATR) with PSA, SMR with metal membrane gas separation, and ATR 

with metal membrane gas separation.

• Estimated costs of materials, manufacture, and assembly using an adapted DFMA methodology to 

arrive at capital costs for each HFA design.

• Using discounted cash flow analysis, identified the SMR-PSA system as the technology to provide 

lowest cost hydrogen ($3.38/kg) for small-scale, small production volume HFAs.

• Estimated up to 45% reduction in cost of hydrogen ( $1.87/kg) from scaling HFA size up by 8x.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

180

Future Directions 

• Evaluate the cost of renewable hydrogen for transportation applications in the 2030-2050 time frame 

based on a variety of renewable resources (wind, biomass, geothermal, solar, etc.), transportation, and 

storage options.

• Determine the most practical and economically feasible plan for the supply of 10 Quads/year of 

renewable hydrogen for transportation applications in 2030-2050.

Introduction

Over several studies, Directed Technologies, Inc. 

has analyzed the costs of representative HFAs to 

supply the early-introduction hydrogen powered 

FCVs and the cost of hydrogen produced by these 

HFAs. In previous studies we evaluated the impact 

of fuel choice on FCV, the cost of other sizes and 

quantities of HFA's, and the infrastructure 

maintenance costs of various fuels. In this study we 

analyzed the costs for an intermediate production rate 

(250/year) of HFAs sized to support communities of 

183 vehicles each (about one-eighth the size of the 

typical new gasoline station). This small HFA is 

chosen to allow economical hydrogen production in 

the early years when there are low numbers of FC's 

present in any geographical area. While the focus of 

this report is on the economics of hydrogen 

production at this small unit size, it is noted that 

significant hydrogen cost reductions can be achieved 

by scaling the HFA unit to a larger size.

For the baseline HFA, we compared the costs 

and efficiencies of two hydrogen-generation 

technologies (steam methane reforming and 

autothermal reforming) and two hydrogen 

purification technologies (pressure swing adsorption 

and metal membrane gas separation). Each HFA 

includes components for natural gas desulfurization, 

reformation, hydrogen purification, compression, 

storage, and dispensing. The processing options 

chosen for this comparison emphasize the relative 

strengths of each process, with the result that there 

are many other potential variations that involve 

tradeoffs between capital cost and efficiency. 

Approach

Each HFA system required a careful chemical 

and mechanical engineering analysis to capture the 

appropriate performance parameters and cost factors. 

Once moderately detailed mechanical designs and 

material and energy balances were created for all 

system components, a complete system Bill of 

Materials was generated. This Bill of Materials 

allowed a line-by-line, element-by-element cost 

assessment to be conducted using a Design of 

Manufacturing and Assembly (DFMA) costing 

approach. This methodology is used extensively by 

industry for product cost estimation and to compare 

the relative cost of competing manufacturing and 

assembly approaches. The DFMA methodology is 

both a rigorous cost estimation technique and a 

method of product redesign to achieve lowest cost.

Once the capital costs for each design were 

determined, a discounted cash flow analysis was 

used to compare reforming options with differing 

initial investments and operating expenses. The cost 

of hydrogen was determined by calculating the cost 

of hydrogen that results in a net-present value of $0 

for the HFA over ten years of operation. Solving for 

the cost of hydrogen at $0 net-present value yields 

the "wholesale price" at which the reformer operator 

realizes an after-tax return on investment equal to the 

cost of capital. The cost of hydrogen calculated in 

this analysis is somewhere between the wholesale 

and retail level. We have included the capital cost 

for storage and dispensing, which would not 

typically be reflected in the wholesale costs of other 

fuels, but have excluded retail markup and profit for 

the HFA operator.

Results

Each HFA system was designed such that the 

reforming system ([RS], not including hydrogen 

compressor, storage, and dispenser) could be 

contained on a skid-mounted pallet (see Figure 1). 

This pallet has an approximately 8 ft by 13 ft 

footprint, stands roughly 10 ft tall, and may be 

enclosed by a canopy and chain-linked fence. The 

compressor, hydrogen storage tanks, and dispenser 

would be housed separately.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

181

Table 1. Cost of Hydrogen Produced from the 115 kg/day 

HFA Options

While the cost of the RS varies considerably 

depending on the reformation and cleanup 

technologies employed, the cost of the hydrogen 

compressor, storage, and dispenser, as well as unit 

installation, are independent of RS design. A cost 

breakdown for each 115 kg/day HFA design and the 

resulting cost of hydrogen are provided in Figure 2 

and Table 1, respectively. Based on this study, we 

find that the most cost-effective option as determined 

by the wholesale cost of hydrogen is SMR coupled 

with PSA hydrogen purification. The initial capital 

cost to install the preferred SMR-PSA to support 183 

Figure 1. Proposed Layout of 10 atmospheres Steam 

Methane Reformer System

Figure 2. Contribution of Subsystems to Capital Cost 

for 115 kg/day HFAs. (The "Miscellaneous" 

category includes on-site installation, freight, 

taxes & insurance, and initial spares. The 

"Reformer System" category includes the 

hydrogen production and gas cleanup 

subsystems.)

Costs in 

$/kg H2

SMR/ 

PSA

ATR/

PSA

SMR/ 

Membrane

ATR/ 

Membrane

Hydrogen 

Cost

$3.38 $3.59 $3.74 $4.28

Capital 

Recovery

1.66 1.50 1.78 1.62

Natual Gas 0.95 1.17 1.01 1.44

Electricity 0.23 0.41 0.37 0.68

O&M 0.33 0.31 0.33 0.33

Taxes & 

Insurance

0.23 0.20 0.24 0.22

Gasoline 

Equivalent 

($/gal)

$1.55 $1.65 $1.72 $1.96

HFA is assumed to run an average of 69% of capacity 

with 98% availability.

Capital Recovery assumes a 10% after-tax return on 

investment over its 10-year life.

A 38% marginal tax rate (34% federal, 4% state and 

local) is included in the return on investment calculation.

Natural gas price is based on the 19-year national 

average commercial rate of $5.34 per thousand scf.

Electricity price is based on the 19-yar national average 

commercial rate of 7.5 cent per kW hr.

The cost for water usage is negligible.

O&M inclludes yearly hydrogen desulfurization bed 

replacement and reformer and shift catalyst replacement 

after five years. It also includes general maintenance for 

compressors, valves, etc. 

Tax and Insurance costs refer to annual property taxes at 

1.5% of capital investment and annual insurance 

premiums at 1% of capital investment. Highway/road 

sales taxes are not included.

Gasoline equivalent price is based on an efficiency gain 

of 2.2 hydrogenc FCVs over current gasoline internal 

combustion engine vehicles.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

182

Table 2. Cost of Hydrogen from 920 kg/day (8x) SMR/

PSA HFA with Optimistic Assumptions

vehicles is $253,014 per unit. The wholesale cost of 

hydrogen for this option, including storage and 

dispensing but excluding sales taxes and retail 

markup, is $3.38/kg, or $1.55 per gallon of gasoline 

equivalent. Autothermal reforming (ATR) of 

natural gas is a lower initial-cost option ($228,957), 

but the resulting cost of hydrogen is higher ($3.59/

kg) because the ATR uses more natural gas and 

electricity than the SMR to produce the same 

quantity of hydrogen. 

Based on the results of the baseline HFA 

analysis, we estimated the potential hydrogen cost 

reduction that would result from increasing the size 

of the HFA from 115 kg/day to 920 kg/day. An 

HFA of this size would support roughly 1464 

vehicles, which is comparable to large modern 

gasoline stations. A breakdown of the estimated cost 

of hydrogen for this HFA is given in Table 2. Using 

scale-up factors common to chemical processes, the 

capital cost of this 8x HFA was estimated to be $1.16 

million, resulting in a hydrogen cost of $1.87-$2.48/

kg (dependent on assumptions about utility 

discounts, natural gas feedstock cost, and equipment 

life). Thus, the "small" HFA derived hydrogen cost 

of $3.38/kg is appropriate when discussing the early 

introduction of fuel cell vehicles, and the 

significantly lower hydrogen cost of $1.87-$2.48/kg, 

produced by a "large" HFA, is appropriate for the 

future years when the FCV population and 

population density are much higher.

Conclusions

For HFA's of the baseline capacity (115 kg/day) 

and production volume (250 units/year), there are 

two general conclusions that can be taken from this 

analysis:

• Steam methane reforming is more efficient 

than autothermal reforming, and the 

efficiency benefit results in a lower cost of 

hydrogen over a ten-year system lifetime 

even with a slightly higher initial capital cost 

($253,014 for SMR vs. $228,957 forATR). 

The difference between the SMR and ATR 

costs of hydrogen shrinks as the cost of the 

natural gas feedstock decreases, but only 

with zero-cost natural gas (i.e. free) does the 

ATR match the SMR. For a given cost of 

hydrogen the SMR and ATR economic 

returns are equal by the fourth year of 

operation, with the SMR advantage 

increasing every year thereafter.

• PSA is a more economical and reliable 

option than any other hydrogen cleanup 

system at this time. Significant reductions in 

the cost and reliability of membrane 

purification systems are required to make 

them competitive with PSA.

The wholesale cost of hydrogen from the SMRPSA HFA is $3.38/kg, which is the equivalent of 

$1.55/gallon of gasoline for an internal combustion 

Costs in $/kg H2 16,000 scfh SMR/PSA HFA

Hydrogen Cost $1.87

Capital Recovery $0.77

Natual Gas $0.59

Electricity $0.15

O&M $0.24

Taxes & Insurance $0.13

Gasoline Equivalent 

($/gal)

$0.85

Estimates are based on a scaled-up version of a 2,000 

scfh HFA. Scale-up may not retain accuracy of original 

analysis.

HFA is assumed to run an average of 69% of capacity 

with 98% availability. 

Capital Recovery assumes a 10% after-tax return on 

investment over a 15-year life.

A 38% marginal tax rate (34% federal, 4% state and 

local) is included in the return on investment 

calculation.

Natural gas price is based on the 19-year national 

average industrial rate of $3.30 per thousand scf.

Electricity price is based on the 10-yar national average 

industrial rate of 4.65 cent per kW hr.

The cost for water usage is negligible.

O&M includes yearly hydrogen desulfurization bed 

replacement and reformer and shift catalyst replacement 

after five years. It also includes general maintenance 

for compressors, valves, etc. 

Tax and Insurance costs refer to annual property taxes at 

1.5% of capital investment and annual insurance 

premiums at 1% of capital investment. Highway/road 

sales taxes are not included.

Gasoline equivalent price is based on an efficiency gain 

of 2.2 hydrogen FCVs over current gasoline internal 

combustion engine vehicles.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

183

engine vehicle after adjustment for the higher 

efficiency of the fuel cell engine. (Note that the 

hydrogen price provided does not include the 

taxation currently applied to gasoline.) This 

equivalent gasoline cost is at the upper end of current 

retail gasoline costs. When there are sufficient FCVs 

to justify a larger number of higher-volume stations, 

the cost of hydrogen will decrease by taking 

advantage of economies of scale in both HFA 

manufacture and the reforming process.

FY 2002 Publications/Presentations

1. "Cost and Performance Comparison of Stationary 

Hydrogen Fueling Appliances", submitted to 

Hydrogen Program Office, Office of Power 

Technologies, U.S. Dept. of Energy, under Grant 

No. DE-FG01-99EE35099, April 2002.

2. "Distributed Hydrogen Fueling Systems AnalysisCost and Performance Comparison of Stationary 

Hydrogen Fueling Appliances", presentation 

made by Brian D. James at 2002 DOE Annual 

Hydrogen Program Review on May 6, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

184

II.E.5 Technical Analysis: Integrating a Hydrogen Energy Station into a Federal 

Building 

Stefan Unnasch (Primary Contact), Scott Fable

TIAX, LLC

1600 De Anza Blvd., Suite 100

Cupertino, CA 95014

(408) 517-1563, fax: (408) 517-1553, e-mail: unnasch.stefan@tiax.biz

DOE Technology Development Manager: Matthew Kauffman

(202) 586-5824, fax: (202) 586-5860, e-mail: Matthew.Kauffman@ee.doe.gov

Main Subcontractor: Bevilacqua-Knight, Inc., Sacramento, CA

Objectives 

• Evaluate combined fuel cell power/hydrogen production systems (Energy Stations):

- Analyze energy station systems with 50 kilowatt (kW) proton exchange membrane fuel cells 

(PEMFCs) that are suitable for installation in Federal buildings

- Analyze options for system components, including direct hydrogen and reformate fuel cells and 

various storage, power production, and hydrogen usage configurations

- Determine cost and energy efficiency for different system configurations

• Assess integration with buildings and potential for cogeneration:

- Analyze potential for heat recovery from fuel cell/hydrogen production systems

- Identify potential for cogeneration in Federal building applications

• Identify potential fleets to use hydrogen for vehicle operation

• Establish partnerships for hydrogen fueling and power sales

• Identify barriers to hydrogen use

• Make recommendations for future development

• Identify potential opportunities to develop fuel cell energy stations

Approach

• Analyze system cost and performance

• Assess public/private fleet size and locations

• Evaluate building integration

Accomplishments 

• Developed list of possible components that will comprise hydrogen generation and dispensing station

• Developed list of relevant system configurations from possible components, with detailed description 

and schematics of proposed system configurations

• Selected a baseline system configuration, and initiated a detailed system cost and performance analysis

• Prepared a comprehensive list of potential operating configurations

• Surveyed potential public/private fleets and federal buildings for siting a hydrogen energy station
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

185

• Initiated evaluation of building integration and prepared comprehensive list of potential building 

interfaces

Future Directions 

• Continue the analysis and identification of energy station applications in Federal buildings:

- Explore specific public and private partnerships to support the establishment of a hydrogen energy 

station in a Federal facility 

- Analyze the cost, emissions, and energy utilization benefits of integrated power and vehicle 

refueling

- Identify the key technology, cost, and public perception barriers to hydrogen use

- Make recommendations for future development

Introduction

The purpose of this project is to analyze the 

development of a hydrogen infrastructure for 

transportation applications through the installation of 

a 50-75 kW stationary fuel cell-based energy station 

at federal building sites. The various scenarios, 

costs, designs and impacts of such a station are 

quantified. It uses a natural gas reformer to provide 

hydrogen fuel for both the fuel cell stack and a 

limited number of fuel cell powered vehicles, with 

the possibility of using cogeneration to support the 

building heating load.

Approach

The project has three major tasks:

Task 1. Analyze System Cost and Performance 

The first task conducted in this project is to 

evaluate all of the competing technologies that could 

be utilized for each of the components in the entire 

fuel cell and vehicle fueling system based on the 

criteria of cost, performance, and technical 

feasibility. The goal of this initial, broad-based 

assessment is to select the most promising (four to 

five) system designs and technologies on the basis of 

the above criteria.

Task 2. Assess Public/Private Fleet Size/Locations

 Data on the potential for energy stations with 

fleets is being collected from a representative and 

diverse composition of stakeholders. We are 

coordinating with automakers to obtain information 

about fuel cell vehicle fleet size, location and type 

projections. Another key source of information for 

projecting hydrogen vehicle fleet size and location 

are the Energy Policy Act (EPAct) fleet 

administrators, who will help us determine their 

current and projected alternative fuel vehicle (AFV) 

fleet practices. Finally, other policies, such as the 

California Zero-Emission Vehicle Mandate and the 

California Air Resources Board transit fleet 

regulation, that will either directly or indirectly 

encourage hydrogen fleets, are being analyzed for 

their potential impacts.

Task 3. Evaluate Building Integration 

Using the results of Task 1 and a limited number 

of system designs and technologies selected for 

further analysis, the likely amounts and grades of 

waste heat that will be produced from the reformer 

and fuel cell stack(s) will be determined. With this 

information, cogenerative heat uses and technologies 

are being researched and evaluated with respect to 

beneficial utilization in a commercial/government 

building setting, as well as the cost and technical 

feasibility of those applications.

Results

Analysis of System Performance (Task 1)

A hydrogen-producing energy station would 

reform an input fuel to produce hydrogen for fuel cell 

operation and for dispensing to hydrogen-powered 

vehicles. The electrical power generated by the fuel 

cell and/or the residual heat from the system 

processes may be used to support energy station and 

nearby building power and heating loads. The 

fraction of reformer output used for hydrogen 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

186

vehicles would be purified and stored for dispensing 

upon demand. Figure 1 shows the various major 

components that make up a hydrogen energy station.

In order to determine which system 

configurations and operational patterns are most 

viable for an energy station, TIAX developed several 

criteria for selecting a representative set of 

technology configurations. TIAX applied these 

criteria to all possible technology configurations to 

determine an optimized set, as shown in Figure 2. 

The remaining cases best illustrate the range of 

viable energy station configurations and operational 

profiles. These representative configurations, along 

with the baseline case, will be used to develop a 

representative cost and energy output estimate for the 

energy station (see Figure 3).

The possible operational scenarios for each of 

the station configurations include peak power 

shaving, constant baseload operation, scheduled 

operation, on demand operation, and/or load 

following. These options are not necessarily 

exclusive - in some cases they may be used in 

combination. Figure 4 shows an example operational 

mode where the reformer load remains constant, 

Figure 2. Application of Filters to Determine Optimal 

Configurations for Analysis

Figure 1. Several Technology Options Exist for System 

Configuration

Figure 3. Representative Energy Station System 

Component Configurations

Figure 4. Example Fuel Cell and Reformer System 

Operation Scenarios
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

187

while the fuel cell load follows the combined station 

and building loads. 

Assessment of Public and Private Fleet Size and 

Locations (Task 2)

In its effort to identify candidate federal facilities 

for the placement of a hydrogen fueling station, 

TIAX worked with its subcontractor, BevilacquaKnight, Inc. (BKI), to create a list of characteristics 

that the ideal location should possess. These 

characteristics, shown in Figure 5, formed the criteria 

by which the facilities would be judged.

For each federal agency contacted, BKI 

attempted to speak with both the fleet manager and 

the facility's energy manager. Fleet managers were 

asked about their existing vehicle fleet, experience 

with AFVs and plans for future acquisitions. TIAX 

was particularly interested in facilities that currently 

operate compressed natural gas (CNG) vehicles since 

CNG is a gaseous fuel with many properties similar 

to those of hydrogen. In addition, each agency was 

asked about how their vehicles were acquired. 

Lastly, TIAX asked how the facility planned to meet 

future EPAct requirements.

Evaluation of Building Integration (Task 3)

In order to take advantage of potential 

cogenerative heat uses and technologies, the likely 

amounts and grades of waste heat that will be 

produced from the reformer and fuel cell stack(s) will 

need to be determined. Using the representative 

technology configurations above, the opportunities 

for cogeneration are currently being examined. We 

are evaluating the potential cogeneration heat 

requirements in terms of heat load and seasonal 

variations as well as the hardware requirements 

required to integrate an energy station into a 

building.

Conclusions

• TIAX has identified a set of representative 

technologies and representative operational 

scenarios that are being analyzed to estimate 

the size, power output, and cost of a 

hydrogen energy station. 

• Several options have been identified for 

system configuration and operation, with 

Figure 5. The Process for Choosing 

Facilities that Would Most 

Likely Benefit from an Energy 

Station
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

188

each focusing on a different benefit: 

conventional system components, lower 

cost, small-scale operation, and design 

simplicity. 

• Several Federal facilities have been 

identified as potential host sites, meeting 

most of the energy station host criteria 

developed as a part of this project. Energy 

and cost estimates will be presented in the 

final report of this project.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

189

II.F Crosscutting Hydrogen Production and Delivery Analysis

II.F.1 Hydrogen Technical Analysis

Stephen Lasher (Primary Contact), Masha Stratonova, and Johannes Thijssen

TIAX LLC

Acorn Park

Cambridge MA, 02140

(617) 498-6108, fax: (617) 498-7054, e-mail: lasher.stephen@tiax.biz

DOE Technology Development Manager: Matthew Kauffman

(202) 586-5824, fax: (202) 586-5860, e-mail: Matthew.Kauffman@ee.doe.gov

Objectives

• Identify promising hydrogen (H2) purification technologies that DOE does not currently fund

• Characterize technical maturity and risks of selected technologies

• Perform detailed performance and cost analysis for the selected purification technologies integrated 

into a hydrogen fueling station concept and compare to baseline technologies

• Identify key barriers and possible development paths for promising alternative purification 

technologies

Approach

• Screen purification technologies and select three for detailed analysis

• Evaluate current and projected performance and cost of the selected purification technologies

• Develop system models for each purification technology with various hydrogen fueling station design 

concepts

• Calculate overall costs and primary energy use based on system model results and capital cost 

estimates from developers and internal analyses

Accomplishments

• Selected amorphous membranes without noble metals (Zirconium-Nickel [Zr-Ni] alloy), dry 

fluorinated metal hydrides and the application of this fluorinated metal hydride in a slurry as the three 

most promising non-DOE funded purification technologies

• Projected future performance and cost parameters for the selected purification technologies based on 

developers' input and internal analyses

• Calculated overall system efficiencies and hydrogen costs for each purification technology integrated 

with various reformer types and storage options

• Identified fluorinated metal hydrides as the most attractive option to pursue further, especially in a 

slurry-based system. Identified need to examine system-level interactions on production / purification 

technology in hydrogen energy mini-grid

Future Directions 

• Evaluate combined fueling and power concepts utilizing central production and storage for both directhydrogen vehicle fueling and direct-hydrogen PEMFC power systems
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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• Evaluate the use of fluorinated metal hydride slurries in a mini-hydrogen grid concept for enhancing 

co-gen opportunities from combined fueling and power systems

• Determine if combined fueling and power or mini-hydrogen grid concepts provide cost or efficiency 

savings or other benefits that could encourage hydrogen and PEMFC use

Introduction

There is increasing interest in the development of 

small-scale (< 1 million standard cubic feet per day) 

hydrogen fueling stations to support direct hydrogen 

fuel cell vehicles when and if these vehicles capture a 

significant fraction of the U.S. passenger vehicle 

fleet. Hydrogen for fuel cell vehicle refueling could 

be generated from conventional or emerging fuels at 

the fueling station with an on-site system including a 

reformer, hydrogen purification, storage, and 

dispensing, along with the necessary safety systems 

and controls. For this purpose, both higher pressure 

(around 10 atmospheres [atm]) and lower pressure 

reformers are being designed. Higher pressure 

systems would integrate well with the pressure 

requirements of conventional purification 

technologies (pressure swing adsorption [PSAs] and 

membranes). Lower pressure reformers (1-3 atm) 

would take advantage of designs originally intended 

for integrated reformer/fuel cell systems for 

automotive and stationary power applications and 

could result in lower cost due to synergies with those 

systems, though they would require the use of 

expensive and inefficient reformate compressors for 

integration with conventional purification 

technologies. It is thus clear that purification 

technology drives component and system design 

decisions. 

Approach

Three small-scale purification technologies not 

currently being funded by DOE for on-site hydrogen 

production at vehicle refueling stations were 

evaluated. They were analyzed in the context of a 

larger (690 kilograms [kg] H2/day) and a smaller (69 

kg H2/day) refueling station and in the context of 

high and low pressure on-board storage technologies. 

The analysis included assessments of technical 

maturity and risks, performance, cost, and a 

comparison to baseline technologies, as well as the 

identification of key barriers and an evaluation of 

possible development paths. We developed detailed 

flowsheet models for each of the options considered. 

These were used to estimate the conditions, 

flowrates, power requirements, and heat duties 

needed for sizing the necessary equipment. Based on 

the equipment sizes so calculated, we developed cost 

estimates from a combination of quotes and existing 

bottom-up cost models. The three purification 

technologies selected for analysis are:

Fluorinated Metal Hydrides (Dry)

If properly protected from certain impurities, 

metal hydrides could purify reformate streams at 

much lower pressure than conventional technology. 

Forming a porous fluoride film on the surface of 

metal hydride particles is a promising way to protect 

the metal hydride from poisoning by non-hydrogen 

species that are less likely to penetrate through the 

fluoride film than hydrogen molecules (particularly 

carbon monoxide and water). Combining this low 

pressure purification with hydrogen storage in the 

same metal hydride has the potential to simplify 

system integration and improve efficiency and cost 

for fueling metal hydride vehicles.

Metal Hydride Slurries

 Utilizing fluorinated metal hydrides in slurries 

could improve system integration even further. The 

metal hydride slurry is pumpable, allowing for its use 

as a medium for hydrogen purification, storage and 

transportation simultaneously. Slurry systems also 

have faster absorption/desorption times than dry 

metal hydrides, allowing them to be used for 

purification only with compressed H2 storage and 

dispensing. The fast absorption/desorption time also 

reduces the amount of metal hydride material 

required for purification, thus minimizing capital 

cost of the purification process.

Non-Palladium Metal Membranes

 Non-palladium metal membranes are a potential 

low-cost alternative to palladium-based membranes 

currently in use. Japanese researchers have 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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promising results from amorphous alloy membranes 

without noble metals (Zr-Ni). Alloys without noble 

metals may be two orders of magnitude cheaper than 

palladium-based materials on a weight basis (Hara 

2000).

Results

Hydrogen Recovery (Figure 1)

Hydrogen recovery was estimated for each 

purification technology and inlet condition. 

Demonstrated performance and our assumptions for 

inlet and outlet pressures, operating temperature, and 

hydrogen recovery are shown in Figure 1. Hydrogen 

recovery for the PSA case was based on vendor 

quotes for typical autothermal reformer (ATR) and 

steam reformer (SR) impurity concentrations. Zrbased membrane recovery was estimated based on 

current and estimated membrane performance 

characteristics, hydrogen pressure gradient across the 

membrane, and assumed permeability decrease due 

to carbon monoxide presence in the feed stream. 

Fluorinated metal hydride recovery was estimated 

based on the operating conditions and metal hydride 

cycling hydrogen capacity.

Efficiency (Figures 2 and 3)

• Steam reformer based systems result in 

lower primary energy use than autothermal 

reformer systems largely because steam 

reformers can utilize the non-recovered 

hydrogen from the purification step.

• For high-pressure dispensing options 

(compressed H2 vehicles), PSA purification 

with a high-pressure steam reformer results 

in the lowest primary energy use, provided 

highly efficient waste heat integration is 

possible.

• PSA and membrane purification for use with 

low pressure reformers tend to have higher 

power-based primary energy use due to the 

need for compression prior to purification.

• Fluorinated metal hydride (Fl MH) 

purification options achieve very high 

hydrogen recovery rates compared with a 

PSA; but dehydriding energy requires an 

auxiliary burner for use with steam 

reformers, raising energy consumption.

• Autothermal reformers have enough waste 

heat to significantly reduce or eliminate an 

auxiliary burner for use with Fl MH systems, 

provided a significant fraction of the waste 

Figure 1. Demonstrated and Assumed Purification 

Performance

Figure 2. Primary Energy Use for Compressed H2

Vehicle Fueling Stations

Figure 3. Primary Energy Use for MH Vehicle Fueling 

Stations
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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heat can be stored and used as needed during 

fueling.

With Fl MH purification, hydrogen recovery 

does not strongly depend on reformate quality, and 

hence is the preferred option with ATRs and 

purification of syngas streams from renewable 

sources (e.g. biomass gasification or pyrolysis).

Hydrogen Cost (Figures 4 and 5)

Notes on figures: purification category includes 

reformate compressor costs for low-pressure 

reformers with PSA and membrane purification. Cost 

categories include energy, maintenance, and capital 

recovery costs. "Other" costs include labor, rent, 

utilities, profit, and capital recovery for site 

preparation and central controls and safety.

• Under our cost assumptions, low-pressure 

(high production volume) reformers are 

cheaper than high-pressure (low production 

volume) reformers, but result in about the 

same overall cost for hydrogen due to higher 

purification costs.

• Although membrane cost may ultimately be 

low for non-palladium membrane 

purification, compression costs off-set the 

benefits this provides compared with PSA 

purification, except for use with lowpressure ATRs.

• Unlike PSAs and membranes, Fl MH 

systems are projected to have very similar 

purification cost regardless of reformate 

composition, making them particularly 

suitable for ATR and renewable-based 

hydrogen production.

• Fl MH purification scales down in size better 

than the other purification options, making it 

a more attractive technology for small 

fueling stations, though low-capacity 

stations still cost at least 50% more than 

large-capacity stations (not shown in 

figures).

• Liquid hydrogen delivery is projected to 

have the lowest cost of the central hydrogen 

production options, and the lowest cost of all 

compressed H2 options provided 

transportation distances are short (delivery 

distance is assumed to be 50 miles). 

However, central options could not be used 

ubiquitously, because costs will increase 

significantly with transportation distance.

Conclusions

Our analysis indicates that the use of fluorinated 

metal hydrides in slurry form could reduce overall 

hydrogen cost, especially if the slurry is used for 

purification only. In addition, if high-pressure 

storage is of concern due to safety or regulatory 

issues, Fl MH purification and storage could provide 

significant benefits. Slurries could also provide 

benefits in terms of hydrogen transmission to 

decentralized fuel cell power systems in a minihydrogen grid. It is not likely that significant energy 

savings can be expected over a well-integrated PSA 

combination, though improvements over the state-ofFigure 4. Hydrogen Cost for Compressed H2 Vehicle 

Fueling - 690 kg H2/day Capacity

Figure 5. Hydrogen Cost for MH Vehicle Fueling - 690 

kg H2/day Capacity
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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the-art systems are possible. Some technology 

development will be required to optimize the slurry 

system, and significant development will be required 

to develop a stable and effective fluorinated metal 

hydride that can be produced cost-effectively.

References

1. Hara, S., K. Sakaki, N. Itoh, H.-M. Kimura, K. 

Asami, and A. Inoue. 2000. "An Amourphos 

Alloy Membrane without Noble Metals for 

Gaseous Hydrogen Separation." Journal of 

Membrane Science, 164:289-294

2. Wang, X.-L., K. Iwata, and S. Suda. 1995. 

"Hydrogen Purification using Fluorinated 

LaNi4.7Al0.3 Alloy." Journal of Alloys and 

Compounds, 231:860-864

FY 2002 Publications/Presentations

1. Weber, B., "Future of Hydrogen Fuels, Fuel Cells 

and Alternative Energy Technology", presented at 

7th ASCOPE (ASEAN Council on Petroleum), 

Kuala Lumpur, Malaysia, November 5-8, 2001
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II.F.2 Hydrogen Infrastructure Studies

Susan M. Schoenung (Primary Contact)

Longitude 122 West, Inc.

1010 Doyle Street, Suite 10

Menlo Park, CA 94025

(650) 329-0845, fax: (650) 329-9951, e-mail: schoenung@aol.com

DOE Technology Development Manager: Neil Rossmeissl

(202)586-8668, fax: (202) 586-5860, e-mail: Neil.Rossmeissl@ee.doe.gov

Objectives 

• Address energy efficiency, cost competitiveness and environmental impact of integrated hydrogen 

systems through participation in three integrated system teams as called for by the International 

Energy Agency's (IEA) Hydrogen Agreement Annex 13: "Design and Optimization of Integrated 

Systems."

Approach

• Provide independent modeling and assessment of integrated hydrogen systems, with an emphasis on 

spreadsheet models

• Maintain consistency among the three teams with respect to assumptions of cost and performance

- Lead the Transportation Applications analysis, focusing on hydrogen refueling infrastructure - 

particularly the production sources, distribution, and storage of hydrogen. The effort addresses 

several general areas:

- Cost of hydrogen fuel dispensed to the vehicle

- Sensitivity of that cost to numerous assumptions, including future hydrogen production and delivery 

options

- Emissions (tailpipe and station), compared with alternative vehicle types

- The impact of codes and standards on hydrogen storage footprints

• Attend Expert Team meetings and Task Definition Workshops

• Interact with the U.S. Operating Agent (Cathy Gregóire Padró), as needed

Accomplishments 

• The transportation infrastructure analysis has been completed, including the following sensitivity 

studies:

- Station utilization

- Station size

- Projected component costs for on-site hydrogen generation

- Costs of natural gas and electricity (including renewables)

- Upstream infrastructure costs (new central reformers and pipelines)

- Transport distances

• The fuel economy and emissions analysis evaluated the following for alternative vehicle and fuel 

types:

- Fuel economy
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

195

- Cost of a 300-mile fill-up

- Tailpipe emissions, gallon/mile

- Major local / station emissions (kilogram [kg]/year)

- Minor local / station air pollutants (kg/year) 

• The final report on this analysis has been submitted and is part of an overall IEA package including all 

three project reports and a cost model

• A topical analysis and report of relevant (and changing) fire codes and the impact on station footprints 

were also completed

Future Directions 

• Annex 13 was concluded at the end of June 2002. New tasks for a new Annex were proposed through 

two Task Development Workshops and are currently being developed for approval by the IEA 

Executive Committee. A new Annex or study task could address the following issues:

- Validation of models using data from case studies

- Use of models to assist in the design and optimization of demonstrations / projects

- An analysis of legacy projects that lead from demonstration to commercial practice

- An assessment of the impact of portable hydrogen system development (i.e., small devices) on larger 

system needs

- Additional analysis of the impact of codes and standards on system design and cost

- Comparison of different countries' demands, supplies, experiences and policies

Introduction

The U.S. Department of Energy participates in 

various activities of the International Energy Agency 

(IEA) through an Implementing Agreement and its 

Annexes. Hydrogen Agreement Annex 13, "Design 

and Optimization of Integrated Systems," calls for 

the U.S. to participate in three integrated system 

teams. The three teams and their projects are:

• Remote Power Systems

• Home/Residential Systems

• Transportation Applications

• Longitude 122 West serves as U.S. Team 

leader for Annex 13 activities 

The goal of the analysis has been to provide 

independent modeling and assessment, especially of 

capital and operating costs, for the integrated 

systems. The current emphasis is on spreadsheet 

modeling, to make comparisons between system 

configurations and technologies easier. Other factors 

being considered are efficiency, environmental 

impact, and the role of codes and standards. The 

present task addresses infrastructure to support 

transportation applications.

Approach

The analysis of capital costs, operating costs, and 

footprints, fuel economy and emissions has been 

conducted using Excel spreadsheet modeling. Data 

sources included vendor data sheets and website 

information, vendor quotes and communications, 

case study experience, published literature (including 

Environmental Protection Agency data), theses, and 

engineering estimates. Major assumptions for the 

analysis include: 

• Station serves 100 vehicles per day

• Each hydrogen fueling event delivers 4 kg of 

hydrogen

• Station operates 24 hours/day, 365 days per 

year

• Liquid hydrogen is delivered weekly; round 

trip delivery distance is 1,000 miles; storage 

is oversized by 30%
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

196

• Gaseous hydrogen is delivered by pipeline or 

generated on-site; storage is sized for one 

day's service plus 40%

• On-site generators are sized / rated to fill 

storage in 18 to 24 hours, depending on 

electricity rates

The 6 scenarios differ by whether the hydrogen 

is produced off-site and transported by truck or 

pipeline, or whether the hydrogen is produced on-site 

by steam methane reformer (SMR), partial oxidation 

POx) reforming, or grid electrolysis. The scenarios 

are depicted in Figure 1. 

Results

Key results are the cost of dispensed hydrogen 

for the 6 cases. These are compared for a number of 

important parametric variations. The sensitivity to 

station utilization factor is shown in Figure 2, for 

both the base case of 100% utilization and underutilization at 50%. The results are also sensitive to 

the projected cost of on-site production equipment, 

as shown in Figure 3. [1,2]

Another key result is that the construction of 

upstream production and delivery infrastructure 

(central SMR and pipelines) is not ruled out by 

including the amortization of these costs in the 

dispensed hydrogen cost, as shown in Figure 4.

Figure 1. Refueling Station Alternatives Studied in this 

Work

Figure 2. Cost of Dispensed Hydrogen ($/GJ) for Base 

Case and Station Utilized at 100% and 50% 

(100 Cars/Day Capacity)

Figure 3. Sensitivity of Cost Results to Projected 

Costs of On-Site Generation Technologies

Figure 4. Sensitivity of Cost Results to the Inclusion 

of Upstream Infrastructure Costs
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Major and minor emissions from the tailpipe of 

alternative vehicles and the different refueling station 

options were calculated. The results show the 

pipeline and on-site electrolyzer to be the cleanest 

local approaches. Tailpipe emissions for alternative 

vehicles and fuels are shown in Figure 5.

Footprints are strongly dependent on the 

interpretation and implementation of fire codes and 

standards for local hydrogen storage [3]. As shown 

in Figure 6, a conservative safety stand-off zone 

requires a significantly larger footprint than a more 

practical standard.

Conclusions

Hydrogen refueling infrastructure can be 

provided for passenger vehicles by several 

alternative means, including bulk delivery of 

hydrogen to a station via truck or pipeline, or on-site 

generation using electrolysis or reforming 

techniques. The price of the various alternatives can 

be comparable, depending on the transport distance 

and production capacity.

References

1. Schoenung, S. M., "Hydrogen Technical Analysis 

on Matters Being Considered by the International 

Energy Agency - Transportation Infrastructure," 

Proc. DOE Annual Hydrogen Review, May, 2002

2. Thomas, C.E., Directed Technologies, Inc., 

personal communication based on report to Ford 

Motor Company, May 2001

3. Schoenung, S. M., "The Impact of Fire Code 

Specifications on Hydrogen System Footprints for 

IEA Integrated System Cases," draft report 

submitted to DOE Golden Field Office, June, 

2002

FY 2002 Publications/Presentations

1. Susan M. Schoenung, "Hydrogen Vehicle Fueling 

Alternatives: An Analysis Developed for the 

International Energy Agency," in SAE Publication 

SP-1635: Fuel Cells and Alternative Fuels / 

Energy Systems, 2001.

2. Susan M. Schoenung, "A Comparison of 

Hydrogen Vehicle and Refueling Infrastructure 

Alternatives: An Analysis Developed for the 

International Energy Agency," proceedings 14th 

World Hydrogen Energy Conference, Montreal, 

Canada, June 2002 

 3. Technical staff seminar at South Coast Air 

Quality Management District, October 2002

Figure 5. Tailpipe Emissions for Alternative Vehicles 

and Fuels

Figure 6. Footprints of Station Alternatives Showing 

Impact of Varying Fire Codes for Hydrogen 

Storage
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Section III. Hydrogen Storage
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Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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III.A High Pressure Tanks

III.A.1 Hydrogen Composite Tank Program

Neel Sirosh (Primary Contact), Andy Abele, Alan Niedzwiecki

QUANTUM Technologies

17872 Cartwright Road

Irvine, CA 92614

(949) 399-4698, fax: (949) 399-4600, e-mail: nsirosh@qtww.com

DOE Technology Development Manager: Lucito Cataquiz

(202) 586-0729, fax: (202) 586-9811, e-mail: Lucito.Cataquiz@ee.doe.gov

Objectives

• Develop, demonstrate and validate 5,000 pounds per square inch (psi) 7.5 wt % and 8.5 wt% Type IV 

composite hydrogen storage tanks of specified sizes

• Develop and validate 5,000 psi in-tank-regulators 

• Build, assemble, test and supply tank assemblies for DOE Future Truck and Nevada hydrogen bus 

programs

• Demonstrate 10,000 psi storage tanks

Approach

• Optimize materials, design and processes related to QUANTUM "TriShield" composite fuel storage 

tank technology to achieve high gravimetric efficiencies

• Develop tanks for specific sizes and perform safety verification and validation tests based on NGV2-

2000, modified for high pressure hydrogen 

• Supply fully validated tank assemblies to DOE 

Accomplishments

• Achieved "World Record" hydrogen storage mass efficiency of 11.3 wt% on a prototype 5,000 psi 

tank, with Lawrence Livermore National Laboratory and Thiokol Propulsion

• Developed and demonstrated 7.5 wt % and 8.5 wt% Type IV composite hydrogen storage tanks of 

specified sizes

• Commenced shipping high efficiency TriShieldTM hydrogen storage tanks for a number of automotive 

and stationary applications

• Supplied tanks for Hyundai Santa Fe fuel cell electric vehicle, the first to fill to 5,000 psi hydrogen

• Achieved European Integrated Hydrogen Project (EIHP) specifications for 5,000 psi hydrogen storage 

tank, the first all-composite tank to achieve this

• Achieved Canadian Standards Association certification for industry's first 5,000 psi (350 bar) in-tank 

regulation system under NGV 3.1 standards

• Designed and developed industry's first hydrogen 10,000 psi (700 bar) in-tank regulation system

• Shipped tanks for DOE Future Truck and Nevada bus programs
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Introduction

The objective of the DOE Hydrogen Composite 

Tank Project was to design, develop, validate, 

fabricate, and manufacture hydrogen fuel tanks 

(Figure 1) and in-tank regulators (Figure 2) along 

with vehicle integration brackets and isolators and 

have them delivered to Virginia Tech University and 

Texas Tech University in support of the Future Truck 

competition.

This project is part of the DOE program to 

demonstrate the feasibility of the use of compressed 

hydrogen as an automotive fuel. However, the lack 

of convenient and cost-effective hydrogen storage, 

particularly for an on-board vehicular system, is a 

major impediment to its widespread use. 

Improvements in the energy densities of hydrogen 

storage systems, reductions in cost, and increased 

compatibility with available and forecasted systems 

are required before viable hydrogen energy use will 

be realized. Possible approaches to hydrogen storage 

include: compression, liquefaction, chemical storage, 

metal hydrides, and adsorption. Although each 

storage method has desirable attributes, no approach 

currently satisfies all the efficiency, size, weight, 

cost, and safety requirements for transportation or 

utility use. Research continues in these areas, with 

progress being made in all approaches.

Currently there is a strong demand in the 

automotive market for cost-effective and efficient 

high-pressure hydrogen storage systems. The world's 

premier automotive original equipment manufacturer 

(OEMs) developing fuel cell vehicles have 

demonstrated significant interest in compressed 

hydrogen storage systems developed and validated 

by QUANTUM Technologies. The currently 

validated QUANTUM "TriShield" tank technology 

achieves 6% hydrogen by weight, 1,050 W-h/L, and 

2,000 W-h/kg, meeting the DOE targets for percent 

weight and specific energy, and almost meeting the 

energy density target of 1,100 W-h/L. Significant 

cost reductions are possible with further 

optimization.

Approach

The QUANTUM advanced composite tank 

technology incorporates a "TriShieldTM" design 

philosophy. The QUANTUM Type IV TriShieldTM

cylinder, as illustrated Figure 3, is comprised of a 

seamless, one piece, permeation resistant, crosslinked ultra-high molecular weight polymer liner that 

Figure 1. TriShieldTM Hydrogen Storage Tank

Figure 2. In-Tank High Pressure Regulator

Figure 3. TriShieldTM Tank Construction 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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is over wrapped with multiple layers of carbon fiber/

epoxy laminate and a proprietary external protective 

layer for impact resistance. TriShieldTM hydrogen 

tanks feature a single-boss opening to minimize leak 

paths. The path to achieving high gravimetric 

efficiency is optimization in materials, design and 

processes. Numerical methods including the finite 

element method (see Figure 4) were employed to 

optimize the structural shell. 

The TriShieldTM hydrogen tank is designed to 

accommodate QUANTUM's patented in-tank 

regulator, which confines high gas pressures within 

the tank and thus, eliminates high-pressure fuel lines 

downstream of the fuel storage subsystem. By 

combining a check valve to assist tank filling, fuel 

filtering, fuel tank pressure and temperature 

monitoring, pressure relief device and tank lock-off 

in the regulation module, the system cost can be 

significantly reduced. 

Results

The 5,000 and 10,000-psi tanks developed by 

QUANTUM Technologies have been validated to 

meet the requirements of DOT FMVSS304, NGV2-

2000 (both modified for hydrogen) and the draft 

EIHP standard. Typical safety tests completed, in 

order to ensure safety and reliability in an automotive 

service environment included burst tests (2.35 safety 

margin), fatigue, extreme temperature, hydrogen 

cycling, bonfire, severe drop impact test, flaw 

tolerance, acid environment, gunfire penetration, 

accelerated stress, permeation and material tests 

(Figrues 5 and 6). The developed "In-TankRegulators" meet the requirements of NGV3.1 and 

EIHP.

Hydrogen poses challenges, both real and 

perceived, as a transportation fuel. The most 

challenging application is the light-duty vehicle or, 

more specifically, the automobile. Automobiles 

impose the greatest constraints with respect to 

available space on-board the vehicle and consumer 

expectations for vehicle range. In the near-term, fuel 

cell vehicles will likely first be introduced for fleet 

applications in 2003-05. Fleet applications will 

likely have centralized refueling available, so a 

vehicle range of 100 - 150 miles (160 - 241 km) 

would be acceptable. In terms of mass of hydrogen, 

this range could be achieved with about 3 kg of 

hydrogen supplying a fuel cell vehicle. Mature 

compressed and liquid hydrogen storage 

technologies of reasonable size and weight could 

achieve this short-term goal, as shown Table 1. 

Metal hydrides, although providing more compact 

storage, would impose a significant weight penalty.

Figure 4. Composite Shell Finite Element Model

Figure 5. Gunfire Test Example

Figure 6. Bonfire Test Example
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Table 1. Current Status of Potential Short-term 

Hydrogen Storage Technologies for Volume 

and Weight Storing 3 kg H2

Short-term Goal: 3 kg H2 (215 km)

In the long-term, average consumers will expect 

fuel cell vehicles to be transparent compared to the 

gasoline-powered vehicles they drive today with 

respect to cost, convenience and operation. In fact, it 

is likely that fuel cell vehicles will have to offer a 

significant value proposition to encourage consumers 

to adopt a new technology rather than continue with 

something that is tried and true. Vehicle range will 

be an important factor to consumers, especially as a 

hydrogen-refueling infrastructure begins to develop. 

Fuel cell vehicle range of over 400 miles (644 km) 

will be needed, or roughly 7 kg of hydrogen stored 

on-board. Advanced storage materials, including 

alanate hydrides and carbon nano-structures, will 

have to emerge from the current conceptual stage to 

reduce hydrogen storage system size and weight, as 

shown in Table 2. However, both of these solid-state 

storage media are years from commercialization. 

QUANTUM's 10,000 psi TriShieldTM could 

potentially meet this long-term goal without 

significantly impacting either the passenger or 

storage compartments. 

Table 2. Current Status of Potential Long-term Hydrogen 

Storage Technologies for Storing 7 kg H2

Long-term Goal: 7 kg H2 (700 km)

Conclusions

The technologies developed and validated under 

the DOE Hydrogen Composite project have played a 

key role in the commercialization of QUANTUM 

TriShieldTM tanks. In the near term, the markets for 

high-pressure hydrogen storage technology appear to 

be growing. Major automotive OEMs and bus 

OEMs are expected to be the major markets for this 

technology. In addition, QUANTUM sees growing 

interest in stationary and, especially, hydrogen 

refueling infrastructure applications for its advanced 

TriShieldTM storage tanks.

Presentations

1. Neel Sirosh, "Breakthroughs in Compressed 

Hydrogen Storage", Carbon Fiber 2000, San 

Antonio (2000)

2. Andris R. Abele, "Quantum's Experience - 

Leveraging DOE Funding to Accelerate 

Technology Development and Commercialization 

of Advanced Hydrogen Storage", NHA 12th 

Annual U.S. Hydrogen Meeting, Washington 

D.C. (2001)

3. Alan P. Niedzwiecki, "Advanced Hydrogen 

Storage to Enable Fuel Cell Vehicles", 14th 

World Hydrogen Energy Conference, Montreal, 

Quebec (2002)

4. Neel Sirosh, "Compressed Hydrogen Storage 

Technology", Hydrogen Storage: Gateway to 

Energy Security Workshop, Hilton Head Island 

(2002)

Technology

Storage System 

Volume

Storage System 

Weight

5,000 psi Compressed H2 Tanks 145 L 45 kg

10,000 psi Compressed H2 Tanks 100 L 50 kg

Metal Hydrides 55 L 215 kg

Liquid H2 90 L 40 kg

Technology

Storage System 

Volume

Storage System 

Weight

5,000 psi Compressed H2Tanks 320 L 90 kg

10,000 psi Compressed H2 Tanks 220 L 100 kg

Metal Hydrides 200 L 222 kg

Nanotubes ~130 L ~120 kg
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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III.A.2 Hydrogen Storage Using Lightweight Tanks

Andrew Weisberg (Primary Contact), Blake Myers, Gene Berry

Lawrence Livermore National Laboratory

P.O. Box 808

Livermore, CA 94551

(925) 422-7293, fax (925) 424-3731, e-mail: weisberg1@llnl.gov

DOE Technology Development Manager: Lucito Cataquiz

(202) 586-0729, fax : (202) 586-9811, e-mail : Lucito.Cataquiz@ee.doe.gov

Objectives 

• Learn how to build and operate the best hydrogen container technologies

• Explore the performance of recently discovered non-pressure-vessel structural containment options for 

compressed hydrogen

• Demonstrate fundamental improvements in hydrogen containment safety

Approach

• Quantify optimality with valid (correct Dimensional Analysis) consumer-preferred mixtures of 

volume, mass, and cost

• Fix computer aided engineering models to include 3D effects, conserve fibers, and predict matrix 

strength effects

• Continue to push the limits of mass performance through experiments with the smallest representative 

test articles

• Adopt process research based on statistical performance to save a predicted 30% in mass and cost

Accomplishments 

• Engineered minimal diameter (4.5 inch) pressure vessel representative of all larger scales based on 

Balanced Ovaloid end dome contour

• Pioneered first use of recent computer aided manufacture (CAM) prototyping techniques for tank 

manufacture employing XLS, VBA, TCW, DWG, and STL computer languages

• Developer wider, more fundamental flavor of analyses applicable to new systems (including hydrogen 

infrastructures), as well as motor vehicles

Future Directions 

• Account for the "missing 7%" in the record-breaking tanks burst in July 2000, then extend models to 

forecast performance across wide classes of hydrogen containment structures

• Observe spectacular "turn to dust" failure modes with real time instrumentation

• Conduct a statistical hydroburst test program to demonstrate substantial cost and mass savings

Introduction

The easiest near-term solution to storing 

hydrogen onboard motor vehicles may also be the 

best long-term solution for most hydrogen vehicles 

and infrastructure options. Compressed hydrogen 

must be contained in structures that can safely hold 

high pressures with low permeation. Pressure vessels 

that satisfy numerous hydrogen vehicular safety 

standards at pressures up to 5,000 pounds per square 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

206

inch (psi) are already commercially available. More 

advanced compressed hydrogen containment 

technologies have been the objective of research at 

Lawrence Livermore National Laboratory (LLNL) 

for almost a decade. Our research has been 

responsible for the most advanced pressure vessels 

(capable of safely containing 5,000 psi hydrogen) 

now nearing commercialization.

Recent theoretical results suggest that the best 

hydrogen containment solutions must store gas at 

pressures as high as 15,000 psi. LLNL has been 

seeking the lowest mass hydrogen storage 

technologies. Until 2002, the best hydrogen gas 

storage solutions employed pressure vessels 

(colloquially called tanks) that carry the high stresses 

due to high internal pressure in composite materials 

wound around almost impermeable liners. New 

structural containment solutions need not resemble 

tanks carrying stresses through their interiors in mass 

produced structural components rather than around 

them in strong shells. Both new and proven 

conventional solutions rely on advanced materials 

and analyses to deliver improved mass and cost 

performance.

Approach

Recently, record-breaking and mass-performance 

leading commercializable hydrogen tanks were 

developed from LLNL specifications with DOE 

funding. Because LLNL tank development to date 

has employed expensive aerospace manufacturing 

processes, continued experimentation progress on the 

frontiers of hydrogen tankage mass-performance has 

been jeopardized by the high cost of test articles. For 

the past year, LLNL advanced compressed hydrogen 

storage has therefore been directed at prototyping 

affordable test articles.

The prototype tanks LLNL is developing solve 

vehicle component cost problems as well as 

experimental tank affordability. Their small size does 

more than conserve costly advanced structural 

materials, direct costs, and fabrication costs - it 

prevents them from competing with existing or 

planned commercial products. They have been sized 

at the minimum scale that will yield experimental 

data relevant to calibrated predictions at all larger 

scales (4.5" diameter ~12" long), yet they remain 

applicable in future vehicle integration 

demonstration projects for strategic (no barriers to 

adoption) small vehicles: wheelchairs, motorcycle 

scooters, skidoos, etc.

Tank prototyping provided an opportunity to 

employ modern CAM techniques (developed in the 

1990s), which have yet to be adopted in aerospace or 

industrial tank manufacture. These techniques 

conserved costly LLNL manpower and would have 

shortened the protected design process, if not for a 

sequence of increasing fundamental discoveries their 

fresh application unleashed. Details of the shape 

calculated for prototype tank end dome contours 

received detailed examination before substantial 

investments could be made responsibly in liner mold 

tooling. That scrutiny uncovered an implicit violation 

in assumptions used to derive the Balanced Ovaloid 

contour, especially in regions of negative curvature 

(where the end dome is convex in one direction and 

concave in the other). More consideration of those 

violated assumptions raised the possibility of 

deliberately manufacturing composite structures with 

regions of negative curvatures that would allow them 

to 'nest' in replicated geometries that fill space. 

Questions asked by LLNL colleagues about the 

advantages of such space filling structures lead to 

new forms of analysis that are widely applicable to 

hydrogen storage onboard vehicles and in future 

infrastructures. These forms of analysis will be 

explored and calibrated with experiments.

Results

Mass efficient compressed hydrogen containers 

will be the most cost efficient for any chosen 

structural material, although the highest strength 

materials cannot repay their high cost with mass 

savings. Container volume remains the greatest 

challenge to storing hydrogen onboard motor 

vehicles due to the low density of hydrogen in any of 

its storable forms (chemically bound, gas, or liquid). 

Structural improvements can deliver slight volume 

reduction, but storage volumes can be dramatically 

improved by increasing stored hydrogen pressure 

(and by decreasing temperature). These 

improvements reach diminishing returns above 

roughly 15,000 psi, and continued structural 

innovations will be required to withstand these 

higher pressures with affordable mass and cost. The 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

207

fundamental improvements LLNL is making in 

vehicle and infrastructure analyses allow mass, 

volume, and cost performance that reflect consumer 

preferences (e.g. gasoline vehicle range) to be 

assessed.

Preliminary results suggest volume 

improvements will be roughly twice as valuable as 

mass improvements (as ratios to existing 

technology). Increases in container mass required to 

hold higher pressures can be offset by the structural, 

operating, design, and materials improvements 

LLNL is investigating with small prototypes. Figure 

1 points to locations in those prototypes (on their end 

dome cross section solid models) where discoveries 

have already emerged (in early 2002) from LLNL 

prototyping. That prototyping was intended to 

demonstrate predicted 30% savings in cost and mass 

that LLNL expects from Statistical Process Research, 

which must hydroburst (test to destruction) large 

(>25) numbers of test articles. Experimental 

statistics are expected to replace much of the 

controversial uncertainty in current structural "safety 

factors" with quantitative reliability methods. These 

methods, shown in Figure 2, were developed in the 

1980's for maximizing mass in solid rockets, and for 

minimizing the cost of semiconductors.

Discoveries made during tank prototyping have 

begun to explain the rule of thumb used in modern 

finite element analysis tank design methods to avoid 

high-variance (and quite unsafe) failures in end 

domes. Actual wound tanks depart from the 

assumptions of axial symmetry embedded in their 2D 

design, in ways that can stress their composite's 

matrix with excessive local variations (in 3D) unless 

40-80% excess fiber is used in helical windings. 

These discoveries, and LLNL colleagues' questions 

about their implications, led to a new formalism 

capable of mixing mass, volume, and cost 

performance. That formalism dissects an application 

into a hierarchy of components that can be 

quantitatively described by dimensionless ratios, 

which can be arbitrarily manipulated with nonlinear 

functions. The Calculus of Variations can be applied 

on top of such models to constrain consumer 

preference computables, such as vehicle range, while 

optimizing other consumer preferred performance 

measures (i.e. cost-per-mile or vehicle capital cost). 

Figure 3 illustrates several of the structural 

innovations that emerged from the discoveries made 

at LLNL in the first half of 2002. It remains to be 

seen which of these innovations are best and/or 

affordably testable in the near term, but all are likely 

to improve on conventional tanks. Several important 

‘holes’ in current theory and analyses emerged 

during the recent discovery process. These ‘holes’ 

are big enough that several PhD theses may not 

suffice to fill each one. Fiber number flex 

conservation, departures from constant (assumed) 

fiber/matrix ratio, and actual curvilinear (nonaxisymmetric, nongeodesic) fiber trajectories will 

contribute arduous but necessary improvements to 

current composite design methods. 

Figure 1. Locations of Discoveries Made by Tank 

Prototyping Based on Methods Predating 

Finite Element Analysis

Figure 2. Statistical Methods Developed for Solid 

Rockets Provide the Basis for Predicted 

Savings
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

208

Experiments will be necessary to prove the 

existence, behavior, and engineering of a new class 

of physical instability. Tensor solitary waves have 

been hypothesized that are related to debonding 

instabilities first detected in particulate composites in 

the early 1980’s. Figure 4 shows the characteristics 

of that simpler instability. Figure 5 captures a 

mysterious, ultrafast failure mode first observed in 

2000, whose explanation may be similar to Figure 4’s 

particulate (not fiber) composite results, but whose 

morphology differs due to the extreme anisotropy of 

carbon fiber composites. LLNL structural hydrogen 

storage research has made progress in 2002 towards 

explaining the consistent fiber strain at failure loss of 

7% observed during the same 2000 experiments. 

(This loss departed from Thiokol's data base of over 

10,000 bursts performed with the same composite 

and winding techniques.) LLNL efforts have a 

longer-term goal of understanding and harnessing 

this failure mode into a safety breakthrough, 

dissipating the significant mechanical stored energy 

(implicit in high-pressure containment) during an 

accident.

Conclusions

Higher pressures are likely optimal for 

compressed hydrogen storage onboard motor 

vehicles, and hydrogen permeability must be 

Figure 3. Forms of Hydrogen Storage Can Use 

Containment Structures That Do Not 

Resemble Tanks

Figure 4. Recent Discoveries Include Debonding 

Waves First Observed in Particulate 

Composites

Figure 5. Observed Failure Modes Can Turn Tanks to 

Dust, Dissipating Stored Structural Energy 

Very Rapidly (< 200 Microseconds in this 

Frame), and Potentially Providing a Safety 

Breakthrough
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

209

measured at those pressures for appropriate barrier 

materials to confirm their feasibility.

New analytic formalisms can provide a valid 

basis for optimizing consumer benefits from many 

forms of advanced hydrogen containment, including 

recent structural innovations unlike conventional 

pressure vessels. 

Unmodeled departures from assumed axial 

symmetry, combined with low matrix shear strength 

in epoxy matrix composites, potentially accounts for 

consistent 7% strength loss in the record-settings 

tanks LLNL built and tested in mid 2000; and is 

expected could handicap conventional tank designs 

mass performance as pressure ratings increase.

References

1. Composite Reliability, E.M. Wu, ASTM STP 580 

(Conf. Las Vegas 1974).

2. A Statistical Theory of the Strength of Materials, 

Weibull and Waloddi, Ingeniors Vetenskops 

Akadamien-Hawdlingar, Stockholm 1939, No. 

151, p. 1-45.

3. Cellular Solids, Lorna J. Gibson and Michael F. 

Ashey, Pergammon Press, Oxford 1988.

FY 2002 Publications/Presentations 

1. DOE Annual Program Review for 2002, May 8, 

2002, Denver, CO
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

210

III.A.3 Hydrogen Storage in Insulated Pressure Vessels

Salvador M. Aceves (Primary Contact)

Lawrence Livermore National Laboratory

PO Box 808, L-644

Livermore, CA 94551

(925) 422-0864, fax: (925) 423-7914, e-mail: saceves@llnl.gov

DOE Technology Development Managers: Lucito Cataquiz

(202) 586-0729, fax: (202) 586-9811, e-mail: Lucito.Cataquiz@ee.doe.gov

Objectives 

• Demonstrate the advantages of insulated pressure vessels for hydrogen storage in terms of improved 

packaging, reduced evaporative losses and reduced costs.

• Write standards for assuring the safety of insulated pressure vessels.

• Demonstrate the insulated pressure vessel technology in two pickup trucks.

Approach

• Conduct experiments and analysis to verify safety of insulated pressure vessels.

• Study existing standards for hydrogen storage in vehicles.

• Test performance of two insulated pressure vessels on pickup trucks.

Accomplishments 

• Acquired funding from the South Coast Air Quality Management District to perform a demonstration 

project where we will install insulated pressure vessels in two trucks. 

• Built 6 full size (130 liter internal volume) insulated pressure vessels according to our current design. 

• Generated a preliminary list of tests for certification of insulated pressure vessels. 

• Conducted the ISO/Department of Transportation (DOT) drop test and bonfire test on our pressure 

vessels. Our tanks passed both tests. 

Future Directions 

• Conduct a demonstration project at SunLine transit, where the insulated pressure vessels will be 

installed in two trucks.

• Generate a draft document proposing a set of rules for certification of insulated pressure vessels. 

• Start work on building 12 additional insulated pressure vessels according to our current design. 

• Subject tanks to the Society of Automotive Engineers (SAE) cryogenic drop and bonfire tests.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

211

Introduction

The goal of this project is to develop a hydrogen 

storage technology that can satisfy light-duty vehicle 

storage needs in a cost-effective way. This high 

pressure, low temperature vessel has the packaging 

advantages of liquid hydrogen tanks (low weight and 

volume) with much reduced evaporative losses, 

infrastructure flexibility, lower energy consumption, 

lower cost, enhanced user convenience, and safety. 

Insulated pressure vessels are being developed as 

an alternative technology for storage of hydrogen in 

light-duty vehicles. Insulated pressure vessels can be 

fueled with either liquid hydrogen or compressed 

hydrogen. This flexibility results in advantages 

compared to conventional hydrogen storage 

technologies. Insulated pressure vessels are lighter 

than hydrides, more compact than ambienttemperature pressure vessels, and require less energy 

for liquefaction and have less evaporative losses than 

liquid hydrogen tanks. 

We plan to demonstrate that insulated pressure 

vessels that have packaging characteristics similar to 

liquid hydrogen and that are superior to ambient 

temperature pressure vessels. Compared with liquid 

hydrogen, insulated pressure vessels give increased 

flexibility to the fueling infrastructure, since the 

vehicle can be fueled with liquid hydrogen for long 

trips, or with less-energy-intensive ambient 

temperature hydrogen for daily driving. The highpressure capability of the pressure vessel and the 

thermodynamic properties of hydrogen result in 

virtually zero boil-off losses for insulated pressure 

vessels. Finally, due to their high-pressure capability, 

insulated pressure vessels never run out of hydrogen 

after a long period of parking. This may be a major 

issue for liquid hydrogen tanks that can lose all the 

hydrogen due to evaporation.

Approach 

We are conducting experiments and analysis to 

verify that insulated pressure vessels are a safe 

technology for vehicular storage of hydrogen. We 

have conducted a long list of DOT/ISO tests and we 

are planning to conduct two SAE tests that apply to 

cryogenic pressure vessels. 

We are planning demonstration experiments to 

prove the feasibility of insulated pressure vessels in 

vehicles. To accomplish this task, we have secured 

funding from the South Coast Air Quality 

Management District, SCI and SunLine.

Results

During this year, we prepared a proposal to the 

South Coast Air Quality Management District to 

obtain funding to perform a demonstration project at 

SunLine Transit, where we will install insulated 

pressure vessels in two of the SunLine fleet trucks. 

The proposal has been approved and we will use 

these funds to complement the budget received from 

the hydrogen program.

We also have built 6 full-size (130-liter internal 

volume) insulated pressure vessels according to our 

current design (see Figures 1 and 2). Two of these 

vessels will be used for the SAE cryogenic drop and 

bonfire tests, while the other vessels will be used for 

vehicle demonstration at SunLine Transit.

We have generated a preliminary list of tests for 

certification of insulated pressure vessels. The list of 

tests will be sent to pressure vessel manufacturers for 

their comments. We have conducted all of the DOT/

ISO tests for pressure vessel certification. 

 Figure 1. Insulation design for pressure vessel. The 

figure shows a vacuum space for obtaining 

good performance from the multilayer 

insulation, instrumentation for pressure, 

temperature and level, and a vapor shield for 

reducing hydrogen evaporative losses.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

212

Finally, we are working on testing 5000-psi tanks 

for application in insulated pressure vessels. As a 

part of this work, we cycle tested two 5000-psi tanks 

100 times down to liquid nitrogen temperatures. The 

tanks were then burst tested. The tanks failed at a 

pressure high enough to satisfy the DOT/ISO 

standards.

Conclusions 

For reduced cost and complexity, it is desirable 

to use commercially available aluminum-fiber 

pressure vessels for insulated pressure vessels. 

However, commercially available pressure vessels 

are not designed for operation at cryogenic 

temperature. A series of tests has been carried out to 

verify that commercially available pressure vessels 

can be operated at cryogenic temperature with no 

performance losses. All analysis and experiments to 

date indicate that no significant damage has resulted. 

Future activities include a demonstration project in 

which the insulated pressure vessels will be installed 

and tested on two vehicles. A draft standard will also 

be generated for obtaining certification for insulated 

pressure vessels.

FY 2002 Publications/Presentations 

1. Performance Evaluation Tests of Insulated 

Pressure Vessels for Vehicular Hydrogen Storage, 

S. M. Aceves, J. Martinez-Frias, F. EspinosaLoza, Proceedings of the World Hydrogen 

Conference, Montreal, Canada, June 2002.

2. Insulated Pressure Vessels for Vehicular 

Hydrogen Storage: Analysis and Performance 

Evaluation, S. M. Aceves, J. Martinez-Frias, O. 

Garcia-Villazana and F. Espinosa-Loza, Paper 

IMECE2001/AES-23668, Proceedings of the 

2001 ASME International Mechanical 

Engineering Congress and Exposition, November 

11-16, New York, NY.

3. Certification Testing and Demonstration of 

Insulated Pressure Vessels for Vehicular 

Hydrogen Storage, S. M. Aceves, J. MartinezFrias and F. Espinosa-Loza, Proceedings of the 

U.S. DOE Hydrogen Program Review Meeting, 

Denver, Colorado, May 2002.

4. Certification Testing and Demonstration of 

Insulated Pressure Vessels for Vehicular 

Hydrogen and Natural Gas Storage, Salvador M. 

Aceves, Joel Martinez-Frias and Francisco 

Espinosa-Loza, Randy Schaffer, William Clapper, 

Proceedings of the 8th International Conference 

and Exhibition on Natural Gas Vehicles, 

Washington, DC, October 8-10, 2002.

Special Recognitions & Awards/Patents 

Issued 

1. Project was featured in the cover and in a 2-page 

article in "Mechanical Engineering" Magazine in 

February 2002.

Figure 2. Finished Insulated Pressure Vessel being 

tested at the Lawrence Livermore National 

Laboratory High-Pressure Laboratory
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

213

III.A.4 Advanced Thermal Hydrogen Compression

David H. DaCosta (Primary Contact), Mark Golben

Ergenics, Inc.

373 Margaret King Ave.

Ringwood, NJ 07456

(973) 728-8815, fax: (973) 728-8864, e-mail: dacosta@warwick.net

DOE Technology Development Manager: Lucito Cataquiz

(202) 586-0729, fax: (202) 586-9811, e-mail: Lucito.Cataquiz@ee.doe.gov

Objectives 

• Develop a hydride thermal hydrogen compressor that operates in conjunction with advanced hydrogen 

production technologies and improves the efficiency and economics of the compression process.

• Determine to what extent the hydride compression process can perform the dual function of 

compression with purification, to remove impurities that adversely affect fuel cells. 

Approach

• Construct a single stage hydride compressor that employs miniature hydride heat exchangers and three 

purification technologies (passive purification for water vapor and diatomic oxygen [O2], inert gas 

purification, and elevated temperature desorption for carbon monoxide [CO] and carbon dioxide 

[CO2]).

• Test the compressor on impure hydrogen streams to determine threshold contamination levels (levels 

at which compressor performance is affected) for water (H2O), O2, CO, and methane (CH4). 

• Investigate compressor capabilities to perform the dual function of compression with purification for 

impurities that adversely affect fuel cell operation (CO and diatomic nitrogen [N2]).

• Engineer and test hydride alloys suitable for long term operation at high pressures over 5,000 pounds 

per square inch gauge (psig).

• Validate the entire compressor process in a multi-stage, pilot scale system.

Accomplishments 

• Demonstrated operation over 5,000 psig with hydride alloys from two separate "families," providing 

versatility to meet application-specific needs.

• Modified design operating conditions to increase efficiency, reduce energy consumption and reduce 

complexity, with a corresponding economic improvement via lower capital and operating costs.

• Engineered hydride alloys that can endure cycling at elevated temperatures without damage. 

Future Directions 

• Complete construction of a single stage hydride compressor and compressor test stand. The 

compressor includes hydrogen purification capabilities and the test stand includes fast response, 

continuous impurity monitors for the gathering of real-time operating information.

• Quantify the hydride compressor's tolerance to impurities in tests occuring in the Fall of 2002. 

• Validate the entire thermal compression process in a pilot scale system that includes purification 

provisions and boosts hydrogen pressure to over 5,000 psig. The flow rate capability of the pilot-scale 

system will be similar to that required for overnight refueling of a hydrogen fuel cell automobile.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

214

• Evaluate the commercial viability of the hydride compression process compared to existing 

mechanical compression and hydrogen purification technologies.

• Following a successful conclusion to this portion of the project, build and field demonstrate a full-scale 

compressor prototype sized for a hydrogen vehicle refueling station, and compare side-by-side with a 

mechanical compressor. 

Introduction

Ergenics is investigating the application of its 

novel hydride hydrogen compression process to 

hydrogen produced from renewable resources. 

Hydride hydrogen compressors have offered 

significant operational and economic advantages 

over traditional mechanical compressors when the 

hydrogen is pure and flow rates are relatively low. 

However, hydrogen produced from renewable 

resources can contain impurities that might damage a 

hydride compressor and, if hydride compressors are 

to play a major role as hydrogen becomes an 

increasingly important part of America's energy 

supply, increased flow rate capabilities must be 

economical. 

The primary focus of this project is to develop 

methods that allow hydride alloys to absorb non-pure 

hydrogen streams likely to result from renewable 

hydrogen production processes (DaCosta 2000). 

Three hydrogen purification techniques have been 

identified and will be tested during the fall of 2002. 

Increased flow capability will be accomplished by 

using miniature hydride heat exchangers (Golben 

2001). 

 During the course of hydride compressor 

development, a number of additional insights have 

been gained regarding requirements for commercial 

hydride compressor viability. These insights are 

important for the overall success of the project and 

have been included in the project scope:

• Compression with purification may mitigate 

fuel cell degradation from CO. If the 

purification techniques used to protect the 

compressor's hydride alloys can be used to 

eliminate CO from hydrogen streams, 

alternative methods of extending fuel cell 

life may be unnecessary. A secondary 

benefit would be to remove impurities that 

damage the new hydrogen storage media 

now under development, such as sodium 

aluminum hydride and carbon nanotubes.

• Hydride compressors can compress 

hydrogen to the very high pressures under 

consideration for vehicular storage (5,000 to 

10,000 pounds per square inch [psi]) much 

easier than mechanical compressors. For 

example, an electrically heated hydride 

compressor can achieve very high 

compression ratios in a single stage, as 

shown in the performance curve in Figure 1. 

• Using natural gas as the energy source for a 

hydride compressor reduces energy costs to 

less than half that of a mechanical 

compressor. Lower compression energy cost 

reduces gasoline-equivalent hydrogen cost 

by 14 to 20 cents per gallon. 

• The third insight has proven to be important 

for commercial viability. The ability to 

compress hydrogen using the low-grade heat 

energy in hot water is a compelling 

advantage of the hydride compression 

process. However, many applications either 

do not have adequate waste heat or solar hot 

water, or the waste heat or solar hot water is 

difficult to access economically. In these 

cases, traditional fuels can be used to provide 

compression energy, but the relatively low 

Figure 1. A Single stage Hydride Compressor Boosts 

Outlet Pressure to over 5,000 psi (350 bar) for 

Vehicular Storage
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

215

operating efficiency of the hydride 

compression process must be increased by 

using higher temperatures. A new class of 

hydride alloys that will perform the 

compression function at elevated 

temperatures have been identified.

Approach

The hydride compressor is a form of "heat 

engine" based on the Carnot cycle. Its energy 

efficiency is about 50% of Carnot efficiency. Carnot 

efficiency is based on the temperature difference 

between the hot energy source and the cold heat sink. 

Efficiency plotted as a function of hot water (energy 

source) temperature appears in Figure 2.

Waste heat is usually available in the 80 to 90oC 

range. With a 30oC cooling water temperature, 

Carnot efficiency is from 13 to 16 percent and 

hydride compressor efficiency is from 41⁄2 to 61⁄2 

percent. If waste heat is free, cycle economics can 

endure this level of efficiency.

By using a traditional form of heat energy, such 

as natural gas, cycle economics will benefit from an 

increase in hot water temperature. Using a heat 

transfer fluid from a gas fired heater at 130oC, Carnot 

efficiency is almost 25 percent, and hydride 

compressor efficiency increases to 15 percent. While 

15 percent is about 1/2 that for a mechanical 

compressor, electricity is about 6 times costlier than 

natural gas, so the hydride compressor will enjoy a 

67% lower energy cost. A simplified schematic of a 

natural gas powered hydride compressor appears in 

Figure 3.

An added benefit of higher temperature 

operation is a substantial reduction in the number of 

stages needed for a given compression ratio. 

Operation at 130oC in lieu of 90o

C cuts by half the 

number of stages, with an associated reduction in 

system complexity, size and capital cost.

Unfortunately, when hydride alloys traditionally 

used for compressors are cycled at temperatures over 

100o

C, their performance can deteriorate through a 

process termed "disproportionation." In relatively 

few cycles, reversible hydrogen absorption capacity 

is lost, which would cause a hydride compressor to 

stop working. 

Ergenics pioneered the development of high 

temperature, disproportionation resistant alloys in 

1995, while applying a hydride heat storage system 

to heat an automotive catalytic converter when the 

car was started. A hydride heater bed was placed in 

the exhaust pipe between the exhaust manifold and 

the catalytic converter. When activated, the heater 

bed temperature would increase from ambient to 

400o

C in a few seconds. The bed would be heated to 

over 500o

C during normal driving. The alloy used in 

the heater bed had to endure these high temperatures 

for 25,000 start cycles and over the time it takes to 

travel 100,000 miles. Ergenics has extended its 

Figure 2. Increasing Hot Water Temperature Increases 

Compressor Efficiency

Figure 3. Simplified Schematic of a Natural Gas 

Powered Hydride Thermal Hydrogen 

Compressor
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

216

original disproportionation-proof alloy development 

to the search for compressor alloys that can survive 

elevated temperatures.

Starting with the alloy family used in the 

catalytic converter heater, Ergenics modified alloy 

formulations to adjust the pressure-temperature 

performance. A correlation was developed between 

the formulations and pressure-temperature 

performance to permit the engineering of alloys 

appropriate for the different pressure stages in a 

hydride compressor. The alloys were then tested for 

resistance to disproportionation.

Results

During its original high temperature alloy 

development work in the mid 1990's, Ergenics 

developed a "Soak Test" procedure to screen alloy 

candidates. An alloy sample is placed within a test 

reactor vessel and is fully hydrided at high pressure. 

The test vessel is then held at high temperature for an 

extended duration to try to induce disproportionation. 

Pressure is monitored during the test. The 

temperature is high enough that a small amount of 

hydrogen is lost via diffusion through the reactor 

vessel wall. This diffusion loss is manifested by a 

small pressure decrease during the test. A pressure 

decrease in excess of the amount anticipated for 

diffusion may indicate alloy disproportionation.

The test reactor is subsequently weighed to rule 

out whether pressure loss not due to diffusion might 

be attributed to leakage. Finally, the sample is 

refilled with hydrogen to ascertain cycle-ability.

Figures 4 and 5 show the soak test results for two 

alloy candidates, one that experienced performance 

loss (Figure 4) and one with a new formulation that 

did not (Figure 5). 

Conclusions

Increasing the heating fluid temperature of a 

hydride "thermal" hydrogen compressor from 80o

C 

to 130oC more than doubles efficiency while 

reducing system complexity, size and cost. If natural 

gas is available as the heating source, energy costs 

can be three times lower than for an electric-motordriven mechanical compressor.

Disproportionation-proof alloys that will survive 

elevated temperature operation have been 

engineered.

References 

1. DaCosta, David H. 2000. "Advanced Thermal 

Hydrogen Compression." In Proceedings of the 

2000 U.S. DOE Hydrogen Program Review, 720-

727. San Ramon, CA: NREL/CP-570-28890.

Figure 4. Soak Test Results Showing Alloy 

Disproportionation at Elevated Temperatures

Figure 5. Soak Test Results for an Alloy that is Stable 

at Elevated Temperatures
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

217

2. Golben, M., DaCosta, D.H. 2001. "Advanced 

Thermal Hydrogen Compression." In 

Proceedings of the 2001 U.S. DOE Hydrogen 

Program Review, Baltimore, MD: NREL/CP-570-

30535.

FY 2002 Publications/Presentations 

1. D. DaCosta, M. Golben. "Disproportionation 

Resistant Alloy Development for Hydride 

Hydrogen Compression", Proceedings 2002 U.S. 

Department of Energy Hydrogen Program Annual 

Review Meeting, Golden, May 6-8, 2002, NREL.

2. D. DaCosta, M. Golben, D.C. Tragna. "Metal 

Hydride Thermal Hydrogen Compression", 

Proceedings 14th World Hydrogen Energy 

Conference, Montreal, June 9-13, 2002.

3. D. DaCosta, M. Golben. "Thermal Hydrogen 

Compression with Purification", International 

Energy Agency Hydrogen Implementing 

Agreement, Task 17 - Solid and Liquid State 

Hydrogen Storage Materials Workshop, Seattle, 

WA, February 21-22, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

218

III.A.5 Development of a Compressed Hydrogen Gas Integrated Storage System 

for Fuel Cell Vehicles 

Mr. John Wozniak (Primary Contact)

Johns Hopkins University Applied Physics Laboratory

11100 Johns Hopkins Road

Laurel, Maryland 20723-6099

(240) 228-5744, fax: (240) 228-5512, e-mail: john.wozniak@jhuapl.edu

DOE Technology Development Manager: Lucito Cataquiz

(202) 586-0729, fax: (202) 586-9811, e-mail: Lucito.Cataquiz@ee.doe.gov

Main Subcontractor: General Dynamics Armament & Technical Products (GDATP), Lincoln, 

Nebraska

Objectives

• Advance the technology elements required to develop a semi-conformal, Compressed Hydrogen Gas 

Integrated Storage System (CH2-ISS) for light-duty fuel cell vehicles (FCVs)

• Conduct engineering research to: 

- Develop materials and treatments to reduce hydrogen gas permeation through tank liners

- Develop an optimized carbon fiber/epoxy resin tank overwrap

- Determine alternative designs and materials for constructing the unifying elements of the integrated 

storage system 

Approach 

• Develop baseline CH2-ISS design consistent with notional FCV packaging and driving range 

requirements

• Develop tank liner surface treatments and measure hydrogen gas permeation

• Build and performance test all-carbon overwrap tanks with alternative toughened epoxy resin systems

• Explore with manufacturers alternative materials and means for low-cost production of the ISS outer 

shell and unitary gas control system

• Develop a roadmap identifying the steps needed to prototype the CH2-ISS and safety certify the 

container for FCV applications

Accomplishments 

• Developed computer-aided drafting (CAD) models of alternative ways to construct the CH2-ISS 

• Developed a process for surface treating the high density polyethylene (HDPE) tank liner to reduce 

hydrogen gas permeation

• Measured gas permeation and met allowable with acceptable margin

• Built a series of all-carbon overwrap hydrogen gas tanks with alternative toughened epoxy resin 

systems and conducted burst and gunfire tests

• Established an all-carbon overwrap design that passes gunfire test at the minimum factor of safety 

(2.25)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

219

• Conducted a manufacturing trade study of alternative means and materials for fabricating the CH2-ISS 

outer protective shell

• Designed two alternative means for building the CH2-ISS unitary gas control unit

Future Directions

• Continue to develop liner materials and processing (metalization and surface coatings) to further 

reduce hydrogen gas permeation

• Optimize tank overwrap toughened resin system with respect to cost, minimizing impact on service 

temperature and tank manufacturability

• Conduct series of tests to quantity the performance of the CH2-ISS tank design

• Conduct flammability and impact tests on alternative CH2-ISS outer shell materials; select optimum 

for prototype build

• Detail design and prototype build the unitary gas control system 

Introduction

FCVs are identified by the DOE, and virtually 

every major automaker, as a potential solution to 

problems of air quality and dependency on foreign 

fuel. Fuel cells produce electricity by combining 

hydrogen with oxygen from air to produce electrical 

power and give off only water vapor. The onboard 

storage of hydrogen fuel can consist of compressed 

hydrogen gas (cH2) systems, cryogenic liquid 

hydrogen tanks or chemical or metal hydride storage 

systems. Another source of hydrogen is derived 

from gasoline, diesel, methane, or natural gas by 

using an onboard reformer. Of the many means of 

carrying hydrogen, cH2 is one of the most attractive 

technologies because of fast refueling times, 

unlimited refueling cycles, ease of low temperature 

startup, superior long-term stability, and true zero 

vehicle emissions.

The storage of cH2, however poses challenges in 

the areas of relatively low energy density, system 

cost, crashworthiness, and vehicle packaging. A 

solution to these challenges is offered by the 

Integrated Storage System (ISS) technology (U.S. 

Patent No. 6,257,360 issued July 2001) jointly 

developed by Johns Hopkins University Applied 

Physics Laboratory (JHU/APL) and General 

Dynamic Armaments and Technical Products 

(GDATP) (formerly Lincoln Composites). Under 

DOE Cooperative Agreement DE-FC36-01G011003 

the ISS technology is being advanced to support 

development of a 5,000 pounds per square inch (psi) 

hydrogen gas service pressure, 5% or better gas mass 

fraction system that meets safety, vehicle packaging, 

and production cost objectives.

Technical Approach

 ISS uses Type IV all-composite tanks 

constructed with a high-density polyethylene 

(HDPE) thermoplastic liner structurally overwrapped 

with carbon fiber and epoxy resin. The tanks are 

encapsulated within a high-strength outer shell 

unitizing the individual cylinders into a single 

container and providing protection from 

environmental exposure. Additional physical 

protection of the tanks is provided by urethane foam 

surrounding the tank dome region (location of 

highest stress concentration during impact). A 

unitized gas control module is incorporated into the 

ISS package and provides all necessary gas flow 

control and safety features. Figure 1 is a CAD image 

of the CH2-ISS design. The objective of this project 

is to advance the technologies needed to support 

development and safety certification of a CH2-ISS.

There are four specific tasks: (1) HDPE 

treatment and development of alternative tank liner 

materials for hydrogen gas permeation reduction; (2) 

enhancing epoxy resin toughness to improve the tank 

carbon fiber overwrap performance; (3) materials 

and process evaluation for manufacturing the ISS 

protective shell; and (4) engineering an optimized 

unitary gas control module. An additional task (5) is 

the formulation of a roadmap for prototyping and 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

220

safety certifying the CH2-ISS for potential mass 

production. 

Result

Task (1) ISS uses Type IV high-pressure gas 

storage tanks using a HDPE thermoplastic liner, (see 

Figure 2) overwrapped with carbon fiber and epoxy 

resin. The liner serves as a permeation barrier, 

mechanical interface to aluminum bosses, and a 

stable mandrel for the filament winding process. The 

main focus of the permeation task has been to 

quantify and control the hydrogen gas permeation 

rate through the HDPE. In FY02 a low-cost, 

proprietary surface treatment process was developed 

to reduce the hydrogen permeation. The tests were 

conducted on both the untreated and surface treated 

HDPE liners. Testing at 5,000 psi indicated a 

permeation rate of about 0.8 standard cubic 

centimeters per hour per liter (scc/hr/l) for the 

untreated HDPE and about 0.2 scc/hr/l for the 

treated. The current draft standard (e.g. ISO/DIS 

15869) allows a permeation rate of 1.0 scc/hr/l. 

Additional work was done to develop a process for 

applying a coating to the surface of the HDPE liner. 

The permeation rate through the propriety surface 

coating has yet to be quantified. 

Task (2) In FY02, a series of Type IV, all-carbon 

(T-700) tanks were designed, fabricated and 

performance tested. The objective was to develop 

the technology to construct small-diameter tanks for 

an operating pressure of 5,000 psi that would pass the 

critical gunfire test at the minimum allowable burst 

factor of safety (FOS) of 2.25. The overwrap 

technology investigation involved using winding 

patterns that maximize interspersion between helical 

and hoop layers. In addition, series of resin 

formulations were evaluated to assess their impact on 

tank gunfire performance. The brittle nature of 

structural epoxy resins is suspected of contributing to 

localized delaminating of the overwrap, resulting in 

catastrophic tank rupture under gunfire testing. Two 

toughening agents, polyether sulphone and amineterminated butadiene acrylonitrile, formulated into 

GDATP's standard resin, in combination with the 

enhanced winding pattern, led to successful gunfire 

tests for an all-carbon fiber, 2.25 FOS tank 

construction. Based on this work, a preliminary tank 

design was developed (see Figure 3) for the CH2-ISS 

application. 

Task (3) The ISS uses a high-strength, 

lightweight shell/cover in conjunction with flexible 

Figure 1. Assembly View of the CH2-ISS

Figure 2. High Density Polyethylene Liner

Figure 3. CH2-ISS Tank Preliminary Design
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

221

urethane impact-absorbing foam to encapsulate and 

protect the individual tanks into a single unitized 

container. In FY02, the shell technology work 

focused on identifying a manufacturing process and 

materials that result in the optimum combination of 

component strength, toughness, weight, tooling and 

part cost, trimming and assembly cost, and chemical 

resistance. Two Pro/ENGINEER CAD designs were 

developed to support an evaluation of alternative 

means for high-volume production of the CH2-ISS 

outer shell and gas control cover. Working with 

industry, a trade study was performed that examined 

a number of materials/processes and resulted in a 

downselect of two alternatives for further 

investigation - fabrication via (1) compression 

molding with Sheet Molding Compound (SMC) and 

(2) preform fabrication using Directed Fiber Preform 

combined with Structural Reaction Injection 

Molding. 

Task (4) The ISS is assembled as a single, 

inseparable container, requiring only one manual 

service valve, one solenoid, and one thermally 

activated pressure relief device, all incorporated into 

a gas control module (see Figure 4). The added cost 

and complexity of redundant components when using 

multiple, separable cH2 tanks is avoided by this 

approach. The gas control system is safeguarded 

from physical damage with impact absorbing foam 

CH2-ISS Performance Estimate

within a high-strength protective cover. In FY02, 

two alternative Pro/ENGINEER CAD notional 

models were developed focused on a fully unitize 

affordable gas control module. The two designs are 

variants of JHU/APL's patented design "Compressed 

Gas Manifold" (U.S. patent # 6,321,775, dated 

November 27, 2001). 

Task (5) The technology tasks completed in 

FY02 and the work needed to continue development 

was assembled into an overall project roadmap. The 

roadmap identifies out-year tasks needed to fully 

develop and safety-certify a CH2-ISS for potential 

mass production. The roadmap identifies important 

studies and/or subsystem developments and tests that 

minimize the risk of undertaking the full CH2-ISS 

development.

Conclusions

Substantial progress has been made in 

developing a high energy density, near-rectangular, 

safety-certified and affordable container for the 

onboard storage of compressed hydrogen gas for use 

in FCVs. The work has focused on the Integrated 

Storage System design, hydrogen tank permeation 

Figure 4. Unitary Gas Control Module Design

Total Empty Weight 73 Kg

Service Perssure 340 bar

Total Hydrogen Capacity 4.2 Kg

Gas/Container Mass Fraction 5.7%

External Volume 266 liter

Internal Gas Volume 166 liter

Figure 5. Estimated CH2-ISS Characteristics
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

222

reduction and overwrap development, and a trade-off 

study of protective shell and gas control 

manufacturing options. The information developed 

has been formulated into a preliminary CH2-ISS 

design with performance estimated (see Figure 5). 

Continued component development and critical tests 

are proposed for FY03 which will enable future full 

development of a CH2-ISS and its safety 

certification. 

FY 2002 Publications/Presentations

 1. Development of a Compressed Hydrogen Gas 

Integrated Storage System (CH2-ISS) for Fuel 

Cell Vehicles- Midterm Report, ADS-02-014, 

April 2002

2. Development of a Compressed Hydrogen Gas 

Integrated Storage System (CH2-ISS) for Fuel 

Cell Vehicles- Peer Review Presentation CD/

ROM Report, June 19, 2002

Special Recognition & Awards/Patent Issued

1. U.S. patent No. 6,418,962 entitled "Low Cost 

Compressed Gas Fuel Storage System", awarded 

July 16, 2002
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

223

III.A.6 Low Permeation Liner for Hydrogen Gas Storage Tanks

Paul A. Lessing (Primary Contact)

Idaho National Engineering & Environmental Laboratory (INEEL)

P.O. Box 1625

Idaho Falls, ID, 83415-2218

(208) 526-8776, fax: (208) 526-0690, e-mail: pal2@inel.gov

INEEL Technical Advisor: Raymond P. Anderson

(208) 526-1623, fax: (208) 526-9822, e-mail: anderp@inel.gov

DOE Technology Development Manager: Lucito Cataquiz

(202) 586-0729, fax: (202) 586-9811, e-mail: Lucito.Cataquiz@ee.doe.gov

Main Subcontractor: University of California at Los Angelos, Los Angeles, CA

Objective

• Develop a polymer liner that greatly limits hydrogen losses from commercial, light-weight, composite, 

high-pressure hydrogen tanks. 

Approach

• Select and fabricate polymeric materials with the necessary electron and proton conducting properties

• Fabricate a "bench-top" model of a tri-layer, electrochemically-active protection device that greatly 

reduces hydrogen permeation through polymer "substrates"

• Demonstrate the successful functioning of the bench-top device 

• Demonstrate a successful prototype of an active, electrochemical hydrogen barrier system within a 

high-pressure, polymer-lined, composite hydrogen storage tank

Accomplishments 

• Invented a unique concept for an electrochemically active, tri-layer device to prevent hydrogen 

permeation through a polymeric tank liner 

• Negotiated a cooperative agreement with a high-pressure hydrogen tank manufacturer

• Negotiated a statement of work for a major subcontract with a university that is actively engaged in 

research on conductive polymer compositions

Future Directions 

• Select the proper materials of construction

• Fabricate tri-layer coatings having the necessary structural and electrochemical properties

• Experimentally verify that operation of the barrier provides hydrogenation/permeation protection
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

224

Introduction

State-of-the-art high-pressure gas storage tanks 

consist of an inner liner, made from a polymer such 

as cross-linked polyethylene or nylon, overlaid with 

a continuous graphite fiber/epoxy reinforcement 

layer. These tanks have successfully stored highpressure methane gas. It is desired to extend the 

application of this type of tank to high-pressure 

hydrogen. However, hydrogen has a significantly 

higher permeability rate through these polymer liners 

than does methane. Permeation leads to a gradual 

loss of hydrogen pressure, and the hydrogen is 

thought to damage and weaken the reinforcement 

layer.

This project was recently begun to develop a 

hydrogen diffusion barrier that can be applied to the 

interior of the polymer liner. To be effective, the 

barrier must have the following attributes: (1) low 

permeability of hydrogen, (2) good adherence to the 

polymer liner, (3) stiffness (modulus) of the coating 

that matches the underlying polymer to avoid 

cracking when the tank is pressurized, (4) an 

application method that allows for coating inside a 

tank with a narrow neck and results in hermetic (gastight) coatings that are devoid of pin-holes, and (5) a 

material and coating method that does not 

appreciably add to the overall cost or weight of the 

tank.

Approach

An electrochemically "active" hydrogen barrier, 

fabricated from polymers, will be developed. A 

schematic of this barrier is shown in Figure 1. 

The development plan includes the following:

• The barrier is to be constructed of three 

layers of polymers consisting of a protonconducting electrolyte (electronic insulator) 

sandwiched between electronically 

conductive polymer electrodes. Candidate 

polymer compositions will be selected based 

upon existing knowledge. If this knowledge 

is not sufficient, new or modified 

compositions will be developed. Appropriate 

catalyst materials will be added at the 

electrolyte/electrode interfaces.

• The methods to manufacture the layers will 

be adapted from existing techniques or 

developed during the project. This could 

include dip coating or spraying of monomers 

followed by polymerization. Other 

possibilities will be explored and successful 

manufacturing technologies will be 

developed.

• The device is designed as a galvanic-type 

device that functions to prevent hydrogen 

permeation through application of a small 

direct current (dc) voltage using small 

currents. Methods to provide attachment of 

the dc voltage will be developed.

The hydrogen partial pressure established by the 

voltage is extremely low at the underlying polymer 

interface. The hydrogen partial pressure can be 

calculated using the Nernst equation (relates the 

voltage of a cell to its thermodynamic properties), as 

shown in Figure 1. An appropriate level of voltage 

will be calculated and experimentally verified.

Results

This project has only recently begun, having 

been funded late in FY 2002. A patent application 

was drafted and submitted to the U.S. Patent Office. 

The application covers the basic concept, designs, 

and possible manufacturing methods. An initial 

literature search was conducted for the polymeric 

Figure 1. Schematic Showing Tri-layer Hydrogen 

Barrier Concept
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

225

materials that are intended to comprise the 3 layers of 

the electrochemically active coating.

A Cooperative Research and Development 

Agreement was negotiated between an industrial 

partner that manufacturers composite, high-pressure, 

INEEL (Bechtel BWXT Idaho). Additionally, a 

statement of work was negotiated with a university 

subcontractor (University of California at Los 

Angeles).

Conclusions

The project is just beginning, so conclusions are 

not yet available.

Patent

1. U.S. Patent Application: Paul A. Lessing, 

"Polymeric Hydrogen Diffusion Barrier, HighPressure Storage Tank so Equipped, Method of 

Fabricating a Storage Tank, and Method of 

Preventing Hydrogen Diffusion", September, 

2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

226

III.B Carbon Materials

III.B.1 Hydrogen Storage in Carbon Single-Wall Nanotubes 

A.C. Dillon, K.E.H. Gilbert, P.A. Parilla, J.L. Alleman, G.L. Hornyak, K.M. Jones, and M.J. Heben 

(Primary Contact) 

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401

(303) 384-6641, fax: (303) 384-6655, e-mail: michael_heben@nrel.gov

DOE Technology Development Manager: JoAnn Milliken

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Objectives

• Determine the extent to which carbon single-wall nanotubes (SWNTs) can reversibly store hydrogen.

• Discover the mechanism of hydrogen storage in SWNTs.

• Develop simple, reproducible, and potentially scalable processes for producing SWNTs.

Approach

• Decouple the two steps in the ultrasonication process used to activate SWNTs for hydrogen storage, 

i.e., cutting and metal hydride introduction, to improve process control and to determine the relative 

contribution of each to the hydrogen storage capacity. 

• Develop new methods for cutting SWNTs that avoid the introduction of the metal alloy and develop 

separate processes to introduce metal hydrides to the SWNTs in a controlled manner.

• Develop techniques to determine and measure the key characteristics of SWNTs that yield high 

hydrogen storage capacities. 

Accomplishments

• Developed two different dry cutting methods for cutting SWNTs, which are in the process of being 

patented. Neither process involves sonication and therefore, cut samples that are free from metals can 

be produced.

• Improved control over pulsed laser synthesis of SWNTs, producing samples with hydrogen storage 

capacities of 4 weight percent (wt%). 

• Developed a Raman analysis technique that can be used to characterize the purity and defects in 

SWNT materials. Raman analysis can also be used to determine the degree of cutting in bulk SWNT 

samples. 

Future Directions

• Correlate the degree of SWNT cutting with hydrogen storage capacities in order to understand the 

hydrogen adsorption mechanism more completely.

• Probe possible adsorption pathways in order to explain why only specific nanotubes appear to be 

optimal for hydrogen storage applications.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

227

• Develop a method for the controlled incorporation of metal catalyst particles of discrete sizes and in 

specific locations so that SWNT hydrogen storage capacities may be reproducibly optimized.

• Optimize the purity, production rate, diameter, and chirality of the laser-generated SWNT samples to 

reliably achieve 6-7 wt% hydrogen storage.

Introduction

Hydrogen storage technology must be 

significantly advanced in performance and cost 

effectiveness if the U.S. is to establish a hydrogenbased transportation system. Gas-on-solid 

adsorption is an inherently safe and potentially high 

energy density hydrogen storage method that could 

prove to be more energy efficient than other 

hydrogen storage methods under evaluation, such as 

chemical or metal hydrides and compressed gas 

storage. Carbon single-wall nanotubes (SWNTs) and 

other nanostrucured carbon materials are being 

evaluated for this application. The long-term goal is 

to scale up production of optimized SWNT materials 

to enable efficient adsorption of hydrogen at ambient 

temperature and pressure and at system energy 

densities specified by the DOE Hydrogen, Fuel Cells, 

and Infrastructure Technologies Program (6.5 wt% 

and 62 kg/m3

).

Approach

Currently, the high-power ultrasonication 

method used to activate SWNTs for hydrogen storage 

simultaneously cuts purified SWNTs into shorter 

segments and introduces a metal hydride alloy 

(TiAl0.1V0.04) into the SWNTs. However, the 

sonication process does not provide for detailed or 

independent control of either cutting or metal 

incorporation. Differing degrees of cutting, amounts 

of metal, and metal particle sizes are found in 

processed samples even when identical sonication 

parameters (sonication time, sonication power, acid 

concentration, hydrodynamics, etc.) are employed. 

This lack of process control leads to variability in the 

performance of the final SWNT materials, which 

show hydrogen storage capacities on the tube 

fraction ranging from 0 to 8 wt%.

This research project is focusing on increasing 

control of the process used to activate the SWNTs for 

hydrogen, as well as developing reliable methods to 

determine and control the characteristics necessary 

for optimizing the hydrogen storage capacity of 

SWNTs. 

Results

Control of Laser-Production of Tailored SWNT Size 

and Type Distributions

Currently, SWNT materials are synthesized 

using a laser vaporization process. Samples with 

hydrogen storage capacities of ~7 wt% have been 

produced in a free running Nd:YAG laser (1064 

nanometer [nm]) synthesis. Initial samples made 

with the Alexandrite laser (755 nm) showed less than 

1 wt% storage. Multi-colored Raman measurements 

show that the Alexandrite laser was producing 

SWNTs that differ in diameter and chirality from 

those produced by the Nd:YAG laser. Past research 

on laser-generated SWNTs established that as the 

laser peak pulse power increases, SWNT diameter 

distributions shift to smaller diameters and SWNT 

chirality distributions result in semiconducting 

(rather than metallic) material properties. Using 

these two findings together, researchers have 

produced nanotube diameter and type distributions 

with the Alexandrite laser that are nearly identical to 

the Nd:YAG laser, as illustrated in Figure 1. 

Subsequent syntheses with the same peak power 

showed that the production of this SWNT size and 

type distribution is highly reproducible. With better 

control over SWNT production, samples with 

hydrogen storage capacities of 4 wt% have been 

fabricated with the Alexandrite laser. 

Poor Repeatability of High Hydrogen Adsorption 

Capacities

The hydride alloy (TiAl0.1V0.04) accounts for a 

portion of the hydrogen storage capacity of the alloy/

nanotube composite material that is formed in the 

ultrasonication process. Figure 2 displays a plot of 

hydrogen storage capacity versus alloy metal content 

for numerous purified SWNT samples that were 

treated with the ultrasonic probe process. About one-
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

228

half of the samples show hydrogen adsorption 

capacities that are too high to be explained by the 

presence of the alloy alone, indicating that these 

SWNTs have been activated for hydrogen storage. 

Assuming the hydrogen storage capacity of the 

TiAl0.1V0.04 alloy is 2.99 wt%, the SWNTs have 

hydrogen storage capacities between 0-8 wt%, with 

~8 wt% being a maximum value, independent of the 

amount of alloy present. Possible explanations for 

the observed variability include (1) the extent of 

destruction to the SWNTs caused by the ultrasonic 

cutting process and (2) the size of the metal alloy 

particles incorporated.

Development of Controlled Cutting Method Without 

Metal Hydride Incorporation

To reduce the variability in the performance of 

the activated SWNTs, research has focused on 

decoupling the cutting and metal introduction 

processes. Controlled cutting of carbon single-wall 

nanotubes has been achieved via a new cutting 

method that does not employ ultrasonication. 

Transmission electron microscopy analyses and 

Raman spectroscopy show that significant cutting 

occurs without significant damage to the SWNTs. 

Figure 3 compares hydrogen temperature 

programmed desorption spectra of a purified SWNT 

sample and a SWNT sample cut with the new 

method. The spectrum of the cut sample shows an 

additional hydrogen desorption peak at ~65oC, 

indicating the presence of hydrogen that is stabilized 

at ambient temperatures. This is the first time hightemperature adsorbed hydrogen has been observed 

Figure 1. Raman spectra in the radial breathing mode 

region for a) a Nd:YAG-produced sample 

with a H2 adsorption capacity of ~7 wt%, and 

b) a sample produced with the Alexandrite 

laser operating with a 200 ns pulse width at a 

peak power of 10.5 MW/cm2

. The red curves 

(highest curve on each figure) are for Raman 

excitation at 632.8 nm and show the SWNT 

size distribution for excited metallic and 

semiconducting tubes. The blue curves 

(lowest curve on each figure) were obtained at 

488 nm and show predominantly 

semiconducting tubes.

Figure 2. Plot of total sample hydrogen wt% content 

versus metal alloy content for SWNT samples 

following high energy sonication in HNO3

with an ultrasonic probe. Lines are drawn as a 

guide to the eye to show the anticipated 

hydrogen storage based on metal alloy content 

alone. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

229

on laser-generated materials without using the 

sonication activation process.

A Simple Method to Determine Degree of SWNT 

Cutting

In order to establish if a relationship exists 

between cutting and hydrogen storage capacities, a 

Raman spectroscopy technique was developed to 

quantify the degree of cutting obtained in 

macroscopic SWNT samples. Using an analysis of 

the SWNT Raman mode at 1350 cm-1, labeled the 

nanotube D-band, and the mode at 1593 cm-1, or 

nanotube G-band, the degree of cutting can be 

tracked. The D-band increases when the nanotubes 

are cut and new defects are introduced. An increase 

of ~25% is observed for the D-band intensity in the 

spectrum of the cut SWNTs in Figure 4. The SWNT 

G-band feature serves as a useful spectral feature for 

normalization because it does not change in intensity 

with cutting or the introduction of new defects. 

Figure 5 shows that the D/G ratio is nearly the same 

for three samples before and after identical cutting 

procedures, suggesting that the D/G ratio is 

correlated with the degree of cutting.

Conclusions

• Obtaining activated SWNT hydrogen storage 

materials with highly reproducible 

adsorption capacities has not yet been 

achieved. One reason may be that hydrogen 

storage is only optimized for a very specific 

and narrow distribution of SWNTs of distinct 

types and diameters. 

• Laser synthesis conditions that reproducibly 

produce SWNTs with size and type 

distributions previously found to have 

optimal hydrogen storage capacities of ~7 

wt% have been established.

Figure 3. Temperature programmed desorption 

spectroscopy of purified SWNT materials 

before and after dry cutting process. The 

signal at 65 oC for the cut sample is similar to 

the one we reported previously for arcdischarge SWNTs, but it occurs at a 

temperature which is ~65 degrees higher. 

Figure 4. Raman spectra at 488 nm for a purified and 

purified/cut sample. The spectra are 

normalized to the G-band intensity at ~1593 

cm-1, which is off-scale. The D-band 

intensity is enhanced relative to the G-band 

intensity in the cut sample.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

230

• A new controlled dry cutting method that 

non-destructively cuts nanotubes without 

incorporating a metal hydride alloy has been 

developed. 

• A new Raman spectroscopy-based technique 

that promises to allow the extent of SWNT 

cutting to be quantified has been developed.

FY 2002 Publications/Presentations

1. Dillon, A.C.; Gilbert, K.E.H.; Parilla, P.A.; 

Alleman, J.L.; Gennett, T.; Grigorian, L.; Jones, 

K.M.; Heben, M.J. “Hydrogen Storage in SingleWall Carbon Nanotubes.” In Proceedings of the 

14th World Hydrogen Energy Conference 

Montreal, Quebec, Canada, June 2002.

2. Hornyak, G.L.; Grigorian, L.; Dillon, A.C.; 

Parilla, P.A.; Jones, K.M.; Heben, M.J. “A 

Temperature Window for Chemical Vapor 

Decomposition Growth of Single-Wall Carbon 

Nanotubes.” J.Phys. Chem B 2002, 106, 2821-

2825.

3. Dillon, A.C.; Parilla, P.A.; Gennett, T.; Alleman, 

J.L.; Jones, K.M.; Heben, M.J. “A Narrow and 

Defect-activated Raman D-Band in Pure Bulk 

Carbon Single-wall Nanotubes.” Submitted to 

Phys. Rev. Lett.

4. Grigorian, L.; Hornyak, G.L.; Dillon, A.C.; 

Parilla, P.A.; Heben, M.J. “Synthesis of All ZigZag Single-Wall Carbon Nanotubes by CVD.” 

Manuscript in preparation.

5. Maness, P.-C.; Smolinski, S.; Dillon, A.C.; 

Heben, M.J.; Weaver, P.F. “Characterization of the 

Oxygen Tolerance of a Hydrogenase Linked to a 

Carbon Monoxide Oxidation Pathway in 

Rubrivivax gelatinosus.” To appear in Appl. Env. 

Microbiology.

Special Recognitions & Awards/Patents 

Issued

1. Grigorian, L.; Hornyak, G.L.; Dillon, A.C.; 

Heben, M.J. “Continuous Growth of SWNTs by 

CVD.”

2. Dillon, A.C.; Parilla, P.A.; Heben, M.J. “Bulk 

Cutting of SWNTs.” In preparation.

Figure 5. The ratio of the D-band intensity to the Gband intensity for a few samples before and 

after cutting. The D/G intensity ratio 

increases by a fixed amount after the same 

cutting procedures were applied.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

231

III.B.2 Doped Carbon Nanotubes for Hydrogen Storage

Ragaiy Zidan (Primary Contact)

Savannah River Technology Center

773-41A, Savannah River Site

Aiken, South Carolina

(803) 725-1726, fax: (803) 725-4129, e-mail: ragaiy.zidan@srs.gov

DOE Technology Development Manager: JoAnn Milliken 

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Objectives 

• Develop reversible high-capacity hydrogen storage material with the following properties:

- Hydrogen capacity greater than 6 weight % 

- Favorable thermodynamic and kinetics suitable for transportation applications 

- Stable with hydriding/dehydriding cycling 

- Resistant to trace contaminates

Approach

• Create a weak covalent bond between hydrogen and carbon by doping carbon nanotubes with metals to 

manipulate the electronic structure

• Produce consistent size metal dopants and structures of carbon nanotubes

• Control the type and size of the tubes and clusters inside the tubes 

• Tune the material for hydrogen sorption to occur at desired temperatures and pressures

• Conduct thermodynamic and energetic characterization on hydrogen sorption

• Conduct spectroscopic characterization and elemental analysis to guide the effort

Accomplishments

• Developed Dopant Encapsulation, a novel method for producing metal doped carbon nanotubes with 

controlled size and structures (patent is applied for), which allows gram quantities of doped nanotubes 

with high purity to be produced

• Produced samples with different dopants, alloyed dopants

• Preliminary hydriding and dehydriding of samples showed hydrogen uptake and release of about 1.0 

by weight % (more than expected from physisorption)

• Preliminary testing of cycling of hydrogen uptake and release showed consistent uptake and release 

over 10 cycles

Future Directions 

• Continue producing nanotubes with different dopants and configurations using Dopant Encapsulation 

method

• Tune structure and control amount of dopants to optimize hydrogen binding energy (via achieving 

dihydrogen bonding)

• Conduct thermodynamic characterization of hydrogen uptake and release 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

232

• Utilize different spectroscopic methods (e.g. scanning electron microscopy [SEM], transmission 

electron microscopy [TEM], energy dispersive spectroscopy [EDS], etc.) to identify the type and size 

of nanotubes and clusters of dopants that result in a reversible high hydrogen capacity 

• Tune conditions that result in a high yield of material possessing favorable characteristics such as 

storage capacity greater than 6 weight % hydrogen

• Perform cycling tests on material and investigate the effect of contaminants on hydrogen sorption

• Coordinate research and development effort with other DOE Laboratories and organizations working 

on carbon for hydrogen storage

Introduction

A major obstacle to a transition to a hydrogen 

economy has been the absence of a practical means 

for hydrogen storage. The goal of researchers has 

been to develop a high-density hydrogen storage 

system that can release hydrogen at temperatures 

lower than 100°C. It has been recognized that 

developing a suitable solid-state hydrogen storage 

material will be ideal for engineering a practical 

storage system. Carbon nanotubes represent a new 

direction for solid hydrogen storage, especially if 

these materials can be altered to store large amounts 

of hydrogen at room temperature. Widespread 

research activity into the properties and applications 

of the nanometer scale cylindrical carbon tubes has 

been reported [1-3], with much focus on the use of 

carbon nanotubes for hydrogen storage [4-8]. 

Simple mechanisms for hydrogen uptake and 

release involving physisorption and/or chemisorption 

cannot account for the unusual sorption of hydrogen 

by carbon nanotubes. In some cases, however, the 

unique nanotube structure and configurations could 

give rise to polarization and condensation of 

hydrogen inside the tubes. The research presented 

here is focused on modifying carbon nanotubes in an 

attempt to enhance and tune their hydrogen storage 

capabilities using metal dopants. The objective of 

this research has been to introduce transition metals 

and/or metal clusters inside the tubes that allow for 

hydrogen uptake and release. Establishing a 

relatively weak nanotube-hydrogen bond (not as 

weak as physisorption bond) should allow hydriding/

dehydriding to occur at mild conditions of 

temperature and pressure. Producing consistent 

structures is also necessary for reliable results and 

reproducible data.

Approach

Introducing nano-particles (dopants) to carbon 

nanotubes to create a weak covalent bond has been 

the general approach of this work. The goal has been 

to establish an interaction between hydrogen and 

carbon nanotubes based on a weak covalent bond 

where the electron donation from the (σ) orbital of 

hydrogen to the doped tubes weakens but does not 

break the hydrogen-hydrogen bond [9,10]. The 

unique strategy of this research is not just to dope 

carbon nanotubes with metals, but also to control the 

type and size of the tubes and the encapsulated metal 

clusters. This allows the electron density to be 

manipulated and the material to be tuned for 

hydrogen sorption at desired temperatures and 

pressures. The process is intended to take advantage 

of the nano scale properties of the system. This 

research is also aimed at producing gram quantities 

of consistent structures and sizes. Scanning and 

transmission electron microscopy are used to 

investigate configuration of tubes and dopants and to 

guide the development of the materials. 

Thermogravimetric and thermovolumetric analyzers 

are used to measure and quantify hydrogen uptake 

and release. 

Results

The synthesis of different doped carbon 

nanotubes has been achieved using the Dopant 

Encapsulation method we developed. This method 

was used to dope the tubes not only with metals, but 

also with alloyed clusters of different metals. The 

Dopant Encapsulation method was utilized to 

produce large quantities of metal doped carbon 

nanotubes of consistent structure (see Figures 1 and 

2). A thermogravimetric system capable of operating 

at a wide range of temperatures was used to measure 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

233

hydrogen uptake and release. The system was 

enclosed in an inert atmosphere glove box to avoid 

contamination from water and reactive gases. 

Preliminary results showed consistent hydrogen 

uptake and release of 1% by weight. The sample was 

cycled 10 times without deterioration of hydrogen 

capacity.

Conclusions 

The immediate objective of this work was to 

produce large quantities of carbon nanotubes with 

consistent structures that can be modified as needed. 

Therefore, a novel method for producing and 

controlling configuration and structure of carbon 

nanotubes was developed and demonstrated. The 

Dopant Encapsulation method enables the production 

of doped carbon nanotubes with transition metals and 

alloys that can give rise to weak covalent bonds 

similar to dihydrogen. The encapsulation of a metal 

at the tip of the tube eliminates the need for opening 

or cutting the tube. Preliminary results, using a 

thermogravimetric analyzer, showed hydrogen 

uptake and release of 1% by weight. Figure 1. Shows SEM Images of Large 

Quantities of Nanotubes Doped with 

Different Metals (Gram Quantity 

Samples were Produced). 

Figure 2. Shows the Tip of a Nanotube with 

Encapsulated Metal Particle 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

234

Acknowledgement

This research work was done in collaboration 

with Dr. Apparao M. Rao, Department of Physics, 

Clemson University, South Carolina.

References

1. S. Iijima, Nature, 354 (1991) 56

2. S. Iijima and T. Ichihashi Nature, 363 (1993) 603

3. D. S. Bethune, C.H. Kiang, M. S. de Vries, G. 

Gorman, R. Savoy, J. Vazquez and R. Beyers, 

Nature, 363 (1993) 605

4. A.C. Dillon, K. M. Jones, T. A. Bekkedahl, C.H. 

Kiang, D. S. Bethune and M.J. Heben Nature, 386 

(1997) 377

5. Y. Ye, C.C. Ahn, C. Witham, B. Fultz, J. Liu, 

A.G. Rinzler, D. Colbert, K.A. Smith, and R.E. 

Smalley, Applied Physics Letters 74, 2307 (1999)

6. C. Liu, Y.Y.Fan., M. Liu, H.T. Cong, H.M. Cheng, 

and M. Dresselhaus, Science 286, 1127 (1999)

7. P.,Chen, X. Wu, J. Lin, and K.L. Tan, Science 

285, 91 (1999)

8. R. Chahine and P. Bénard, IEA Task 12: Metal 

Hydrides and Carbon for Hydrogen Storage 

(2001)

9. G.J Kubas, R.R. Ryan B. I. Swanson, P.J. 

Vergamini, and .J. Wasserman, J. Am. Chem. 

Soc. 106, 451 (1984)

10. G.J. Kubas, Acc. Chem. Res. 21, 120 (1988)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

235

III.B.3 Hydrogen Storage in Metal-modified Single-Walled Carbon Nanotubes

Channing Ahn (Primary Contact)

 California Institute of Technology

1200 E. California Blvd, MS 138-78

Pasadena, CA 91125

(626) 395-2174, fax: (626) 795-6132, e-mail: cca@caltech.edu

DOE Technology Development Manager: JoAnn Milliken

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Objectives 

• Alter adsorption enthalpy of hydrogen on single walled nanotubes (SWNTs) by use of a potassium 

intercalant.

• Increase number of adsorption sites in SWNTs by increasing the surface area through the use of 

intercalant.

• Improve the hydrogen storage capacity of SWNTs.

Approach

• Investigate potassium intercalation synthesis procedures and measure sorption behavior of flaked 

graphites.

• Apply synthesis “recipes” to SWNT intercalation.

• Use Sieverts apparatus to measure hydrogen sorption isotherms.

Accomplishments 

• Optimized synthesis procedures for KC24 and KC48 intercalated graphites.

• Performed neutron powder diffraction of as-prepared and deuterided intercalated graphites.

• Showed for the first time that K-intercalated graphites undergo 5% lattice expansion beyond the 5.35 D

intercalated layer spacing when deuterided, indicating slit-pore sorption behavior for this system.

• Determined preliminary structure verifying 8.49D a-b spacing for potassium dodecal structure within 

graphene planes.D

Future Directions 

• Purification and intercalation of SWNTs.

• Structural characterization of purified and intercalated SWNTs.

• Volumetric hydrogen adsorption measurements of SWNTs.

Introduction

Hydrogen physisorption on pure carbon 

materials will not meet DOE targets, owing to the 

thermodynamic enthalpy of hydrogen adsorption on 

carbon. For instance, our previous work on SWNTs 

yielded a value of 38 milli-electron volt [1] or 3.6 

kilojoule per mole (kJ/mole), values consistent with 

adsorption on a graphene surface [2]. Our work for 

this project has concentrated on the use of potassium 

to increase the adsorption enthalpy in a way that will 

allow us to reduce the high pressures, and increase 

the low temperatures presently required for high 

hydrogen gravimetric densities. An issue of nearly 

equal importance is the number of sites for hydrogen 

sorption, since this sets the ultimate hydrogen storage 

capacity.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

236

Potassium-intercalated graphite can readily 

adsorb and desorb hydrogen at ~1 weight % [3]. The 

level is much higher than can be attained in pure 

graphite, due to a larger thermodynamic enthalpy of 

absorption. Increased enthalpy allows hydrogen 

sorption at higher temperatures. Potassium also has 

beneficial effects that enable the design of a new 

material that include: a) Increased absorption 

enthalpy in potassium-intercalated graphite 

compared to pure graphite reduces the pressure and 

increases the temperature required for a given 

fractional coverage of hydrogen absorption. We 

expect the same effects in potassium-intercalated 

SWNTs and; b) As an intercalant, potassium 

separates c-axis planes in graphite. Potassium also 

separates the individual tubes of SWNTs ropes 

producing swelling and increased surface area. 

Increased surface area provides more adsorption 

sites, giving a proportionately higher capacity.

Intercalation of graphene planes separates the 

normal a-b spacing from 3.35 D to a potassium 

containing graphene spacing of 5.35 D. These 

potassium-containing planes form a dodecal 

structure, which, on the basis of space filling 

arguments, is capable of accommodating four 

hydrogen molecules, yielding 1.2 weight % 

gravimetric density. The hydrogen sorption energies 

for KC24 are ~40 kJ/mole [4], roughly an order of 

magnitude greater than for hydrogen on a graphene 

surface.

Adopting the approach of increasing the 

adsorption enthalpy for graphites should have a 

similar effect for SWNTs, and also have the effect of 

increasing the surface area of SWNTs. Nanotubes 

typically form rope structures due to van der Waals 

interactions which promote rope formation, limiting 

the surface area to ~300 m2

/gm (interior and exterior 

surface areas for a SWNT material should be above 

2,600 m2/gm). Potassium intercalation of SWNTs 

will separate the individual tubes. Computational 

work on SWNTs shows that under certain conditions, 

increasing the van der Waals gap will increase the 

amount of hydrogen that can be adsorbed [5].

Approach

We have been exploring 2-zone furnace 

procedures for the synthesis of KC24 and KC48. 

Following 30-year-old synthesis techniques, we have 

used 2 different battery grade graphites deemed 

suitable for intercalation work. One is a high-purity 

plated graphite from Diemasters product G-1 and the 

other is a milled graphite from Superior Graphite 

designated SL-20. Having anticipated the 

importance of the analysis of these materials, we 

applied for beamtime at the Neutron Powder 

Diffractometer (NPD) at the Lujan Center at Los 

Alamos National Laboratory (LANL).

The initial goal of our work was to find the 

occupancy sites of deuterium atoms. Unlike 

hydrogen, deuterium is an effective coherent 

scatterer for neutrons, while its thermodynamic 

behavior with respect to carbon is similar to that of 

hydrogen. Thus, we would expect the presence of 

deuterium to alter the neutron diffraction pattern in a 

way that would reveal its location in the lattice. 

Deuterium is similar enough in size and physical 

behavior that such information would guide 

strategies for determining optimal positions for 

potassium on a graphite lattice, and provide a 

suitable foundation from which to calculate and 

understand hydrogen uptake in these intercalated 

graphites.

Three vanadium can assemblies, for the sample 

environment on the NPD at the LANL, were 

designed and constructed at Caltech. These 

assemblies incorporated conflat and VCR fittings 

(special fittings designed for high temperatures and 

pressures) in such a way as to accommodate the large 

temperature range available to us using the displex 

cooler on NPD. The vanadium cans were purchased 

from B&J Enterprises, a company that specializes in 

the manufacture of vanadium cans for neutron 

diffraction work. The stainless components were 

purchased from Norcal. All components were silversoldered except for the vanadium-to-stainless joint, 

which was assembled using a high performance 

strain-gauge epoxy, M-bond 610 from Micromeasurements. These assemblies were tested to 77 

degrees Kelvin and 10 bar pressure of hydrogen. In 

addition, a gas manifold was assembled at Caltech in 

order to provide a range of D2 overpressures, 

necessary to accommodate absorption during sample 

cooling. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

237

Approximately 1 gram of each of these samples 

was loaded into the vanadium assemblies under Ar 

atmosphere in our glove box at Caltech and sealed 

and shipped to LANL.

Results

Figure 1 shows one of the first runs of the Stage 

2 compound taken over a period of ~4 hours. The 

lower trace shows a simulation of diffraction data for 

a perfect crystal of the KC24 compound. Lack of the 

basal plane graphite reflection at 3.35 D indicates 

that no decomposition or air exposure of this sample 

occurred.

The NPD data for the 300 degrees Kelvin run of 

the Stage 4 compound is seen in Figure 2. While the 

synthesis conditions used to make this sample were 

similar to the conditions used to make the Stage 2 

compound, we believe that subtle differences in the 

nature of the starting graphite resulted in slower 

intercalation kinetics. In fact, this sample also 

contained a small amount of Stage 3 material. Both 

the (0 0 10) reflection from the Stage 4 phase as well 

as the (0 0 4) reflection corresponding to the Stage 3 

phase can be observed in simulated and indexed 

diffractions for both phases in the lower traces.

Our analysis of the diffraction data upon cooling 

is shown in the lower traces of Figure 3 and reveals 

the normal lattice contraction expected for the c-axis. 

The upper traces show the lattice expansion in the 

deuterided material, and we can infer from a 

comparison of Stage 2 with Stage 4 data that the 

lattice expansion is consistent with deuterium only 

residing on the potassium-containing planes.

We have begun an initial set of computations for 

pair distribution analysis of our data with the hope 

that specific correlations can be drawn regarding the 

precise location (if any) of the deuterium molecules. 

In any event, these data do show deviations between 

35 degrees Kelvin data sets for vacuum and 

deuterided KC24 as shown in Figure 4. These 

deviations begin beyond the 5.35 D spacing of the 

Figure 1. NPD initial run of KC24 intercalated graphite 

compound. Simulated data is shown in the 

lower trace with major planar indices as 

noted.

Figure 2. Neutron diffraction pattern from Stage 4 

intercalated graphite. Indexed simulated peaks 

appear in the lower traces. Reflections from a 

Stage 3 phase (0 0 4) at 3.02 D overlap with the

Stage 4 (0 0 10) reflection at 3.09 D. Lattice 

spacing measurements were determined by 

gaussian deconvolution.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

238

potassium containing graphine distance, as shown in 

the residual in the lower trace.

Conclusions

The lattice expansion associated with deuteriding 

shows the dependence of absorption on potassiumcontaining planes in intercalated graphite and the 

importance of this system in serving as a suitable 

baseline for our subsequent measurements on 

SWNTs.

References

1. Y. Ye, C. C. Ahn, C. Witham, B. Fultz, J. Liu, A. 

G. Rinzler, D. Colbert, K. A. Smith and R.E. 

Smalley, Appl. Phys. Lett. 74, 2307 (1999).

2. E. L. Pace and A. R. Siebert, J. Phys. Chem. 63, 

1398 (1959).

3. M. Colin and A. Herold, Bull. Soc. Chim. Fr., 6, 

1982 (1971).

4. K. Ichimura, E. Takamura and M. Sano, Synth. 

Met., 40, 355, (1991).

5. V. V. Simonyan, J. K. Johnson, J. Alloys Comp. 

330-332, 659 (2002).

FY 2002 Publications/Presentations

1. Hydrogen Storage and Neutron Powder 

Diffraction of Deuterided KC24. C. C. Ahn, J. J. 

Vajo, R. Yazami, B. Fultz and D. W. Brown, Oral 

Presentation in symposium V (Materials for 

Energy Storage, Generation, and Transport), 2002 

Spring Meeting, Materials Research Society.

2. Hydrogen Storage and Neutron Powder 

Diffraction of Deuterided KC24 and KC48, C. C. 

Ahn, Invited Presentation, in Symposium S2 

(Hydrogen Storage Materials and Hydrogen 

Generators), 201st Meeting of the 

Electrochemical Society in Philadelphia, May, 

2002.

3. Hydrogen Storage in Carbons, C. C. Ahn, Invited 

Presentation, American Nuclear Society Annual 

Mtg., November 2002, Washington, D. C. 

Figure 3. Basal plane lattice parameter changes as a 

function of temperature for Stage 2 and Stage 

4 compounds under vacuum (lower traces) 

and deuterided (upper left traces). Figure 4. Pair distribution functions for Stage 2 

intercalated graphite, extracted from NPD 

data for sample held under vacuum and 

deuterided. A plot of the difference between 

these two PDFs is shown in the lower trace.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

239

III.C Hydrides

III.C.1 Catalytically Enhanced Hydrogen Storage Systems

Craig M. Jensen (Primary Contact), Dalin Sun, Sesha Raman, Michael Eberhard, Keeley Murphy, 

Zhaohui Wang, Kristin Kumashiro, Walter Neimczura

University of Hawaii

Department of Chemistry

Honolulu, Hawaii 96822

(808) 956-2769, fax: (808) 956-5908, e-mail: jensen@gold.chem.hawaii.edu

DOE Technology Development Manager: JoAnn Milliken

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Objectives

• Develop hydrogen storage materials based on complex aluminum hydrides that: a) have a hydrogen 

cycling capacity > 6 weight %; b) undergo dehydriding and rehydriding at temperatures below 100°C 

at rates that are sufficient for vehicular applications; and c) maintain >95% of their hydrogen capacity 

through >200 dehydriding/rehydriding cycles.

• Determine the kinetics and mechanism of the fundamental dehydriding and rehydriding reactions 

occurring in the doped hydride. 

• Develop a catalyst that can affect the reversible dehydrogenation of cycloalkanes to arenes at rates that 

are sufficient for vehicular applications at temperatures of $100°C.

Approach

• Determine the minimum dopant levels to affect dehydriding of NaAlH4 at adequate rates.

• Determine energetic barriers to the dehydrogenation of NaAlH4 to Na3AlH6/Al and Na3AlH6 to NaH/

Al and the reverse hydrogenation reactions by volumetric techniques.

• Differentiate hydride species present in doped hydride by solid state nuclear magnetic resonance 

(NMR) spectroscopy.

• Identify active catalyst through solid state NMR spectroscopy.

• Determine the activity of the iridium arsino pincer complex as a catalyst for alkane dehydrogenation.

Accomplishments

• Measured the rates of dehydrogenation of 2 mol % Ti and Zr doped NaAlH4 to Na3AlH6/Al at 80-

110°C and Na3AlH6 to NaH/Al at 120-150°C under 1 atm of H2.

• Determined activation enthalpies, ∆H‡, for the dehydrogenation for Ti and Zr doped hydride as 78 and 

116 kJ/mol, respectively.

• Discovered through solid state 1H NMR spectroscopy that there are two distinguishable populations of 

hydrogen in both doped and undoped NaAlH4, the minor population having unusually high solid state 

mobility. 

• Discovered that the doping of the hydride results in the changes in the bulk structure of the hydride 

rather than the introduction of surface localized catalytic sites. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

240

• Developed a model of the doped hydride in which doping entails substitution of Na+ ions by M4+ at 

low (#2 mol %) doping levels and M3+ at higher doping levels together with the requisite number of 

lattice vacancies. 

• Directly observed Ti3+ in 6 mol % Ti doped NaAlH4 by electron spin resonance (ESR) spectroscopy 

studies conducted in collaboration with Sandia National Laboratory.

• Determined that ~20% conversion of cycloalkanes to arenes can be achieved with the iridium arsino 

pincer catalyst than is obtained with the analogous phosphino catalyst.

Future Work 

• Determine the hydrogen cycling kinetics of NaAlH4 to NaH/Al of hydride that is doped solely with 

Ti3+, Ti4+, Zr3+, and Zr4+.

• Detect and quantify the amount of M3+, M2+, and/or M0 that are present in 1 and 6 mol % Ti and Zr 

doped hydride.

• Characterize the “mobile hydrogen” in NaAlH4 by solid state NMR spectroscopy, inelastic neutron 

scattering, optical spectroscopy and neutron diffraction studies.

Introduction

During the initial dehydriding reaction of 

NaAlH4, seen in equation 1, NaAlH4 rapidly evolves 

3 NaAlH4 ----------> Na3AlH6 + 2 Al + 3 H2 (1)

hydrogen at moderate temperatures upon doping with 

2 mole percent Ti(On

Bu)4 [1-13]. At 100°C, 

hydrogen flow rates of 0.01 g H2/s per kg under a 

constant pressure of 1 atm have been measured to 

evolve from hydride doped through methods 

developed in our laboratory [2,3]. This dehydriding 

performance is adequate to meet the demands of a 

fuel cell operating under practical conditions. We 

have also found that NaH and Al doped with 2 mole 

percent Zr(OnPr)4 absorbs 4.4 weight percent 

hydrogen within 15 minutes at 120°C under 125 atm 

of hydrogen. However, despite this progress in 

maximizing the catalytic enhancement of both the 

dehydriding and rehydriding process, it has not yet 

been demonstrated that ~5 weight percent hydrogen 

can be reversibly released from these materials under 

conditions that are required for the practical 

operation of an onboard fuel cell. Most notably, the 

rates of the second dehydriding reaction, seen in 

equation 2, 

Na3AlH6 ----------> 3 NaH + Al + 3/2 H2 (2)

and the reverse, hydriding of NaH and Al to NaAlH4, 

are impractical for hydride that is doped with 

titanium, and materials which exhibit improved 

kinetics in this second dehydriding reaction must be 

produced to achieve commercial viability. 

The PCP pincer complex, IrH2{C6H3-2,6-

(CH2PBut

2)2}, is the first reported homogeneous 

catalyst for the dehydrogenation of cycloalkanes to 

arenes [14-19]. Unlike the heterogeneous catalysts 

for this reaction, it shows appreciable activity at low 

concentrations at temperatures as low as 100°C. The 

pincer complex also catalyzes the hydrogenation of 

arenes to cycloalkanes under moderate (10 atm) 

pressures of hydrogen. The two-way, hydrogenation/

dehydrogenation activity of the catalyst suggests its 

application in a hydrogen storage system. Such a 

system meets the criteria of low cost and high 

hydrogen density (>6 wt %) required for a practical 

hydrogen storage system. The major drawback of a 

system based on cycloalkanes and the PCP pincer 

catalyst is that pronounced product inhibition occurs 

after about 10% dehydrogenation of cycloalkanes. 

Thus, an improved catalyst must be developed.

Results

Determination of the Energy Barriers Heights of the 

Fundamental Reactions 

We have measured the rates of dehydrogenation 

of 2 mol % Ti and Zr doped NaAlH4 to Na3AlH6/Al 

at 80-110°C and Na3AlH6 to NaH/Al at 120-150°C 

under 1 atm of H2. Eyring plots of the data show that 

the ∆H‡ of dehydrogenation reactions are 78 and 116 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

241

kJ/mol respectively for the Ti doped hydride and 113 

and 93 kJ/mol for the Zr doped hydride. We obtained 

predictions for the ∆H‡ of the reverse, hydrogenation 

reactions from reaction profile diagrams that were 

constructed using the values of ∆H‡ obtained from 

our studies and ∆H that were previously established 

for these reactions. We have also measured the rates 

of hydrogenation reactions and determined the 

activation enthalpy for ∆H‡ from Eyring plots of the 

data. As illustrated in Figure 1, we find that the 

experimentally determined values of ∆H‡ closely 

match the predicted by the reaction profile diagrams. 

This demonstrates that the kinetics of both hydriding 

reactions are limited by the micro-reverse of the 

fundamental Al-H bond breaking process. This data 

also confirms our earlier conclusion [3] that the best 

kinetic performance for the reversible dehydriding of 

NaAlH4 to Na3AlH6/Al is achieved by Ti doping, 

while the best kinetic performance for the reversible 

dehydrogenation of Na3AlH6 to NaH/Al is achieved 

by Zr doping.

Solid State NMR and ESR Studies

The extremely narrow signal that is observed for 

one of the hydrogen species establishes that it has 

unusually high solid state mobility. This finding is in 

agreement with recent X-ray diffraction studies we 

conducted with the National Institute of Advanced 

Industrial Sciences and Technology that have shown 

that the doping results in the changes in the bulk

structure of the hydride rather than the introduction 

of surface localized catalytic sites [13]. As illustrated 

in Figure 2, we have hypothesized that structural 

changes result from substitution of Na+ ions by M4+

and M3+ ions together with the requisite number of 

lattice vacancies. The presence of Ti3+ in 6 mol % Ti 

doped NaAlH4 has recently been confirmed by 

electron spin resonance spectroscopy studies that 

were conducted in collaboration with Sandia 

National Laboratory.

Testing of Arsino Pincer Catalyst 

We have found that the higher levels of 

conversion of cycloalkanes to arenes can be achieved 

with the iridium arsino pincer complex, IrH2{C6H3-

2,6-(CH2AsBut

2)2} than are obtained with the 

analogous phosphino catalyst. However, inhibition 

of the arsino pincer catalyst is observed at the ~20% 

dehydrogenation level for methylcyclohexane, 

decalin, and dicyclohexyl.

Figure 1. Energy-Reaction Profile for the Reversible 

Dehydrogenation of NaAlH4 to NaH + Al

Figure 2. Schematic Illustration of the Changes in the 

NaAlH4 Lattice upon Increased Level of 

Doping (a) Undoped hydride; (b) Substitution 

of Na+ by M4+ and requisite formation of 3 

Na+ vacancies upon doping with 2 mol % 

M4+; (c) increasing substitution without 

increasing Na+ vacancies requires M to be 

present as M3+ or M2+ at higher doping 

levels.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

242

Conclusions

Our studies of doped NaAlH4 have given 

important insights into the highly promising but 

enigmatic hydrogen storage properties of this 

material. Our kinetic studies strongly suggest that the 

rate of the dehydrogenation and hydrogenation 

reactions are limited by the micro-reverse of the 

fundamental Al-H bond breaking process. Our Xray diffraction and solid state NMR studies have 

shown that doping results in bulk changes to the 

crystal lattice of the hydride rather than the 

generation of surface isolated catalytic sites 

[1,4,5,9,11]. This structural augmentation of the 

hydride affects bulk perturbation and mobilization of 

hydrogen. These observations that bulk structural 

changes occur upon doping the hydride have led us to 

develop a new model of the doped hydride which 

accounts for the structural changes as the result of 

substitution of Na+ ions by M4+ and M3+ ions. In 

support of this “Na+ substitution” model, the 

presence of Ti3+ in samples NaAlH4 that were doped 

with a variety of titanium precursors has been 

confirmed through electron spin resonance studies.

We have attempted to develop a hydrogen 

storage system based on the reversible 

dehydrogenation of cycloalkanes to arenes utilizing 

iridium “pincer” complexes, IrH2{C6H3-2,6-

(CH2AsBut

2)2} and IrH2{C6H3-2,6-(CH2PBut2)2}. 

These complexes show appreciable catalytic activity 

at low concentrations at temperatures as low as 

100°C. The complexes also show appreciable 

catalytic activity for hydrogenation of arenes to 

cycloalkanes under moderate (10 atm) pressures of 

hydrogen. Despite this two-way hydrogenation/

dehydrogenation activity, their practical application 

in a hydrogen storage system seems unlikely as the 

dehydrogenation activity of the pincer catalysts was 

found to be inhibited by the arene products of all of 

the substrates tested after about 10-20% conversion. 

References

1. B. Bogdanovic, M. Schwickardi, J. Alloys Comp. 

1997 253, 1.

2. C.M. Jensen, R.A. Zidan, N. Mariels, A.G. Hee, 

C. Hagen, Int. J. Hydrogen Energy 1999, 24, 

461.

3. R.A. Zidan, S. Takara, A.G. Hee, C.M. Jensen, J. 

Alloys Comp.1999 285, 119.

4. B. Bogdanovic, R.A. Brand, A. Marjanovic, M. 

Schwickardi, J. Tolle, J. Alloys Comp. 2000, 302, 

36.

5. K.J. Gross, S. Guthrie, S. Takara, G. Thomas, J. 

Alloys Comp. 2000 297, 270.

6. A. Zaluska, L. Zaluski, J.O. Ström-Olsen, J. 

Alloys Comp. 2000 298, 125.

7. C.M. Jensen and K.J. Gross, Appl. Phys. A. 2001

72, 213.

8. B. Bogdanovic and M. Schwickardi, Appl. Phys. 

A. 2001 72, 221.

9. K.J. Gross, C.M. Jensen, G.J. Thomas, J. Alloys 

Comp. 2002 330-332, 683.

10. G. Sandrock, K. Gross, G. Thomas, C. Jensen, D. 

Meeker, S. Takara, J. Alloys Comp. 2002 330-

332, 696.

11. G.J. Thomas, K.J. Gross, N.Y.C. Yang, C. M. 

Jensen, J. Alloys Comp. 2002 330-332,702.

12. G.P. Meisner, G.G. Tibbetts, F.E. Pinkerton, C.H. 

Olk, M.P. Balogh, J. Alloys Comp. 2002 337, 

254.

13. D. Sun, T. Kiyobayashi, H. T. Takeshita, N. 

Kuriyama, C. M. Jensen, J. Alloys Comp. 2002

337, L8.

14. M. Gupta, C. Hagen, W.C. Kaska, R. Flesher, 

and C.M. Jensen, J. Chem. Soc. 

Chem.Commun., 1996 2083.

15. M. Gupta, C. Hagen, W.C. Kaska, R.E. Cramer, 

C.M. Jensen, J. Am. Chem. Soc., 1997, 119, 840.

16. M. Gupta, W.C. Kaska, and C.M. Jensen, J. 

Chem. Soc., Chem. Commun., 1997, 461.

17. X. Xu, G.P. Rosini, M. Gupta, C.M. Jensen, W.C. 

Kaska, K. Krough-Jespersen, and A.S. Goldman, 

J. Chem. Soc. Chem. Commun., 1997, 2273.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

243

18. C.M. Jensen, J. Chem. Soc., Chem. 

Commun., 1999, 2443

19. Liu, E.B. Pak, B. Singh, C.M. Jensen, and A.S. 

Goldman, J. Am. Chem. Soc. 1999, 121, 4086.

FY 2002 Publications

1. “Development of Catalytically Enhanced 

Sodium Aluminum Hydride as a Hydrogen 

Storage Material.” Craig M. Jensen and Karl J. 

Gross, Appl. Phys. A. 2001, 72, 221.

2. “Catalyzed Alanates for Hydrogen Storage.” 

K.J. Gross, C.M. Jensen, S. Takara, D. Meeker, 

and G.J. Thomas, J. Alloys Comp. 2002, 330-332, 

683.

3. “Engineering Considerations in the Use of 

Catalyzed Sodium Alanates for Hydrogen 

Storage.” G. Sandrock, K. Gross, G. Thomas, C. 

Jensen, D. Meeker, and S. Takara, J. Alloys 

Comp. 2002, 330-332, 696.

4. “Microstructural Characterization of Catalyzed 

NaAlH4.” G.J. Thomas, K.J. Gross, N.Y.C. Yang, 

C.M. Jensen, J. Alloys Comp. 2002, 330-332, 

702.

5. “X-ray Diffraction Studies of Titanium and 

Zirconium Doped NaAlH4: Structural Basis of 

the Enhanced Hydrogen Storage Properties 

Resulting Upon Doping.” Dalin Sun, Hiroyuki T. 

Takeshita, Tetsu Kiyobayashi, Nobuhiro 

Kuriyama, and Craig M. Jensen, J. Alloys Comp. 

2002, 337, 8.

FY 2002 Presentations

1. “Recent Progress in the Development of PCP 

Pincer Complexes as Catalysts for Organic 

Transformations.” 2000 International Chemical 

Congress of the Pacific Basin Societies, 

Honolulu, Hawaii, 12/17/01.

2. “PCP Pincer Complexes as Catalysts for Novel 

Organic Transformations.” University of Utah, 

10/25/01.

3. “Recent Advances in the Development of Doped 

NaAlH4 as a Hydrogen Storage Material: X-ray 

Diffraction and Solid State 1

H, 27Al, and 23Na 

NMR Studies.” The 2nd International 

Symposium on New Protium Function, 

Miyazaki, Japan, 12/14/01.

4. “Solid state 1

H, 27Al, and 23Na NMR Studies of 

Doped and Undoped NaAlH4.” Symposium on 

the Fundamentals of Advanced Materials for 

Energy Conversion, 2002 meeting of the 

Minerals, Metals, and Materials Society, Seattle, 

Washington, 2/20/02.

5. “PCP Pincer Complexes as Catalysts for Novel 

Organic Transformations.” University of 

Washington, 2/24/02.

6. “PCP Pincer Complexes as Catalysts for Novel 

Organic Transformations.” 81st meeting of the 

Chemical Society of Japan, Tokyo, Japan, 

3/27/02.

7. “Recent Advances in the Development of Doped 

NaAlH4 as a Hydrogen Storage Material: X-ray 

Diffraction and Solid State 1H, 27Al, and 23Na 

NMR Studies.” Symposium on Hydrogen 

Storage Materials and Hydrogen Generators, 

201st meeting of the Electrochemical Society, 

Philadelphia, PA, 5/13/02.

8. “Sodium Aluminum Hydride: Fundamental 

Studies and Development of a Promising New 

Hydrogen Storage Material.” Universal Oil 

Products, 8/13/03.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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III.C.2 Complex Hydrides for Hydrogen Storage

Darlene K. Slattery (Primary Contact), Michael D. Hampton

Florida Solar Energy Center

1679 Clearlake Road

Cocoa, FL 32922

(321) 638-1449, fax:(321) 638-1010, e-mail: dkslatt@fsec.ucf.edu

DOE Program Managers: JoAnn Milliken

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Objectives 

• Identify and prepare a complex hydride that reversibly stores at least 6.0 wt% hydrogen

• Optimize kinetics by the addition of a catalyst

Approach

• Determine hydrogen uptake and release characteristics of each compound in pure and catalyzed form

• Study mechanisms of catalyst action using physical methods such as x-ray photoelectron spectroscopy 

(XPS), Auger electron spectroscopy (AES) and x-ray diffraction (XRD)

Accomplishments 

• Characterized uncatalyzed materials using differential scanning calorimetry (DSC) and 

thermovolumetric analysis (TVA)

Future Directions 

• Develop method to synthesize solvent- and by-product-free complex hydrides

• Characterize these pure complexes for suitability

• Identify "best" candidate for further testing

• Initiate extended cycling tests

Introduction 

A major obstacle to the implementation of a 

hydrogen economy is an efficient, safe and 

economical method for storing hydrogen for 

automotive applications. An acceptable storage 

system should allow for a range of 300 miles per 

charge and should be reversible. Complex hydrides, 

such as sodium aluminum hydride, show great 

promise, but there are still problems with kinetics 

and weight percent of available hydrogen. 

Complex hydrides were previously thought to be 

irreversible. However, Bogdanovic and Schwickardi 

(1) showed that the addition of a catalyst, such as 

titanium, facilitated rehydrogenation. The primary 

problem is that, upon heating, the decomposition 

products are sodium hydride, aluminum and 

hydrogen. The hydrogen that remains tied up as 

sodium hydride is unavailable for use as a fuel and, 

as a result, the reversible hydrogen is only 5.5 wt%. 

Approach 

While sodium aluminum hydride was the first 

complex hydride shown to be reversible, there is a 

family of these compounds with high hydrogen 

content (Figure 1). In order to develop a system that 

meets the DOE target of greater than 6.0 wt% 

hydrogen, it is necessary either to start with a 

complex hydride containing a greater hydrogen 

density, or to develop a catalyst that will facilitate the 

release of the hydrogen from the decomposition 

product, sodium hydride. Sodium hydride has been 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

245

long known and extensively studied, with no 

progress toward reducing its stability. The option of 

investigating other complex hydrides appears to be 

the more judicious approach. 

Four of the complex hydrides of interest are 

commercially available. The others require 

synthesis, either by literature methods or by methods 

to be developed in-house. In order to determine the 

effect of the newly recognized hydrogenation/

dehydrogenation catalysts, it was necessary to 

investigate the compounds in their pure state. Only 

by having these baseline measurements would it be 

possible to ascertain the effect of an added catalyst. 

Also of importance in the study of hydrogen 

storage materials is an understanding of the 

mechanism of any catalyst. Only by understanding 

how a catalyst functions is it possible to improve 

upon its performance. The catalyst mechanism may 

be surmised by determining the fate of the catalyst in 

the storage compound, which maybe accomplished 

using techniques such as XPS, AES and XRD.

Results 

As a new project, it was necessary to first 

refurbish and update the instrumentation necessary 

for characterizing the hydrides. While the equipment 

was being updated, the synthesis of materials with 

literature preparations was begun. It has been 

determined that some of the literature reports contain 

erroneous information, resulting in synthetic 

difficulties. The literature preps for many of these 

compounds also result in a product that is 

contaminated with solvent and, therefore, the 

hydrogen released is contaminated. Additionally, 

these products are frequently contaminated with 

byproducts that neither react with hydrogen nor 

facilitate the reaction with hydrogen and, thus, 

decrease the apparent hydrogen capacity of the 

product. This effort has demonstrated the necessity 

to develop new methods for preparing contaminantfree hydrides.

The purchased hydrides were all subjected to 

characterization in their as-received state, using both 

differential scanning calorimetry (DSC) and 

thermovolumetric analysis (TVA). The baseline data 

from the two methods of characterization, shown in 

Figure 1. Available Hydrogen in Select Complex 

Hydrides

Figure 2. Thermovolumetric Analysis of LiAlH4

Figure 3. DSC Thermogram of LiAlH4
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

246

Figures 2 and 3, were found to corroborate the data in 

the literature. The dehydriding proceeds via a twostep mechanism and, without a catalyst, is not 

reversible. The TVA data, in addition to illustrating 

the kinetics of the hydride, allowed the calculation of 

the weight percent of hydrogen released from the 

material. The TVA data for the sodium aluminum 

hydride and the lithium aluminum hydride showed 

obvious release temperatures, while the 

corresponding borohydrides did not. It was also 

determined that the TVA and the DSC are 

complimentary techniques, providing data that match 

literature values while operating on significantly 

different sample sizes and theoretical principles.

Conclusions 

• Analysis using DSC and TVA gives 

complementary information. 

• Baseline studies were consistent with 

literature reports.

• Literature methods for synthesizing complex 

hydrides result in materials of low purity. 

New methods need to be developed.

References 

1. Bogdanovic, B., and Schwickardi, M. J. Alloys 

and Compounds, (1997) 253, 1-9. 

FY 2002 Publications/Presentations 

1. Slattery, D.K. and Hampton, M.D., "Complex 

Hydrides for Hydrogen Storage," Semi-annual 

contract report submitted to DOE under 

cooperative agreement DE-FC36-01GO11094. 

May 2002.

2. Slattery, D.K. and Hampton, M.D., "Complex 

Hydrides for Hydrogen Storage," Proceedings of 

the U.S. DOE Hydrogen Program Annual Review, 

Golden, CO, May 6-8, 2002.

3. Hampton, M.D and Slattery, D.K., "Complex 

Hydrides for Hydrogen Storage," Presented at the 

Alanate Working Group Meeting, January 31, 

2001.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

247

III.C.3 High-Density Hydrogen Storage Demonstration Using NaAlH4 Based 

Complex Compound Hydrides

Donald Anton (Primary Contact), Daniel Mosher

United Technologies Research Center

MS 129-22

411 Silver Lane

East Hartford, CT 06108

(860) 610-7174, fax: (860) 610-7253, e-mail: antondl@utrc.utc.com

DOE Technology Development Manager: JoAnn Milliken

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

ANL Technical Advisor: Thomas Benjamin

(630) 252-1632, fax: (630) 252-4176, e-mail: Benjamin@cmt.anl.gov

Subcontractors: Hydrogen Components, Inc. (HCI), Littleton, CO; QuesTek Innovations, LLC, 

Evanston, IL

Objectives

• Improve the charging and discharging rates of the NaAlH4 based hydrogen storage medium. 

Specifically, in collaboration with other efforts, 

- Increase the reversible weight fraction of hydrogen stored to 7.5% from the current 5.5%.

- Enhance the hydrogen evolution rate from 0.1 wt%/hr. at 80°C to 0.55 wt%/hr. to meet steady-state 

fuel cell demand.

- Increase the regeneration rates from the documented 0.5 wt%/hr to the 90 wt%/hr to achieve five 

minute refill requirement.

• Determine the safety and risk factors associated with the enhanced compositions.

• Design, develop and evaluate a hydrogen storage system having a 5 kg hydrogen capacity and 

installation capability in a fuel cell-powered mid-size sedan.

Approach

• Create thermodynamic models of the NaAlH4 system to determine optimum catalyzed compositional 

ranges designated as Complex Compound Hydrides (CCH).

• Cyclically evaluate selected CCH compositions to determine degradation mechanisms and 

ameliorations as well as compatibility with construction materials.

• Conduct standardized safety testing related to the classification of hazardous materials.

• Develop preliminary designs through the evaluation of existing systems, generation of weight/volume/

cost improvements, and high-level optimization to balance automotive demands.

• Perform heat and mass flow modeling for detailed optimization of the required system volume and 

mass. Evaluate methods to enhance heat conduction into the CCH powder.

• Fabricate and evaluate 1-kg H2 and 5-kg H2 capacity hydrogen supply systems in conjunction with 

proton exchange membrane fuel cell (PEMFC) systems.

• Conduct preliminary performance modeling of the combined PEMFC and hydrogen supply system 

under steady-state and transient conditions to establish dynamic control requirements.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

248

Accomplishments

This project is in the early stages, having received contract finalization two weeks prior to the writing of 

this report with some anticipatory work having been conducted at a reduced level over the past two 

months. 

• Safety testing procedures have been selected and the majority of the unique test fixturing has been 

fabricated.

• An assessment of system preliminary design options has been initiated along with first order cost 

modeling for high volumes of 1 million units per year.

Future Directions

• Sufficient material to perform the safety analysis and cyclic testing will be prepared by ball milling 

utilizing a composition of 2m% TiCl3 catalyzed NaAlH4, designated CCH#0. 

• Continue development of safety testing procedures and conduct initial tests on the CCH#0 

composition. 

• Generate additional concepts for the storage system tank to reduce system volume, weight, and cost.

• Conduct analytical, numerical, and experimental studies on a variety of heat conduction enhancement 

methods (metal foams, screens, wires, wools).

Introduction

One of the most significant barriers to the 

widespread application of hydrogen-based 

propulsion is the development of on-board storage 

systems which can provide the needed quantity of 

hydrogen with acceptable volume, weight, cost, and 

safety risk. The major classes of established 

hydrogen storage methodsncompressed gas, liquid, 

metal hydrides and chemical hydridesnall have 

advantages and disadvantages, but none are clearly 

superior for automotive applications. In particular, a 

disadvantage of metal hydrides is their low hydrogen 

capacities of less than 2 wt% for alloys with 

discharge temperatures where the waste heat of a 

PEMFC (∼ 90 deg. C) can be used to release the 

hydrogen. Many chemical hydride materials, while 

having high capacities, are classified as irreversible, 

which requires that the entire material be replaced 

during refueling rather than simply charging with 

hydrogen gas. The current project is focusing on the 

reversible chemical hydride, NaAlH4, with a 

theoretical hydrogen capacity of 5.5 wt%, and seeks 

to enhance the material for improved charging and 

discharging rates as well as increased capacity. The 

project seeks to apply this material in the 

development of a system which will reversibly store 

a high wt% of hydrogen at low pressure for an 

indefinite amount of time. Safety studies of the 

enhanced material will also be conducted to support 

the technology as it is driven toward 

commercialization.

The storage system which contains the CCH 

powder must serve two primary functions: 

(1) exchange heat between the powder and a working 

liquid to drive the absorption/desorption of hydrogen 

and (2) support elevated hydrogen pressure during 

refueling. These functions must be performed with a 

minimum of weight, volume and cost. In addition, 

there are other secondary characteristics such as (i) 

allowing for significant volumetric change of the 

powder, (ii) exchanging hydrogen without the loss of 

the fine CCH powder particles, (iii) maintaining 

chemical compatibility with the CCH powder and 

hydrogen, (iv) producing minimal impurities going 

to the PEMFC, and (v) fitting into a conformable 

volume.

Approach and Results

Over 200 kg of catalyzed NaAlH4 will be 

required for this project. An acceptable vendor has 

been identified to furnish the pure material within the 

budget of the project, and an order has been placed 

with a two month lead time which will slightly 

impact project schedule.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

249

Determination of the charging and discharging 

reaction rates for catalyzed NaAlH4 are well under 

way, both under internal UTC funding and through 

other DOE contracts by other investigators. 

Hydrogen discharge rates sufficient to deliver 

hydrogen to PEMFC powered vehicles at ~20 mph 

using 80°C water have been readily achieved. 

Hydrogen charging rates required to achieve 2 hr 

charging times are also within reach with significant 

improvements in this area foreseen.

Safety issues related to accidental damage of 

CCH systems and subsequent environmental 

exposure are a concern, and little information is 

available in the open literature. Safety studies 

examining how this material will react upon sudden 

exposure to heat, moist air, water or sudden impact 

are being examined by the subcontractor HCI. These 

tests will be based on the United Nations document 

“Recommendations on the Transport of Dangerous 

Goods - Manual of Tests and Criteria” (Reference 1) 

that serves as the basis for U.S. Department of 

Transportation (DOT) Hazardous Materials 

(HAZMAT) shipping classifications. While these 

tests are not specific to automotive fuel tanks, 

following these established procedures will put 

catalyzed NaAlH4 into perspective with a large 

database of other flammable, self-heating and water 

reactive materials. The equipment has been 

constructed for the burn rate, self-heating, 

pyrophoricity and water reaction tests. Figure 1 

shows a powder train of surrogate material produced 

by standardized sizing and settling procedures. The 

burn rate is determined by the time the flame takes to 

travel between the 80 mm and 180 mm marks.

To address the system needs, existing designs, 

such as the one from SRTC sketched in Figure 2, will 

be evaluated and novel ideas generated to improve 

upon the performance/cost as well as to better 

integrate with the particular characteristics of the 

CCH powder and PEMFC. Since the material 

characteristics are being modified, the required 

charging pressure to achieve the desired refueling 

rate has yet to be determined. Therefore, a number of 

pressure conditions will be examined using the 

design guidelines of the ASME Pressure Vessel 

Code.

During the discharging of hydrogen, heat must 

be provided to the CCH powder in order to release 

hydrogen, and during charging, heat must be 

removed rapidly to prevent the powder from melting. 

However, the powder has a very low thermal 

conductivity which is on the order of 1/1000th that of 

aluminum. Different types of heat transfer 

enhancement will be examined to improve 

conduction into the hydride powder. Analytical and 

numerical models using the ABAQUS finite element 

code will be constructed, and experiments will be 

performed which evaluate the heat transfer 

performance of different enhancement methods 

including metal foams, screens, wires and wools. 

Cost, weight and chemical compatibility will also be 

factored into the selection of the method.

Conclusions 

Significant progress has been made in hydrogen 

charging and discharging kinetics in a relatively short 

time. It is not anticipated that kinetics will be limiting 

for this material.

A reasonable set of safety guidelines and 

experiments have been identified which will be used 

to classify the chemical hazards associated with 

utilizing NaAlH4 type compounds.

Figure 1. Photograph of the safety test set up measuring 

powder burn rate.

Figure 2. Sketch of an existing baseline design from 

SRTC indicating the major storage system 

elements.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

250

References

1. “Recommendations on the Transport of 

Dangerous Goods - Manual of Tests and 

Criteria,” 3rd edition, 1999, United Nations 

Publication ST/SG/AC.10/11/Rev.3.

Presentations

1. Winter 2002 IEA Working Group on Hydrogen 

Storage, Annex 17, Seattle, WA, February, 2002.

2. DOE Alanate Working Group Meeting, 

Livermore, CA, January 2002. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

251

III.C.4 Standardized Testing Program for Emergent Chemical Hydride and 

Carbon Storage Technologies

Richard A. Page (Primary Contact) and Michael A. Miller

Southwest Research Institute

P. O. Drawer 28510

6220 Culebra Road

San Antonio, TX 78228-0510

(210) 522-3252, fax: (210) 522-6220, e-mail: rpage@swri.org

DOE Technology Development Manager: JoAnn Milliken 

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

ANL Technical Advisor: William Swift 

(630) 252-5964, fax: (630) 972-4473, e-mail: swift@cmt.anl.gov

Subcontractors: Teledyne Energy Systems, Hunt Valley, MD; The National Hydrogen Association, 

Washington, D.C.; Energy Conversion Devices, Inc., Troy, MI

Objectives

• Develop and operate a standard testing and certification program specifically aimed at assessing the 

performance, safety and life cycle of emergent chemical hydride and carbon adsorption/desorption 

hydrogen storage materials and systems. 

• Work with industry and the U.S. government to develop an accepted set of performance and safety 

evaluation standards.

Approach 

• Task 1: Perform a comprehensive review of the current accepted practices for testing the performance 

of chemical hydride and carbon storage media.

• Task 2: Define the equipment and test protocols that will be used in the standardized testing program. 

• Task 3: Design and construct the test facilities for characterizing the performance of chemical hydride 

and carbon storage media.

• Task 4: Develop a chemical process-engineering model that can be used to compute the thermal and 

chemical performance of storage systems at any scale. 

• Task 5: Evaluate the operation of the test facility with actual sample materials to verify that all 

components operate correctly pursuant to the test protocols developed in Task 2. 

• Task 6: Validate and optimize the performance model so that the performance characteristics of most 

any chemical hydride or carbon storage media can be viewed independently of scale. 

• Task 7: Analyze a select number of emergent chemical hydride and carbon storage materials in 

accordance with the protocols established in Task 2. 

• Task 8: Work for the adoption of the test protocols developed in this program by a recognized national 

or international standards organization. 

Accomplishments

• A comprehensive review of current accepted practices was initiated. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

252

• Discussions with potential suppliers of test equipment have been initiated.

• Participated in the May 21, 2002 ISO TC 197 US TAG Meeting on standards for hydride storage 

systems. 

Future Directions 

• Based on the review of current accepted practices, a report detailing the proposed test protocols will be 

submitted to DOE. 

• Following DOE approval of the test protocols, design and construction of the test facility will 

commence. 

Introduction

The choices of viable hydrogen storage systems 

at this time are limited to compressed hydrogen gas 

(CH2), cryogenic liquid hydrogen (LH2), chemical 

hydride adsorption, and carbon hydrogen adsorption. 

While each of these enabling storage technologies 

have specific advantages and disadvantages, 

chemical hydride and carbon adsorption storage 

systems may offer advantages in terms of storage 

capacity and, most importantly, safety. 

The realization that chemical hydride and carbon 

storage systems will most efficiently meet the storage 

capacity and safety requirements of a hydrogenbased infrastructure has led to significant interest and 

monetary investment to accelerate the development 

of complete hydrogen adsorption storage systems. 

However, there are no standard guidelines, dedicated 

facilities, nor certification programs specifically 

aimed at testing and assessing the performance, 

safety and life cycle of these emergent systems. The 

development of a standardized protocol and testing 

system for assessing the performance of these 

materials and systems would allow both DOE and the 

R&D organizations to assess the potential 

performance of the wide array of materials and 

systems and focus their efforts on those that show the 

most promise. 

Approach

In anticipation of the availability of many new 

materials and technologies for hydrogen storage, the 

purpose of the present effort is to develop an 

evaluation facility with established evaluation 

protocols and standards for the testing and 

assessment of these emergent chemical hydride and 

carbon storage materials and systems. Upon 

thorough validation of the experimental apparatuses 

and associated protocols, the testing facility and the 

technical staff that supports it will be available as the 

focal testing center to any prospective innovator of 

chemical hydride or carbon hydrogen storage 

materials or systems. Although the final form of the 

test protocol and equipment will be defined from the 

survey results, it is anticipated that the test system 

will be centered around hydrogen sorption/

desorption measurements of smaller quantities of 

storage media. These measurements may be 

performed using a magnetically coupled 

thermogravimetric analyzer, as shown in Figure 1. 

An ability to test complete storage systems will also 

be included. Testing of complete systems is required 

in order to validate the system performance models 

that are developed as part of the project.

The performance characteristics of candidate 

materials will be determined through a 

comprehensive materials characterization and 

systems testing approach. This approach will 

encompass the elements described below.

Certification of Chemical Composition and 

Crystallographic Properties

Materials selected for evaluation will be 

analyzed to determine or verify their elemental 

composition and crystallographic properties using 

appropriate analytical capabilities: atomic adsorption 

spectroscopy (AAS), X-ray fluorescence (XRF), 

Raman spectroscopy, Fourier transform infrared 

spectroscopy (FTIR), and powder X-ray diffraction. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

253

Evaluation And Certification Of Performance 

Parameters

The intrinsic thermodynamic characteristics of 

candidate storage materials, where existing data is 

not available, will be evaluated by modulated 

differential scanning calorimetry (MDSC). Data of 

this sort that has already been generated by others 

will be used to the extent that it is relevant to the 

specific goals of the present study. The intrinsic 

thermodynamic characteristics that will be derived 

from the MDSC analysis include the following:

• Determination of first- and second-order 

phase transitions

• Heat of transition

• Transition temperature

• Non-reversible transitions (such as in 

decomposition) 

• Decomposition temperature 

• Decomposition exotherm

• Crystalline versus amorphous compositions

Once the intrinsic thermodynamic characteristics 

are firmly established, the storage materials will be 

subjected to the performance assessment test 

protocols. The performance parameters and 

conditions that will be derived from the testing 

regime are as follows.

• Specific energy contained in storage system 

(LHV H2 per mass of total system)

• Sorption/desorption cycle life

• Resistance to exogenous contaminates

• Average refueling time

• Most favorable thermal-cycle conditions

• Impact resistance (only applicable to 

complete hydrogen storage container 

technologies)

• Vibration resistance (only applicable to 

complete hydrogen storage container 

technologies)

• Fire resistance (only applicable to complete 

hydrogen storage container technologies)

Results

The project is a new start and has been underway 

for only two months. During that period the 

comprehensive review of current accepted practices 

was initiated. Discussions with potential suppliers of 

test equipment were also initiated.

Future Work

Effort in the immediate future (6-9 months) will 

focus on completion of the review of current 

accepted practices and initiation of the definition and 

design of the test facilities. Visits to a number of 

leading laboratories in hydrogen storage 

measurement will be included as part of the review of 

current practices.

FY 2002 Presentations

1. Project overview presented at International 

Hydrogen Infrastructure Program Meeting, 

August 23, 2001, Washington, D.C.

Figure 1. Magnetically Coupled Thermogravimetric 

Analyzer
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

254

2. Project overview presented at DOE New Project 

Kick-Off Meeting, October 30, 2001, 

Washington, D.C.

3. Project overview presented at Hydrogen 

Program Annual Review, May 6-8, 2002, 

Golden, CO.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

255

III.C.5 Hydrogen Fueled ICE Scooter with On-Board Metal Hydride Storage

Krishna Sapru (Primary Contact), S. Ramachandran, Z. Tan and P. Sievers

Energy Conversion Devices, Inc.

1621 Northwood Dr, Troy, MI 48084

(248) 362-4780, fax: (248) 362-0012, e-mail: ksapru@ovonic.com

DOE Technology Development Manager: JoAnn Milliken

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Objectives

• Convert a gasoline internal combustion engine (ICE) scooter into a commercially viable hydrogen 

fueled scooter. 

• Design and fabricate a metal hydride storage system (MHSS) for on-board hydrogen storage.

• Integrate the MHSS into the scooter for optimum utilization of the exhaust waste heat to release the 

stored hydrogen.

• Minimize backfiring and nitrogen oxide (NOx) emissions. Optimize power, range, and overall 

efficiency/vehicle performance. 

• Develop preliminary business plan to involve scooter manufacturers, hydrogen producers and other 

entities needed for commercialization.

Approach

• Convert 80-250 cc four-stroke, gasoline-ICE scooters to operate on hydrogen, which involves making 

changes to the fuel delivery and ignition systems.

• Maximize engine power output with minimum emissions by optimizing suitable air/fuel ratio and 

ignition timing.

• Design improved metal hydride storage system and integrate into the exhaust system of the hydrogenICE (H-ICE) scooter.

• Perform chassis dynamometer tests under steady-state conditions, and road tests to evaluate fuel 

consumption and drivability.

• Install and operate an electrolyzer to deliver hydrogen as one means to charge the metal hydride 

storage system on-board the scooter.

• Perform a market study to determine the feasibility of introducing H-ICE scooters in developing 

countries.

Accomplishments 

• Successfully converted and demonstrated a working hydrogen ICE Scooter.

• Designed, fabricated, and integrated an air-cooled metal hydride storage system into the H-ICE 

scooter.

• Performed extensive dynamometer and road testing. 

• Acquired, installed and operated an electrolyzer which produces 10 normal cubic meters per hour 

(approximately 1 kilogram per hour) hydrogen. Tested the purity, dryness, flow rate, and hydrogen 

delivery pressure, for compatibility with Energy Conversion Devices, Inc.’s (ECD’s) (Ovonic) metal 

hydrides.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

256

• Completed an extensive market study, which indicates a very large market for H-ICE small vehicles in 

developing countries. Used India as a case study. 

• Study performed to determine the availability and cost of hydrogen from various renewable sources.

• Generated substantial awareness and interest in hydrogen for both transportation and distributed power 

generation as a result of meetings and presentation in India to automotive manufacturers, hydrogen 

producers and several key government agencies.

Future Directions

• Use knowledge/experience gained to improve overall H-ICE efficiency. This will be accomplished by 

further research on the engine/vehicle performance (increase power, fuel economy and reduce NOx 

emissions).

• Identify optimal engine operational parameters such as air-flow, compression ratio, spark/fuel control, 

and valve timing, and develop an on-board fuel gauge.

• Incorporate improved metal hydride alloys and improve heat exchanger design along with additional 

engine work to increase the range from present 35 kilometers (km) to greater than150 km .

• Perform accelerated testing to check the compatibility between hydrogen and materials (i.e. corrosion 

and embrittlement) of various engine parts.

• Convert a liquid cooled 250 cc scooter to simulate the size of a 3-wheeler taxi in developing countries. 

Liquid heat exchange between engine coolant and metal hydride should provide better heat transfer.

• Leverage knowledge gained with hydrogen engine development for small vehicles (2 and 3 wheelers) 

and demonstrate H-ICE for distributed power generation.

• Explore federal/private partnerships for demonstrations and optimization.

Introduction

The global 2- and 3-wheeler fleet is in excess of 

300 million units, most of them in highly polluted 

and rapidly developing nations such as China and 

India. While the Organization for Economic 

Cooperation and Development (OECD) countries are 

currently the largest contributors to greenhouse gas 

emissions, the Asia and Pacific regions are expected 

to replace OECD countries as the largest source of 

greenhouse gas emissions worldwide by about 2015. 

Development of small vehicles and power generation 

devices to run on hydrogen would result in dramatic 

improvement in air quality, in addition to economic 

and energy security benefits for all. 

Developing clean hydrogen combustion 

technologies will not defer, but speed up a global 

transition to fuel cell technologies by promoting 

early hydrogen infrastructure development. Fuel cell 

power will be more energy efficient in the long run, 

but it is at least 15-20 years away from 

commercialization, especially in the industrialized 

nation where the per capita energy demand and 

performance expectations are very high. ICE 

manufacturing and maintenance capabilities are 

already established and only minimal re-tooling is 

needed. In addition to hydrogen conversion 

technologies, widespread availability of cost 

effective hydrogen fuel is required. A study was 

undertaken to compare the cost and availability of 

hydrogen from renewable sources in India. This 

study showed three possible sources:

• Use of low cost electricity from the bagasse 

co-generation in sugar mills to produce 

hydrogen via electrolysis of water

• Hydrogen by-product from the chlorinecaustic industry

• Direct gasification of biomass to hydrogen

Metal hydrides that reversibly store and deliver 

hydrogen at low temperatures and pressures offer a 

compact and safe means to carry hydrogen on-board 

small vehicles. Storage of hydrogen as a solid offers 

superior safety and volumetric advantages versus 

gaseous or liquid storage. In addition, large-scale 

metal hydride production facilities are already in 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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place (due to commercialization of the nickel/metal 

hydride battery technology), and this investment can 

be leveraged to produce alloys for hydrogen storage.

Approach

Our approach is to work with small ICE vehicles 

with engines in the 80-250 cc range, since this covers 

the broadest segment of the market. Vehicle 

conversion involves making changes to the fuel 

delivery and ignition systems. We will work on the 

vehicle to obtain maximum engine power with 

minimum emissions by determining suitable air/fuel 

ratio and ignition timing over the operating range of 

the engine.

 In addition to vehicle optimization, we will use 

higher capacity metal hydride alloys developed at 

ECD, coupled with improved heat exchangers. This 

improved metal hydride storage system will be 

integrated into the vehicle for optimum utilization of 

waste heat. Detailed performance characteristics 

under different sets of driving conditions will 

determine areas of further improvement if necessary.

Results

We successfully converted an 80 cc gasoline ICE 

scooter to run on hydrogen fuel (Figures 1 and 2). 

This scooter was demonstrated at the U.S. DOE 

Annual review meeting in Denver, Colorado in May, 

2002, and also at the World Hydrogen Energy 

Conference in Montreal in June, 2002. The 

conversion was achieved by making changes to the 

fuel delivery system and the ignition system. The 

scooter uses a fuel injector controlled by an engine 

control unit. The carburetor was removed and a 

throttle body was designed to replace the carburetor.

A driving test was done on a warm day in 

Michigan when the temperature was 92o F, the 

barometric pressure 30 inches of mercury and 

humidity range of 46-55%. The on-board metal 

hydride storage system was charged with 140 grams 

of hydrogen and a range of 35 kilometers was 

obtained, with an approximate fuel consumption of 

3.8 grams of H2 per kilometer. The average speed 

during this test run was 32 km/hour and the top speed 

was 40 km/hour. 

The metal hydride used in the 80 cc scooter had 

1.5 weight % reversible hydrogen-storage capacity. 

Within the geometrical constraints, using the same 

alloy, up to 240 grams of hydrogen can be carried onboard resulting in a range increase from the present 

35 km to 60 km. Additionally, we recently developed 

new alloys having reversible hydrogen-storage 

capacities of 2.6 weight % (Figure 3). Using these 

Figure 1. 80 cc, Four-Stroke, Single Cylinder Scooter 

Converted to Run on Hydrogen

Figure 2. ECD's Proprietary Metal Hydride Storage 

System On-Board, Under the Seat
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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new alloys along with planned improvements in 

engine/vehicle performance will allow us to increase 

the vehicle range to 150 km. A 50 km to100 km 

vehicle range could be commercially acceptable in 

many developing countries, where the average daily 

driving range is less than 20 km, and gasoline prices 

are between U.S. $4 to $5 per gallon. These are also 

regions where air quality is among the worst in the 

world. 

Distributed Power Generation for Portable and 

Stationary Use

It is estimated that 40% of the world’s population 

is without electric power. These non-electrified 

regions of the world are potential markets for 

distributed small-scale (0.5-3 kilowatt) power 

systems. Also, because of severe power shortages 

and frequent outages in regions that do have 

electricity, there is a need to replace highly polluting 

diesel engines, gasoline and kerosene generators 

currently being used extensively; thus, the demand 

for hydrogen for power generation can be enormous. 

Figure 4 shows ECD’s laboratory prototype of a HICE generator.

Conclusion

With support from the U.S. DOE hydrogen 

program, ECD has demonstrated the viability of HICE scooters with metal hydride for on-board 

hydrogen storage. Hydrogen fueled small ICE 

vehicles and distributed power generation devices 

can improve global air quality and reduce our 

dependence on fossil fuels. These products can be 

commercialized in a relatively short time frame (3-5 

years) and pave the way to a hydrogen economy. 

However, additional research and demonstration 

projects are needed. Research should focus on 

improving fuel economy, reducing nitrogen oxides, 

improving power and vehicle range, materials 

compatibility and reducing overall cost.

Presentations

1. K. Sapru, S. Ramachandran, Z. Tan, 12th Annual 

US National Hydrogen Association, March 6-8, 

2001, meeting in Washington, DC.

2. K. Sapru, S. Ramachandran, Z. Tan “HydrogenThe New Oil- for Sustainable Transportation & 

Distributed Power Generation”, invited talk at 

“International Symposium & Exposition on 

Alternative Energy Vehicles”, Indian Institute of 

Technology, November 23-25, 2001, Kanpur, 

India.

3. K. Sapru, “Hydrogen –The New Oil. Near Term 

Business Opportunities for Hydrogen in 

Developing Countries”, The 2002 Hydrogen 

Investment Forum, April 3-4, 2002, Washington, 

DC,

4. K. Sapru, Hydrogen – “The New Oil”, Hydrogen 

for Transportation and Distributed Power for 

Figure 3. Hydrogen Desorption Kinetics of Proprietary 

Ovonic Hydrogen Storage Alloys at 100oC 

FY 2002

Figure 4. Laboratory Model of Ovonic Hydrogen ICE 

Generator Powered by Metal Hydride Storage 

Providing 3 hours of Back-Up Power at 2 kilo 

watts electrical
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

259

India, invited talk presented at the Science & 

Technology India Conference, April 10-12, 2002, 

New Delhi, India.

5. Z. Tan and K. Sapru, “Calcium Lithium Based 

Hydrogen Storage Materials”, Canadian 

Hydrogen Storage Workshop sponsored by 

Canadian NRC, February, 2002, Ottawa, Canada.

6. K. Sapru, First Indo-US Fuel Cell Meeting, June 

2-4, 2002, Washington, DC.

Patent Applications

During 2001-2002, the following patent applications 

have been filed:

1. S. Ramachandran, P. Sievers, K. Sapru and Z. Tan, 

A Hydrogen Powered Scooter, US patent pending.

2. Z. Tan and K. Sapru, High Capacity Calcium 

Lithium Based Hydrogen Storage Material and 

Method of Making the Same, US patent pending. 

3. K. Sapru, Z. Tan, M. Bazzi, and S. 

Ramachandran, High Capacity Transition Metal 

Ti-V-Cr-Mn based Hydrogen Storage Materials, 

US patent pending.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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III.C.6 Hydride Development For Hydrogen Storage

Karl Gross (Primary Contact), E. Majzoub, G.J. Thomas, G. Sandrock 

Sandia National Laboratories

P.O. Box 969

Livermore, CA 94551

(925) 294-4639, fax: (925) 294-3410, e-mail: kjgross@sandia.gov

DOE Technology Development Manager: JoAnn Milliken

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Objectives 

• Develop new complex hydride materials with 6 weight percent system hydrogen capacity.

• Improve the kinetics of absorption and desorption and thermodynamic plateau pressures of Ti-doped 

sodium alanate metal hydrides.

• Improve processing and doping techniques of Ti-doped sodium alanate which will lower cost.

Approach

• Developing new complex hydrides to achieve higher capacities.

• Innovate methods to synthesize the complex hydrides and improve the doping process to improve both 

rates and capacity. Test different Ti-halide catalyst-precursor materials and other Ti-containing alloys 

and hydrides to determine the efficacy of Ti-doping with other starting materials.

• Characterize the material properties of each new generation of complex hydrides to aid in further 

improvements. Compare different material responses using kinetics experiments coupled with analytic 

techniques such as X-ray, electron spin resonance (ESR), nuclear magnetic resonance (NMR), Auger 

spectroscopy, etc.

• Determine the hydriding mechanisms through experimental analysis and modeling. Using Sievert’s 

apparatus, measure rates of absorption and desorption of hydrogen from Ti-doped sodium alanate. 

Determine Arrhenius behavior and find activation energies and rate constants. Compare these results 

with mechanistic studies including neutron diffraction and ab initio calculations (electronic structure 

calculations.

• Evaluate the behavior of the materials on an engineering scale to ensure that they are on track for 

eventual commercialization. 

Accomplishments 

• Improved reversible capacities with the use of direct material synthesis and lower weight titanium (Ti)-

halides such as titanium dichloride (TiCl2) as catalyst precursors now give 4.3 weight % hydrogen 

(H2).

• Discovery that Ti-halides with Ti valency of 2+, 3+, and 4+ work as catalysts in the sodium alanate 

system.

• Simplification of processing procedure for manufacture of Ti-doped sodium alanate from raw 

materials of Na, Al, and Ti-halide, resulting in a patent application.

Future Directions 

• Find new complex metal hydrides and catalysts using procedures and techniques developed during the 

sodium alanate investigations.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

261

• Determine the mechanism of action of the Ti in the material for the enhanced kinetics.

• Find new methods to introduce Ti into sodium alanate that may be more beneficial and economical 

than Ti-halide introduction.

Introduction

Ti-doped alanates offer an entirely new prospect 

for lightweight hydrogen storage. These materials 

have nearly ideal equilibrium thermodynamics, good 

packing densities, moderate volume expansion and 

useful sintering properties. However, there is much 

room for improving both absorption and desorption 

kinetics, and the less-than-theoretical reversible 

capacities. Our work has focused on finding 

solutions to these problems to achieve the 

performance requirements needed to supply onboard 

hydrogen for PEM fuel cell powered vehicles.

Approach

Dehydriding and hydriding rates and capacities 

were obtained volumetrically using a Sieverts’ 

apparatus and a cylindrical 316L stainless steel 

reactor (1.3 centemeter [cm] outer diameter by 0.12 

cm wall thickness and length of 12 cm) containing 

about 1.5 gram of catalyzed samples. A 

thermocouple well in the center of the vessel allows 

for accurate temperature measurements during 

cycling. Absorption pressure changes were 

quantified with a calibrated 200 atmosphere absolute 

(atma) pressure transducer and desorption pressures 

with a 1000 Torr (1.3 atma) Baratron® capacitance 

manometer. Data were recorded via computer, and 

measurements lasted from minutes to several days, 

depending on the Ti-doping level, test pressure, and 

temperature conditions.

During absorption, the applied H2 pressure was 

generally in the 80-90 atm range, well above the 30-

40 atma plateau pressure for sodium 

tetrahydroaluminate (NaAlH4) at 125°C. For the 

desorption experiments, the back-pressure during 

NaAlH4 decomposition was kept below 1 atma and 

during trisodium hexahydroaluminate (Na3AlH6) 

decomposition below 0.25 atma, well below the 

Na3AlH6 plateau pressure of about 2 atma. Hydrogen 

capacity data are presented in Figure 1 as weight % 

with respect to the total sample weight, including the 

catalyst.

Isothermal arrhenius analysis were performed as 

follows. Measurements were started after several 

hydriding/dehydriding cycles with samples in the 

fully hydrided condition and cooled to room 

temperature. The pressure rise from desorption into a 

known volume at a given temperature was measured; 

and the temperature was then increased. Desorption 

rates were determined at each temperature from the 

slope of the essentially linear increase in pressure 

with time. This procedure was continued up to 

150°C. The sample was held at this temperature until 

the NaAlH4 decomposition step was finished. The 

rate data are presented as moles of desorbed 

hydrogen per mole active sodium per hour as shown 

in Figure 2.

Results

To improve capacity we have investigated the 

use of Ti-halides other than TiCl3 to catalyze 

hydrogen absorption and desorption in NaAlH4. 

Titanium triflouride (TiF3) and TiCl2 appear to work 

equally as well as TiCl3 and reduce the overall 

capacity loss due to the formation of sodium chloride 

(NaCl) or sodium flouride (NaF). 

Two new generations of materials have been 

developed. These are Generation III and Generation 

IV Ti-doped sodium alanates that are synthesized 

Figure 1. Reversible Hydrogen Capacity as a Function 

of TiCl3 Content
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

262

directly from sodium hydride (NaH), Al, Ti-dopant 

and Na-metal, Al, Ti-dopant, respectively. These 

materials have demonstrated better kinetics than 

materials produced using earlier methods. In 

addition, the direct synthesis is performed without 

the use of solvents. 

The result is a hydrogen storage material that is lessexpensive to produce and delivers hydrogen free of 

hydrocarbon impurities.

Conclusions

We developed a synthesis route to produce 

Na3AlH6 and NaAlH4 directly from Na and Al 

metals (patent application submitted). 

We discovered that it is the titanium that 

contributes to the enhanced kinetics; the Ti-halide 

precursor gives the same results independent of the 

halide that is used. For that reason, the use of Tifluorides or lower Cl content chlorides will provide 

an incremental improvement in the reversible weight 

capacity.

A preliminary investigation shows that the direct 

synthesized alanates undergo an activation consisting 

of 2-3 cycles. Following this, it appears that the 

capacity and rates are quite stable after many cycles.

Aluminum is consumed in forming the alanates. 

It was found that it doesn’t matter where the 

aluminum comes from (i.e. sorption materials or 

container vessel walls). However, the use of alanates 

that are not aluminum deficient did not appear to 

degrade the strength of aluminum-based alloys when 

tested under long-term cycling conditions.

In summary, these results demonstrate that solid 

progress is being made on the development of 

alanates for mobile hydrogen storage applications.

References

1. Bogdanovic, B. and Schwickardi, M. 1997. “Tidoped alkali metal aluminum hydrides as potential 

novel reversible hydrogen storage materials”, J. 

Alloys and Compounds, 253:1.

2. Bogdanovic, B., Brand, R.A., Marjanovic, A., 

Schwikardi, M., and Tölle, J. 2000. “Metal-doped 

sodium aluminum hydrides as potential new 

hydrogen storage materials”, J. Alloys and 

Compounds, 302:36.

3. Bogdanovic, B., Schwickardi M. 2001. “Ti-doped 

NaAlH4 as a hydrogen-storage material – 

preparation by Ti-catalyzed hydrogenation of 

aluminum powder in conjunction with sodium 

hydride”, Applied Physics A, 72 (#2):221.

FY 2002 Publications/Presentations

1. Gross, K. J., Thomas, G. J. and Jensen, C. M., 

“Catalyzed Alanates for Hydrogen Storage”, 

Journal of Alloys and Compounds, review article, 

330-332 (2002) 683.

2. Gross, K. J., Sandrock, G., and Thomas, G. J., 

“Dynamic In Situ X-ray Diffraction of Catalyzed 

Alanates”, Journal of Alloys and Compounds, 

330-332 (2002) 691.

3. Gross, K. J., Majzoub, E.H., Thomas, G. J., and 

Sandrock, G. 2002 " Hydride Development for 

Hydrogen Storage”, Proceedings of the 2002 U.S. 

DOE Hydrogen Program Review NREL/CP-610-

32405.

4. Majzoub, E.H., Somerday, B.P., Goods, S.H., and 

Gross, K.J. 2002. “Interaction between Sodium 

Figure 2. Arrhenius Plot of the Hydrogen Desorption 

Rates vs. 1/T for the Decomposition of 

NaAlH4
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

263

Aluminum Hydride and Candidate Containment 

Materials”, Proceedings of the Conference on 

Hydrogen Effects on Material Behavior, Jackson 

Hole Wyoming, N. Moody editor.

5. G. Sandrock, K. J. Gross, and G. J. Thomas, 

“Effect of Ti-Catalyst Content on the Reversible 

Hydrogen Storage Properties of the Sodium 

Alanates”, Journal of Alloys and Compounds, 339 

(2002) 299-308.

6. G. J. Thomas, G. Sandrock, N. Yang, and K. J. 

Gross, ‘Microstructural Characterization of 

Catalyzed NaAlH4’, Journal of Alloys and 

Compounds, 330-332 (2002) 702.

7. G. Sandrock, K. J. Gross, G. J. Thomas, C. M. 

Jensen, D. Meeker, and S. Takara, “Engineering 

Considerations in the Use of Catalyzed Sodium 

Alanates for Hydrogen Storage”, Journal of 

Alloys and Compounds, 330-332 (2002) 696.

8. Gross, K. J., Majzoub, E.H., “New Reversible 

Complex Hydrides for Practical Hydrogen 

Storage”, presentation World Hydrogen Energy 

Conference, Montreal, Canada, June 9th-13th, 

2002.

9. Gross, K. J., Majzoub, E.H., and Sandrock, G. 

“Complex Hydrides for Light-Weight Hydrogen 

Storage”, presentation TMS Annual Meeting, 

Seattle WA, February 20, 2002.

Special Recognitions & Awards/Patents 

Issued

1. DOE OPT Young Investigator Award – K. J. 

Gross.

2. Patent application. “Direct synthesis of 

lightweight catalyzed hydride for hydrogen 

storage.” May 3, 2001.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Section IV. Fuel Cells
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Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.A Transportation Power Systems

IV.A.1 Atmospheric Fuel Cell Power System for Transportation

Murdo J. Smith

UTC Fuel Cells

195 Governor’s Highway

South Windsor, CT 06074

(860) 727-2269, fax:(860) 727-2399, e-mail: murdo.smith@utcfuelcells.com

DOE Technology Development Manager: Patrick Davis

(202) 586-8061, fax: (202) 586-9811, e-mail: Patrick.Davis@ee.doe.gov

ANL Technical Advisor: Walter Podolski

(630) 252-7558, fax: (630) 252-4176, e-mail: podolski@cmt.anl.gov

Objectives

• Deliver the following to DOE/Argonne National Laboratory (ANL) for functional demonstration 

testing:

- A 50 kW-equivalent gasoline fuel processing system

- A fully integrated, gasoline-fueled 50 kW proton exchange membrane (PEM) power plant

- A fully integrated, gasoline-fueled 75 kW advanced PEM power plant

• Although focused on gasoline operation, the fuel processing system will utilize fuel-flexible reforming 

technology that can be modified to accommodate fuels such as methanol, ethanol and natural gas

Approach

• Deliver and test an autothermal fuel processor

• Deliver and test a 50 kW, ambient-pressure integrated power subsystem

• Deliver and test a 75 kW advanced ambient-pressure integrated power subsystem

Accomplishments

• Delivered and tested a 50 kW-equivalent gasoline fuel processing system

• Delivered and tested a 50 kW integrated power plant configured for system verification testing at UTC 

Fuel Cells (UTCFC) and delivered the power plant to DOE for follow-on testing at ANL

Future Directions

• Completely tear down and analyze the 50 kW power plant

• Deliver and test the 75 kW power plant at UTCFC and deliver to DOE for follow-on testing at ANL
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

268

Introduction

The focus of UTCFC’s program is an ambient 

pressure PEM power plant system operating on 

gasoline fuel and delivering 75 kW net dc power to 

the automotive electrical system.

UTCFC will deliver to DOE a 50 kW-equivalent 

gasoline fuel processing system, a 50 kW PEM 

power plant, and a 75 kW advanced PEM power 

plant.

Approach

Figure 1 provides a schematic of the gasoline 

fuel cell power plant. The major subsystems include 

the Fuel Processing Subsystem, the Power 

Subsystem and the Balance of Plant. The Balance of 

Plant includes the Thermal Management Subsystem, 

the Air and Water Subsystems and the Controller and 

associated electrical equipment. 

Results

50 kW Power Plant

Figures 2 and 3 are photographs of the fully 

integrated 50 kW, ambient pressure, gasoline-fueled 

power plant showing the locations of major 

components.

The power plant was installed for demonstration 

testing at UTCFC’s facilities in South Windsor, 

Connecticut. A California Phase II reformulated 

gasoline (RFG) fuel was used throughout the test 

program. 

A summary of the demonstrated system 

characteristics is shown in Table 1.

Table 2 provides selected comparative DOE 

Technical Targets for a 50 kWe (net) integrated fuel 

cell power system operating on Tier 2 gasoline 

containing 30 ppm sulfur.

Comparing the two tables, the UTCFC power 

plant demonstrated an efficiency level close to the 

DOE “2001 status” for 25% of rated power but was 

lower at rated power. The volume and weight 

numbers are significantly different, with the UTCFC 

power plant being larger and heavier.

Figure 1. Power Plant Schematic

Figure 2. 50 kW Gasoline Fueled Power Plant – side 

view

Figure 3. 50 kW Gasoline Fueled Power Plant – end 

view
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

269

Following testing at UTCFC, the power plant 

was delivered to DOE’s Argonne National 

Laboratory. Figure 4 shows the power plant installed 

in the ANL test facility. Testing at ANL included 

steady-state and transient operation and provided 

experience in the new test facility.

The power plant has been returned to UTCFC 

after completion of the ANL test program. It will be 

torn down and specific components analyzed to 

better understand the impact of operation on their 

physical characteristics. These analyses will focus 

on the cell stack and fuel processing system.

75 kW Power Plant

In the second phase of the project, UTCFC will 

deliver to DOE an advanced 75 kW, gasoline-fueled 

PEM fuel cell power plant. This power plant will 

address opportunities for distributing components 

throughout the automobile structure. 

Conclusions

A fully-integrated, ambient-pressure, 50 kW 

PEM power plant was assembled and tested at 

UTCFC and then delivered to ANL for follow-on 

testing. The power plant has been returned to 

UTCFC for teardown and analysis. Under Phase 2 of 

the project, UTCFC will deliver to DOE an advanced 

75 kW gasoline-fueled ambient pressure PEM power 

plant. 

Characteristic Anticipated Demonstrated

Rated net power ≥50 kWe 53 kWe

Efficiency at 50 

kWe

--- 25%

Efficiency at 25% 

rated power

≥32% 32%

Specific power 

based on wet weight

1550 lbs. 1825 lbs.

Power density ft3

kW

28.5 ft3 30.7 ft3

Fuel compatibility CA Phase II 

RFG

CA Phase II 

RFG

Start time to full 

power

45 min. >45 min.

Voltage range ≤220 voltage 

≤400 Vdc

≤250 voltage 

≤420 Vdc

Table 1. Power Plant System Characteristics

Characteristic Units 2001 

Status

2005 2010

Energy Efficiency 

@ rated power

% 31 33 35

Energy Efficiency 

@25% of rated 

power

% 34 40 45

Power Density W/L 140 250 325

Specific Power W/kg 140 250 325

Table 2. DOE Fuel Cell Power System Technical Targets

Figure 4. 50 kW power plant installed in ANL test 

facility
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IV.A.2 Fuel Cell Systems Analysis

Romesh Kumar (Primary Contact), Rajesh Ahluwalia, E. Danial Doss, and Michael Krumpelt

Argonne National Laboratory

9700 South Cass Avenue

Argonne, IL 60439-4837

(630) 252-4342, fax: (630) 252-4176, e-mail: kumar@cmt.anl.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Identify key design parameters and operating efficiencies of direct hydrogen and reformed gasolinefueled automotive fuel cell systems.

• Assess design-point, part-load, and dynamic performance of automotive fuel cell systems and system 

components.

Approach

• Develop, document, and make available an efficient, versatile system design and analysis code.

• Develop models of different fidelity (mechanistic detail) for fuel cells, stacks, and balance-of-plant 

components, such as reactors, condensers, and radiators.

• Apply models and modeling to issues of current interest as they evolve.

Accomplishments

• Developed new models:

- An application package for the analysis of kinetic data from microreactors;

- A generic model for metal hydrides, including kinetics with heat transfer;

- A model for a desulfurizer based on zinc oxide sorbent; and

- A kinetic model for the autothermal reforming of iso-octane using the Argonne catalyst.

• Developed a variety of GCtool-ENG models of fuel cell system components based on GCtool 

architecture for the speed and accuracy appropriate for fast transients in vehicle simulations by PSAT 

and similar MATLAB-based models.

• Working with DOE and others, developed R&D targets for the direct hydrogen fuel cell systems and 

components.

• Analyzed an 80-kW pressurized direct hydrogen system for efficiency and for heat and water 

management in an SUV application.

Future Directions

• Validate models with data from the Nuvera fuel processor system.

• Analyze the performance of ambient-pressure direct-hydrogen systems.

• Analyze reformed liquid-fueled systems on drive cycles.

• Model fast-start and load-following fuel processors.

• Analyze high-temperature-membrane fuel cell systems.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Introduction

While different developers are addressing 

improvements in individual components and 

subsystems in automotive fuel cell propulsion 

systems (e.g., cells, stacks, fuel processors, balanceof-plant components), we are using modeling and 

analysis to address issues of thermal and water 

management, design-point and part-load operation, 

and component-, system-, and vehicle-level 

efficiencies and fuel economies. Such analyses are 

essential for effective system integration.

Approach

We use Argonne’s GCtool software package to 

devise and analyze system configurations and 

operation. We develop additional component models 

as needed to address evolving issues.

Results

During FY 2002, one of our major activities was 

to model and analyze an 80-kW pressurized direct 

hydrogen fuel cell system, potentially for an SUV 

application. The modeled system used compressed 

hydrogen fuel and operated at 3 atm, 80oC, and a cell 

potential of 0.7 V at the rated power point. 

Performance data for the compressor-expander 

module (CEM) were obtained from a DOE 

development program. The fuel cell stack 

polarization curve was based on data from Los 

Alamos National Laboratory, extrapolated to various 

pressures and temperatures by the detailed fuel cell 

model in GCtool. The anode and cathode feed gases 

were heated/cooled to 70oC and humidified to 90% 

relative humidity at the stack temperature. The 

modeled fuel cell system was analyzed for water and 

heat management issues, parasitic losses and system 

efficiency at normal and high ambient temperatures 

and elevations, and startup and dynamic response 

and efficiency in drive cycles.

Water Management

At the rated power, the dew point of the cathode 

exit gas that is needed to maintain water selfsufficiency is higher than the stack operating 

temperature, so no condensation of the water from 

the exhaust gas is needed. As the system operates at 

part load, however, the pressure ratio decreases from 

3 toward 1. At pressure ratios below about 1.8, the 

required dew point decreases below 80oC (the stack 

temperature), indicating that condensation of water 

from the exhaust is needed. The needed dew point as 

a function of the pressure ratio is shown in Figure 1. 

The figure shows the base case for 25% ambient 

relative humidity and 1 atm ambient pressure (at 

mean sea level), as well as cases for 100% relative 

humidity and 0.75 atm ambient pressure (at elevated 

locations, such as Los Alamos, New Mexico). 

The corresponding heat duty of the condenser is 

shown in Figure 2. As discussed above, the 

condenser is needed only at pressure ratios less than 

about 1.8. The condenser duty increases with 

decreasing pressure ratios from ~1.8, reaching a 

maximum at a pressure ratio of ~1.2. At still lower 

pressure ratios, the condenser duty decreases due to 

the reduced air flow rates. Figure 2 also shows the 

effect of varying the oxygen utilization from 60% to 

30% (50% is the base case). With decreasing oxygen 

utilization, the condenser duty increases; the 

maximum condenser duty more than doubles for 

operation with 40% oxygen utilization versus 

operation with 60% oxygen utilization.

Figure 1. Dew point of the cathode exhaust required for 

water self-sufficiency in the fuel cell system. 

Dew points lower than the stack temperature 

must be achieved by condensing out some of 

the water from the exhaust. Operation at 

higher elevations requires more water to be 

recovered.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

272

Air Heater/Humidifier Duties

As is the case for the condenser, the maximum 

heat duty required at the cathode feed air heater/

humidifier is not at the rated power point; rather, the 

maximum heat transfer requirement occurs at the 

part-load pressure ratio of approximately 1.6, as 

shown in Figure 3. At higher pressure ratios, the 

compression itself provides the major portion of the 

heating and humidification heat duty. The 

compressor contributes a successively lesser fraction 

of the needed heating as the pressure ratio decreases 

from 3 at the rated power point toward 1.6 at 

approximately 20% of full load. Figure 3 also shows 

that the maximum heat duty increases with 

decreasing oxygen utilization, with the maximum air 

heater duty with 30% oxygen utilization being about 

twice the heat duty with 60% oxygen utilization.

Parasitic Losses and Efficiencies

In the pressurized direct hydrogen fuel cell 

system, the two major parasitic power consumers are 

the CEM and the radiator fan. Parasitic power 

consumption becomes significantly greater as the 

ambient temperature increases from the nominal 300 

K (27°C, 80°F) to 320 K (47°C, 116°F), as shown in 

Figure 4. At the lower ambient temperature, the total 

parasitic power consumption at the rated power is 

approximately 6 kW (for an 80-kW net power 

system), most of which is due to the power consumed 

by the CEM. At the higher ambient temperature, the 

system is unable to deliver the full rated power of 80 

kW net. At 90% of the rated power, the CEM and the 

radiator fan each consume over 6 kW, with a total 

parasitic power consumption of nearly 14 kW (for a 

net 72 kW delivered by the system).

The cell and overall system efficiencies (based 

on the lower heating value of hydrogen) at various 

power factors are shown in Figure 5. At the rated 

power and the nominal 300 K ambient temperature, 

the cell and system efficiencies are approximately 

58% and 52%, respectively. The corresponding cell 

and system efficiencies at 320 K and 90% of rated 

power are approximately 57% and 46%, respectively.

Figure 2. Condenser heat duty in the 80-kW system as a 

function of pressure ratio and oxygen 

utilization. The heat duty reaches a maximum 

at part load.

Figure 3. Heat duty of the air heater/humidifier in the 

80-kW system as a function of pressure ratio 

and oxygen utilization. The maximum heat 

duty is required at part load.

Figure 4. The compressor module and the radiator fan 

are the biggest parasitic power consumers in 

the system. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

273

Startup and Dynamic Response on Drive Cycles

We have analyzed the performance of the 

pressurized direct hydrogen system during cold and 

warm startup at 300 K and at 320 K. Figure 6 shows 

the calculated efficiencies at various power factors 

for different operating conditions. In particular, at 

power factors less than about 0.5, i.e., at net power 

deliveries of 40 kW or less [the power most 

commonly called for from the 80-kW fuel cell 

system on the Federal Urban Driving Schedule 

(FUDS) and the Federal Highway Driving Schedule 

(FHDS)], the system efficiency can vary by more 

than 5 percentage points, depending on the state of 

the fuel cell system and the ambient conditions.

The key factors for the dynamic performance of 

the fuel cell system are the response characteristics of 

the CEM and of its controller. An example of the 

system's dynamic response is given in Figure 7, 

which shows the power demand for the SUV and the 

power available from a warmed-up fuel cell system 

during a 100-second portion of the FUDS. During 

rapid power up-ramps, the power generation by the 

fuel cell lags behind the demand. The magnitude of 

this difference depends primarily on the response 

time of the CEM and the operating logic of its 

controller. 

Conclusions

Our analysis of the pressurized direct hydrogen 

system shows that:

• A condenser is required at part load for water 

self-sufficiency.

• The condenser and the air heater/humidifier must 

be designed for the maximum heat duties, which 

occur at part load rather than at the system’s 

design operating point.

• The compressor-expander module and the radiator fan are the biggest parasitic power consumers 

in the system, taking up nearly 15% of the gross 

power generated.

• Efficiencies of the system range from ~45% at 

the rated power to ~65% at part load.

Figure 5. Fuel cell and system efficiencies as a function 

of power factor and ambient temperature.

Figure 6. System efficiency at various power factors for 

different ambient temperatures and different 

cold and warm start conditions.

Figure 7. Dynamic response of the system on a portion 

of the FUDS. The fuel cell system's power 

generation lags behind the driving schedule's 

power demand during rapid power up-ramps.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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• In load-following mode, the response characteristics of the CEM and its controller cause the 

power delivered to lag behind the power demand 

during the sharp transients of the FUDS.

FY 2002 Publications/Presentations

1. Ahluwalia, R. K., Doss, E. D., and Kumar, R., 

"Performance and Specific Power Attributes of 

PEFC Systems for Transportation," IEA Annex 

XV Meeting, Sacramento, CA, December 10–11, 

2001. 

2. Kumar, R., Ahluwalia, R., Doss, E., Krumpelt, 

M., “Fuel Cell Systems Analysis,” 2002 Annual 

National Laboratory R&D Meeting, DOE Fuel 

Cells for Transportation Program, Golden, CO, 

May 9–10, 2002.

3. Ahluwalia, R. K., Doss, E. D., and Kumar, R., 

“Performance of High-Temperature Polymer 

Electrolyte Fuel Cell Systems,” IEA Annex XI 

Phase II Meeting, Philadelphia, PA, May 17–18, 

2002.

4. Ahluwalia, R. K., DeVille, B., Zhang, Q., Doss, 

E. D., Rousseau, A., and Kumar, R., 

"Performance of Hydrogen Fuel Cell Systems 

and Vehicles," IEA Annex XV Meeting, 

Dusseldorf, Germany, June 28, 2002.

5. Rousseau, A. and Ahluwalia, R. K., "Modeling 

and Control of Fuel Cell Vehicle Transient 

Behavior," Future Car Congress, June 3–5, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.A.3 Fuel Cell Vehicle Systems Analysis

Keith Wipke (Primary Contact), Tony Markel

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401

(303) 275-4451, fax: (303) 275-4415, e-mail: keith_wipke@nrel.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Develop and validate models and simulation programs to predict fuel economy and emissions and aid 

in setting performance targets for fuel cell electric and fuel cell hybrid electric vehicles

• Provide DOE and industry with modeling tools and early design insights that lead to introduction and 

application of advanced technology

• Quantify benefits and impacts of DOE fuel cell technology development efforts at the vehicle level

Approach

• Apply vehicle systems analysis expertise and software tools to study the impacts of DOE component 

technology development programs and a variety of design scenarios

• Develop and link existing component and vehicle models to enhance systems analysis capabilities

• Collect experimental data and models from DOE contractors to validate system model predictions and 

to provide systems level insights to component developers

Accomplishments

• Completed a series of three technical papers that evaluated how several vehicle and component 

characteristic parameters could influence the optimal vehicle design for neat and hybrid fuel cell 

vehicles

• Released a vehicle simulation model, ADVISOR 2002, with a reorganized, configurable subsystem 

fuel cell model library

• Enhanced fuel cell system thermal network model developed by Virginia Tech based on FutureTruck 

competition vehicle

• Initiated fuel cell component data collection effort with DOE contractors and received data from 

several parties

• Contributed to the development of Society of Automotive Engineers (SAE) recommended practice for 

measuring fuel economy and performance of a fuel cell hybrid electric vehicle

Future Directions

• Optimize fuel cell hybrid vehicle system, considering a variety of energy storage options and system 

operating characteristics, including fuel cell idling and start-up/shut-down

• Continue to collect available data and models from fuel cell program contractors to enhance modeling 

capabilities 

• Evaluate options for enhancing fuel cell system performance and reducing cost in a vehicle application
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

276

• Complete the enhanced fuel cell system thermal model under development at Virginia Tech

• Work with industry partners to validate model predictions and perform studies that support fuel cell 

technology introductions

Introduction

The U.S. Department of Energy has supported 

the development of vehicle and subsystem computer 

models to provide research and development 

program guidance for promising future research 

directions and to evaluate applications of existing 

advanced technologies. The vehicle simulation 

model ADVISOR (Advanced Vehicle Simulator) has 

been developed and is supported by the staff of the 

National Renewable Energy Laboratory. The model 

uses the MATLAB/Simulink programming 

environment and has an easy-to-use graphical user 

interface. ADVISOR is used mainly for target 

setting, systems analysis, and optimization. 

In this project, ADVISOR was used to simulate 

different fuel cell vehicle design scenarios and to 

quantify the impacts of several influential 

parameters. The effects of designing for a specific 

drive cycle were analyzed. Likewise, vehicle 

scenarios for optimal fuel economy were derived for 

vehicles with a range of fuel cell system performance 

attributes. These studies have established the 

groundwork for future studies to be performed based 

on existing and planned technology deliverables in 

the DOE Fuel Cells for Transportation Program.

Approach

This analysis effort has focused on two areas: 1) 

model enhancement and validation with data 

collected from DOE contractors and 2) application of 

the model to understand some of the design tradeoffs associated with fuel cell vehicles. The approach 

has been to work closely with industry partners to 

ensure that the models are accurate, to focus on 

appropriate systems issues, and to disseminate the 

study results in peer reviewed forums when possible.

Results

Data Collection and Analysis

The vehicle systems modeling tools can be used 

to understand the impacts, specifically on fuel 

economy and performance, of single or multiple 

component characteristics. Characteristic 

performance data will be collected from the several 

DOE contractors working on developing 

technologies for fuel cell systems. The data being 

requested includes attributes like the fuel cell 

polarization curve, the load vs. flow rate for an air 

compressor or compressor/expander unit, or the fuel 

usage vs. the net power out of the complete system. 

After the component data has been imported into 

ADVISOR, a variety of studies can be performed. 

For example, if the use of a different catalyst 

improves a portion of the polarization curve but has 

no impact on other operating regions, does this have 

any impact on the overall vehicle performance? 

Such questions as “under what design scenarios will 

a change have an impact and what is the value of the 

impact?” can be investigated.

Data has been collected from several air 

compressor suppliers and from a fuel cell system 

supplier. The air compressor data provides realistic 

inputs to estimate the parasitic load placed on the 

fuel cell stack for pressurized operation. The fuel cell 

system data is being used to investigate several 

options to overcome the start-up issues of current 

fuel cell systems.

Fuel Cell Vehicle Optimization Studies

At the vehicle systems level, there are thousands 

of interacting parameters that can influence the 

performance of a fuel cell vehicle. ADVISOR makes 

the task of quantifying the impacts of these 

parameters easier. However, studies that go beyond 

one or two parameters are difficult to do through 

manual iteration. Optimization tools have been 

incorporated into ADVISOR by NREL to automate 

the process of multi-dimensional analysis of fuel cell 

hybrid vehicles.

Two fuel cell vehicle analysis studies have been 

completed using ADVISOR and optimization 

techniques. In both studies, the optimizer was 

allowed to vary component parameters including fuel 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

277

cell peak power, the motor peak power, the battery 

power, and the battery capacity. In addition, the 

optimizer was allowed to adjust energy management 

parameters including minimum and maximum fuel 

cell power settings, minimum off time for the fuel 

cell, and the maximum charge power to be requested 

from the fuel cell. In each case, the vehicle was 

required to meet or exceed a set of performance 

constraints that were derived from the comparable 

baseline conventional vehicle. The performance 

constraints are summarized in Table 1.

In the first study, optimal component and control 

strategy parameters were derived to provide the best 

fuel economy on 4 individual drive cycles. The drive 

cycles included

• Comp. - City/Highway composite, a weighted 

value composed of the results of one highway 

cycle and one Federal Test Procedure (FTP) 

cycle

• US06 – high speed, high acceleration rate profile 

to be used in the U.S. Environmental Protection 

Agency Supplemental Federal Test Procedure 

(SFTP)

• NEDC – New European Drive Cycle including 

both low speed urban and high speed highway 

driving

• 1015 - Japan 1015 Mode Cycle, representing 

congested urban driving typical in Japan.

The four optimized vehicles were then simulated 

over the other three cycles. The fuel consumption 

results are summarized in Figure 1. In all cases, the 

vehicle designed for the cycle (indicated with a “D”) 

was better (lower fuel consumption) than all other 

vehicles over the drive cycle for which it was 

designed. Additionally, it was observed that the 

vehicle designed for the NEDC cycle was always the 

next best vehicle over the off-design cycles. This 

indicates that designing for the NEDC provides a 

reasonable vehicle design that is robust to variance in 

fuel economy.

It was assumed in the drive cycle study that the 

fuel cell system could respond to a transient power 

request from 10-90% peak power in 2 seconds, based 

on current DOE R&D Plan technical targets. In the 

follow-on study, all other assumptions were held the 

same while the transient power response capability 

was varied between 0 seconds (fast response, i.e. 

direct hydrogen) to 40 seconds (slow response, i.e. 

gasoline reformed system). Again the optimizer was 

allowed to vary the component sizes and the energy 

management parameters to find the design scenario 

that provided the best fuel economy while satisfying 

the performance constraints.

Figure 2 summarizes the key results of the 

response time study. It provides the vehicle fuel 

economy (squares) and the fuel cell specific power 

(triangles) data for three vehicle designs, an ICE 

conventional vehicle, a neat (no energy storage) fuel 

cell vehicle, and a fuel cell hybrid vehicle. The key 

conclusion to be drawn from these results is that the 

Type Description Condition

Acceleration

0-96.5 km/h (0-60 mph) <= 11.2 s

64-96.5 km/h (40-60 mph) <= 4.4 s

0-137 km/h (0-85 mph) <= 20.0 s

Gradeability

@ 88.5 km/h (50 mph) for 20 

min. at Curb Weight + 5 

passengers and cargo (408 

kg)

>= 6.5%

Drive Cycle

Difference between drive 

cycle requested speed and 

vehicle achieved speed at 

every second during the 

drive cycle

<= 3.2 km/h

(2 mph)

SOC 

Balancing

Difference between final and 

initial battery state of charge <= 0.5%

Table 1. Performance Constraints for Fuel Cell Vehicle 

Studies

Figure 1. Fuel Consumption of Fuel Cell Vehicles Over 

Both On- and Off-Design Drive Cycles
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

278

flexibility of a hybrid design can be used to provide 

the same fuel economy performance independent of 

the fuel cell system response capability. However, as 

response time increases (the fuel cell system 

responds more slowly) the size of the fuel cell system 

grows rapidly, and the fuel economy begins to 

decline significantly in the case of a neat fuel cell 

vehicle. The neat option does provide about a 65% 

fuel economy improvement over a conventional 

internal combustion engine vehicle. An additional 

50% improvement over the neat fuel cell vehicle case 

is available through regenerative energy and other 

techniques when the fuel cell vehicle is hybridized.

Conclusions

The results of the fuel cell vehicle optimization 

studies completed this year have contributed 

substantially to the bulk of knowledge on fuel cell 

vehicle design for both neat and hybrid design 

scenarios. It was concluded that the drive cycle can 

have a significant influence on the optimal design 

and that designing for the NEDC cycle actually 

provides a fairly robust vehicle design. Additionally, 

it was observed that hybridization provides 

substantial benefits and flexibility in overcoming 

possible shortfalls in fuel cell system performance 

caused by slow transient response capability.

A data collection effort was initiated with fuel 

cell program partners. Component data, including 

polarization curves, fuel cell system efficiency, air 

compressor loads, and system response 

characteristics have been collected. The experimental 

data and predictions are being used to 1) validate the 

existing models and 2) quantify the system level 

benefits of the technology developments and the 

progress being made toward satisfying the DOE 

technical targets.

Publications/Presentations

1. Markel, T.; Wipke, K. “Optimization 

Techniques for Hybrid Electric Vehicle Analysis 

Using ADVISOR.” Proceedings of ASME 

International Mechanical Engineering Congress 

and Exposition. New York, New York. 

November 11-16, 2001.

2. Markel, T.; Wipke, K.; Nelson, D. “Vehicle 

System Impacts of Fuel Cell System Power 

Response Capability.” SAE Future Car 

Congress. Arlington, Virginia. June 3-6, 2002.

3. Wipke, K.; Markel, T.; Nelson, D. “Optimizing 

Energy Management Strategy and Degree of 

Hybridization for a Hydrogen Fuel Cell SUV.” 

18th International Electric Vehicle Symposium.

Berlin, Germany. October 20-24, 2001.

Figure 2. Impacts of Transient Response Capability for 

Hybrid and Neat Fuel Cell Vehicles on 

Combined City/Highway Driving Fuel 

Economy
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.A.4 Cost Analyses of Fuel Cell Stack/Systems

Eric J. Carlson (Primary Contact) and Dr. Johannes H.J. Thijssen

TIAX LLC

Acorn Park

Cambridge, MA 02140-2390

(617) 498-5903, fax: (617) 498-7012, e-mail: carlson.e@tiax.biz

DOE Technology Development Manager: Nancy Garland 

(202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

ANL Technical Advisor: Robert D. Sutton

 (630) 252-4321, fax: (630) 252-4176, e-mail: sutton@cmt.anl.gov

Objective

• To develop an independent cost model for proton exchange membrane fuel cell (PEMFC) systems for 

transportation applications and to assess cost reduction strategies for year 2000 to 2004 development 

programs.

Approach

• In the first two years, develop a baseline system configuration and cost estimate based on best 

available and projected technology and manufacturing practices, and assess the impact of potential 

technology developments on system cost reduction 

• In the subsequent four years, annually update the baseline cost model and system scenarios based on 

assessments of developments in PEMFC system technologies and manufacturing processes.

Accomplishments

• Assessed the potential for reductions in platinum loading by conducting an electrochemical kinetic 

analysis of the impact of catalyst loading, temperature, and pressure on polarization of the cathode.

• Developed future cost projections for reformer and direct hydrogen systems.

Future Direction

• Develop projections of future system performance and cost based on continued industry feedback, 

alternative system scenarios, and projected technology developments.

Introduction

In 1999, a baseline cost estimate for a 50 

kilowatt (kW) PEMFC system for passenger vehicles 

was developed based on technology available in the 

Year 2000, using a high production volume scenario 

(i.e., 500,000 units per year). In Year 2000, we 

solicited feedback from system and component 

developers on the system configuration, design and 

performance parameters, and manufacturing process 

and costing assumptions. The impact of alternative 

system design approaches were also assessed, 

including the impact of sizing the stack at the high 

power point rather than 0.8 volts, and the impact of 

hybridization, i.e., reducing or increasing rated 

power, on the fuel cell system power cost ($/kW). In 

Year 2001, we focused on the development of future 

costs based on projected technology. In 2002, an 

electrochemical model for the relationship between 

catalyst loading, temperature, pressure, and power 

density was combined with the cost model to 

understand the tradeoffs between catalyst loading 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

280

and cost of the stack. The cost model was used to 

develop projections for direct hydrogen fueled 

systems.

Approach

The factors influencing platinum loading were 

assessed to develop an estimate of future fuel cell 

stack cost for reformate and hydrogen systems. 

Projections of minimum platinum requirements were 

estimated based on an analysis that considered:

• Impact of catalyst particle size and catalyst 

activity on kinetics

• Impact of electrolyte adsorption on catalyst 

kinetics

• Development of polarization curves based on 

electrochemical kinetics

• Impact of ohmic resistance losses on 

polarization curve

The assumption of relatively high unit cell 

voltages (e.g., 0.8 volts) to achieve overall system 

efficiency targets simplified the analysis because 

cathode kinetics then dominate the voltage losses 

within the stack. Tafel kinetics were used to assess 

the effect of operating conditions and cathode 

voltage losses. Voltage drops were then assigned to 

the anode and ohmic components based on 

experimental data. 

The polarization curves and functional 

relationships between platinum loading and 

performance were then combined with the stack cost 

model to assess the relationship between platinum 

loading and materials cost. Several overall 

assumptions are important to understanding the basis 

of the analysis. First, we assumed the performance 

of the catalyst is not limited by diffusion, the 

structure of the electrode, or the dispersion of the 

catalyst. In the early days of PEMFC development, 

significant performance gains were made while 

significantly decreasing the catalyst loadings. In our 

analysis, reduction in platinum loading leads to lower 

power density. Second, introduction of ohmic 

resistance losses into the analysis reduces the power 

density that can be achieved by increasing catalyst 

loading or by decreasing the cell voltage. Voltage 

losses across the ohmic resistances (I2R) in the 

system reduce the voltage available to perform useful 

work at the electrodes. Third, in the baseline cost 

estimate, the fuel stack materials represent over 90% 

of the stack cost. Consequently, in the following 

analysis, we only consider the cost of materials in the 

stack (i.e., MEA, gas diffusion layer, and bipolar 

plate). The assumptions used to make the future 

projections are summarized in Table 1.

Table 1. Assumptions Used to Project Future Fuel 

System Costs

Results

Figure 1 shows polarization curves generated for 

different platinum loadings and temperatures 

assuming 3.5 nanometer catalyst particle size and 3 

atmospheres pressure. The DOE fuel cell target for 

current density and voltage is highlighted by the 

circle. The polarization curve for the stack must lie 

above this circle to allow for additional voltage 

losses from the electrolyte, bipolar plates, and anode.

Figure 1. Polarization Curve at Different Temperatures 

and Platinum Loadings at 3 Atmospheres and 

with 3.5 nanometer Catalyst Particle Size
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

281

Figure 2 shows the material cost ($/kilowatt 

electrical [kWe]) versus cathode platinum loading for 

stacks operating at 3 atmospheres, 160o

C, and 0.8 

volts with direct hydrogen and reformate. 

Assumptions in this analysis include use of an alloy 

catalyst having a kinetic activity two times that of 

platinum, a unit cell resistance of 0.1 ohm centimeter 

squared (cm2), and an anode catalyst loading equal to 

one half the cathode loading.

 The analysis produced an “L” shaped curve 

where material costs rise sharply at low platinum 

loadings (low power density) and then show weak 

dependence with increasing platinum loading. 

Figure 3 shows the flat portion of the curve for 

various values of ohmic resistance. Independent of 

the resistance value, all of the curves have a 

minimum cost in the region of 0.1 to 0.3 mg/cm2.

Figure 4 shows the cost projections for the future 

system scenarios. The contribution of precious metal 

cost to each system is broken out separately to 

highlight its impact on system cost. This analysis 

compares the cost of reformate and direct hydrogen 

systems on a 50 kWe basis. In practice, the lighter 

weight of direct hydrogen systems will produce 

equivalent vehicle performance (e.g., acceleration, 

hill climb) at lower net system power. The higher 

efficiency of the hydrogen system may also lead to 

operation of the stack at lower voltages (higher 

power density) leading to lighter, less costly stacks. 

Hence, the cost of the hydrogen system could be 

reduced further relative to the reformate system.

Conclusions

The analysis of minimum platinum loading and 

projection of cost for future scenarios provided 

several important insights, including:

Figure 2. Fuel Cell Stack Material Cost versus Cathode 

Platinum Loading

Figure 3. Impact of Ohmic Resistance on the Cost 

versus Platinum Loading Relationship
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

282

• Analysis of a series of scenarios involving 

catalyst loadings, pressures, and 

temperatures led to the conclusion that the 

stack would have to operate at high 

temperature (e.g., 160oC) and elevated 

pressure (e.g., 3 atmospheres) to satisfy DOE 

fuel cell power density (kW/cm2

) goals.

• The cost of non-active materials (gas 

diffusion layer, membrane, and bipolar 

plates) dominate stack cost at very low 

platinum loadings, while ohmic losses limit 

the benefit of increasing platinum loading 

beyond some point.

• The future fuel system costs presented here 

are significantly lower than earlier cost 

estimates based on near-term technology. 

However, the projected costs for reformate 

and hydrogen systems are still higher than 

FreedomCAR goals of $45/kWe. The direct 

hydrogen system is closest to the 

FreedomCAR target, but it will need 

technology advances in high temperature 

membranes and further reduction in material 

and component costs to achieve the cost 

goals.

Figure 4. Projections of Future Reformate and Direct 

Hydrogen System Costs for a 50 kW System 

Produced in Large Volume (500,000 units per 

year)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

283

IV.B Stationary Power Systems

IV.B.1 Alkaline Fuel Cell Development

Timothy Armstrong (Primary Contact), Dane Wilson, Lynn Klett 

Oak Ridge National Laboratory

PO Box 2008

Oak Ridge, TN 37831-6084

(865) 574-7996, fax: (865) 574-4357, e-mail: armstrongt@ornl.gov 

Wayne Smith (Primary Contact) 

Los Alamos National Laboratory

PO Box 1663

Los Alamos, NM 87545

(505) 667-2635, fax: (505) 665-4292, e-mail: wsmith@lanl.gov 

DOE Technology Development Manager: Nancy Garland

202-586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov 

Objectives 

• Jointly develop alkaline fuel cell research and development (R&D) roadmap 

• Improve existing alkaline fuel cell anode by eliminating platinum

• Improve power density of alkaline fuel cell

Approach

• Address needed improvements in current technology and propose research breakthrough technologies 

based on evaluation of all existing alkaline fuel cell documentation and company site visits

• Evaluate new polymer-based hydroxyl conducting membranes

• Determine CO2 tolerance of other aqueous and molten salt based alkaline electrolytes

• Evaluate new anode catalysts to promote high efficiencies and operating temperatures

• Develop high conductivity composite bipolar plates to allow high power density designs to be 

developed

Accomplishments 

• Draft R&D roadmap completed in August 2002

Future Directions 

• Evaluate new polymer-based hydroxyl conducting membranes

• Determine CO2 tolerance of other aqueous and molten salt based alkaline electrolytes

• Evaluate new anode catalysts for high efficiencies and operating temperatures

• Develop high conductivity composite bipolar plates to allow high power density designs to be 

developed
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

284

Introduction 

Alkaline fuel cells are potentially the lowest cost 

fuel cell due to the materials and manufacturing 

processes used to make them. They are efficient 

(51% system), restorable (replacing the electrolyte 

restores output to near new), and recyclable. The 

reliability of alkaline fuel cells has been 

demonstrated convincingly over 30 years of service 

in space missions. The new low-cost alkaline fuel 

cells being developed by other manufacturers are 

equally reliable but at a fraction of the cost. They are 

fabricated from relatively inexpensive components 

and catalysts, and can be manufactured using simple 

production techniques in an inexpensive factory. 

Their low cost, even in small volume production, will 

enable the alkaline fuel cell to be used in niche 

markets (i.e., peaking and/or stationary power) 

before the mass production envisioned for other fuel 

cell types (proton exchange membrane [PEM], solid 

oxide fuel cell [SOFC]) brings the price of these 

technologies to a competitive level. However, 

additional development is needed to improve the 

sensitivity of alkaline fuel cells to atmospheric CO2, 

increase their efficiency, and to improve their power 

density. 

Approach

This is a new project initiated in early spring 

2002. The initial goal is to develop an understanding 

of the development needs of alkaline fuel cells 

through visits to developers and by analysis of 

published records and literature. Upon completion of 

this analysis, development of critical materials or 

components will commence with the emphasis on 

advancing current alkaline technology. To obtain 

higher temperature, higher power density cells and 

stacks in the future.

Results

A collaborative laboratory effort between 

Oakridge National Laboratory and Los Alamos 

National Laboratory has recently been undertaken to 

evaluate the alkaline fuel cell literature and develop a 

research and development program plan. To date, 

the team evaluated the literature and drafted a review 

of the state-of-the-art. Based on this and input from 

industrial participants, a research plan is being 

drafted and will be presented to the Office of 

Hydrogen, Fuel Cells and Infrastructure 

Technologies in August 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

285

IV.B.2 Development of Advanced, Low-Cost PEM Fuel Cell Stack and System 

Design for Operation on Reformate

Michel Fuchs 

Teledyne Energy Systems, Inc.

1501 Northpoint Parkway, #101

West Palm Beach, FL 33407

(561) 688-0506 x239, fax: (561) 688-0766, e-mail: michel.fuchs@teledynees.com

DOE Technology Development Manager: Donna Ho 

(202) 586-8000, fax: (202) 586-9811, e-mail: Donna.Ho@ee.doe.gov

ANL Technical Adivsor: William Swift 

(630) 252-5964, fax: (630) 252-4176, e-mail: Swift@cmt.anl.gov

Objectives

• Design and demonstrate a reformate-capable fuel cell stack, utilizing CO-tolerant membrane electrode 

assemblies (MEAs) and low cost bipolar collector plates.

• Design, integrate and demonstrate a natural gas fueled 7-kWnet fuel cell power plant.

Approach

• Phase I: Demonstration and delivery of a PEM ten cell stack with reformate capability and ten 

additional bi-polar plates manufactured by the compression molding process.

• Phase II: Demonstration and delivery of a high efficiency reformate tolerant 7-kWnet fuel cell stack 

and power plant utilizing molded bipolar plates and natural gas fuel processor to Argonne National 

Laboratory for independent testing and verification. 

Accomplishments

• Built and operated a 3-kWnet fuel cell power plant with integrated natural gas reformer.

• Began construction of second 3-kWnet fuel cell power plant with advanced features and controls.

• Built and tested reformate tolerant 60-cell 5.0-kWgross Teledyne Perry NG2000 stack.

• Have accumulated over 2500 hours of 10-cell stack operation on synthetic reformate.

• Developed control architecture capable of compensating for reformer response and effectively meeting 

transient power demands.

• Developed system design that utilizes improvements generated from 3-kWnet plant testing.

• Established design criteria to achieve neutral water balance.

Future Directions

• Develop a 7-kWnet fuel cell system with integrated natural gas fuel processor.

• Continue evaluations of new MEA materials for optimal reformate performance and longevity.

• Fabricate, assemble and test 7-kWnet power plant and prepare it for delivery.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

286

Introduction

Current work is associated with the development 

of a 7-kWnet fuel cell power plant with integrated 

natural gas reformer based on Teledyne Energy 

Systems’s 3-kWnet prototype stationary power plant. 

The development effort will focus on a systems 

approach broken down into three areas: PEM fuel 

cell stack, natural gas reformer and integrated 

system.

Approach and Results

PEM Fuel Cell Stack

Taking into account commercial objectives and 

goals, a Teledyne Perry NG2000 stack configuration 

was chosen to meet requirements for the 7-kWnet

power plant. Two 60-cell stacks rated at 5.0-kWgross

(Figures 1 and 2), electrically connected in parallel, 

will be utilized to meet total power demands. 

The NG2000 has an active area size of 300 cm2

and is designed to operate on pure hydrogen or 

reformate, e.g. 45% H2, 35% N2, 20% CO2, 10 ppm 

CO. The MEAs are designed for continuous 

operation with CO concentrations of 10 ppm and can 

tolerate transients approaching 100 ppm. Excellent 

cell-to-cell consistency has been demonstrated 

throughout the stack’s operating range (Figure 3). 

Running on reformate, the NG2000 can be scaled to 

meet a variety of power requirements from 360-W to 

10-kWgross.

The NG2000 is capable of operating between 0.2 

and 3 atm and up to 70°C. Tables 1 and 2 show 

specifications and capabilities of the 60-cell stack 

respectively. Ongoing work is focused on attaining 

10,000 hours of operation in the near-term with a 

final objective of 40,000 hours. So far over 2500 

hours of continuous operation has been demonstrated 

on a 10-cell NG2000 stack running on synthetic 

reformate. 

A duplicate of the 60-cell stack that will be used 

in the power plant was recently constructed and then 

tested on synthetic reformate. Figures 4 and 5 show 

the performance of the stack on hydrogen and 

synthetic reformate respectively. Operating on 

reformate, the 60-cell exhibits near pure hydrogen 

performance. 

In situ evaluation of a 60-cell stack was 

demonstrated in Teledyne Energy Systems’s 3kWnet

Figure 1. Teledyne Perry NG2000 60-Cell Stack

Figure 2. Teledyne Perry NG2000 60-Cell Undergoing 

Testing

Figure 3. Teledyne Perry NG2000 60-Cell Steady-State 

Performance with Synthetic Reformate
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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prototype stationary power plant which incorporated 

a 7-kW natural gas reformer (Figure 6). 

Reformer

A 10-kW natural gas fuel processor will be 

integrated into the power plant. The processor is 

capable of starting up and producing fuel cell quality 

reformate in less than 60 minutes. Furthermore, it is 

able to transition from minimum power to full power 

(2 kW to 10 kW) in less than 60 seconds. The 

reformer is a larger version of the unit used in the 3-

kWnet stationary plant, which has demonstrated 

good transient response and low CO output (less than 

50 ppm throughout its operating envelope).

Integrated System

The 7-kWnet system will consist of the fuel cell, 

reformer and ancillary systems. The final packaged 

system will be optimized for laboratory use and 

outfitted with an extensive, PC based, data 

acquisition system. 

To compensate for the response of the fuel 

processor, a control architecture was developed to 

allow a battery system to provide for peak power 

demands. The power plant has been designed to 

maintain the batteries’ state of charge at an optimal 

level while the batteries provide the capacitance 

necessary to meet any load topography. In this 

configuration, the transient-following capabilities of 

the power plant are greatly enhanced. 

The ancillary systems are designed to track the 

load demands placed on the power plant. For 

instance, compressors, pumps and fans will be 

operated to provide only the conditions necessary to 

allow the stack to meet a given power demand. This 

will enable optimal efficiency to be maintained at all 

operating conditions. 

Table 1. Teledyne Perry, NG2000 60-Cell Stack 

Specifications

Reactants: Air/Reformate

Active area 292 cm2

Operating volt. range 38-57 V

Operating pressure 0.2 to 3.0 atm.

Operating temperature 60 to 70°C

Stack volume 21.2 Liters

Stack weight 50 kg

Table 2. Teledyne Perry, NG2000 60-Cell Stack 

Performance

Max cont. power 5.4-kW @ 38 VDC

Power density 255 W/L

Reformate

composition as tested

45% H2, 35 % N2, 20%

CO2, 10 ppm CO

Figure 4. Teledyne Perry NG2000 60-Cell Performance 

with Hydrogen Fuel

Figure 5. Teledyne Perry NG2000 60-Cell Performance 

with Synthetic Reformate Fuel
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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A model based on the performance on the 3-

kWnet stationary power plant was developed to assist 

in designing the 7-kWnet system. Table 3 shows 

results obtained from the model at various operating 

conditions. 

Sensitive to the necessity to reduce costs critical 

to the successful commercialization of fuel cell 

technology, a concerted effort has been placed on 

designing a system that is as simple as possible and 

that strives to implement components from well 

established industries, e.g. automotive and appliance.

Conclusion

Teledyne Energy Systems, Inc. will construct a 

7-kWnet stationary fuel cell power plant that will 

utilize natural gas and enable an in-depth evaluation 

of a fuel cell and reformer package. The design of the 

system will be based on Teledyne Energy Systems’s 

commercially oriented 3-kWnet stationary product, 

which is currently under development.

Presentations/Publications:

1. M. Fuchs, F. Barbir and M. Nadal, “Performance 

of Third Generation Fuel Cell Powered Utility 

Vehicle #2 with Metal Hydride Fuel Storage”, 

presented at the 2001 European Polymer 

Electrolyte Fuel Cell Forum, Lucerne, 

Switzerland, July 2001

2. F. Barbir and J. Braun, “Development of Low 

Cost Bi-Polar Plates for PEM Fuel Cell”, Proc. 

Fuel Cell 2000 Research & Development, 

Strategic Research Institute Conference, 

Philadelphia, PA, September 2000

3. M. Fuchs, F. Barbir and M. Nadal, “Fuel Cell 

Powered Utility Vehicle with Metal Hydride Fuel 

Storage”, presented at the GlobeEx 2000 

Conference, Las Vegas, NV, July 2000

4. F. Barbir, “Recent Progress and Remaining 

Technical Issues in PEM Fuel Cell Development”, 

submitted to the World Hydrogen Energy 

Conference, WHEC XIII, Beijing, China, June 

2000

5. F. Barbir, “Air, Water and Heat Management in 

Automotive Fuel Cell Systems”, presented at the 

Intertech Conference Commercializing Fuel Cell 

Vehicles 2000, Berlin, Germany, April 2000

6. M. Fuchs, F. Barbir, A. Husar, J. Neutzler, D. 

Nelson and M. Ogburn, “Performance of 

Automotive Fuel Cell Stack”, presented at the 

2000 Future Car Congress, Arlington, VA, April 

2000 

7. F. Barbir, “Bi-polar Plates, Flow Fields and Stack 

Design Criteria”, presented at the American 

Physical Society Meeting, Minneapolis, MN, 

March 2000

Table 3. 7-kWnet Fuel Cell Power Plant Model Results

Parameter @

7kWnet

@

5kWnet

@

2kWnet

Stack

array pwr

9.2 kW 6.5 2.7

Stack

array volt

41.1 V 43.9 V 47.8 V

Ancillary

load

2.2 kW 1.5 kW 0.7 kW

Stack

thermal

Eff. (LHV)

55% 58% 63%

Figure 6. 7-kW Reformer Test Stand
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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8. F. Barbir, M. Fuchs, A. Husar and J.Neutzler, 

“Design and Operational Characteristics of 

Automotive PEM Fuel Cell Stacks”, Fuel Cell 

Power for Transportation, SAE SP-1505, Proc. 

SAE International Congress & Exhibition, 

Detroit, March 2000, pp. 63-69, SAE, 

Warrendale, PA, 2000

9. V. Gurau, F. Barbir and H. Liu, “An Analytical 

Solution of a Half-cell Model for PEM Fuel 

Cells”, Journal of Electrochemical Society, Vol. 

147(7), 2000
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.B.3 Proton Exchange Membrane Fuel Cell Power System on Ethanol

Ahmed Amrani (Primary Contact), Thomas Richards

Caterpillar Inc.

Technical Center, P.O. Box 1875

Peoria, Illinois 61656 - 1875

(309) 578-3913, fax: (309) 578-9900, e-mail: Amrani_Ahmed@cat.com

DOE Technology Development Manager: Kathi Epping

(202) 586-4725, fax: (202) 586-9811, e-mail: Kathi.Epping@ee.doe.gov

ANL Technical Advisor: William M. Swift 

(630) 252-5964, fax: (630) 972-4473, e-mail: swift@cmt.anl.gov 

Main Subcontractors: Nuvera Fuel Cells, Cambridge, Massachusetts; Williams Bio-Energy, Pekin, 

Illinois

Objectives

• Caterpillar, Nuvera Fuel Cells, and Williams Bio-Energy have teamed up to develop and demonstrate a 

15 kilowatt (kW) ethanol-fueled proton exchange membrane (PEM) fuel cell system. The primary 

objectives of this project are to:

- Demonstrate performance, durability and reliability

- Remove technical uncertainties 

- Understand correlation and reduce gaps between stationary and transportation application

- Collect data to evaluate economic feasibility

- Assess commercial viability of total system

Approach

• Nuvera will assess and modify advanced fuel cell power module designs that are now under 

development in separate projects to develop the power module for this project.

- Caterpillar will design the power converter module and will integrate the system.

- Williams will supply the ethanol and host the site to test the unit and conduct endurance testing.

Accomplishments

• A preliminary design review between Nuvera, Williams and Caterpillar took place May 20 - 21, 2002.

• Power module design specifications have been completed.

• The ethanol reformer has been tested for a short period of time at rated power.

• The fuel cell stack has been tested for a short period of time at 1⁄4 rated power with output from the 

reformer.

• Power converter specifications have been completed.

• The design and release of the power converter is near completion.

• Preliminary site specifications exist and a safety codes and standards review has been scheduled. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

291

Future Directions

• Prepare and conduct a final design review with cooperative team and sponsors 

• Conduct independently the functional test of both the power module and the power converter. This is 

targeted for January-February 2003.

• Prepare the test site building, which will be the endurance-testing place for the fuel cell system. This is 

targeted to be completed in the January 2003 time frame.

• Ship the functional unit to the test site and start the endurance-testing phase. This is targeted to start in 

February 2003.

Introduction

Nuvera will design, build, test, and deliver a 15 

kilowatt electrical (kWe ) direct current (DC) fuel 

cell power module that will be specifically designed 

for stationary power operation using ethanol as a 

primary fuel. Two PEM fuel cell stacks in parallel 

will produce 250 amps and 60 volts at rated power. 

The power module will consist of a fuel processor, 

carbon monoxide (CO) clean-up, fuel cell, air, fuel, 

water, and anode exhaust gas management 

subsystems. A state-of-the-art control system will 

interface with the power system controller and will 

control the fuel cell power module under start-up, 

steady-state, transient, and shutdown operation. 

Temperature, pressure, and flow sensors will be 

incorporated in the power module to monitor and 

control the key system variables under these various 

operating modes. The power module subsystem will 

be tested at Nuvera and subsequently be delivered to 

the Williams Bio-Energy Pekin, Illinois site.

Approach

Nuvera plans to modify advanced fuel cell power 

module designs that are now under development in 

separate projects for use in this project. They will 

start with a power module design that is a multi-fuel, 

1 atmosphere, 20 kWe power module designed for 

transportation (light duty vehicle) applications. The 

purpose of using this design baseline is twofold.

• By using an existing design, much of the 

design effort and technical risk associated 

with a completely new power module design 

will be avoided.

• By using a transportation-based design, this 

demonstration will simultaneously illustrate 

that renewable ethanol can be used in fuel 

cell power systems applied to stationary 

power generation as well as transportation.

Caterpillar will design, build, test and deliver a 

power converter module that converts the DC output 

of the power module into AC power. Caterpillar will 

also provide system level control to insure all major 

subsystems work in harmony and provide constant 

power (14 kWe) to the industrial load on site. The 

fuel cell system will add power to the overall power 

at the Williams Bio-Energy ethanol production site in 

Pekin, Illinois.

The power converter design will rely on 

Caterpillar's experience with state-of-the-art solidstate power converters that employ switches, 

inverters and pulse width modulation to shape a 

sinusoidal voltage and current in time with the 

existing power source on site.

Caterpillar also aims to demonstrate technology 

to the greatest extent possible that can meet the dual 

requirements of the transportation industry and the 

stationary electric power generation industry. In 

addition to low levels of emissions, we intend to 

demonstrate high efficiency, durability and 

reliability. These technical objectives will enable us 

to calculate the cost of electricity ($/kW-hr) for 

transportation and stationary power applications.

Williams Bio-Energy will host the industrial site 

for this demonstration. Williams works with Nuvera 

and Caterpillar to provide them with site electrical 

load requirements. They will prepare the site to 

ensure that the fuel cell system links to their power 

network and will supply ethanol fuel and other 

utilities. During the demonstration, Williams' 

personnel will monitor and service equipment and 

permit visitors to witness the demonstration in 

comfort and safety.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

292

Results

The cooperative team has demonstrated several 

milestones. 

Power Converter

The overall system block diagram, system level 

wiring diagram, and power converter diagram have 

all been finalized. This is depicted in Figure 1. The 

overall schematic and bill of material have identified 

the long lead items, which are now being procured. 

A system level functional specification is being 

revised with a baseline allowing configuration 

control and management.

Power Module

Several rig tests to study contaminant formation 

from ethanol reforming were conducted to finalize 

the selection of the proper catalyst, and a burner was 

re-engineered and sized to meet the different power 

requirement. 

Cold start testing of the reformer using ethanol 

was completed at half power and operability of the 

reformer using new sensors and controllers was 

demonstrated at full power, resulting in reformate 

with less than 20 parts per million CO and with 37% 

of hydrogen (H2) under stable condition. (See 

Figures 2 and 3.)

A 45-stack baseline system test (fuel cell stack 

and reformer) was conducted to demonstrate stability 

and high H2 utilization (75%-80%). This was 

followed by an 80-stack design test at full power for 

over 45 minutes, resulting in high H2 utilization. 

Cold start of the reformer without afterburner was 

completed. 

The overall process and instrumentation diagram 

as well as the interface diagram are now completed.

Conclusions

A preliminary design review was held at Nuvera 

in Cambridge on May 20, 2002, focusing on refining 

the project plan with milestones, target critical design 

review dates and visiting the existing building where 

the fuel cell system will be hooked up and tested. 

Figure 1. System Level Block Diagram

Figure 2. Startup Profile of Reformer System

Figure 3. Stack Performance at Full Power Cell 

Conditions 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

293

Also reviewed were the power converter and 

module specifications, power topology, power flow 

requirement, a common data acquisition system, the 

different control flow charts, the system wiring 

diagrams, and the different protocols for data 

acquisition and monitoring. 

The cooperative team has also established a 

common FMEA (Failure Mode Evaluation and 

Analysis) system using the power converter FMEA 

from Caterpillar as a template, and expanding this 

approach to define a preliminary HazOps analysis to 

be conducted in the future.

At this phase no technical hurdles are 

anticipated. Future actions include conducting a 

safety design review (HazOps analysis), establishing 

an activity-based target date for a critical design 

review, and generating a system level functional 

specification document which will help define the 

research boundaries for this project.

Procurement of critical long lead hardware will 

continue. This will allow a sound forecasting in 

planning the shakedown testing of the power module 

and the power converter separately. The unit will be 

then assembled and ready for the endurance testing. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.B.4 Fuel Cell Distributed Power Package Unit: Fuel Processing Based on 

Autothermal Cyclic Reforming 

George Kastanas, Court Moorefield, Parag P. Kulkarni, Shawn Barge, Vladimir Zamansky, Ravi 

Kumar (Primary Contact)

GE Energy and Environmental Research Corporation

General Electric Company

18 Mason

Irvine, CA 92618

(949) 859-8851 ext.159, fax: (949) 859-3194, e-mail: ravi.kumar@ps.ge.com

DOE Technology Development Manager: Kathi Epping

(202) 586-7425, fax: (202) 586-9811, e-mail: Kathi.Epping@ee.doe.gov

Goals and Objectives

• The overall goals of the project are to:

- Design, fabricate and operate a precommercial integrated fuel processor;

- Create a design for mass manufacturing of the system; 

- Assess the performance of the system in terms of total efficiency, electrical production efficiency, 

and cogeneration value; and 

- Assess the economics of the design.

• The specific performance objectives of the fuel processor are to:

- Convert natural gas to a proton exchange membrane (PEM) fuel cell grade hydrogen-rich stream 

(< 10 ppm CO);

- Achieve fully automatic operation during normal, start-up, shut-down and stand-by modes;

- Operate in a fully automatic mode for over 100 hours; 

- Achieve 75% fuel processor efficiency on a higher heating value (HHV) basis; and

- Achieve a capital cost target that is less than $1000/kW and electricity cost that is less than $0.06/

kWh, when the system is mass produced.

Approach

• Design a 50 kW fuel processor capable of producing PEM fuel cell grade hydrogen-rich stream.

• Fabricate and operate a fully automated 50 kW fuel processor capable of operating on natural gas. 

• Conduct an economic and manufacturability analysis to reduce costs for the system and to provide 

information on the high volume manufacturing cost of the fuel processor.

Accomplishments

• Design of 50 kW integrated fuel processor, which includes reformer, shift reactor, steam generator and 

preferential oxidation reactor.

• Fabrication of reformer, shift reactor, and steam generator.

• Design and programming of automated control system.

• Shakedown of steam generator, valves and feed metering systems

• Preliminary economic analysis. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

295

Future Directions

• Fabricate preferential oxidation reactor.

• Operate and optimize the fully integrated fuel processor.

• Analyze the reliability of the fuel processor.

• Perform a detailed economic analysis.

Introduction

GE Energy and Environmental Research 

Corporation (GE EER) is developing a PEM fuel cell 

based distributed power generation (DPG) system. 

The DPG system uses a proprietary fuel processor to 

convert fossil fuels to a hydrogen-rich gas for use in 

the fuel cell. The project is currently in Phase II, 

which is a demonstration of the integrated fuel 

processor operating in a fully automatic mode for 

over 100 hours to continuously generate a PEM fuel 

cell grade hydrogen-rich stream (<10 ppm CO) with 

thermal efficiency of 75% on a HHV basis.

GE EER will design, fabricate and operate a precommercial integrated fuel processor, develop a 

design for mass manufacturing of the system, and 

assess the potential cost and performance.

Approach

A precommercial, integrated 50 kWe fuel 

processor that can produce a PEM fuel cell grade 

hydrogen-rich stream will be designed and 

fabricated. The Autothermal Cyclic Reforming 

(ACR) and Low Temperature Shift (LTS) 

technologies that have been successfully 

demonstrated during the earlier part of the project 

will be used. In order to reduce the concentration of 

CO to less than 10 ppm, GE EER will only consider 

technologies that are commercially available or are 

close to commercialization. The technologies that are 

commercially available are Pressure Swing 

Adsorption (PSA) and Selective Hydrogen 

Membrane Permeation. The technologies that are in 

the developmental stage but potentially are near 

commercialization are Preferential Oxidation 

(PROX) of Los Alamos National Laboratory and 

Methanation. The major deliverable will be a report 

on continuous operation of the fuel processor in fully 

automatic mode for over 100 hours. An economic 

analysis will be conducted to identify the 

opportunities for reducing costs of the system and to 

provide improved information on the high volume 

manufacturing cost of the fuel processor.

Results, Conclusions, and Future Directions

The autothermal cyclic reformer, LTS reactor, 

steam generator and desulfurizer have been designed, 

fabricated and installed on the skid. The desulfurizer 

absorbs sulfur components from the natural gas 

upstream of the reformer. A conventional Copper/

Zinc catalyst was selected for the LTS reactor. The 

PROX reactor, which reduces CO level to less than 

10 ppm in the hydrogen-rich gas, has been designed. 

The PROX catalyst was selected and has been 

ordered. The skid platform, the flow panels and the 

feed metering systems have been fabricated. The 

piping to all vessels has been installed and leak 

checked. The flow control system, control hardware 

and independent safety systems have been installed. 

The automatic control system has been designed and 

programmed. The shakedown of the steam generator, 

valves and feed metering systems has been 

completed. The PROX reactor will be fabricated and 

the integrated fuel processor will be operated and 

optimized. The 50 kW fuel processor is shown in 

Figure 1. 

Figure 1. 50 kW Integrated Fuel Processor
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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The results to date are highly promising and 

indicate that the GE reforming technology is on the 

road to success to meet DOE goals. The fuel 

processor promises to advance the current state of 

fuel cell technology and will provide clean hydrogen 

generation, allowing for distributed reforming at high 

efficiency, with reduced pollutant emissions, and fuel 

flexibility, at lower cost. The development and 

commercialization of ACR-based fuel processors 

will remove the barriers for fuel cell development, 

which is presently being stifled by the lack of small 

scale reformers and the lack of hydrogen distribution 

systems.

A template for calculating cost of electricity has 

been developed. The analysis considers efficiency, 

capital costs, operating and maintenance costs, 

capital recovery factor, availability, fuel price and 

other factors. A detailed economic analysis will be 

performed. 

GE EER and GE's Global Research Center 

(GRC) will analyze the design for reliability (DFR) 

of the fuel processor. The components that require a 

design review to reduce capital costs have been 

identified. DFR templates that have been developed 

by GRC to record all failures will be used. This data 

will be analyzed and all identified reliability issues 

will be addressed during the design of the next 

system. The DFR plan also includes component 

testing that will help identify failures of subsystems 

and components. Information from DFR analysis 

will be combined with the economic analysis to 

determine the economic benefits of the advanced fuel 

processor system. 

FY 2002 Publications and Presentations

1. R.V. Kumar, "Autothermal Cyclic Reforming 

Based Hydrogen Refueling System", IEA Annex 

XV Fuel Cells for Transportation Meeting, 2002, 

Sacramento, California.

2. R.V. Kumar, G. Kastanas, S. Barge, V. Zamansky, 

R. Seeker, "Autothermal Cyclic Reforming Based 

Hydrogen Refueling System", DOE Annual 

Hydrogen Program Review, 2002, Golden, 

Colorado.

3. R.V. Kumar, G. Kastanas, P. Kulkarni, C. 

Moorefield, S. Barge, V. Zamansky, R. Seeker, 

"Hydrogen Energy Park Based on Autothermal 

Cyclic Reforming", Fuel Cell Seminar, 2002, 

Palm Springs, California.
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297

IV.B.5 Research and Development on an Ultra-Thin Composite Membrane For 

High-Temperature Operation in Proton Exchange Membrane Fuel Cells

Chao-Yi Yuh (Primary Contact)

FuelCell Energy, Inc.

3 Great Pasture Road

Danbury, CT 06813

(203) 825-6112, fax: (203) 825-6273, e-mail: cyuh@fce.com

DOE Technology Development Manager: Kathi Epping 

(202) 586-7425, fax: (202) 586-9811, e-mail: Kathi.Epping@ee.doe.gov

Main Subcontractors: University of Connecticut, Storrs, Connecticut and Ion Power, Inc., Bear, 

Delaware

Objectives

• Develop an ultra thin, durable membrane (< 75 μm) capable of operation at 100-140oC with the 

following properties:

- <0.2 Ωcm2 (Ohm-centimeter-squared) membrane ohmic resistance and <1% crossover

- High ionic conductance with negligible electronic conductivity

- High mechanical strength

- >0.6 volts (V) performance at 400 mA/cm2 (milliamps/centimeters squared) under ambient 

reformate/air operation at 120oC

Approach 

• Develop a solid superacid-Nafion®composite membrane electrode assembly (MEA) with the 

following components:

- Solid superacids as high-temperature proton conductors and moisture retainers

- Nafion® phase as proton conducting binder phase

- Inert support phase may be added to enhance strength

Accomplishments

• Demonstrated atmospheric MEA performance of ~600 mV at 400 mA/cm2 under actual system 

operating conditions (atmospheric, low relative humidity, high utilizations) at 120oC for 500 hours (h)

• Achieved membrane ohmic resistance and cross-over objectives 

Future Directions

• Optimization of the promising membrane-electrode assembly

• Scale-up to nominal 300 cm2 and validation in single cell

• 300 cm2 short stack evaluation 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

298

Introduction

Fuel cells offer the best alternative to 

conventional power generation technologies. They 

are inherently very efficient and clean. For fuel cells 

to be commercially competitive, issues such as cost, 

size, and functionality need to be addressed. The 

specific goal of this fuel cell for buildings 

applications project is to develop an atmosphericpressure natural gas-fueled proton exchange 

membrane fuel cell (PEMFC) system with >35% 

efficiency (higher heating value), >100oC operation 

for cogeneration, simple construction, >40,000 h 

reliable life, and <$1500/kW system cost. For the 

PEMFC to be commercially viable, the performance 

of critical components, such as the polymer 

electrolyte membrane in particular, needs to be 

improved.

At present, the state-of-the-art PEMFC is 

operated at ~80o

C. Carbon monoxide (CO) 

poisoning of the PEMFC anode's precious metal 

catalyst is a major technical barrier for utilizing 

hydrocarbon feedstocks such as natural gas. CO 

clean-up from the fuel stream requires a complicated 

and expensive fuel processor. Since the 

chemisorption of CO on the anode catalysts is 

exothermic and therefore weakens considerably with 

temperature, one approach to mitigate the CO 

poisoning is to operate the PEMFC at higher 

temperatures. Many other advantages can also be 

realized, such as faster electrode kinetics, lower 

voltage loss, higher quality waste heat for 

cogeneration, cathode flooding mitigation, and 

greater ability to remove waste heat. 

The baseline Nafion® membrane is deficient in 

terms of ionic conductivity above 100o

C and at low 

relative humidity required for atmospheric-pressure 

building applications. Such conditions tend to dry 

out the membrane, drastically reducing membrane 

proton conductivity. Furthermore, the loss of water 

causes membrane embrittlement, resulting in 

membrane cracking, reactant cross-leakage and poor 

electrode-membrane contact. Therefore, a costeffective membrane, with proton conductivity that is 

less sensitive to change in water content, is needed. 

Another important issue for >100o

C operation is 

cell voltage loss. Only a minor portion of the cell 

voltage loss is in fact caused by the membrane ohmic 

resistance increase. The majority of the voltage loss 

increase is due to the increase in cathode 

polarization. In order to achieve the hightemperature cell performance goal, cathode 

performance improvement is essential.

Based on the literature survey, no membranes or 

MEAs reported so far can achieve all the above 

required goals. This research is directed at 

developing novel high-temperature, composite 

proton exchange membrane-electrolyte assemblies 

for PEMFC for building applications.

Approach

The overall objective is to operate PEMFCs at 

100-140oC to improve CO tolerance, mitigate water 

and thermal management challenges and reduce 

membrane cost. The basic approach is to develop a 

composite membrane consisting of mechanical 

support and high-temperature proton conduction 

phases. In order to improve cathode performance, 

modification of cathode formulation and structure is 

on-going. Promising solid superacids are 

incorporated into the cathode.

Results

A number of composite membranes and MEAs 

have been developed to improve water retention and 

proton conduction at 120oC. Additives/modifiers 

with specific properties have been synthesized. The 

performance of the fabricated MEAs in laboratoryscale cells has been characterized to screen 

promising formulations. The negligibly low anode 

polarization loss at >100oC has been verified. 

Significant improvements in 120o

C performance and 

endurance have been achieved. The ohmic resistance 

and cross-over goals of the membrane have been 

met. MEA performance of ~0.6 V at 400 mA/cm2

under realistic system operating conditions 

(atmospheric, low relative humidity, high 

utilizations) has been achieved in a 500 h 25-cm2 cell 

endurance test (Figure 1). The MEA Pt loading was 

0.4 mg/cm2 for each electrode. This represents one 

of the best cell performances ever reported in the 

literature. Performance of >750 mV at 120oC was 

also achieved under pressurized operating condition 

(30 psig). These results are highly promising.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

299

The main activities for the remaining part of this 

program will focus on optimization of the promising 

membrane-electrode assembly, scale-up to nominal 

300 cm2 and validation in single cells followed by 

short stack evaluation. The program is scheduled to 

be completed in February 2003.

Conclusions

An MEA performance of ~600 mV at 400 mA/

cm2 under realistic system operating conditions has 

been demonstrated, representing a major milestone 

towards developing a viable atmospheric PEMFC 

system. To further enhance cell performance (to 

desired operating conditions of 0.8 V at 400 mA/

cm2

), optimization of cathode structure and 

formulation to enhance proton conduction and 

cathode catalyst utilization is required.

Publications/Presentations

1. C. Yuh, P. Patel, R. Kopp, S. Katikaneni and S. 

Grot, "Novel Composite Membrane-Electrode 

Assembly for High-Temperature PEMFC," 3rd 

International Symposium on Proton Conducting 

Membrane Fuel Cells, The Electrochemical 

Society Fall Meeting, Salt Lake City, Utah, 

October 20-24, 2002.

2. C. Yuh, "R&D on an Ultra Thin Composite 

Membrane for High-Temperature Operation in 

PEMFC," Annual Report to US DOE, for the 

Period of September 1999 to August 2000.

Figure 1. MEA performance of ~0.6 V at 400 mA/cm2

under realistic system operating conditions 

(atmospheric, low relative humidity, high 

utilizations) has been achieved in a 500 h 25-

cm2

 cell endurance testing.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

300

IV.C Fuel Processing Subsystem and Components

IV.C.1 Next Millennium Fuel ProcessorTM for Transportation Fuel Cell Power 

System

Prashant S. Chintawar (Primary Contact), James Cross, Brian Bowers, Robert Rounds, and Zhi-Yang 

Xue

Nuvera Fuel Cells, Inc.

35 Acorn Park

Cambridge, MA 02140

(617) 498-6577, fax: (617) 498-6664, e-mail: chintawar.p@nuvera.com

DOE Technology Development Manager: Patrick Davis

(202) 586-8061, fax: (202)586-9811, e-mail: Patrick.Davis@ee.doe.gov

ANL Technical Advisor: Walter Podolski

(630) 252-7558, fax: (630) 972-4430, e-mail: podolski@cmt.anl.gov

Subcontractors/Partners: SudChemie, Inc.; STC Catalysts, Inc.

Objectives

• Validate Argonne National Laboratory (ANL) computer models by integrating existing fuel processing 

technology into a 10 kWe multi-fuel power system. 

• Utilize integrated STAR (Substrate based Transportation application Autothermal Reformer) fuel 

processor, MPR (Modular Pressurized Reformer – a disintegrated fuel processor), high temperature 

material test facility, and microreactors to perform endurance testing that will identify and address 

component and fuel processor degradation mechanisms. 

• Design and test the 50kWe STAR fuel processor. 

Approach

• Integrate fuel processing (existing Model B based technology) and fuel cell sub-systems.

• Develop control strategies on 10 kWe fully automated fuel cell power system (FCPS) and deliver to 

ANL.

• Perform automotive system analysis and identify strategies for STAR to meet FreedomCAR targets.

• Set targets and develop key technologies and components to be used in STAR.

• Design and test STAR on four fuels and investigate efficiency, emissions, steady state and transient 

performance, and reformate purity.

• Integrate STAR fuel processor and fuel cell, investigate the performance of the power system, and 

identify system level integration issues. Deliver the integrated fuel processor system to ANL.

• Investigate and address degradation and durability issues of STAR fuel processor both on the 

component and integrated fuel processor level.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

301

Accomplishments

• Tested the fuel cell sub-system and fuel processor sub-system.

• Developed sub-system and integrated power plant control strategies.

• Performed steady state and transient testing on gasoline and delivered integrated FCPS to ANL.

• Developed design criteria for scrubber media and validated them during full-scale operation of fuel 

processor and STAR systems.

• Selected materials for high temperature zones of the fuel processor and designed test facility to 

investigate long term stability of such materials.

• Performed deactivation studies of the STAR catalyst suite in microreactor.

• Tested >100 catalysts for STAR and selected final candidates.

• Designed substrate-only fuel processor and devised control strategies for fuel processor and FCPS.

• Tested partially integrated fuel processor (version 1) and demonstrated 74% H2 efficiency (at high 

temperature shift exit).

• Tested partially integrated fuel processor (version 2) and demonstrated improvements in thermal stress 

and serviceability over version 1, and 80% syn gas efficiency (at high temperature shift exit).

• Designed and characterized reformate tolerant fuel cell on hydrogen.

Future Directions

• Support ANL’s testing efforts and modeling studies, and provide necessary assistance.

• Bring the high temperature material test facility on-line.

• Complete the long term stability studies of the STAR catalyst suite and deduce equations to describe 

degradation.

• Perform long term stability studies of the integrated STAR fuel processor with gasoline.

• Demonstrate ≥50 kWe power from an integrated FCPS and characterize fuel processor on four fuels.

• Perform emission characterization of integrated FCPS.

• Deliver fuel processor system to ANL.

Introduction

Nuvera is working with the Department of 

Energy to develop efficient, low emission, on-board 

multi-fuel processors for the transportation 

application. The fuels include gasoline, methanol, 

ethanol, and natural gas.

In the first part of the project, Nuvera integrated 

an existing fuel processing technology into a 10 kWe 

multi-fuel power system in order to allow validation 

of computer models developed by ANL. This 

integrated fuel cell power system was delivered to 

ANL in June 2002.

The Substrate based Transportation application 

Autothermal Reformer (STAR) will contain highactivity, low-cost, transportation specific catalysts 

and substrates to address power density, specific 

power, and start-up tie issues. To address the issue of 

system durability, we are developing fuel purification 

(sulfur removal) and reformate clean-up 

technologies.

Results

Based on component technologies produced in 

previous years, we completed design of the STAR 

fuel processor in the reporting period (Figures 1 and 

2). The design shown contains all the reaction zones 

and has a volume of ~70 L. This fuel processor also 

has the shape factor necessary for installation in the 

fuel cell vehicle.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

302

We have collected operation data from the 

partially integrated STAR fuel processor (Figure 3). 

Gasoline was used as a fuel in this testing at 175 

kWth feed rate and we expect the maximum feed rate 

to be ~200 kWth. The H2 efficiency and CO 

concentration approach equilibrium values 

Figure 1. Conceptual Design of STAR Fuel Processor

Figure 2. STAR Fuel Processor on Test Cart

Figure 3. Performance Data of Partially Integrated 

STAR Fuel Processor

Technical targets: fuel processorsa to generate hydrogencontaining fuel gas from reformulated gasoline containing 

30 ppm sulfur, average, for 50 kWe (net) fuel cell systems

(Excludes fuel storage; includes controls, shift reactors, CO 

cleanup, heat exchangers)

Characteristics Units Calendar year

2001

statusb 2005 STAR 

2002c

Energy efficiencyd % 78 78 78

Power density W/L 500 700 836

Specific power W/kg 450 700 585

Coste $/kW 85 25 65

Cold start-up time to 

maximum power

 @+20 oC ambient min <10 <1 <10

Transient response 

(time for 10% to 90% 

power)

sec 15 5 15

Durabilityf hours 1000g 4000h 1000

Survivabilityi oC TBD –30 TBD

CO content in product 

streamj

 steady state

 transient

ppm

ppm

10

100

10

100

<50

<100

H2S content in 

product stream ppb <200 <50 <100

NH3 content in 

product stream ppm <10 <0.5 <1

 aWith catalyst system suitable for use in vehicles.

 b

Projected status for system to be delivered in late 2002: 80% efficiency, 900 

W/L, 550 W/kg.

 c

Projected status for STAR fuel processor in 2002. d

Fuel processor efficiency = total fuel cell system efficiency/fuel cell stack 

system efficiency, where total fuel cell system efficiency accounts for thermal 

integration. For purposes of testing fuel-processor-only systems, the efficiency 

can be estimated by measuring the derated heating value efficiency (lower 

heating value of H2 H 0.95/ lower heating value of the fuel in) where the 

derating factor represents parasitic system power losses attributable to the fuel 

processor.

 e

High-volume production: 500,000 units per year.

 f

Time between catalyst and major component replacement; performance 

targets must be achieved at the end of the durability period.

 gContinuous operation.

 h

Includes thermal cycling.

 i

Performance targets must be achieved at the end of an 8-hour cold-soak at 

specified temperature.

 j

Dependent on stack development (CO tolerance) progress.

Table 1. Comparison of FreedomCAR Targets and STAR 

Performance Projections
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

303

suggesting the validity of our design basis. We have 

accumulated >50 hrs of gasoline operation on STAR 

fuel processor (version 2) and have subjected it to 

>30 thermal cycles. Table 1 compares Nuvera’s 

projections of the STAR fuel processor performance 

and FreedomCAR targets. 

The STAR fuel processor represents a 

culmination of three years of intensive R&D and 

design efforts. Prior to their use in the integrated fuel 

processor, all components were tested in the MPR. 

Figure 4 compares the expected and obtained 

performance of the water-gas-shift catalyst in the 

MPR. Similarly, the MPR testing validates the 

desulfurizer performance data collected on the bench 

scale reactor (Table 2). The sulfur capacity was the 

same in both the MPR and the bench scale reactor.

The STAR fuel cell stack, shown in Figure 5, 

was characterized via H2/air operation (Figure 6). 

Figure 6 data are limited to 66 kWe although the 

stack is capable of higher power – load bank 

limitations have prevented us from higher power 

operation. 

The performance of adsorbent clean-up media 

was evaluated and validated. We anticipate the use 

of such media between the fuel processor and fuel 

cell sub-systems to safeguard the fuel cell from 

various trace species generated and/or present in 

gasoline. Figure 7 shows the performance of 

medium “A” after being used on the fuel cell power 

system for 30 hrs. We have also carried out 

extensive short-term and long-term durability testing 

of the STAR catalyst suite (Figure 8).

Parameter Bench-Scale MPR

Adsorbent Weight (g) 9 3330

Physical Form Powder Structured

Table 2. Comparison of Bench-Scale and MPR 

Performance of Desulfurizer

Figure 4. Comparison of Expected vs. Obtained 

Performance of WGS Catalyst in MPR

Figure 5. STAR Fuel Cell Stack

Figure 6. Polarization Data on STAR Fuel Cell for H2/

Air Operation

Figure 7. Performance of Adsorbent “A” after Being 

Used on Fuel Cell Power System for 30 hours
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

304

Over the last year, we retrofitted the existing fuel 

processor sub-system, designed the fuel cell subsystem, and integrated the two units. The integrated 

power plant was delivered to ANL in June 2002. 

Figure 9 shows typical performance of the integrated 

system on gasoline.

Conclusions

• A substrate only multi-fuel processor has been 

designed and tested. Preliminary data on 

gasoline indicate 80% efficiency (at HTS exit). 

Detailed testing is expected to validate the 

performance projections of specific power, 

power density, and emissions.

• Thermal stress and fluid flow distribution 

constitute major design challenges with such fuel 

processors.

Figure 8. Longevity of STAR ATR Catalyst

Figure 9. Fuel Cell Power System Performance on 

Gasoline
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

305

IV.C.2 Multi-fuel Processor for Fuel Cell Electric Vehicle Applications

Tom Flynn (Primary Contact)

McDermott Technology, Inc.

1562 Beeson Street

Alliance, OH 44601-2196

(330) 829-7622, fax: (330) 829-7283, e-mail: tom.j.flynn@mcdermott.com

Brian Engleman

Catalytica Energy Systems, Inc.

430 Ferguson Drive

Mountain View, CA 94043-5272

(650) 940-6391, fax: (650) 960-0127, e-mail: bde@catalyticaenergy.com

DOE Technology Development Manager: Nancy Garland 

(202) 586-567, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

ANL Technical Advisor: Walter Podolski 

(630) 252-7558, fax: (630) 972-4430, e-mail: podolski@cmt.anl.gov 

Main Subcontractors: Catalytica Energy Systems and NexTech Materials, Ltd. (NexTech)

Objectives

• Design, build and demonstrate a fully integrated, 50-kilowatt electric (kWe) catalytic autothermal fuel 

processor system. The fuel processor will produce a hydrogen-rich gas for direct use in proton 

exchange membrane (PEM) fuel cell systems for vehicle applications. 

Approach

• Develop preliminary design of 50-kWe fuel processor system and performance goals for individual 

components.

• Evaluate alternate approaches for the major catalytic components (e.g., desulfurizer, reformer, shift 

reactor and selective oxidation reactor). 

• Conduct subsystem testing of major components utilizing best catalyst approach.

• Develop final design of overall system and design specifications for individual components.

• Assemble 50-kWe fuel processor system.

• Perform demonstration testing on gasoline and methanol. 

• Ship fuel processor system to Argonne National Laboratory.

 Accomplishments

• Completed peer review of final design.

• Produced required amount of Catalytica Energy System's autothermal reformer (ATR) catalyst.

• Produced required amount of NexTech platinum (Pt)/ceria medium-temperature-shift (MTS) catalyst. 

• Obtained Los Alamos National Laboratory preferential oxidation (PROX) reactor.

• Obtained Battelle/Pacific Northwest National Laboratory micro-channel steam generator. 

• Obtained Precision Combustion, Inc. dual-fuel catalytic burner. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

306

• Completed fabrication and assembly of fuel processor system.

• Completed checkout of components, controls and instrumentation.

Future Directions

• Conduct performance tests of fuel processor system.

• Ship fuel processor system to Argonne National Laboratory for further evaluation and testing.

Introduction

Development of a compact, efficient and lowcost processor for converting carbon-based fuels to 

hydrogen is an important aspect of the successful 

implementation of fuel cells for transportation 

applications. A catalyst-based reforming approach 

for fuel processing can provide fast start-up and 

transient response, high efficiency and compactness. 

When coupled with a liquid-fuel desulfurizer, the 

multi-fuel processor under development by 

McDermott Technology, Inc./Catalytica Energy 

Systems promises to approach the FreedomCAR fuel 

processor targets. 

Approach

The fuel processor consists of a liquid-phase 

desulfurizer, a catalytic reformer, two stages of 

water-gas-shift reaction, a selective oxidizing unit, 

and ancillary components including pumps, heat 

exchangers and controls [1]. A general arrangement 

concept drawing of the fuel processor system is 

shown in Figure 1. The project consists of 5 major 

tasks: preliminary design, catalyst development, 

subsystem testing, final design, and prototype 

assembly and demonstration. 

The liquid fuel desulfurizer reduces sulfur in 

gasoline to less than 3 parts per million (ppm). The 

reformer unit operating at an average temperature of 

800°C produces a hydrogen-rich gas from the fuel 

feed. Two reformer approaches were evaluated - a 

packed bed comprising a single catalyst and a platebased catalyst system. A bi-functional ATR catalyst 

developed by Catalytica Energy Systems was 

selected for use over the plate-based design. The 

plate design showed possible advantages in size but 

could not be developed in the contract time frame. 

The ATR is followed by a shift reactor consisting of 

two stages. The first stage contains a mediumtemperature-shift catalyst developed by NexTech. 

The second stage contains a commercial low 

temperature shift (LTS). The shift reactors reduces 

the CO concentration in the reformate gas to 

approximately 2,000 ppm. Final reduction of CO is 

achieved in a preferential selective oxidation reactor.

McDermott Technology, Inc. developed the 

overall system design including heat integration, 

mechanical design, ancillary equipment, and 

instrumentation/controls. Catalytica Energy Systems 

developed the catalytic components, including a 

state-of-the-art autothermal reforming catalyst. 

NexTech contributed its expertise and technology in 

the area of shift catalysts. 

Results

During this reporting period, a peer review of the 

final design was completed. The review was 

performed by independent experts and was attended 

by DOE and team members. The reviewers approved 

the final design. Following the review, general 

arrangement drawings for the system and detailed 

fabrication drawings of the U-tube pressure vessel 

and internal components were completed.

The predicted performance of the system is 

summarized in Table 1. Three loads were used to 

develop the design. The maximum efficiency design 

point is 25% load (12.5 kWe). Thermal integration 

was optimized around the 60% load (30 kWe) case. 

The maximum continuous rated design point is 50 

kWe. The predicted fuel processor efficiency is 

80.6% at 25% load assuming 80% hydrogen 

utilization and 50% efficiency in the fuel cell.

Size and weight predictions are summarized in 

Table 2. The system power density and specific 

power are 283 W/L and 165 W/kg, respectively. The 

size and weight are actual size and weight using 

commercially available components or 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

307

developmental components for control and thermal 

management. The compressor/expander and start-up 

burner are excluded from the totals. A humidifier is 

included in the fuel processor scope as part of the 

water management system.

The catalyst scheme is summarized in Table 3. 

The required amount of Catalytica Energy Systems 

ATR catalyst was produced and installed in the 

reactor. The required amount of NexTech shift 

catalyst was produced and installed in the first stage 

shift reactor. The NexTech shift catalyst is a 

medium-temperature shift catalyst that remains 

active in the oxidized or reduced state and is less 

sensitive to condensed moisture [2]. All catalysts are 

currently in pellet form; however, noble metal wash 

coating on monolith substrates is existing 

technology. Therefore, once the catalyst and system 

performance are verified, it will be straightforward to 

convert these catalysts to monoliths. The reactors 

Table 2. Summary of Sized and Weights of Components and 

System 

Subsystem Totals Size (L) Weight (kg)

Reformate Generator 128.00 28-.0.25

Steam Regenerator 6.50 7.70

Reformate Conditioner 45.00 30.00

Fuel Supply 11.28 22.63

Water Supply 18.80 40.70

Controls & Piping (1/10 demonstration unit) 19.48 15.15

Overall Total 222.38 380.63

Power kWe (Gross 62.86 62.86

Power Density/Specific Power 283 165

DOE FreedomCAR 2000 Target (W/L, W/kg) 600 600

DOE FreedomCAR 2004 Target (W/L, W/kg) 750 750

Figure 1. Schematic of McDermott's Fuel Processor

1

Table 1. Predicted Performance for Authothermal 

Processor System

Characteristic Units Predicted Performance

Nominal Design Maximum

Load kWe 

(net)

12.5 30 50

Reformer S/C Ratio 2.00 2.00 2.00

Total S/C Ratio 2.58 2.89 3.31

Total A/F Ratio 

(includes PrOx)

13.4 14.5 16.1

Reformer 

Stoichiometry

0.23 0.25 0.28

Fuel Equivalence 

Ratio

4.31 3.98 3.58

Fuel Value of 

Gasoline, LHV

kW 35.1 92.7 167.2

Fuel Value of H2 to 

Fuel Cell, LHV

kW 31.2 80.4 141.0

Electrical Output kWe 

(gross)

13.97 35.81 62.86

Electrical Output kWe 

(net)

12.74 30.68 50.38

Carbon Conversion % 99.82 99.45 99.76

Cold Gas Efficiency 

(LHV)

% 88.92 86.74 84.37

Fuel Processor 

Efficiency 

% 80.58 82.42 81.99

Overall System 

Efficiency (LHV)

% 32.84 31.43 29.26

Compressor 

Efficiency

% 67.0 74.4 73.0

Expander Efficiency % 75.7 81.8 85.0

Expander Output kWe 0.4 2.3 4.0

Parasitic Loads kWe 1.6 7.5 16.5

Radiator Heat 

Rejection

kW 13.8 34.6 63.5

Fuel Cell Operating 

Temperature

°C 60 60 60

Fuel Cell Voltage 

(Assumed)

V 0.7 0.7 0.7

Fuel Cell H2

Utilization

% 80.11 79.83 79.86

Fuel Cell O2

Utilization

% 50.07 49.90 49.91

Fuel Cell Efficiency, 

LHV

% 44.78 44.54 44.58

PrOx O2/CO Ratio 0.98 0.98 0.98

PrOx Selectivity 0.51 0.51 0.51

PrOx CO 

Conversion

% 99.78 99.66 99.47

Sy Pressure Drop KPa 6.74 15.75 38.69
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

308

have been designed to accommodate standard 

monolith sizes.

Los Alamos National Laboratory provided a 

preferential oxidation reactor suitable for 

demonstration with monolith catalysts. Pacific 

Northwest National Laboratory provided a steam 

generator based on micro-channel heat exchanger 

technology. Precision Combustion, Inc. provided a 

dual-fuel catalytic burner.

The tube pressure vessel and its internals were 

fabricated and assembled as shown in Figure 2. The 

tube pressure vessel thermally integrates many major 

components including the ATR reactor, reformate 

heat exchanger, gas desulfurizer, fuel vaporizer, and 

MTS and LTS reactors. In addition, internal water 

spray cooling is used for temperature control. Upon 

completion of the pressure vessel and receipt of 

vendor-supplied components, the fuel processor 

system was assembled on a test stand as shown in 

Figure 3 with controls and instrumentation. To date, 

all components, controls and instrumentation have 

been checked out. 

Conclusions

A fully integrated autothermal fuel processor 

based on a bi-functional ATR catalyst has been 

designed, fabricated and checked out. The unit 

continues to show progress towards the 

FreedomCAR targets and will be tested in the 

summer of 2002.

References

1. Flynn, T. J., Privette, R. M., Perna, M. A., 

Kneidel, K. E., King, D. L. and Cooper, M., 

"Compact Fuel Processor for Fuel Cell-Powered 

Vehicles," International Congress and Exposition, 

Detroit, MI, March 1-4, 1999, SP-1425, pp 47-53.

2. Swartz, Scott, L. "Nanoscale Water-Gas-Shift 

Catalysts," Snapshots of Cooperative Automotive 

Research for Advanced Technologies Projects, 

Phase 2, published by Argonne National 

Laboratory, Transportation Technology R&D 

Center, March 2000, pp 11-12.

FY 2002 Publications

1. Flynn, T. J., Privette, R. M., Perna, M. A., 

Kneidel, K. E., King, D. L. and Cooper, M., 

"Compact Fuel Processor for Fuel Cell-Powered 

Vehicles," International Congress and Exposition, 

Detroit, MI, March 1-4, 1999, SP-1425, pp 47-53.

Table 3. Catalyst Scheme

Catalyst Beds Clean-up Beds

Parameter ATR MTS LTS PROX Sulfur 

Removal

NH3

Removal

Temperature 

(

o

C)

807 399 263 94 322 None

Catalyst Rh Pt Cu/

ZnO

Pt ZnO None

Support Alumin

a

Ceria/

Zirconia

ZnO/

Al2O3

Alumina None None

GSHV 

(1 hour)

9.165 13,833 13,623 25,000 134,405 None

Bed Volume 

(L)

10.0 10.0 11.2 7.4 1.0 None

Bed Weight 

(kg)

14.4 15.0 15.0 2.23 1.4 None

Figure 2. Fuel Processor Tube Pressure Vessel

Figure 3. Integrated Fuel Processor Test Stand
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

309

IV.C.3 Quick-Starting of Fuel Processors

S. Ahmed (Primary Contact), C. Pereira, H.K. Liao, S. Lottes, M. Krumpelt

Argonne National Laboratory,

9700 S. Cass Ave., Argonne, IL 60439

(630) 252-4553, fax: (630) 972-4553, email: ahmed@cmt.anl.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Develop strategies to meet the rapid-start targets for on-board fuel processors in gasoline-fueled fuel 

cell vehicles.

Approach

• Identify constraints that limit fuel processors from reaching rated hydrogen production capacity within 

30 seconds.

- Identify the fundamental technical barriers – thermal mass, fuel consumption, feed limitations, etc.

- Set up component and hardware models, and validate with experimental study of rapid heat-up 

behavior. 

• Develop a heat-up strategy to enable 30-second start-up of the fuel processor.

• Demonstrate fast-start strategy in a laboratory-scale fuel processor. 

Accomplishments

• Evaluated burner feeds and heat load required to warm up the fuel processor to full capacity.

- The mid-temperature (200-400°C) zones represent ~70% of the total heat load.

- Air flows required at the burner for meeting the appropriate hot gas temperatures in the various 

zones are nearly five times that required for operation in reforming mode at rated power. 

- Parallel heating of the various components is preferable to sequential heating, since parallel heating 

allows better temperature control of the hot gas and permits starting the fuel processor at partial 

capacity.

• Developed a computational fluid dynamics (CFD) model to simulate heat-up of individual reactor 

zones. 

• Designed, fabricated, and installed a generic fuel processor and test stand to study the heat transfer 

characteristics of monolith loaded reaction zones. 

- Initiated experiments to validate the CFD model.

Future Directions

• Study the effect of hot gas temperature, gas hourly space velocity, adjacent environments, and flow 

patterns (adjacent zones with co- or counter-current flow, parallel vs. series heating, etc.) on the heatup rates. 

• Validate model with experimental data and use model to design a fuel processor capable of rapid start.

• Establish a start-up strategy (identify necessary components, hot gas and flow specifications, heating 

sequence, etc.) to achieve fast start

• Demonstrate rapid start-up of an engineering-scale (~5 kilowatts electrical [kWe]) fuel processor. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

310

Introduction

To achieve significant market penetration, fuel 

cell vehicles will have to meet or exceed the 

performance baseline established by today’s sparkignition engine vehicles. These performance criteria 

include improved gas mileage, rapid acceleration, 

and turn-key start-up. The goal of this work is to 

develop strategies that will result in demonstration of 

a fuel processor for fuel cell vehicles that starts 

rapidly. The Department of Energy has set a start-up 

time of 30 seconds (from 20°C to maximum power) 

for the year 2010. 

Approach

This project will identify the constraints that 

prevent existing fuel processors from reaching rated 

capacity in 30 seconds or less. A fundamental 

technical barrier is the thermal mass of the catalysts 

and structural materials. Reductions in thermal mass 

require improvements in catalyst materials and 

effective heat transfer. Other limiting factors are 

related to auxiliary equipment and process design, 

such as available gas blowers and burners, the fuel 

injection system, sensor response, and hot gas 

distribution within the processor.

The development approach will be to set up 

component and hardware models for rapid heat-up 

and to validate the models experimentally. The 

models will then be used to determine optimal feed 

distributions, anisotropies in gas flow, and patterns of 

heat transfer. Further experiments will be conducted 

to validate the models. The initial goal is a thorough 

understanding of the heat transfer characteristics of 

monolithic catalysts. Studies will include the effect 

of geometry, flow and distribution of the heating 

medium, and material compositions. 

Fundamental studies of heat transfer, combined 

with a basic understanding of the underlying kinetics 

of the combustion process, will be used to develop a 

model of the fast-start reactor. The model will then 

be used to design a fast-start reactor that can meet the 

prescribed operational targets. 

Accomplishments

As a first step in development, the heating 

requirements for a fast-start reactor were defined. 

The processor was sized according to existing 

catalyst technology, and the design was based on our 

previous fuel processor’s test systems.

The processor can be divided into four zones 

based on the operating temperature: reformer, 

scrubber-high temperature shift (S-HTS), low 

temperature shift (LTS), and preferential oxidation 

(PROX). Operating temperatures are nominally 

700°C in the reformer, 400°C in the S-HTS, 200°C in 

the LTS, and 100°C in the PROX. In actual 

operation, temperatures are not discrete; rather, there 

is a gradual decrease between each zone. The middle 

zones, S-HTS and LTS, comprise ~70% of the total 

heat required during start-up. The fuel requirements 

and heat flow for a 50-kilowatt (kW) processor are 

shown in Figure 1.

Two primary options for heating the fuel 

processor were considered: heating the different 

components in sequence or in parallel. Heating the 

components in parallel is preferable to heating them 

sequentially since it allows direct temperature control 

of the hot gas within each zone. A parallel system 

also avoids sending all of the hot gas through the 

reformer catalyst. A negative feature is the 

requirement of multiple injection points.

For a parallel system with a central burner, the 

air flow required to achieve the appropriate 

temperatures during start-up is nearly five times that 

required for steady operation at the rated reforming 

capacity. The additional air is required to maintain 

temperatures within allowable ranges for each of the 

various zones. A possible design for a parallel 

heating system utilizing a fuel burner is shown in 

Figure 2.

Figure 1. Fuel Requirements for a 50-kW Processor
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

311

A CFD model was developed to simulate heat-up 

of a generic fuel processor based on a cylindrical 

geometry. The model was based on a simplified fuel 

processor design that consisted of three concentric 

zones bounded and separated by three concentric 

cylinders. The adjacent zones can represent either a 

layer of insulation or another catalyst bed. The heat 

transfer characteristics are studied by varying the 

weight of catalyst in each zone, the temperatures of 

the hot gases used to heat up the zones, and the 

direction (co- or counter-current) of flow of the hot 

gases in adjacent zones.

Figure 3 shows the temperature progression from 

the CFD model for a cylindrical reactor containing a 

cordierite monolith that is heated to 700°C. This 

result suggests that the reformer monolith can attain 

its desired temperature in 30 seconds if a hot gas at 

730°C is fed at a space velocity of 45,000 per hour 

(h-1), assuming no heat losses. Similar start-up 

scenarios can be obtained for the other zones. 

To validate the CFD model, a generic reactor, 

shown in Figure 4, was fabricated and is being used 

for the heating studies. Electrically heated air rather 

than hot combustion gas, is used to heat the catalyst 

beds.

 As in the CFD model, the three concentric zones 

were loaded with monoliths and insulation. Other 

structural forms such as heat exchangers can be 

installed as needed to study their heat-up 

characteristics (rate, heat transfer effectiveness, 

temperature distribution, etc. The model is being 

updated to account for deviations between simulated 

and experimental data. 

Figure 3. Initial Temperature Progression in Reformer

Figure 2. Parallel Heating of the Fuel Processor 

Components

Figure 4. A test reactor is used to validate the CFD 

model.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

312

Conclusion

Analysis of thermal requirements to attain 

operating temperatures in the fuel processor indicates 

that, at the space velocities required in fuel 

processors typical today, the shift reactor zone 

represents the largest thermal mass. The hot zones in 

the fuel processor can be heated up with hot 

combustion gas. Parallel heating of the various zones 

is preferable to sequential heating because it allows 

individual control of the hot gas streams into each 

zone. The total air required to limit the combustion 

gas temperatures within the bounds of tolerance of 

the catalyst zones is significantly higher than during 

reforming operations, and the air blower needs to be 

sized accordingly. Similarly, the cross-sectional area 

of each zone must be large enough to accommodate 

the larger flow during heat-up. 

Future Directions

The fast-start test reactor will be used to 

determine the effect of hot gas temperature, gas 

hourly space velocity, adjacent environments, and 

flow patterns on the heat-up rates of catalysts and 

materials. The temperature progression within the 

reactor will be a function of the effectiveness of heat 

transfer between the hot gas and the catalyst. 

Variations in flow patterns that will drive the design 

of a fast-start processor include the effect of countercurrent versus co-current flow of the gas streams in 

adjacent zones and of heating the zones in series 

versus parallel. The temperature distributions in 

adjacent zones will determine the insulation 

requirements and drive the design of the heat 

exchangers. 

The results of these tests will be used to validate 

the heat transfer model. Once the heat transfer 

characteristics are understood, the model will be 

expanded to include the effects of using a fuel:air 

combustion mixture to generate the hot gas to heat up 

the system. An overall start-up strategy will be 

defined that will achieve rapid start and transition to 

steady-state operation. The strategy will identify the 

necessary components, the hot gas flow 

specifications, and the heating sequence. These data 

will be incorporated into the design of a 5-kWe 

engineering-scale fuel processor that will 

demonstrate a start-up time of 2 minutes or less. 

Fy 2002 Publications

1. C. Pereira, S.H.D. Lee, T.D. Kaun, S. Ahmed and 

M. Krumpelt, “Fuel Processor for Fuel Cell 

Systems,” presented at the Annual Meeting of 

AIChE, Reno, NV, November 2001.

2. C. Pereira, S. Ahmed, S.H.D. Lee, and M. 

Krumpelt, “Integrated Fuel Processor 

Development,” 2002 Future Car Congress 

Proceedings, Arlington, VA, June, 2002. 

Figure 5. Heat-up of a Cylindrical Zone using Hot Gas, 

Flowing at a Space Velocity of 60,000 h-1
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.C.4 Microchannel Fuel Processor Development

Kriston P. Brooks, James M. Davis, Chris M. Fischer, Adam R. Heintzelman, David L. King, V. Susie 

Stenkamp, Ward E. TeGrotenhuis, Robert S. Wegeng, Greg A. Whyatt, and Larry R. Pederson 

(Primary Contact)

Pacific Northwest National Laboratory

PO Box 999

Richland, WA 99352

(509) 375-2731, fax: (509) 375-2167, e-mail: larry.pederson@pnl.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-3480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202)586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Develop a compact, steam reformation-based fuel processing system for the onboard reformation of 

hydrocarbon fuels that meets FreedomCAR performance targets for energy density, efficiency, 

residual CO content, durability, rapid start-up, and transient response.

• Develop highly effective reactors, fuel and water vaporizers, recuperative heat exchangers, and 

condensers broadly applicable to fuel processing and fuel cell systems.

Approach

• Emphasize endothermic steam reformation to best take advantage of unique heat and mass transfer 

advantages available in engineered microstructures.

• Utilize a differential temperature approach for the water gas shift reactor to provide an optimum 

balance of rapid kinetics at high temperature and favorable thermodynamics at lower temperature.

• Use a two-stage preferential oxidation reactor to reduce CO concentrations to acceptable levels, with 

active heat exchange for superior temperature uniformity. 

• Achieve high efficiency through integration of steam reforming, water gas shift, and preferential 

oxidation reactors with microchannel recuperative heat exchangers, fuel and water vaporizers, 

condensers, and separators.

Accomplishments

• Fuel flexibility of the fuel reforming subsystem was demonstrated using methane, propane, butane, 

methanol, ethanol, isooctane, and benchmark gasoline. A 1000-hour catalyst and reactor durability 

test was completed using benchmark gasoline. Warm transient response of less than 5 seconds was 

achieved for 10 to 90% of full reformer capacity. A three-fold increase in reformer productivity was 

achieved compared to the previous year, due to improved catalyst performance and more uniform flow 

within the reactor. Reactor concepts that would meet FreedomCAR’s rapid start-up targets were 

developed.

• A differential temperature water gas shift reactor was designed based on tests performed with 

engineered catalysts in a microchannel configuration. Conversion rates in the differential temperature 

reactor were higher than achievable in two isothermal stages.

• Residual CO concentrations less than 15 ppm were achieved in two microchannel preferential 

oxidation stages at gas hourly space velocities greater than 200,000 using catalysts obtained from 

commercial developers.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

314

• Heat exchangers and vaporizers with very low pressure losses have been developed and are being 

supplied to interested collaborators for evaluation. A low pressure-drop water vaporizer sufficient to 

supply a 50 kWe autothermal reformer was designed, constructed, and delivered to McDermott 

Technology, Inc. Vaporizers and heat exchangers were provided to other industrial partners as well. 

Future Directions

• Demonstrate rapid reformer start-up based on low pressure-drop concepts. This reactor design should 

also provide improved transient response characteristics.

• Incorporate a sulfur management subsystem into the steam reformer.

• Complete optimization of the reformer, water gas shift, and preferential oxidation catalyst 

compositions and forms.

• Complete integration of the steam reforming, water gas shift, and preferential oxidation subsystems.

• Conduct lifetime testing of reactors, heat exchangers, and catalysts using transportation fuels.

• Continue to engage industrial partner(s) to facilitate reformer system development.

Introduction

Steam reforming is an attractive fuel processing 

option for several reasons. Steam reforming is 

endothermic and thus can make use of heat from the 

catalyzed combustion of unutilized fuels in the fuel 

cell exhaust. The hydrogen content in the reformate 

stream is higher than obtained using other fuel 

processing options because it is not diluted by 

nitrogen from air. High reformate pressures can be 

efficiently generated by pumping fuel and water in 

liquid form; compression of air is not necessary. 

While conventional hydrocarbon steam reformation 

requires long residence times and relatively large 

reactor sizes because of heat transfer limitations, the 

heat and mass transfer advantages offered by 

engineered microchannels allow steam reformation 

to be conducted in a compact, energy-efficient 

system. Rapid kinetics for steam reforming in 

heated microchannels was first demonstrated by 

PNNL in 1999. Steam reforming reactors in the 10-

20 kWe range were later demonstrated, coupled with 

a network of microchannel heat exchangers that 

significantly improved energy efficiency (Whyatt et 

al. 2001).

Approach

A modular, steam-reforming test stand with an 

internal volume of 51 cc that would support fuel 

processing rates in the 50 to 1000 We range was 

designed to conduct fuel flexibility and long-term 

durability testing (Figure 1). A network of 

microchannel heat exchangers was included in the 

test stand for water and fuel vaporization, 

recuperation of reformate to preheat reactants and for 

preheating of combustion air using the combustion 

exhaust. The heat exchangers were fabricated as 

Figure 1. Modular Steam Reforming Test Stand 

Capable of Testing in the 100 to 1000 We 

Capacity Range
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

315

individual components and then connected via 

tubing.

The superior heat transfer achievable in 

engineered microchannels can be used to optimize 

temperature profiles in a reactor, which can lead to 

smaller reactor sizes and improved conversion. For 

reversible exothermic reactions such as water gas 

shift, the microchannels make it possible not only to 

remove the heat of reaction, but also to reduce the 

reaction temperature. By maintaining heat transfer 

length scales on the order of 100 microns, minimal 

temperature gradients across the catalyst were 

maintained while achieving precise control of 

temperature down the reactor. This approach 

provides an optimum balance between rapid kinetics 

at high temperature and favorable thermodynamics 

for conversion as the temperature is reduced. 

Results

Steam Reforming Subsystem

Through improvements in gas flow 

characteristics and engineered catalyst performance, 

the volumetric productivity of the steam reforming 

reactor was improved by approximately a factor of 

three compared to our previous efforts. The catalyst 

that was used in these tests is a proprietary 

formulation obtained from Battelle Memorial 

Institute. For a full-sized, complete fuel processing 

system, projected power densities are more than 

double FreedomCAR targets, as shown in Table 1. 

To meet FreedomCAR targets for specific power, the 

mass of the system will need to be reduced, expected 

to be met through further improvements in reactor 

productivity and the use of lightweight alloys where 

appropriate.

The steam reforming subsystem was shown to 

exhibit good fuel flexibility. Tests were conducted 

using multiple fuels, including methane, propane, 

butane, methanol, ethanol, isooctane, and benchmark 

gasoline, a mixture of isooctane, xylene, methyl 

cyclohexane, and 1-pentene. The results of these 

tests are given in Figure 2, which shows conversion 

versus gas hourly space velocity (GHSV). The steam 

to carbon ratio was maintained at 3 to 1 for all nonalcohol fuels. For alcohols, the oxygen to carbon 

ratio was maintained at 3 to 1. Methanol was the 

most easily reformed, and was completely reacted to 

the highest space velocities tested. A conversion 

greater than 99.9% is necessary for fuels such as 

gasoline to prevent downstream condensation, 

whereas lower conversion may be acceptable for 

volatile fuels such as methane.

Performance Criteria Current

Performance

2005 

FreedomCAR 

Target

Explanation

50 kWe System Volume <1 cubic foot

(<28 L)

2.5 cubic feet

(71 L) Projected from tests conducted on a smaller scale.

Energy Efficiency 81% 78% High efficiency is the result of extensive thermal integration 

using effective heat exchangers.

Durability >1000 h 4000 h Testing beyond 1000 hours not conducted; expanded 

durability testing planned for FY 2003.

Power Density,

Specific Power

1800 W/L,

320 W/kg

700 W/L,

700 W/kg

Improvements in specific power expected from improved 

productivity and use of lightweight alloys for components 

intended for low temperature operation.

Transient Response 5 s 5 s Further improvements expected with incorporation of low 

pressure-drop components.

Start-Up to Full Power, 

20o

C

30 s (low dP) 

projection

15 min current

<1 min

Low combustion-side pressure drop is key to start-up; 

redesign of reactors using low pressure-drop concepts is 

expected to meet start-up goals.

Table 1. Comparison to FreedomCAR Performance Targets
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

316

To evaluate the durability of both the reactor and 

reforming catalyst, a 1000-hour test was performed 

using benchmark gasoline containing 10 ppm sulfur. 

The space velocity was chosen to obtain a small 

fraction of unconverted fuel (0.2%) at the start of the 

test, which aided in tracking changes in conversion 

versus time. Conversion fell by several percent over 

the first 500 hours, as shown in Figure 3, believed 

due to the effects of sulfur. The catalyst was then reactivated in clean hydrogen and steam, which 

returned the performance to near initial levels.

Warm transient response characteristics of the 

steam reforming subsystem were evaluated, shown in 

Figure 4. Fuel inflow was varied from 10 to 100% of 

full-scale, and reformate outflow was measured 

versus time. Because the residence time for fuel in 

this reactor and heat exchangers is very short, these 

portions of the system are capable of very rapid 

transient response. Major limiting factors are 

associated with fuel and water vaporizers. Scale-up 

is not expected to diminish transient response 

characteristics since a greater number of 

microchannels with similar aspect ratios would be 

used.

Water Gas Shift Subsystem

Research supporting the development of a 

compact water gas shift (WGS) reactor subsystem 

included catalyst screening studies, kinetic model 

development, and test reactor design and 

performance evaluation. Water gas shift catalysts 

obtained from commercial and other developers were 

converted into an engineered form and tested versus 

temperature, space velocity, and steam-to-gas ratio in 

single-channel reactors. Both base metal and 

precious metal catalyst formulations were included in 

the studies.

While both base metal and precious metal 

catalyst formulations performed well in a simulated 

high temperature WGS feed stream (~15% CO), 

precious metal catalysts were clearly superior when 

tested with a low temperature WGS feed stream 

(~5% CO). Results for a Süd-Chemie copper zinc 

catalyst (T2650) and a Süd-Chemie precious metalceria catalyst (PMS5) are shown in Figure 5, tested in 

a simulated low temperature WGS feed stream. 

Equilibrium was achieved for the PMS5 catalyst for 

Figure 2. Conversion versus Space Velocity for 

Multiple Fuels

Figure 3. Conversion of Benchmark Gasoline versus 

Time in a Steam Reforming Reactor

Figure 4. Warm Transient Response of the Steam 

Reforming Reactor from 10 to 100% of Full 

Capacity
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

317

temperatures greater than 250oC at a gas hourly 

space velocity of 75,000, whereas the T2650 copperzinc catalyst gave more modest performance. Thus, 

the PMS5 catalyst was used primarily in additional 

testing.

A kinetic model was developed from the results 

of catalyst screening studies that relates reaction rates 

to temperature, space velocity, and steam to gas ratio. 

A finding of kinetic modeling studies is that 

conversion of carbon monoxide could be enhanced in 

a thermal gradient compared to reactions conducted 

isothermally. By managing the temperature profile 

of a reactor, reactants can be fed at a high 

temperature where rapid kinetics promotes an initial 

approach to equilibrium. As the reaction mixture is 

cooled, conversion is increased due to more 

favorable thermodynamic driving forces. 

To optimize the performance of a microchannelbased water gas shift reactor, the temperature profile 

of the reactor was adjusted as a means to provide the 

best trade-off of rapid kinetics at high temperature 

and favorable thermodynamics at low temperature. 

A schematic for one microchannel configuration is 

shown in Figure 6, where catalytic monoliths are 

located at the center of an array of reaction channels, 

interleaved with heat exchange channels. A heat 

exchange fluid flowing co- or counter-current 

(shown in Figure 6) to the reaction flow removes the 

heat of reaction and cools the gas, thereby 

establishing a temperature trajectory for the reaction. 

The choice of coolant, the temperature and flow of 

the coolant, and the geometry are all design variables 

for achieving an optimal temperature profile to 

maximize the productivity of the catalyst.

An experimental validation of modeling 

predictions is given in Figure 7, comparing the 

performance of a reactor run in a differential 

temperature mode versus isothermally. This 

experiment was performed using a low temperature 

feed stream, corresponding to an initial CO 

concentration of 4.9% (wet basis). For a space 

velocity of 76,000 hr-1, as steam to dry gas ratio of 

0.52, and an initial temperature of 350oC dropping to 

280oC, a CO concentration at the outlet of 0.84% 

was achieved. Conversion was always less when 

performed isothermally in the same reactor at an 

identical space velocity.

Figure 5. Conversion of CO versus temperature for 

engineered forms of Sud-Chemie T2650 

(copper-zinc) and PMS5 (precious metal 

ceria) catalysts. Results correspond to a 

simulated low temperature WGS feed stream 

at a steam to gas ratio of 0.5.

Figure 6. Two-dimensional schematic of a repeat unit 

for a microchannel reactor with countercurrent heat exchange. Dashed lines indicate 

symmetry planes.

Figure 7. Comparison of a Microchannel WGS Reactor 

Run in Isothermal and Differential 

Temperature Modes on a Simulated Low 

Temperature Feed Stream
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

318

Preferential Oxidation Subsystem

Microchannel reactor designs may hold 

advantages for use in the preferential oxidation 

subsystem because of the ability to operate under 

strictly isothermal conditions and because of the 

ability to suppress undesired reactions (methane 

formation and reverse water gas shift) through the 

use of short residence times. Engineered forms of 

precious metal and base metal preferential oxidation 

catalysts obtained from commercial suppliers were 

evaluated in a microchannel reactor to show whether 

this approach is a viable means to meet 

FreedomCAR targets for conversion and selectivity. 

We have shown that less than 15 ppm CO in a 2 stage 

microchannel reactor can be obtained. For the first 

stage, operation at approximately 200oC, oxygen to 

carbon ratio = 1.0, and GHSV greater than 200,000 

resulted in a reduction of CO from approximately 1% 

to approximately 500 ppm (0.05%). For the second 

stage, operation at 100o

C, oxygen to carbon ratio = 

4.0, and GHSV = 200,000 resulted in conversion of 

CO to below 15 ppm. To date, these two stages have 

not been tested together, nor has the catalyst 

durability been established. Discussions with 

catalyst vendors indicate that improved catalysts over 

what we have already tested are available, and such 

catalysts will be evaluated.

Water Vaporizer

A full-scale water vaporizer exhibiting extremely 

low gas-side pressure drop has been developed 

during the past year and provided to industrial 

collaborators for evaluation. Sufficient to support a 

50 kWe autothermal reforming system, the 

dimensions of the vaporizer panels are 22.2 cm x 10 

cm x 1.8 cm, with a weight of 2.4 kg when 

constructed using 316L austenitic stainless steel, as 

shown in Figure 8. At the maximum operating point, 

the heat exchanger duty is 24.6 kW, with a heat 

exchange intensity of 60 W/cm3

. The pressure drop 

on the gas side was minimized by making the flow 

distance very short and by providing a large crosssectional area for gas flow. Multiple vaporizer 

panels were fabricated in a single diffusion bonded 

stack, separated using wire electric discharge 

machining methods. One of the steam generator 

panels is currently undergoing testing by McDermott 

Technology Inc. in a 50 kWe autothermal steam 

reforming system. This particular panel was 

designed to vaporize more than 4 g/s water to 

produce steam at 225o

C and 425 kPa. The expected 

combustion-side pressure drop is approximately 250 

Pa.

Conclusions

• Power densities in excess of FreedomCAR 

targets, fuel flexibility, greater than 1000-hour 

reactor and catalyst life, and less than 5 second 

transient response have been demonstrated in a 

microchannel-based steam reformer. Future 

development activities will focus on rapid startup and improving specific power.

• A differential temperature water gas shift reactor 

was developed that provides an optimum balance 

between fast kinetics at high temperatures and 

favorable thermodynamics at low temperatures.

• Residual CO concentrations less than 15 ppm 

were achieved in two microchannel preferential 

Figure 8. Microchannel Steam Generator Panel 

Sufficient to Support a 50 kWe Autothermal 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

319

oxidation stages at gas hourly space velocities 

greater than 200,000.

• Heat exchangers and vaporizers exhibiting very 

low pressure losses have been developed and are 

being supplied to interested collaborators for 

evaluation, including a unit sufficient to supply a 

50 kWe autothermal reformer provided to 

McDermott Technology, Inc.

References

1. Whyatt, G. A., W. E. TeGrotenhuis, J. G. H. 

Geeting, J. M. Davis, R. S. Wegeng, and L. R. 

Pederson. “Demonstration of Energy Efficient 

Steam Reforming in Microchannels for 

Automotive Fuel Processing,” Proceedings of the 

5th International Conference on Microreaction 

Technology, May 27-30, 2001.

2. Van Herwinen, T. and W. A. DeJong. J. 

Catalysis 63, 3 (1980).

FY 2002 Publications/Presentations

1. TeGrotenhuis, W. E., D. L. King, K. P. Brooks, 

B. J. Golladay, and R. S. Wegeng. “Optimizing 

Microchannel Reactors by Trading-Off 

Equilibrium and Reaction Kinetics Through 

Temperature Management,” IMRET 6 – 6th

International Conference on Microreaction 

Technology, AIChE, New Orleans, March 10-

14, 2002.

2. Whyatt, G. A., C. M. Fischer, and J. M. Davis. 

“Progress on the Development of a 

Microchannel Steam Reformer for Automotive 

Applications,” IMRET 6 – 6th International 

Conference on Microreaction Technology, 

AIChE, New Orleans, March 10-14, 2002.

Special Recognitions and Awards/Patents 

Issued

1. “Active Microchannel Fluid Processing Unit and 

Method of Making”, USP 6,192,596
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

320

IV.C.5 Plate-Based Fuel Processing System

Ralph Dalla Betta (Primary Contact and Principal Investigator)

Catalytica Energy Systems

430 Ferguson Drive

Mountain View, CA 94043

(650) 940-6310, fax: (650) 965-4345, e-mail: rdallabetta@catalyticaenergy.com

DOE Technology Development Manager: Donna Ho 

(202) 586-8000, fax: (202) 586-9811, e-mail: donna.ho@ee.doe.gov

ANL Technical Advisor: Walter Podolski

(630) 252-7558, fax: (630) 972-4430, e-mail: podolski@cmt.anl.gov

Subcontractors: National Fuel Cell Research Center, Irvine, CA

Objectives

• Design, build and demonstrate a fully integrated, plate-based fuel processor system that will convert 

EPA Tier 2 gasoline into a hydrogen-rich gas for direct use in proton exchange membrane (PEM) fuel 

cell systems for vehicular applications.

Approach

Phase 1

• Complete conceptual design of plate-based reformer, water gas shift and preferential oxidation reactors 

and simulation models of each reactor using available catalyst kinetics. Begin optimization studies 

and parametric sensitivity analysis. 

• Obtain catalyst performance data and kinetic data as required, including initial data on catalyst 

deactivation rate.

• Assess feasibility of reactor configurations, understand performance advantages, and develop initial 

cost analysis of reactor components.

Phase 2

• Perform prototype proof of concept testing at about 2-kW scale for laboratory component reactors.

Phase 3

• Develop 50-kW component reactors and assemble complete integrated fuel processor. Evaluate 

performance.

Accomplishments

• Identified sources of high local stresses in the plate reformer design that would result in short cyclic 

life. Developed improved designs with cyclic life approaching 250,000 cycles.

• Identified the need for a unique reactor design that would allow close control of reaction temperature 

under conditions typical of the reactor concepts being developed. 

• Developed detailed reactor models for steam reforming, water gas shift and preferential oxidation 

reactor designs.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

321

• Developed new proprietary catalyst for the water gas shift reaction that is non-noble metal, nonpyrophoric, and does not require pre-reduction.

• Began development of a fuel processor simulation tool to assess the overall integration and 

performance of the complete fuel processor utilizing the novel component reactors being developed. 

Future Directions

• Establish kinetic models for the primary catalyst candidates for each of the component reactors (steam 

reforming, water gas shift, and preferential oxidation). Update the reactor models for the component 

reactors and establish performance for the various reactor configurations. 

• Use the fuel processor simulation tool to evaluate the performance of a fuel processor based on the 

reactor design and establish catalyst performance criteria required for optimum performance of the 

component reactors and desired performance of the fuel processor.

• Complete initial catalyst stability studies for each of the component reactors. Establish catalyst 

stability improvement targets if required.

• Develop mechanical design for a steam reformer meeting the durability requirements including cyclic 

life.

Introduction

The Catalytica Energy Systems, Inc. (CESI) 

project is directed at developing unique reactor 

designs and the associated catalyst materials that will 

provide advantages toward meeting the DOE 

performance goals. The general approach is to 

utilize where feasible a plate-based reactor design 

that closely integrates heat exchange with the 

catalytic process to optimize component and system 

performance. The program consists of 3 phases as 

described above, with the first phase concentrating 

on component conceptual design and catalyst 

development.

Approach

The approach taken in this project is to utilize 1) 

steam reforming of gasoline as the first step to 

produce a reformate that has a high concentration of 

hydrogen, followed by 2) sulfur removal, 3) water 

gas shift, and 4) preferential oxidation to yield PEM 

fuel cell quality hydrogen. Work is ongoing on each 

of these four catalytic processes, including the 

development of a process simulation model that 

includes catalyst reaction kinetics, heat and mass 

transfer effects, etc. to adequately model the 

important aspects of the reactor design. Kinetics are 

either taken from the literature or are measured 

experimentally. 

Results

Plate Reactor Design Development

In previous work, a prototype plate reactor was 

developed for methane steam reforming. This unit 

was operated for 400 hours at 100% load but with 

minimal (approximately 20) slow start-up cycles. An 

automotive fuel processor would have to demonstrate 

significantly higher levels of durability, including a 

large number of fast start-up cycles. It was assumed 

that the system would undergo 250,000 start-up and 

load transients as a worst case scenario (5,000 hours 

fuel processor life, one cycle every 1.2 minutes and 

similar stress levels from start-up and load 

transients). For a typical ferritic steel, this would 

require that the strain levels remain below 0.25%. 

Finite element analysis of a very fast start-up 

transient (30 seconds) resulted in high local stresses, 

in the range of 0.5 to 0.8% in the baseline reactor 

design. Alternative mechanical designs were 

evaluated, including designs that would provide a 

more realistic gas flow path and flow distribution. A 

derivative design was developed that gave a 

calculated strain of 0.28%, close to the target value 

and in an acceptable range.

Gasoline Steam Reforming Catalyst Evaluation

Initial catalyst development for direct steam 

reforming of gasoline was done in an integral reactor 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

322

system operating at design conditions including 

pressure and space velocity as shown below. In 

these tests, the H2 and CO levels at the reactor exit 

are near the expected equilibrium values.

Conditions

Results

It should be noted that these space velocities are 

similar to those typically found in autothermal 

reforming (ATR) so that catalyst volumes will not be 

excessive compared to autothermal reforming 

processes. Catalyst activity was found to be 

reasonably stable for the short duration tests in this 

work. However, the extremely endothermic nature 

of the reaction and the integral operation of the test 

reactor made it difficult to extract reaction kinetics. 

A new test reactor design was developed and 

fabricated, and work is in progress to obtain 

simplified kinetics for the gasoline steam reforming 

reaction adequate to model the catalytic process in 

the plate reactor simulation.

Water Gas Shift Catalyst Development

CESI is developing an improved water gas shift 

catalyst formulation that targets transportation 

applications with catalyst characteristics such as 1) 

no pre-conditioning requirement, 2) no air 

sensitivity, 3) preferably non-precious metal based, 

and 4) low sensitivity to condensed water. For the 

data analysis, the integral fixed bed reactor design 

equation was used with an empirical rate expression 

and a first-order deactivation model. Catalysts were 

quantitatively compared on the basis of the initial 

activity, k’ [=] moles/(gram cat.-hr-atm2

), and the 

deactivation constant, kd [=] hr-1. The best Pt-based 

material tested did exhibit reasonable initial activity 

(k’ = 0.287 at 250oC), but rapid deactivation was 

observed throughout the temperature window of 

250oC to 350oC. The value of kd = 0.008 for that 

catalyst indicates a 50% loss of activity in just 

87 hours time-on-stream, implying a very rapid loss 

in activity with time, making these catalysts 

inappropriate for commercial application [1-2].

Significant work during this period was directed 

at developing a non-precious metal-based or base 

metal water gas shift catalyst (Figure 1). The initial 

activity, k’, and the deactivation rate, kd, are 

determined from a fit of the measured conversion 

curve shown in Figure 1 after the first 5 to 10 hours. 

These kd and k’ values for these catalysts are 

summarized in Table 1 with the Pt catalyst reported 

in Reference 2 included for comparison.

Gasoline flow rate (as C8H18) 0.522 mmol/min

Steam to carbon ratio (S/C) 3.1

Pressure 3 atm

Catalyst amount 2.0 g

Weight hourly space velocity 1.75 g/g/hr

Reactor outlet temperature 795°C

Conversion (based on C species) 95.6%

Carbon mass balance 100.6%

Product composition (dry basis) mole fraction

 H2 0.666

 CO 0.158

 CO2 0.160

 CH4 + C2+ 0.016

Catalyst kd k’ Half life

hr-1 mol/(g-hr-atm2) hr

WGS 49 0.0812 0.014 8.5

WGS 68 0.0047 0.44 147

WGS 80 0.0022 1.39 315

WGS 92 0.0016 1.21 433

Pt-catalyst 0.008 0.287 86.6

Table 1. Performance of Base-Metal and Pt-Based Water 

Gas Shift Catalysts after 5 to 10 Hours on 

Stream

Figure 1. Catalyst Performance Test Results for Water 

Gas Shift Catalyst Materials 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

323

Currently, the best base-metal catalyst developed 

by CESI possesses much better activity and stability 

than the reported Pt-based catalyst and is comparable 

to commercial catalysts in long term activity. 

However, while the WGS 92 catalyst shows very 

good stability, the kd value of 0.0016 still implies a 

half life of about 433 hours, and if this deactivation 

rate is maintained throughout 2,000 hours of 

operation, the catalyst activity would decrease by 25 

fold. Work is in progress to develop static aging 

procedures to measure activity out to 5,000 hours and 

to accelerate the development of more stable catalyst 

systems.

Preferential CO Oxidation

A detailed computational model was developed 

for several different innovative designs for the 

preferential carbon monoxide (CO) oxidation reactor 

using a kinetic mechanism and reaction sequence 

derived from a micro-kinetic model and literature 

data for the specific adsorption coefficients and 

kinetic parameters for a platinum-based catalyst. 

The course of the reaction calculated by such a 

kinetic model is shown in Figure 2, where the space 

time is varied over a wide range in an isothermal 

reactor operating at 150°C. At nearly 100% CO 

conversion, the selectivity is high due to the selective 

adsorption of CO over H2; it drops as H2 begins to 

oxidize.

The results of a parametric study exploring the 

effect of mass transport limitations on this reaction 

gave the results shown in Figure 3. For this study, 

the reactor was assumed to be isothermal, and the 

conversion data of Figure 3 show the final 

composition exiting the reactor. The ideal (kinetics 

only) result gives the expected high conversion and 

selectivity due to the selective CO reaction. As mass 

transport limitation is added, the maximum CO 

conversion drops (Table 2) due to CO depletion near 

the surface since O2 is in excess.

These results and other parametric studies show 

the importance of the reactor and catalyst design. 

However, some of these results deviate from 

measured kinetics and CO selectivity and suggest 

that the assumed kinetics may not be fully 

representative of reality. The strong dependence of 

the results on the kinetic and equilibrium parameters 

suggest that it is absolutely essential that the kinetic 

parameters be validated by experimental tests, and 

this work is in progress.

Figure 2. Reaction profile during the preferential 

oxidation of CO using the simulation model 

described in the text. This models an 

isothermal reactor operating at 150°C with a 

1% CO reformate stream typical of the exit 

composition from the water gas shift reactor.

Simulation conditions Minimum CO level

Kinetics only ~0 ppm

1X mass transport limitations 30 ppm

10X mass transport limitations 140 ppm

Table 2. Effect of Mass Transport Limitations on the 

Minimum Level of CO that Can Be Obtained in 

the Preferential Oxidation of CO

Figure 3. Simulation model results showing the effect 

of transport limitations on the preferential 

oxidation of CO. This models an isothermal 

reactor operating at 150°C with a 1% CO 

reformate stream typical of the exit 

composition from the water gas shift reactor.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

324

Conclusions

Initial work on the steam reforming of Tier 2 

gasoline demonstrated that equilibrium composition 

reformate can be obtained with space velocities 

typical of autothermal reforming catalysts, 

supporting the feasibility of a compact and effective 

gasoline steam reforming reactor. A new reactor 

design has been developed to obtain kinetics under 

well controlled conditions for highly exothermic or 

endothermic reactions.

A water gas shift catalyst has been developed 

that is very active and reasonably stable, does not 

require pre-reduction, is non-pyrophoric, and does 

not contain precious metals. The kinetics of this 

catalyst are being more fully explored to allow 

process and reactor modeling, including modeling in 

a plate reactor configuration, and work has been 

initiated to develop a long-term, cost effective aging 

process to estimate performance at the target 2,000 to 

5,000 hour life. 

A process simulation tool for the full fuel 

processor has been developed, and parametric studies 

have shown the importance of catalyst and reactor 

design in obtaining the target CO levels of 10 ppm.

References and Publications

1. Zalc, J.M., Park, T., Sokolovskii, V.D., and 

Löffler, D.G., “Optimal Design of a Water-Gas 

Shift Reactor for Use in Automotive 

Applications,” American Institute of Chemical 

Engineers Annual Meeting, Reno, Nevada, 

November 6, 2001, Paper 167a.

2. Zalc, J.M., Sokolovskii, V.D. and Löffler, D.G., 

“Are Noble Metal-Based Water-Gas Shift 

Catalysts Practical for Automotive Fuel 

Processing?” Journal of Catalysis, 206[1], 169-

171, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

325

IV.C.6 Fuel Processors for PEM Fuel Cells

Levi Thompson (Primary Contact)

University of Michigan

Department of Chemical Engineering

3026 H.H. Dow Building

Ann Arbor, MI 48109-2136

(734) 647-7150, fax: (734) 763-0459, e-mail: ltt@umich.edu

DOE Technology Development Manager: Patrick Davis

(202) 586-8061, fax: (202) 586-9811, e-mail: Patrick.Davis@ee.doe.gov

Subcontractor: Ricardo, Inc. Plymouth, MI 

Objectives

The key objectives of this project are to:

• Demonstrate high performance desulfurizer, catalyst, microreactor and microcombustor/

microvaporizer concepts that will enable production of compact fuel processors for proton exchange 

membrane (PEM) fuel cells;

• Design, fabricate and evaluate a 1 kW fuel-flexible (including EPA Phase II reformulated gasoline) 

fuel processor; and

• Design, fabricate and evaluate a fuel-flexible (including EPA Phase II reformulated gasoline) fuel 

processor capable of producing a hydrogen-rich stream for up to a 10 kW PEM fuel cell.

The 1 kW fuel processor will be completed during the first 36 months of the project. Following a go/no-go 

decision, the larger fuel processor will be completed within 48 months.

Approach

Tasks devised to accomplish the program objectives include:

• Component design and modeling;

• Sorbent development;

• Catalyst development and catalyst/microreactor integration;

• Microcombustor/microvaporizer development;

• Microchannel reactor system development;

• Component evaluations;

• Fuel processor design, modeling, fabrication and evaluation; and

• Cost analysis.

Accomplishments

• Models have been developed for the entire fuel processor system (ASPEN) and several of the 

microchannel reactors (FEMLAB and FLUENT).

• Demonstrated that π-complexation sorbents out-perform commercial sorbents by a wide margin for 

the adsorption of model sulfur compounds like thiophene.

• High activity carbide and supported gold water gas shift (WGS) catalysts have been demonstrated. 

Some of the materials possess rates that exceed those for Cu-Zn-Al commercial catalysts.

• Fabricated and tested several micro-reactors.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

326

Future Directions

• We are in the first year of the project. We have not identified better strategies; therefore, we plan to 

execute the tasks outlined above.

Introduction

Fuel cells are being developed to power cleaner, 

more fuel efficient automobiles. The fuel cell 

technology favored by many automobile 

manufacturers is proton exchange membrane (PEM) 

cells operating with H2 from liquid fuels like 

gasoline and diesel. A key challenge to the 

commercialization of PEM fuel cell based 

powertrains is the lack of sufficiently small and 

inexpensive fuel processors. Improving the 

performance and cost of the fuel processor will 

require the development of better performing 

catalysts and new reactor designs, as well as better 

integration of the various fuel processing 

components.

Approach

Prototype gasoline fuel processors will be 

produced and evaluated against the Department of 

Energy technical targets. Significant improvements 

over the present state-of-the-art will be achieved by 

integrating low-cost microchannel systems, high 

activity catalysts, π-complexation sorbents, and high 

efficiency microcombustors/microvaporizers being 

developed at the University of Michigan. The 

microchannel system will allow (1) more efficient 

thermal coupling of the fuel processor components 

and minimization of the heat exchanger 

requirements, (2) improved catalyst performance due 

to optimal reactor temperature profiles and increased 

heat and mass transport rates, and (3) better cold start 

and transient responses. The project will be 

accomplished in 3 phases. The Phase I effort will 

focus on demonstrating compact desulfurizer, 

microreactor and microcombustor/microvaporizer 

components for a 1 kW fuel processor, and 

developing low-cost microdrilling and micromilling 

methods for the production of microchannel systems. 

The components will be third-party tested and will 

provide the basis for design and fabrication of an 

integrated 1 kW ethanol or gasoline fuel processor 

during Phase II. We will scale-up the smaller 

processor to 10 kW during Phase III.

Results

Component design and modeling. ASPEN, a 

chemical process simulator, is being used to model 

the fuel processor system. These simulations will 

allow determination of the equilibrium constraints 

and heat duties for the different components in the 

fuel processing system. Performance of the microreactors is being simulated using FEMLAB, a finiteelement software package, and FLUENT, a package 

that is capable of handling multi-component 

transport in a flow fluid simultaneously with surface 

reactions. The FEMLAB simulations demonstrated 

that one can control heat transfer in microchannel 

reactors by properly designing thermal bridges 

within the microfabricated system. The FLUENT 

results are being cross-validated against the 

FEMLAB results.

Sorbent development. During liquid-phase 

experiments, π-complexation sorbents adsorbed 

more sulfur (e.g. thiophene) at low concentrations 

than commercial sorbents. Table 1 compares the 

performance of selected sorbents.

.

Catalyst development and catalyst/

microreactor integration. Several ATR, WGS, and 

PrOx catalysts have been prepared. The ATR 

catalysts include beta-alumina supported nickel. 

These catalysts are being evaluated. Transition metal 

carbide and oxide supported gold catalysts were 

demonstrated to be highly active for the WGS 

NaY (commercial) π-Complexation 

Adsorbent

Solvent Saturation Amount (mmol/g)

Benzene 0.102 0.171

n-Octane ---- 0.898

Table 1. Thiophene Adsorption Amounts upon Saturation
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

327

reaction. The carbide catalysts were more active and 

durable than the oxide supported catalysts. The 

oxide supported gold catalysts deactivated 

dramatically during the first 10 hours on stream (see 

Figure 1). The deactivation appears to be a 

consequence of over-reduction of the support by CO. 

We are modifying the supports to improve their 

durability. Preferential oxidation catalysts consisting 

of 5% Pt/15% ceria-85% alumina wash-coated onto 

honeycomb monoliths have been prepared. These 

materials are currently being tested.

Microchannel reactor system development. A 

prototype micro-reactor with concentric tubes has 

been fabricated. The main body is made of 

aluminum with 4 channels produced by deep hole 

micro-drilling. These channels have diameters of 3 

mm and depths of 50 mm. Tubes with outer 

diameters of 650 μm and inner diameters of 300 μm 

were fitted into the channels. The structure included 

4 stainless steel end caps made by milling and microdrilling processes. The prototype reactor is 

illustrated in Figures 2 and 3.

Conclusions/Future Work

While this project is relatively new, significant 

progress has been made regarding the component 

design and modeling, sorbent and catalyst 

development and microchannel system development 

tasks. We will continue to focus on these tasks and 

microcombustor/vaporizer development. In addition, 

methods will be demonstrated to integrate catalysts 

into the micro-reactors.

Figure 1. Deactivation Patterns for the Oxide Supported 

Gold Catalysts

Figure 2. Schematic of the Prototype Micro-Reactor

Figure 3. Photograph of the Prototype Micro-Reactor
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.C.7 Evaluation of Partial Oxidation Fuel Cell Reformer Emissions

Stefan Unnasch (Primary Contact), Scott Fable 

TIAX, LLC. 

1600 De Anza Blvd., Suite 100

Cupertino, CA 95014

 (408) 517-1563, fax: (408) 517-1553, e-mail: unnasch.stefan@tiax.biz

DOE Technology Development Manager: Nancy Garland

(202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

ANL Technical Advisor: Walter Podolski

(630) 252-7558, fax: (630) 972-4430, e-mail: podolski@cmt.anl.gov

Subcontractors: Nuvera Corporation, Cambridge, MA; Air Toxics, Ltd., Sacramento, CA; Clean Air 

Vehicle Technology Center, Hayward, CA

Objectives

• Measure the emissions from a partial oxidation/autothermal fuel processor for a proton exchange 

membrane (PEM) fuel cell system under both cold-start and normal operating conditions. 

• Assess the feasibility of meeting emissions standards for automobiles and light-duty trucks through the 

use of a fuel cell vehicle with a gasoline reformer. 

Approach

• Define a representative test cycle consisting of both cold-start and normal operating conditions. 

• Use the established test cycle to quantify emissions from a partial oxidation reformer before and after 

anode-gas-burner treatment. 

• Measure emissions with continuous monitor measurements supplemented with laboratory analyses of 

speciated hydrocarbons.

• Use reasonable approximations and estimates to convert emissions data from a grams/unit fuel basis to 

a predicted grams/mile basis. 

Accomplishments

• Measured emissions from a fuel processor (without fuel cell) over several operating conditions 

including cold-start. 

• Speciated total hydrocarbon data before and after the anode gas burner.

• Assessed the sensitivity of monitoring equipment over a range of operating conditions.

• Analyzed data to report emissions on a g/kg fuel basis.

• Established testing plans for two additional reformer systems.

Future Directions

• Perform extensive emissions testing of a fuel cell/reformer system to include particulate, 

formaldehyde, and ammonia as well as NOx, hydrocarbons, and CO.

• Develop control strategies to minimize emissions.

• Test emissions from McDermott Technologies fuel processor in August 2002.

• Evaluate on-road emissions from fuel cell vehicles with on-board reformers.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

329

Introduction

Fuel reformer operation is generally divided into 

two operating modes: start-up and normal partial 

oxidation. During start-up, the fuel processor burns 

fuel at near stoichiometric conditions until critical 

system temperatures and pressures stabilize to target 

values. Once the target conditions are reached, the 

reformer operates in normal mode in which the fuel 

processor burns fuel at very rich conditions. Since 

these modes are comprised of considerably different 

operating conditions, it follows that the emissions 

associated with each of these modes are also 

considerably different. 

Since the combustor is typically cold under startup conditions, the emissions produced during this 

brief period (target times are under 30 seconds) can 

be substantially higher than those produced during 

the remaining, much longer portion of the driving 

cycle. The pollutant emissions produced during this 

operating mode include NOx, CO, formaldehyde, and 

organic compounds. These organic compounds, 

which include hydrocarbons, alcohols, and 

aldehydes, are regulated in California and referred to 

as non-methane organic gases (NMOG). 

Under normal operating conditions, in which the 

combustor is sufficiently warm and operated under 

fuel rich conditions, virtually no NOx is formed, 

although the formation of ammonia is possible. Most 

hydrocarbons are converted to carbon dioxide (or 

methane if the reaction is incomplete); however, 

trace levels of hydrocarbons can pass through the 

fuel processor and fuel cell. The shift reactors and 

the preferential oxidation (PrOx) reactor reduce CO 

in the product gas, with further reduction in the fuel 

cell. Thus, of the criteria pollutants (NOx, CO, and 

non-methane hydrocarbons [NMHC]), NOx and CO 

levels are generally well below the most aggressive 

standards. NMOG concentrations, however, can 

exceed emission goals if these are not efficiently 

eliminated in the catalytic burner. 

Approach

In this study, a gasoline fuel processor is 

operated under conditions simulating both cold start 

and normal operation. Emissions are measured 

before and after the anode gas burner in order to 

quantify the effectiveness of the burner catalyst in 

controlling startup emissions. The emissions 

sampling system includes continuous emissions 

monitors (CEMs) for O2, CO2, CO, NOx, and total 

hydrocarbons (THC). Also, integrated gas samples 

are collected in Tedlar bags for hydrocarbon 

speciation analysis via gas chromatography (GC). 

This analysis yields the concentrations of the 

hydrocarbon species required for the California 

NMOG calculation. The particulate matter (PM) 

concentration in the anode burner exhaust is 

measured through either isokinetic sampling or the 

placement of a filter in the exhaust stream. 

Concentrations of the aforementioned species are 

obtained using the emission sampling system shown 

in Figure 1. Since emissions vary significantly 

between startup and normal operation, a wide range 

of analyzer capability is required. 

Emission data will be used to assess on-road 

emissions from fuel cell vehicles and will be 

characterized in terms of cold-start on reforming 

modes. Current fuel processor technologies are not 

configured to follow a vehicle load and may be 

Figure 1. Fuel Processor Schematic
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

330

integrated with a hybrid vehicle. For this project, the 

fuel processor is operated at several steady-state 

points while emissions are monitored for the steadystate conditions and transients between load changes. 

The combination of data during start-up, different 

loads, and transients will be inputs to a vehicle 

emissions model. The model for determining vehicle 

emissions estimates the emissions for each second in 

a driving cycle based on load. Start-up emissions are 

also added to the total driving emissions. The data 

will also be provided to the National Renewable 

Energy Laboratory to support their efforts in vehicle 

emissions modeling.

Results

Our previous report summarized the results of a 

preliminary emissions test of an autothermal fuel 

processor operating without a fuel cell. The test 

focused on NOx and hydrocarbon emissions, 

including speciation of hydrocarbon components. 

Figure 2 shows NOx and THC emission levels as the 

reformer was started up and operated over a duty 

cycle. The testing did not attempt to follow a vehicle 

driving cycle but rather followed a series of steadystate conditions with load changes. THC emissions 

were high during start-up and then varied during the 

test, with spikes occurring when the load was 

increased. 

During reforming, over 90 percent of the THC 

emissions were methane. The composition of the 

hydrocarbons was analyzed and the presence of toxic 

contaminants determined. Figure 3 shows the 

hydrocarbon fractions from fuel processor tests in 

terms of methane and NMHCs. Samples from these 

tests were also analyzed to determine the speciated 

hydrocarbon emissions profile over various operating 

loads. Figure 4 shows the results of the speciation 

analysis, in terms of the fraction of olefins and 

saturated and aromatic hydrocarbons that comprise 

the NMHCs. Aromatics and saturated hydrocarbons 

comprise almost all of the NMHC emissions. The 

fraction of NMHC as aromatics was close to the 

fraction of aromatics in the test gasoline for several 

samples taken from the PrOx and the tail gas 

combustor (TGC). The TGC burned reformer 

product gas.

Figure 2. THC and NOx Concentrations Compared 

with Fuel Processor Load over Time

Figure 3. Hydrocarbon Mass Fraction of Fuel Processor 

Emissions at Various Stages

Figure 4. Speciated Hydrocarbon Composition of Air 

Toxics Samples from the Fuel Processor or 

Tail Gas Combustor at Various Fuel Processor 

Loads
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

331

During warm-up and one mid-power PrOx 

sample (20-22.5 kW), the fraction of NMHC as 

aromatics was higher. Olefins were typically less 

than 1 percent of NMHC in the PrOx and TGC 

samples and also represented less than 1 percent of 

the gasoline. However, for one test point, olefins 

comprised 4% of the NMHC. The presence of the 

toxic components benzene and 1,3-butadiene were 

less than 1 ppm.

Conclusions 

Preliminary emissions data were measured from 

the PrOx and a TGC that combusted all of the 

reformer products. The fuel processor and the 

combustion of reformer products did not represent an 

optimized fuel cell vehicle configuration. Even with 

these limitations, the following conclusions can be 

drawn from the data.

NOx emissions measured from a TGC ranged 

from less than 1 ppm to 5 ppm. These emission levels 

would correspond to approximately 0.01 g/mi of 

NOx over a vehicle driving cycle. These emissions 

would be as low if the TGC were burning hydrogendepleted anode gas. 

NMHC emissions during start-up were over 100 

ppm. In order to meet stringent emission standards, 

the start-up duration will need to be minimized. 

More data on start-up with an optimized fuel 

processor is required before on-road NMHC 

emissions can be estimated.

During reforming, hydrocarbon emissions are 

typically 90 percent methane, which will help reduce 

the NMHC contribution of the fuel processor.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

332

IV.C.8 Catalysts for Autothermal Reforming

Theodore Krause (Primary Contact), Jennifer Mawdsley, Cecile Rossignol, John Kopasz, Daniel 

Applegate, Magali Ferrandon, J. David Carter, and Michael Krumpelt

Argonne National Laboratory,

9700 South Cass Ave.

Argonne, IL 60439

(630) 252-4356, fax: (630) 972-4463, e-mail: krause@cmt.anl.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov 

Objectives

• Improve catalytic activity and reduce the cost of autothermal reforming (ATR) catalyst to decrease the 

size of the fuel processor and reduce start-up time.

• Develop a better understanding of reaction mechanisms in order to optimize catalytic activity, 

minimize deactivation, and improve sulfur tolerance.

Approach

• Synthesize materials that meet Argonne National Laboratory (ANL) selection criteria and DOE cost 

goals.

• Determine H2, CO, CO2, CH4, and CnHm yields versus temperature and space velocity.

• Work with catalyst manufactures to optimize catalyst performance and to support the catalyst on 

structured forms such as a monolith.

• Conduct fundamental studies to gain insight into reaction mechanisms.

Accomplishments

• Demonstrated the performance of Rh-, Ni-, and Pt-CGO (gadolinium-doped ceria) supported on a 

cordierite monolith.

• Demonstrated that the oxidation and reforming reactions are “decoupled.”

• Transferred technology to Süd-Chemie, Inc. under a CRADA to optimize the performance of the 

CGO-based catalyst.

• Demonstrated that modified LaNiO3 and LaCoO3 perovskites are active for autothermal reforming and 

appear to be structurally stable under autothermal reforming conditions.

Future Directions

• Optimize the choice of metals and metal loadings for the CGO-based catalysts supported on structured 

forms, such as monoliths or foams.

• Work with Süd-Chemie, Inc. to optimize the performance of the CGO-based catalysts.

• Increase the activity of the perovskite catalysts.

• Improve the sulfur tolerance of non-Pt catalysts.

• Continue to work with academic collaborators to gain better insight into reaction mechanisms.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

333

Introduction

Catalytic autothermal reforming (ATR) of 

hydrocarbon fuels was first proposed by Argonne 

National Laboratory (ANL) several years ago and 

has been widely accepted as the most promising 

route to meet the efficiency, volume, and cost goals 

of the DOE Hydrogen, Fuel Cells and Infrustructure 

Technologies Program. ANL has developed a new 

family of reforming catalysts that are modeled after 

solid oxide cathode materials. Unlike typical 

industrial steam-reforming catalysts that consist of 

nickel supported on a modified alumina substrate, the 

ANL catalyst consists of selected Group VIII 

transition metals, such as platinum, rhodium, or 

nickel, supported on an oxide ion-conducting 

substrate, such as gadolinium- or samarium-doped 

ceria. The ANL catalyst has demonstrated nearequilibrium yields of H2 from a number of 

hydrocarbon fuels, including natural gas, gasoline, 

and diesel, exhibiting high catalytic activity and 

resistance to coking. The platinum catalyst has been 

shown to exhibit long-term tolerance to sulfur at a 

concentration of 50 ppmw, which is typical of the 

sulfur content in Tier II gasoline. Süd-Chemie, Inc., 

of Louisville, Kentucky, produces the ANL catalyst 

under a licensing agreement. Because of concern 

over the cost of platinum and rhodium, we have 

initiated an effort to develop mixed non-noble metal 

oxides with the ABO3 stoichiometry and the 

perovskite structure as reforming catalysts. 

Perovskites were selected because many are good 

oxygen ion conductors and/or good mixed electronic 

conductors.

 High reforming activity has been exhibited by 

lanthana-based perovskites that have been doped on 

the A-site to improve catalytic activity and on the Bsite to provide structural stability in reducing 

environments.

Approach

Gadolinium-doped ceria (CGO) substrates are 

prepared from nitrate salt precursors by either 

coprecipitation or glycine-nitrate combustion 

techniques. Pt, Rh, or Ni is loaded onto the CGO 

using the incipient wetness technique. Typical weight 

loadings are 1 wt% or less for Pt and Rh and up to 10 

wt% for Ni. Pt-, Rh-, and Ni-CGO supported on 

cordierite monoliths were prepared by Süd-Chemie. 

Core samples from the monoliths were tested in a 

microreactor system for the reforming of isooctane 

and benchmark fuel (74 wt% isooctane, 20 wt% 

xylenes, 5 wt% methylcyclohexane, and 1 wt% 1-

pentene). Temperature-programmed reaction studies 

were performed by exposing powder samples (~50 

mg) of the catalysts to isobutane (C4H10), O2, H2O, 

and N2 at the desired feed ratios over a temperature 

range of 100-800oC using a Zeton Altamira 

Chemisorption Instrument Model AMI-100 equipped 

with a mass spectrometer. Lanthana-based 

perovskites were prepared by mixing selected nitrate 

salt precursors at the appropriate ratios using the 

glycine-nitrate combustion technique. Powder 

samples were tested for isooctane and benchmark 

fuel reforming in a microreactor system. The 

structural stability of the materials was evaluated by 

comparing the X-ray diffraction pattern of samples 

before and after reforming.

Results

Rh-, Ni-, and Pt-CGO Catalysts Supported on a 

Cordierite Monolith

As shown in Figure 1, Rh- or Ni-CGO supported 

on a cordierite monolith were observed to be more 

active than Pt-CGO supported on a cordierite 

monolith based on the higher H2 yield observed with 

Figure 1. Yields of H2, CO, CO2, and CH4 (mole/mole 

of isooctane) from Reforming Isooctane 

Catalyzed by Rh-, Ni-, or Pt-CGO Supported 

on a Cordierite Monolith. Conditions: 700°C, 

O2/C=0.5, H2O/C=1.2, GHSV=11,000 h-1.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

334

Rh-CGO (11.0 moles/mole of isooctane) or Ni-CGO 

(10.4 moles/mole of isooctane) compared with PtCGO (6.7 moles/mole of isooctane) for isooctane 

reforming at 700°C. The 11.0 moles of H2 per mole 

of isooctane produced by Rh-CGO were slightly less 

than the 12.2 moles of H2 predicted by 

thermodynamic equilibrium at 700°C. The higher H2

yield observed with Rh- or Ni-CGO compared to PtCGO is attributed to Rh and Ni being more active 

than Pt for steam reforming. A comparison of the 

temperature-programmed isobutane reforming 

reaction profiles for Rh-, Ni-, and Pt-CGO (Figure 2) 

shows that the temperature at which 50% of the 

maximum H2 yield is observed for Rh-CGO (381°) 

or Ni-CGO (512°) is considerably lower than for 

Pt-CGO (615°C). For Rh-, Ni-, and Pt-CGO, the 

oxidation reactions involving O2 occur at a lower 

temperature than the reforming reactions, which 

produce H2 and CO (not shown in Figure 2). While it 

is possible that H2 and CO may be produced by 

partial oxidation reactions, they are rapidly oxidized 

to H2O and CO2, respectively, as long as O2 is still 

present. For isooctane reforming, the fact that the 

CO2 yield for all three metal catalysts is essentially 

the same (3.9-4.0 moles per mole of isooctane), as 

shown in Figure 1, and the lack of O2 in the 

reformate suggest that all three metals are very active 

oxidation catalysts.

In long-term testing, Rh-CGO supported on a 

cordierite monolith exhibited relatively stable 

performance over a 1000-hr period, producing a 

reformate containing ~30-38 vol% H2 from the 

benchmark fuel at 700°C, as shown in Figure 3. 

Initially, Pt-CGO supported on a cordierite monolith 

exhibited activity similar to Rh-CGO, producing a 

reformate containing ~38 vol% H2 at 675°C 

(Figure 3); however, the concentration of H2 in the 

reformate decreased by ~50% after only a few hours 

on stream. This initial rapid decrease in activity was 

followed by a much slower, continuing decrease in 

activity. After 250 hr, the concentration of H2 in the 

reformate was <10 vol%. Increasing the reaction 

temperature to 725°C resulted in an increase in the 

H2 concentration to ~20 vol%.

Figure 2. Temperature-Programmed Reaction Profile 

for the Flowrate of O2 and H2 in the 

Reformate Produced from Reforming 

Isobutene Catalyzed by Rh-, Ni-, or Pt-CGO 

in Powder Form. Conditions: O2/C=0.5, 

H2O/C=1.0, GHSV=~50,000 h-1, total 

flowrate is 50 mL/min (balance He).

Figure 3. Yields of H2, CO, CO2, and CH4 (mole/mole 

of fuel) from Reforming Benchmark Fuel 

Catalyzed by Rh- or Pt-CGO Supported on a 

Cordierite Monolith. Conditions: O2/C=0.44, 

H2O/C=1.6, GHSV=9,000 h-1.
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Mixed Metal Oxides with the Perovskite Structure

Simple lanthana-based perovskites (LaNiO3, 

LaCoO3, LaCrO3, LaFeO3, and LaMnO3) were 

tested for reforming activity using isooctane at 

700°C. Yields of 14.3 and 11.3 moles of H2 per mole 

of isooctane were observed with LaNiO3 and 

LaCoO3, respectively. The X-ray diffraction patterns 

of LaNiO3 and LaCoO3 after testing suggested that 

the oxides had decomposed into La2O3 and metallic 

Ni and Co, respectively, under the reaction 

conditions. Yields of 2.6 and 2.5 moles of H2 per 

mole of isooctane were observed with LaCrO3 and 

LaMnO3, respectively, while the H2 yield of LaFeO3

was 6.4 moles per mole isooctane. The X-ray 

diffraction patterns of LaCrO3, LaFeO3, and 

LaMnO3 after testing suggested that these 

compounds maintained the perovskite structure 

under the reaction conditions.

In order to stabilize LaNiO3 or LaCoO3, we 

substituted a portion of Ni or Co with selected 

transition metals, termed “B-site modifying”. 

Although the B-site-modified LaNiO3 appeared to be 

structurally stable under reducing conditions (based 

on a comparison of the X-ray diffraction pattern of 

the oxide before and after testing), a decrease in the 

H2 yield was observed compared with the 

unmodified LaNiO3, as shown in Table 1. The H2

yield of the B-site-modified LaNiO3 could be 

improved by substituting a portion of the La with a 

lower valent cation, termed “A-site modifying,” 

which introduces oxide ion vacancies (Table 1). An 

“A,B-site-modified” LaNiO3 exhibited relatively 

stable performance over a 300-hr period, producing a 

reformate containing ~35 vol% H2 from the 

benchmark fuel at 700°C, as shown in Figure 4. The 

“A,B-site-modified” LaNiO3 deactivated rapidly 

when exposed to the benchmark fuel containing 

50 ppmw sulfur added as benzothiophene.

Conclusions

Rh- or Ni-CGO supported on a cordierite 

monolith produced reformates with a higher H2

concentration than Pt-CGO supported on a cordierite 

monolith. The better performance of the Rh- and NiCGO compared with Pt-CGO is attributed to the 

higher steam reforming activity of Rh and Ni. Sulfur 

tolerance is still an issue, since only Pt-CGO has 

shown sulfur tolerance when reforming fuels with 

sulfur concentrations in the 30-80 ppmw range. We 

are working with Süd-Chemie under a CRADA to 

optimize the activity of the CGO-based catalysts.

A,B-site modified LaNiO3 and LaCoO3 were 

demonstrated to be active autothermal reforming 

catalysts and appear to be structurally stable under 

the reducing reaction conditions. Sulfur tolerance is 

still an issue based on the rapid decrease in the H2

concentration in the reformate when reforming 

sulfur-containing fuels. Future work will focus on 

improving the activity and the sulfur tolerance of 

these perovskite catalysts.

Perovskite

Moles of H2/Mole of 

Isooctane

700°C 600°C

LaNiO3 14.3 10.8

B-site modified LaNiO3 12.6 10.0

A,B-site modified LaNiO3 (I) 13.1 13.5

A,B-site modified LaNiO3 (II) 13.2 11.3

Table 1. Effect of A- and B-Site Modification of 

LaNiO3 on the Moles of H2 Produced per Mole 

of Isooctane for Reforming Isooctane. 

Conditions: O2/C=0.5, H2O/C=1.2, 

GHSV=~5,000 h-1.

Figure 4. Yields of H2, CO, CO2, and CH4 (mole/mole 

of fuel) from Reforming Benchmark Fuel 

Catalyzed by an A,B-Site-Modified LaNiO3

in Powder Form. Conditions: O2/C=0.44, 

H2O/C=1.6.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Publications/Presentations

1. M. Krumpelt, T. R. Krause, J. D. Carter, J. P. 

Kopasz, and S. Ahmed, “Fuel Processing for 

Fuel Cell Systems in Transportation and Portable 

Power Applications,” Catalysis Today

(submitted for publication).

2. T. Krause, J. Kopasz, C. Rossignol, J. D. Carter, 

and Michael Krumpelt, “Catalytic Autothermal 

Reforming of Hydrocarbon Fuels for Fuel Cell 

Systems,” 224th American Chemical Society 

National Meeting, Boston, MA, August 18-22, 

2002.

3. A. L. Wagner, J. P. Wagner, T. R. Krause, and J. 

D. Carter, “Autothermal Reforming Catalyst 

Development for Fuel Cell Applications,” 2002 

Future Car Congress, Arlington, VA, June 3-5, 

2002.

4. C. Rossignol, T. Krause and M. Krumpelt, “Role 

of Metal-Support Interactions on the Activity of 

Pt and Rh Catalysts for Reforming Methane and 

Butane,” American Institute of Chemical 

Engineers Spring National Meeting 2002, New 

Orleans, LA, March 10-14, 2002.

5. M. Krumpelt, T. Krause, J. Kopasz, J. D. Carter, 

and S. Ahmed, “Catalytic Autothermal 

Reforming of Hydrocarbon Fuels For Fuel 

Cells,” American Institute of Chemical 

Engineers Spring National Meeting 2002, New 

Orleans, LA, March 10-14, 2002.

Patents

1. K. W. Kramarz, I. D. Bloom, R. Kumar, S. 

Ahmed, R. Wilkenhoener, and M. Krumpelt, 

“Steam Reforming Catalyst,” US Patent 

6,303,098 issued October 16, 2001.

2. S. Ahmed, R. Kumar, and M. Krumpelt, 

“Methanol Partial Oxidation Reformer,” US 

Patent 6,244,367 issued June 12, 2001.

Special Recognitions & Awards

1. R&D Magazine – R&D 100 Award (2001) for 

Autothermal Reforming Catalyst Technology; 

Federal Laboratory Consortium Award (2002) 

for excellence in technology transfer.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

337

IV.C.9 Fuel Processing of Diesel Fuel for Auxiliary Power Units

David A. Berry (Primary Contact), Dushyant Shekhawat, Todd H. Gardner, and William Rogers

U. S. Department of Energy

National Energy Technology Laboratory

P. O. Box 880

3610 Collins Ferry Road

Morgantown, WV 26507-0880

(304) 285-4430, fax: (304) 285-4403, e-mail: david.berry@netl.doe.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov 

Objectives

• Develop understanding of system integration issuesfor diesel fuel powered auxiliary power units 

(APUs) and provide necessary tools (models) and information to fuel cell/fuel process developers and 

system integrators for performance optimization and system control.

Approach

• Conduct a systems analysis to understand reformer integration and operational requirements.

• Utilize computational fluid dynamics (CFD) models to understand and address heat and mass transfer 

issues and reactor performance for steady-state and transient analysis.

• Conduct kinetic rate determination studies in the laboratory to allow for predictive modeling and 

design of diesel fuel reformers.

Accomplishments

• Identified diesel-based 5-kWe fuel cell auxiliary power unit (APU) system with >50% electrical 

conversion efficiency 

• Developed a prototype CFD model including all the key elements of auto-thermal reforming (ATR) 

• Developed a model that accounts for fuel atomization and vaporization, partial oxidation, steam 

gasification, and anode exhaust gas combustion

• Tested the convergence behavior of the model 

• Conducted laboratory kinetic experiments 

• Tested platinum (Pt), palladium (Pd), and ruthenium (Ru) catalysts

• Initial rate measurements made for hexadecane and diesel fuel

Future Directions

• Develop a predictive CFD model (Fluent) for diesel reforming

• Conduct steady-state simulations and validate model with ATR experimental data

• Conduct transient analysis

• Use benchmark fuel for kinetic modeling experiments

• Develop a complex reaction model and validate with CFD

• Ultimately, develop a kinetic rate methodology for diesel autothermal reforming catalyst systems
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

338

Introduction

The U.S. Department of Energy is sponsoring 

development of high temperature fuel cell power 

systems based on solid oxide technology through its 

Solid State Energy Conversion Alliance (SECA) 

program. The program is geared at mass 

manufacturing of fuel cells for high volume markets 

and multiple applications. One of those markets/

applications is a diesel-fueled auxiliary power unit 

(APU) for long-haul truck transportation. The fuel 

processor is a critical component of this system and 

must be able to provide a clean, tailored synthesis gas 

to the fuel cell stack for long-term operation. Key 

characteristics desired for the processor (and the 

system) include low cost, high efficiency, maximum 

thermal integration, low maintenance intervals, and 

acceptable startup and transient response. There are 

several barrier issues that must be overcome to 

achieve these characteristics. Carbon formation, 

particularly upon startup, must be minimized to 

avoid coking of the catalysts in the reformer and 

downstream fuel cell. Fuels containing sulfur can 

poison both the reforming catalysts and the fuel cell 

anode. High thermal mass components (some of 

which may have heat-ramp restrictions) can limit 

startup times and transient response. Finally, cost 

targets must be achieved to ensure commercial 

success. Depending on the system approach taken, 

technology is needed to resolve these barriers.

Approach

The objective of this work is to develop 

understanding of system integration issues for diesel 

fuel powered APUs and provide the necessary tools 

(models) and information to fuel cell/fuel process 

developers and system integrators for performance 

optimization and system control. A systems analysis 

was the first activity conducted to help understand 

reformer integration and operational requirements for 

the system. One of the more important underlying 

assumptions of the study is that the reforming 

catalyst can handle any sulfur content of the fuel, but 

the sulfur must be removed prior to the fuel gas 

entering the fuel cell. This may or may not be 

eventually achieved, but there is some evidence that 

a viable degree of sulfur tolerance can be attained in 

the reformer, especially as sulfur content of the diesel 

itself is being dramatically reduced through 

Environmental 

Protection Agency regulations. This assumption 

could greatly impact the cost/efficiency trade-off of 

dealing with sulfur in the system. One goal of the 

systems analysis is to reduce the number of 

components to keep the system compact and 

economical, while still having the enough thermal 

integration to maximize system efficiency. 

The next task was to model the reformer itself to 

understand design issues and be able to predict 

performance of various reactor/catalyst types and 

transient behavior. However, upon trying to obtain 

kinetic rate expressions for the reforming reactions, it 

was found that very little information existed in the 

public domain. This led to the decision/need to 

develop reaction kinetics for catalytic partial 

oxidation and steam reforming at National Energy 

Technology Laboratory’s (NETL’s) onsite research 

facility.

Results

Systems Analysis: Figure 1 shows a concept 

identified by NETL for a integrated fuel processor/

fuel cell system targeted for diesel APUs. There are 

several favorable attributes of this system. For 

example, startup occurs by firing an internal 

combustor in the dual reactor reformer. This 

provides heat to the ATR reformer (via conduction) 

as well as supplying heat to the fuel cell cathode via 

direct exhaust from the combustor or preheated air 

from the heat exchanger (optional). If necessary, the 

ATR is fired in a partial oxidation mode to aid in 

heatup and to provide heat to the anode side of the 

Figure 1. High Efficiency Integral Combustor/Reformer
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

339

fuel cell. At steady-state, all fuel is diverted to the 

reformer, and the internal combustor acts as a 

polishing bed to fully oxidize any remaining 

unburned hydrocarbons from the fuel cell. The 

figure also depicts a bed of zinc oxide that serves as a 

polishing bed to remove sulfur from the fuel gas 

entering the fuel cell. This is just one of several 

configurations that is being evaluated for this 

particular system. Depending on the rate of 

technology development (e.g., sulfur-tolerant 

reforming catalysts), the system could evolve along 

one of several pathways. Table 1 shows the effect of 

system integration of the fuel processor on the 

efficiency of the overall fuel cell system when 

compared to stand-alone reformer with external (non 

shared heat) combustion of anode exhaust. The 

comparison shows an approximate 7% efficiency 

improvement due primarily to better thermal 

integration in the shared heat reformer concept. Fuel 

flow was kept constant, but it was necessary to vary 

the fuel/air (F/A) ratio of the non-shared heat system 

in order to keep the reformer and fuel cell at 

reasonable temperatures. Increased efficiency of the 

non-shared case could also be obtained with the 

addition of another heat exchanger for independent 

preheat of the reformer and fuel cell inlet air. 

Unfortunately, this leads to higher cost, footprint, 

and complexity.

Table 1. Effect of System Analysis on System Efficiency

Reformer Modeling: NETL is also developing a 

CFD model in Fluent to understand and address the 

heat and mass transfer issues and reactor 

performance for steady-state and transient analysis. 

This model accounts for fuel atomization and 

vaporization, partial oxidation, steam reforming, and 

anode exhaust combustion. It is asumed that the 

partial oxidation reaction is very fast and occurs at 

the top of the catalyst bed along with fuel 

atomization and vaporization. It is also assumed that 

the steam reforming initiates after all O2 is consumed 

in the partial oxidation reaction. Therefore, the 

reactor will initially be considered as two plug-flow 

reactors in series. Figure 2 and 3 depict the inlet 

conditions for the ATR model and results from the 

model, respectively.

Kinetic Measurements: Preliminary studies have 

been conducted for the kinetic model development 

for the autothermal reforming of diesel fuel. Three 

Shared Heat Non-Shared Heat

Fuel (kg/hr) 0.834 0.834

Air – stoichiometric 

units in

5 5.2

ATR F/A Ratio 9 3.5

Steam/Carbon Ratio 0.8 0.8

Efficiency 50.21 42.39

Net Power 5.0 4.221

ATR Temperature 800 800

Fuel Cell Temperature805 813

Figure 2. ATR Model Inlet Conditions

Figure 3. ATR Model Results
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

340

different catalysts (g-alumina supported Pt, Pd, and 

Ru) were evaluated to obtain data for the ATR 

kinetic modeling. 

A fixed bed reactor system was used to conduct 

the diesel ATR experiments. The reactor was 

operated continuously at steady state. The 

temperature was varied between 750 – 850°C, 

oxygen/carbon ratio was 0.6, steam/carbon ratio was 

1.5, and the gasl hourly space velocity was 25,000 - 

200,000 hr-1. Table 2 shows the surface area, 

porosity, pore size distribution, metal loading, and 

metal dispersion of the catalysts used in the study.

Table 2. Physicochemical Properties of Catalyst used in 

Diesel ATR

Figure 4 compares the product distribution from 

ATR of diesel from three different catalysts at 850 

°C. The γ-Alumina supported ruthenium catalyst 

proved to be the most active catalyst in producing 

synthesis gas from diesel ATR.

Kinetic modeling of diesel autothermal 

reforming is extremely complicated. Diesel fuel 

consists of a complex variable mixture of hundreds 

of hydrocarbon compounds containing paraffins, 

isoparaffins, naphthenes, aromatics, and olefins. To 

simplify the model, a steady-state power law rate 

expression for the diesel reforming over each type of 

catalyst used in this study was developed. A 

linearized least-squares method of data analysis was 

used to determine the power law parameters from a 

series of diesel ATR experiments. The power law 

rate model for diesel autothermal reaction may be 

written as:

Equation (I) is linearized so that a linear least 

square approach could be employed to solve for the 

activation energy, EA, and the reaction orders in 

hydrocarbon (HC), a, H2O, b, and O2, c.

The resulting activation energy, preexponential 

factor, and the reaction order with respect to each 

reactant are presented in Table 3. A comparison of 

data predicted from the power law model to the 

experimental data shows the goodness of fit 

(correlation factor: ~92% for Pt and Pd, and ~72% 

for Ru). The ATR rate shows a non-monotonic 

dependence with respect to oxygen varying from 

positive to negative. By looking at the very low 

reaction orders with respect to oxygen from each 

kind of catalyst used in this study, it can also be 

concluded that the rate of diesel ATR is almost 

independent of oxygen. Good agreement has been 

found between Pd and Pt catalysts with respect to 

reaction order and activation energy. The negative 

order with respect to water shows that the water 

present in the system strongly inhibits the rate of 

reaction.

Autothermal reforming of single components 

such as n-hexadecane and toluene was also 

performed at the same reaction conditions as the 

diesel ATR to understand the reaction mechanisms 

and pathways for the ATR system. 

Catalyst

N2 BET 

Surface 

area 

(m2

/g)

Dispersion 

(%)

Pore 

Volume 

(cc/g)

Avg. 

Pore 

Size 

(A)

0.611 wt% Pt 

on γ-alumina

103 60 0.27 104

0.699 wt% Pd 

on γ-alumina

103 88 0.28 107

0.423 wt% Ru 

on γ-alumina

122 33 0.27 87

2 O2 (I) c H O

b

HC RT a

E

rHC ke C C C

− A

− =

ln( ) ln( ) (II)

ln( ) ln( ) ln( )

H 2O O2

HC

A

HC

b C c C

a C

RT

E

r k

+

− = − + +

Figure 4. Product Distribution from ATR of Diesel 

(T=850o

C, O2/C=0.3, S/C=1.5)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

341

Table 3. Kinetic Parameter for Diesel Reforming from 

Three Different Catalysts

Units: 1(L/mol)a+b+c-1/sec; 2kcal/mol

Conclusions

A novel fuel processor is configured at NETL to 

integrate the fuel cell system for process optimization 

and system control. In the proposed system, startup 

occurs by firing an internal combustor in the dual 

reactor reformer, which provides heat to the ATR 

reformer via conduction as well as supplying heat to 

the fuel cell cathode via direct exhaust from the 

combustor.

A CFD model in Fluent was also developed by 

NETL to understand and address the heat and mass 

transfer issues and reactor performance for steadystate and transient analysis.

A power law-type kinetic model for diesel ATR 

has also been presented, which provides preliminary 

insight into reaction kinetics and will provide 

direction for future high level kinetic modeling.

FY 2002 Presentations/Publications

1. Gardner, T. H., Berry, D. A., James, R. E., Lyons, 

K. D., Monahan, M. J. "Fuel Processor 

Integrated H2S Catalytic Partial Oxidation 

Technology for Sulfur Removal in Fuel Cell 

Power Plants". FUEL, Vol. 81, issue 17, 

September 2002.

2. Berry, D. A., Gardner, T. H., James, R. E., 

Rogers, W., Shekhawat, D., "Processing of Diesel 

for Fuel Cell Auxiliary Power Systems", 3rd

Annual Department of Defense Logistic Fuel 

Reforming Workshop, Panama City, Florida, 

August 26 – 29, 2002.

3. Surdoval, W. A. and Berry, D. A, "Solid State 

Energy Conversion Alliance", 3rd Annual 

Department of Defense Logistic Fuel Reforming 

Workshop, Panama City, Florida, August 26 – 29, 

2002.

4. Berry, D. A., Gardner, T. H., James, R. E., 

Rogers, W., Shekhawat, D., "Fuel Processing of 

Diesel Fuel for Fuel Cells", 2002 SECA Core 

Review Conference, Pittsburgh, Pennsylvania, 

June 18 – 19, 2002.

5. Berry, D. A., Gardner, T. H., James, R. E., 

Rogers, W., Shekhawat, D., "Fuel Processing of 

Diesel for Fuel Cells", 2002 Fuel Cells for 

Transportation Program / Lab R&D Review, 

Department of Energy Office of Transportation 

Technology, Denver, Colorado, May 6 – 10, 2002.

Catalyst

PreExponential 

Factor1

Activation 

Energy2

abc

Pt/γ-Al2O3 18.4 16.5 0.87 1.02 0.13

Pd/γ-Al2O3 44.7 16.4 0.74 1.07 0.10

Ru/γ-Al2O3 0.02 9.7 0.50 1.39 0.03
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

342

IV.C.10 Testing of Fuels in Fuel Cell Reformers

Rod Borup (Primary Contact), Michael Inbody, Troy Semelsberger, Lee Perry and Jerry Parkinson

P.O. Box 1663

Los Alamos National Laboratory

Los Alamos, NM 87545

(505) 667-2823, fax: (505) 665-6173, e-mail: Borup@lanl.gov

DOE Technology Development Manager: Nancy Garland

(202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Explore effects of fuels, fuel components, additives and impurities on the performance of hydrogen 

generation technologies

- Examine fuel composition effect on energy efficiency, durability, cold startup, transients, NH3

concentration, cost, and power density

- Understand the parameters that affect fuel processor and fuel cell lifetime and durability

Approach

• Examine fuel effects on fuel processing by testing fuels in automotive scale, adiabatic reactors

- Examine individual fuel components

- Examine fuel component blends

- Examine ‘real’ fuels (reformulated gasoline, naptha)

- Examine fuel additives (anti-oxidants, detergents, impurities)

• Model fuel reforming chemistry

- Model carbon formation

- Model equilibrium gas composition

- Model thermodynamic properties

Accomplishments

• Tested iso-octane, iso-octane/xylene, methylcyclohexane, naptha, reformulated gasoline, diesel 

components, anti-oxidants, and nitrogen containing hydrocarbons; monitored ammonia formation with

- Aliphatic and napthenic hydrocarbons

- Catalytic and homogeneous oxidation

- Nitrogen bound compounds (anti-oxidants)

• Monitored carbon formation with in situ laser diagnostics

- Monitored carbon formation for various fuel components

- Monitored carbon formation during start-up and shut-down

Future Directions

• Evaluate effects of fuel constituents on fuel processor operation

- Monitor carbon formation in situ with an adiabatic reactor and laser scattering
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

343

- Monitor carbon formation during start-up and reactor transients

- Define methods of operation for fast, repetitive start without carbon formation

- Develop capabilities to monitor carbon formation with in situ gravimetric analysis steam reforming 

apparatus

- Delineate carbon formation mechanisms

- Measure carbon effect on reforming kinetics

- Measure carbon formation kinetics

- Measure fuel additive and impurity effects on performance and carbon formation

- Sulfur effect 

- Oxygenated hydrocarbons

• Integrate fuel cell stack testing with fuel processor operation to evaluate system integration effects of 

fuels

Introduction

This report describes our FY02 technical 

progress in examining the effects of fuel on hydrogen 

generation for proton exchange membrane (PEM) 

fuel cells for transportation. The goal of this research 

is to explore the effects of fuels, fuel constituents, 

additives and impurities on the performance of onboard hydrogen generation devices and, 

consequently, on the overall performance of a PEM 

fuel cell system using a reformed hydrocarbon fuel. 

Understanding the fuel effects on the durability of 

PEM fuel cell systems is key for their commercial 

use. 

Different fuels and components have been tested 

in automotive scale, adiabatic reactors to observe 

their relative reforming characteristics with various 

operating conditions. Ammonia (NH3) formation 

was monitored, and conditions were varied to 

observe under what conditions NH3 is made. 

Nitrogen-bound hydrocarbons were added to fuels to 

determine their effect on NH3 formation. Carbon 

formation was monitored during fuel processor 

operation by in situ laser measurements of the 

effluent reformate. Fuel composition effects on 

carbon formation were measured. 

Approach

To examine the effect of the fuel on hydrogen 

production devices, various fuel components and real 

fuels have been tested in autothermal reformers 

(ATRs) and fuel reforming systems. Fuel reformers 

used for these experiments are automotive-scale 

reactors, and are operated adiabatically, such as 

systems likely will operate in vehicles. The analysis 

of the fuel effect on the product composition stream 

is conducted by various analytical techniques, 

specifically laser scattering and laser flourescence, 

gas chromatography, FTIR (fourier transform 

infrared), NDIR (non-dispersive infrared), 

paramagnetic oxygen and GC/MS (gas 

chromatography/mass spectrometry). Ammonia 

formation from various fuels and for different 

operating conditions was measured by FTIR. Carbon 

formation for different operating conditions and fuel 

components was monitored by in situ laser 

scattering. Mapping of the onset of carbon formation 

for different fuel components as a function of 

operating conditions has been conducted with these 

techniques. The reactor with catalyst observation 

windows, laser extinction, and scattering facilities is 

shown in Figure 1. Expected outlet concentrations of 

the fuel reformer and the relative fuel component 

effects on the fuel reformer outlet have been 

modeled. In particular, modeling of equilibrium 

carbon formation has been used to predict the 

operating conditions for the onset of carbon 

formation for various fuel blends. 

Specific fuel compositions and components 

measured include iso-octane, xylene, 

methylcyclohexane, naptha and California 

reformulated gasoline. Additives examined include 

anti-oxidant No. 29 (2,6-Di-Tert-Butyl-4-

methylphenol), anti-oxidant No. 22 (N, N’-Di-SecButyl-P-Phenylenediamine) and DMA-548. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

344

Results

Fuel Effects Comparisons in Catalytic Partial 

Oxidation

The relative rates for catalytic partial oxidation 

for different fuels have been measured for various 

operating conditions. Figure 2 shows relative 

reaction rates for various fuel components, mixtures, 

and a Phillips Petroleum Hydrotreated Naptha stream 

at a S/C of 1.0. The relative reaction rates vary as the 

O/C ratio varies due to temperature changes. At 

lower O/C ratios, the adiabatic temperature rise is 

lower, thus the overall reaction rate is lower. The 

reaction rate for all components are higher at higher 

O/C, and subsequently, higher temperatures. The 

oxidation rates for O/C’s of 0.7 and 0.8 are fastest for 

iso-octane. The addition of aromatics such as xylene 

slows the kinetics and conversion. Real fuel 

composition mixtures such as the Phillips Naptha and 

California reformulated gasoline show an oxidation 

rate faster than that of iso-octane/xylene mixtures 

even though the relative aromatic concentration is 

approximately the same. At high O/C ratios (O/C = 

1.0), the real fuel mixtures show an equal or faster 

oxidation rate compared with pure iso-octane. The 

resulting decrease in kinetics due to the presence of 

aromatic hydrocarbons indicates that the fuel 

composition will have an effect on the required size 

(and cost due to catalyst loading) of the fuel 

processor. If it is possible to make a non-aromatic 

containing fuel available, the fuel processing size and 

cost would be positively effected.

Ammonia Formation

Ammonia formation in the fuel processor is a 

concern, as NH3 is a poison to PEM fuel cell 

membranes and ionomer.1 As ammonia is known to 

degrade the performance of fuel cells, the DOE has 

targeted the outlet concentration for ammonia 

formation is < 0.5 ppm for 2005 and < 0.1 ppm by 

2010. However, little has been published about the 

generation of NH3 in ATR reactors. To examine this 

issue, an FTIR was set up to monitor the reactor 

effluent and calibrated to a detection limit of 400 ppb 

(parts-per-billion) of NH3 with the presence of 

ethylene. Without the presence of ethylene, the 

detection limit of NH3 is significantly lower, < 100 

ppb. Figure 3 shows FTIR spectra for NH3

calibration and of reformate from the partial 

oxidation and reforming of MCH 

(methylcyclohexane). Small amounts of NH3 are 

easily measured in a pure N2 background with the 

major peak at 967 cm-1; however, with the addition 

of ethylene, the sensitivity is greatly reduced, since 

ethylene has a minor peak near 967 cm-1. With the 

addition of 100 ppm ethylene, the NH3 sensitivity is 

reduced to about 400 ppb. Normal catalytic partial 

oxidation of fuel components does not show a 

measureable NH3 concentration (see curve 3(c)). 

Precombustion can occur in a reformer due to 

mixing air/fuel at high temperatures; this is 

essentially homogeneous combustion before the 

catalyst surface and typically an operation mode 

Figure 1. Catalytic partial oxidation with facilities for 

laser extinction and scattering measurements 

with catalyst observation.

Figure 2. Relative oxidation rates of iso-octane, isooctane/20% xylene, Phillips Naptha and 

California reformulated gasoline.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

345

which is avoided. However, when pre-combustion of 

fuels occurs (homogeneous combustion upstream of 

the catalyst) as in 3(c), NH3 is observed, in this case 

at a concentration of 11 ppm. 

Nitrogen-containing hydrocarbons are present in 

gasoline fuels. These can be small amounts of 

naturally occurring hydrocarbons, or they can be 

anti-oxidants or detergents with amine groups added 

to the fuel, such as Anti-oxidant No. 22 (N, N’-DiSec-Butyl-P-Phenylenediamine). To determine the 

conversion products of nitrogen-containing 

hydrocarbons, 50 ppm of Anti-oxidant No. 22 was 

added to MCH to observe potential NH3 formation. 

In addition, pyridine was added to a pure fuel to 

observe whether NH3 formation would occur at 

higher concentrations of nitrogen-containing 

hydrocarbons. Figure 4(a) shows FTIR spectra of 

reformed MCH with 10% pyridine added. The 

measured NH3 in the reformate was 414 ppm NH3. 

When 1% pyridine was added to MCH, the reformate 

analysis measured 54 ppm NH3. When 50 ppm of 

the nitrogen containing anti-oxidant was added, no 

NH3 was observed (Figure 4(c)).

Carbon Formation

Carbon formation is recognized to be a potential 

limiter of fuel processor ATR durability. Equilibrium 

calculations can identify proper operating conditions 

to prevent carbon formation; however, during the 

start-up of the fuel processor, avoiding non-zero 

carbon equilibrium is difficult. Laser extinction 

measurements have been conducted to observe 

carbon formation for different fuel components. An 

example of this is shown in Figure 5. The residence 

time of this reactor was short, about 10 msec. As the 

S/C ratio is decreased, carbon formation is detected 

by a decrease in the laser extinction signal, which is 

converted to a mass flow rate of carbon formed. 

Little measurable carbon was formed until 

equilibrium conditions predicted carbon formation. 

Figure 3. FTIR spectra of (a) 5.2 ppm NH3 in N2, (b) 

3.5 ppm NH3 added to MCH reformate, (c) 

reformate from homogeneous partial 

oxidation of MCH showing ethylene and 11 

ppm NH3, and (d) reformate from the 

catalytic partial oxidation of MCH showing 

ethylene and 0 ppm NH3.

Figure 4. FTIR spectra of reformed (a) MCH 

(methylcyclohexane) with 10% pyridine, (b) 

MCH with 1% pyridine, and (c) MCH with 50 

ppm of anti-oxidant.

Figure 5. Equilibrium modeling of carbon formation for 

various fuels and conditions. The dashed 

conditions are potential start-up scenarios, 

depending upon whether water is available 

during reactor start-up.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

346

Aliphatic hydrocarbons such as iso-octane could be 

reformed without significant carbon formation even 

when equilibrium predicted carbon formation. 

However, the addition of aromatic hydrocarbons 

caused significant carbon formation. The addition of 

anti-oxidants to the fuel stream did not make any 

measurable difference in carbon formation.

Figure 6 shows the minimum temperature at 

which the equilibrium concentration of carbon is zero 

as a function of S/C ratio. During start-up, water 

may not be available to suppress carbon formation. 

In this case, lighting off a partial oxidation reactor 

without water could result in large amounts of carbon 

formation. Figure 7 shows the lightoff of a partial 

oxidation reactor with low amounts of water. As the 

temperature approaches normal operating conditions, 

large amounts of carbon are observed via laser 

scattering.

Carbon formation has been observed to occur 

both in the partial oxidation/steam reforming catalyst 

and in the reformate after it exits the catalyst. 

Analysis of carbon formed in the steam reformer 

catalyst found that the carbon was mostly 

carbonaceous carbon with an approximate H/C ratio 

of 0.2 – thus about 97% carbon. Carbon that formed 

in the reformate after it exited the catalyst (probably 

from unconverted hydrocarbons) has been analyzed 

to contain 30% by weight solidified hydrocarbons.

Conclusions

Fuel component effects are being examined to 

determine their effect on hydrogen generation 

technologies. Measurements show that the fuel 

composition does effect the design and operation of 

the fuel reformer, and fuel blends low in aromatic 

content show higher reforming kinetics, which result 

in a reduced fuel processor size (and thus cost). The 

fuel composition effect also effects the relative 

carbon formation, which will effect the fuel 

processor durability. 

Various fuel components and fuels have been 

tested with various O/C and S/C ratios in partial 

oxidation/steam reforming reactors. The addition of 

aromatics slows the overall reaction rate for catalytic 

oxidation. Real fuels have similar oxidation rates at 

high O/C compared with iso-octane, but lower 

oxidation rates at O/C < 1.0. 

Ammonia formation was not observed at a 

measurable concentration for normal operating 

conditions with expected fuel compositions. Precombustion of fuels lead to the formation of NH3

measured at 11 ppm NH3. Large concentrations of 

nitrogen-containing hydrocarbons lead to higher 

amounts of NH3 formation.

Laser extinction measurements mapping the 

onset of carbon formation have been conducted. 

Carbon formation was quantified by the laser 

extinction measurement. Post analysis of carbon 

formed indicates the method and cause of carbon 

formation lead to different carbonaceous species. 

Figure 6. Mass flow rate of carbon formation for 

various fuel components and component 

blends. O/C = 0.65.

Figure 7. Carbon formation during ATR start-up. 

Reactor was preheated to 250o

C, and started 

up with an O/C=1.0 and S/C = 0.0.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

347

Carbon formed in the steam reformer was mostly 

carbonaceous carbon with an approximate H/C ratio 

of 0.2, while carbon formed downstream from the 

reformer consisted of high amounts of solidified 

hydrocarbons.

Acknowledgments

The authors would like to thank Fred Cornforth 

of Philips Petroleum for supplying the fuels and antioxidants used in this testing.

References

1. Francisco Uribe, Oakridge TN, June 2001 DOE 

Fuel Cells for Transportation Program Review

Presentations/Publications

1. Fuel Effects on Startup for Automotive Fuel Cell 

Systems, Troy A. Semelsberger, Rodney L. 

Borup, Lee F. Brown and Michael A. Inbody, 

AIChE Meeting, Spring 2002, New Orleans, LA, 

Los Alamos National Laboratory publication, 

LAUR-02-1619, March 2002.

2. Fuel Processing for Fuel Cells: Fuel Effects on 

Carbon Formation, Lee Perry, Rod Borup, 

Michael Inbody, Byron Morton, and Troy 

Semelsberger, AIChE Meeting, Spring 2002, 

New Orleans, LA, March 2002.

3. Fuels for Fuel Cells for Transportation 

Applications, Rod Borup, Lee Perry, Mike 

Inbody, Byron Morton, Troy Semelsberger and 

Jose Tafoya, AIChE Meeting, Spring 2002, New 

Orleans, LA, Los Alamos National Laboratory 

publication, LAUR-02-1207, March 2002.

4. Fuel Processing for Fuel Cells: Fuel Effects on 

Carbon Formation, Lee Perry, Rod Borup, 

Michael Inbody, Byron Morton, and Troy 

Semelsberger, AIChE Meeting, Fall 2001, Reno 

NV, Los Alamos National Laboratory 

publication, LAUR-01- 6479, November 2001.

5. Fuel Processing for Fuel Cells: Effects on 

Durability and Carbon Formation, Rod Borup, 

Michael Inbody, Byron Morton, Lee Perry and 

Lee Brown, American Chemical Society, 

Chicago, IL, Los Alamos National Laboratory 

publication, 01-4413, August 2001.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

348

IV.C.11 Sulfur Removal from Reformate

Xiaoping Wang, Theodore Krause (Primary Contact) and Romesh Kumar

Argonne National Laboratory 

9700 South Cass Avenue 

Argonne, IL 60439

(630) 252-4356, fax: (630) 972-4463, e-mail: krause@cmt.anl.gov

DOE Technology Development Manager: Nancy Garland

(202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Adapt proven technologies for on-board fuel processing to be capable of reducing the H2S 

concentration to <1 ppm in reformate.

• Develop new technologies or improve existing technologies to meet the DOE targets for H2S removal: 

(1) H2S concentration of <10 ppb in reformate (FY 2010), (2) a reactor size of <0.06 L/kWe (<0.06 kg/

kWe), and (3) GHSV of 50,000 h-1.

Approach

• Predict the H2S equilibrium partial pressure for candidate adsorbents (metal sulfide-H2S equilibrium) 

and identify candidate materials.

• Synthesize mixed metal oxides consisting of CuO/Cu2O and another first-row transition metal oxide 

based on thermodynamic calculations.

• Conduct experimental studies in a microreactor system to evaluate the H2S concentration in the 

effluent as a function of temperature and the gas composition for candidate mixed metal oxides.

 Accomplishments

• Synthesized various mixed metal oxides consisting of CuO/Cu2O and screened them for H2S uptake in 

a microreactor system.

• Determined that competitive adsorption between H2O and H2S inhibits H2S uptake by these mixed 

metal oxides.

Future Directions

• Work to improve the H2S uptake performance of mixed metal oxides containing predominantly Cu 

oxides.

• Evaluate the use of metal doping to increase the rate of H2S uptake by ZnO.

• Evaluate the impact of using liquid-phase sulfur adsorption on the H2S removal requirements of the 

fuel processor.

• Better define the sulfur removal requirements for the fuel processor based on sulfur tolerance studies 

for the ATR and WGS catalysts.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

349

Introduction

New EPA regulations will significantly lower the 

sulfur content of gasoline from the current average of 

300 ppmw to an average of 30 ppmw with a 

maximum of 80 ppmw by the year 2006. For 

on-board fuel processing for transportation 

applications, reformate produced by autothermal 

reforming of these gasolines will contain 3-8 ppmv 

of H2S. Even at these low concentrations, H2S is 

known to poison many of the catalysts being 

developed for use in the fuel processor and in the fuel 

cell anode for PEMFC systems. For example, an H2S 

concentration of <50 ppb is recommended for 

copper-zinc oxide water-gas shift catalysts. Studies 

have shown that the Pt-anode catalyst in the PEMFC 

is irreversibly poisoned at an H2S concentration as 

low as 50 ppb (Uribe et al. 2002).

Two different approaches are being considered 

for on-board sulfur removal. The first approach 

involves liquid-phase desulfurization of the fuel prior 

to reforming using a nickel-based adsorbent to 

remove organosulfur compounds (Bonville et al. 

2000). While liquid-phase desulfurization can 

significantly reduce the sulfur content of the fuel, it is 

not clear whether the extent of desulfurization 

achieved by this process will meet the requirements 

for the fuel processor and fuel cell stack without 

additional removal of sulfur in the fuel processor. 

The second approach involves gas-phase 

desulfurization of reformate in the fuel processor 

using a metal oxide adsorbent, typically ZnO, to 

remove H2S. Gas-phase desulfurization requires that 

the reforming catalyst be sulfur tolerant at least to the 

concentration of sulfur present in the fuel.

Gas-phase desulfurization using ZnO is the 

approach that we have pursued in past years. ZnO is 

an attractive adsorbent for on-board fuel processing 

because of its favorable sulfidation thermodynamics 

(<1 ppmv). The sulfidation equilibrium for ZnO 

(ZnO + H2S ⇔ ZnS + H2O) is a function of the 

temperature and the ratio of the partial pressure of 

H2O/H2S. To reduce the H2S concentration to 

<0.1 ppmv requires a temperature of 300-350°C 

based on the typical range of H2O concentrations 

present in the reformate (Carter et al. 2001). 

However, it has been observed that although the 

equilibrium becomes more favorable as the 

temperature is lowered, the concentration of H2S in 

the reformate after contacting ZnO actually increases 

with decreasing temperature because of a significant 

decrease in the rate of H2S uptake (Carter et al. 

2001).

We have begun to investigate mixed metal oxide 

systems predominantly based on copper oxide. 

Copper oxides (CuO and Cu2O) have sulfidation 

equilibrium constants among the highest of all metal 

oxides and could potentially achieve sub-ppb 

concentrations of H2S in reformate, as shown in 

Figure 1. Unfortunately, CuO/Cu2O is readily 

reduced to metallic Cu in reformate, which 

significantly reduces the desulfurization efficiency. 

In order to maintain Cu in the +1/+2 oxidation state, 

researchers have focused on combining CuO/Cu2O 

with other metal oxides (Li and FlytzaniStephanopoulos 1997), which is the approach that we 

are investigating.

Approach

Mixed metal oxides consisting of a combination 

of Cu and another first-row transition metal oxide, 

such as Co, Mn, and Ni, were synthesized by various 

techniques, including coprecipitation and glycinenitrate combustion. Some of the mixed metal oxides 

were dispersed on a high-surface-area δ-alumina. 

The H2S uptake of the candidate metal oxides was 

evaluated using a microreactor system with an online gas chromatograph equipped with a flame 

Figure 1. Equilibrium concentration of H2S as a 

function of temperature in the presence of 

20 vol% H2O or H2 for Cu2O, CuO, Cu and 

ZnO.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

350

photometric detector and an on-line H2S analyzer 

equipped with a lead acetate detector. The typical 

experimental protocol involved exposing a sample of 

the mixed metal oxide to four different gas 

compositions (50 ppm H2S/N2, 50 ppm H2S/

reformate [dry], 10 ppm H2S/10%H2O/reformate, 

and 50 ppm H2O/20% H2O/reformate) at 

temperatures ranging from 150 to 550oC using a 

heating rate of 2oC/min. The GHSV was 5,000 h-1. 

The gas composition was varied to study the effect of 

the various components in reformate (H2O, CO, and 

CO2) on the uptake of H2S by the mixed metal oxide.

Results

Figure 2 shows the H2S concentration in the 

effluent from the microreactor for the four different 

gas compositions as a function of temperature for a 

Cu-Co oxide. The H2S concentration in the effluent 

was <1 ppm over a temperature range of 250-450oC 

for the gas composition containing only H2S and N2. 

When the gas composition was changed to a dry 

reformate containing CO, CO2, and H2 in addition to 

N2, an H2S concentration of ~1-2 ppm was observed 

at 330-380oC. At 240-280oC, the H2S concentration 

was ~5 ppm, which is slightly higher than at 

330-380oC; however, it appears that a significant 

portion of the H2S was converted to COS (Figure 3). 

It is not known whether COS is produced by the 

reaction with CO (CO + H2S ⇔ COS + H2) or with 

CO2 (CO2 + H2S ⇔ COS + H2O); however, 

assuming that some of the oxidized Cu or Co is 

reduced to metallic Cu or Co, the CO pathway is 

more probable due to the higher affinity of these 

metals for CO than CO2. The presence of H2O in 

reformate (10 or 20 vol%) resulted in higher H2S 

concentrations in the effluent than in the absence of 

H2O (Figure 2). The observation that the H2S 

concentration in the effluent increased with 

increasing H2O concentration suggests that 

competitive adsorption between H2O and H2S 

inhibits H2S uptake by the oxide. As shown in Figure 

3, the presence of water inhibits the formation of 

COS.

Although H2S uptake data are presented for only 

one Cu-containing composition, i.e., Cu-Co, similar 

behavior has been observed, in terms of the effect of 

H2O and CO/CO2 on H2S uptake, for other Cucontaining oxides investigated.

Conclusions

Although the sulfidation equilibria suggest that 

CuO/Cu2O should be able to reduce the H2S 

concentration in reformate below the 10 ppb DOE 

target, initial screening of various Cu-containing 

mixed metal oxides suggests that competitive 

adsorption between H2O and H2S may inhibit H2S 

uptake. As a consequence, the H2S concentration that 

Figure 2. Concentration of H2S in the effluent as a 

function of temperature for four different gas 

compositions, each containing 50 ppm H2S. 

The adsorbent is a Cu-Co oxide.

Figure 3. Concentration of COS in the effluent as a 

function of temperature for four different gas 

compositions, each containing 50 ppm H2S. 

The adsorbent is a Cu-Co oxide.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

351

is predicted by the sulfidation equilibrium may not be 

achieved. Future work will focus on confirming that 

(1) oxidized Cu can be stabilized in reformate under 

fuel processing conditions, (2) sulfidation is 

occurring at oxidized Cu, and (3) competitive 

adsorption between H2O and H2S inhibits H2S 

uptake.

References

1. F. Uribe, T. Zawodzinski, J. Valerio, G. Bender, 

F. Garzon, A. Saab, T. Rockward P. Adcock, J. 

Xie, and W. Smith, “Fuel Cell Electrode 

Optimization for Operation on Reformate and 

Air,” presented at the DOE Fuel Cells for 

Transportation National Laboratory R&D 

Meeting, May 8-10, 2002, Golden, CO.

2. L.J. Bonville, Jr., C.L. DeGeorges, P.F. Foley, J. 

Garow, R.R. Lesieur, J.L. Reston, Jr., and D.F. 

Szydlowski, U.S. Patent 6,159,256, 2000.

3. J. D. Carter, T. Krause, J. Mawdsley, R. Kumar, 

and Michael Krumpelt, “Sulfur Removal from 

Reformate,” presented at the DOE Fuel Cells for 

Transportation National Laboratory R&D 

Meeting, June 6–8, 2001, Oak Ridge, TN.

4. Z. Li and M. Flytzani-Stephanopoulos, Ind. Eng. 

Chem. Res. 1997, 36, 187-196.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

352

IV.C.12 Nanoscale Water Gas Shift Catalysts

Scott L. Swartz, Ph.D. (Primary Contact)

NexTech Materials, Ltd.

720-I Lakeview Plaza Boulevard

Worthington, OH 43085-4733

(614) 842-6606, fax: (614) 842-6607, e-mail: swartz@nextechmaterials.com

DOE Technology Development Manager: Patrick Davis

(202) 586-8061, fax: (202) 586-9811, e-mail: Patrick.Davis@ee.doe.gov

Main Subcontractors: University of Pennsylvania, Catalyte, LLC, Süd-Chemie, Inc.

Objectives

• Develop synthesis methods for highly active water-gas-shift (WGS) catalysts based on platinum 

supported on nanoscale ceria-based oxides.

• Develop and scale up washcoating process for depositing Pt/ceria catalysts on monolithic supports, 

and demonstrate high WGS activity in monolith-supported catalysts.

• Demonstrate that Pt/ceria catalysts can meet application-specific requirements for the WGS reactors of 

automotive fuel processors, which include: resistance to degradation by exposure to air; ability to 

withstand repeated temperature cycles during operational transients; and stable operation over a wide 

temperature range.

• Demonstrate that DOE technical targets for size, weight and cost of water-gas-shift reactors can be met 

using monolith-supported Pt/ceria catalysts.

Approach

• Use wet-chemical synthesis methods to prepare aqueous suspensions of nanoscale ceria-based oxides 

and to incorporate platinum onto ceria nano-particle surfaces.

• Optimize of catalyst synthesis methods and formulations through extensive micro-reactor testing and 

use of characterization techniques such as temperature programmed reduction and CO chemisorption.

• Collect of long-term micro-reactor test data to assess catalyst deactivation rates, and correlate catalyst 

activity and deactivation rates with catalyst formulation and synthesis methods.

• Collect micro-reactor data at different temperatures and gas compositions to determine kinetics of Pt/

ceria WGS catalysts. Use these kinetic data in a model for estimating the size, weight and cost of 

monolith-supported catalysts for 50-kW scale WGS reactors.

• Modify Pt/ceria catalyst suspensions with surfactants and binders, and washcoat catalysts onto ceramic 

honeycomb monoliths. 

• Conduct extensive sampling of Pt/ceria catalyst powders, pellets, and washcoated monoliths for 

evaluation by Süd-Chemie, HydrogenSource, and other fuel processor developers.

Accomplishments

• A number of highly active and stable Pt/ceria catalyst formulations have been demonstrated, with 

performance sufficient for the automotive fuel processor application.

• A washcoating process has been developed for monoliths with catalyst loadings up to 400 grams per 

liter, and excellent performance has been demonstrated in these monoliths.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

353

• A fundamental understanding of WGS kinetics for Pt/ceria catalyst system has been established, and a 

kinetic model has been developed to allow realistic comparisons of data obtained under different test 

conditions.

• Based on the kinetic model, it is estimated that for a 50-kW scale WGS reactor, CO levels can be 

reduced to less than one percent using a monolith with a weight of less than a kilogram, a volume of 

less than a liter, and a cost of less than $150. 

Future Directions

• This project ends March 31, 2003. Plans for the remainder of the project include scale-up of the 

monolith washcoating process and testing of a 10-kW scale monolith at HydrogenSource.

Introduction

A major technical barrier to commercialization 

of PEM fuel cells in automobiles is the need for a 

fuel processing system to convert liquid fuels, 

including gasoline into a hydrogen-rich gas. The fuel 

processor must be small enough to fit into the 

confined spaces of a vehicle. The system must also 

be able to perform reliably under highly variable 

power loads, be capable of rapid start up, and deliver 

a gas stream containing very low levels of carbon 

monoxide. The water-gas shift (WGS) reactor is a 

critical component of the fuel processor. Its function 

is to reduce carbon monoxide levels to intermediate 

levels, which can then be further reduced in a 

subsequent preferential oxidation step. Commercial 

copper-based WGS catalysts are unsuitable for 

transportation applications because of the tendency 

of the catalysts used in these reactors to degrade 

under the severe conditions encountered in an 

automotive system. 

NexTech Materials is collaborating with the 

University of Pennsylvania, Süd-Chemie, Catalyte, 

HydrogenSource, and McDermott Technology to 

develop catalytic water-gas-shift reactors that meet 

the needs of the automotive PEM fuel cell systems. 

The catalyst being developed is based on nanoscale 

mixtures of ceria-based oxides and uniformly 

incorporated platinum. Compared to existing 

copper-based catalysts, the Pt/ceria system offers 

several advantages: (1) operation at higher 

temperatures (where kinetics are more favorable); (2) 

no need for activation prior to use; (3) no degradation 

upon exposure to air; and (4) availability of 

conventional washcoating technologies for ceriabased catalysts (reduced size and weight, improved 

ruggedness). 

Approach and Results

Results of work performed during the past year 

are summarized below:

Catalyst Characterization and Testing: 

NexTech's micro-reactor was refined to allow 

collection of reliable test data over extended time 

periods. Much of the catalyst testing work focused 

on long-term catalyst performance, to support the 

development of high-activity and stable catalysts. In 

parallel, catalysts were characterized by surface area, 

temperature-programmed reduction (TPR), and CO 

chemisorption methods. The results suggest that 

optimization of platinum dispersion (as measured by 

CO chemisorption) is important to achieving high 

activity and suppressing deactivation. Reducibility 

of the precious metal (as measured by TPR) does not 

appear to be related to WGS activity.

Formulation Development: Improvements in 

WGS performance were achieved by optimizing the 

ceria composition, synthesis processes for the 

nanoscale ceria support, and platinum incorporation 

methods. Long-term micro-reactor test results 

suggest that proper synthesis conditions are required 

to produce highly active and stable catalysts (Figures 

1 and 2). Low de-activation rates were achieved by 

modifying the ceria support composition and by 

optimizing the precious metal dispersion. Pt/ceria 

catalysts can be regenerated by heating in air (Figure 

3).

Monolith Washcoating and Testing: A process 

was developed for applying Pt/ceria catalyst coatings 

onto ceramic honeycomb monoliths (see Figure 4), 

and high catalyst loadings (>350 grams per liter) 

were achieved. Results obtained at Süd-Chemie 

indicate that these monoliths provide exceptional 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

354

performance (Figure 5). The construction and 

commissioning of NexTech's WGS monolith-testing 

reactor also was completed, with design support 

provided by Catalyte. 

Size/Weight/Cost Modeling: A kinetic model 

was established for estimating the size, weight and 

cost of monolith reactors with washcoated Pt/ceria 

catalysts, using Arrhenius data obtained from microreactor tests. A reaction rate expression for Pt/ceria 

catalysts was derived from kinetic data, which was 

used to estimate the amount of catalyst required to 

achieve equilibrium conversions at a given 

temperature for any input reformate gas composition. 

This model (Figures 6 and 7) suggests that a WGS 

monolith reactor scaled to 50 kilowatts will have a 

volume of less than 1 liter, a weight of less than 1 

kilogram, and a cost of less than $150. This reactor 

will operate at 350oC and will provide an exit CO 

content of less than 0.9 percent. 

Conclusions

• Pt/ceria water-gas-shift catalysts are 

sufficiently active and offer a number of 

Figure 1. Comparison of temperature dependence of Pt/

ceria and commercial (Cu/ZnO) catalysts.

Figure 2. Comparison of long-term performance of Pt/

ceria and commercial (Cu/ZnO) catalysts at 

300oC.

Figure 3. CO conversion versus time at 300oC for a Pt/

ceria catalyst sample, before and after 

regeneration by annealing in air at 375oC.

Figure 4. SEM micrograph of a washcoated Pt/ceria 

catalyst layer on a cordierite monolith.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

355

practical advantages for automotive fuel 

processors for PEM fuel cell systems. 

• Pt/ceria catalysts are substantially more 

active than commercially available copperbased catalysts at temperatures above about 

270oC.

• Careful synthesis and processing is required 

to minimize long-term de-activation of Pt/

ceria catalysts. Regeneration of deactivated 

catalysts can be achieved by heating in air.

• Washcoating of monoliths with Pt/ceria 

catalysts provides a viable path for achieving 

rugged and volumetrically efficient 

packaging of catalysts in WGS reactors of 

automotive fuel processors. 

• Based on current performance levels, 

modeling suggests that a WGS reactor based 

on monoliths loaded with Pt/ceria catalysts 

will exceed DOE technical targets for reactor 

volume and weight. The reactor cost will be 

less than $3.00 per kilowatt.

Figure 5. WGS performance of a Pt/ceria monolith 

Figure 7. Estimated cost and platinum content of a 

WGS monolith washcoated with Pt/ceria 

catalysts.

Figure 6. Estimated weight and volume of a WGS 

monolith washcoated with Pt/ceria catalysts.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

356

IV.C.13 Water-Gas Shift Catalysis

Deborah J. Myers (Primary Contact), John F. Krebs, Sara Yu, Michael Krumpelt 

Argonne National Laboratory, Argonne, IL 60439-4837

(630) 252-4261, fax: (630) 252-4176, e-mail: Myers@cmt.anl.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov 

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Develop water-gas shift catalysts that:

- Meet the DOE goals of 90% CO conversion, 

- 99% selectivity, 30,000 hr-1 gas hourly space velocity (GHSV), <$1/kilowatt electric (kWe)

- Eliminate the need for careful in situ catalyst activation

- Are tolerant to temperature excursions

- Have operating lifetimes of >5000 hours

Approach

• Develop metal-support combinations to promote bifunctional mechanism of catalyst action:

- One component to adsorb carbon monoxide (CO), e.g., metal with intermediate CO adsorption 

strength

- Another component to adsorb and dissociate water (H2O), e.g., oxides with redox properties or 

oxygen vacancies under reformate conditions

Accomplishments

• Fabricated copper/mixed oxide catalyst as extrudates with no loss in activity

• Demonstrated <1% CO at 20,000 per hour) with Cu/mixed oxide vs 16,000 hr-1 for iron oxidechromium oxide + copper/zinc oxide (Fe-Cr + Cu/ZnO)

• Determined sulfur tolerance of copper (Cu)/mixed oxide catalyst; catalyst loses all WGS activity after 

45 hours on 4.5 ppm hydrogen sulfide (H2S)

• Improved activity of ruthenium (Ru) and Co catalysts while suppressing methanation by using a 

promoter

Future Directions

• Demonstrate <1% CO out at 30,000 hr-1 using a structured non-precious metal catalyst

• Determine lifetime and durability of catalysts under actual reformate conditions

• Improve low-temperature activity (<300°C) of catalysts to >50 μmoles CO/sec-g catalyst (currently 11 

at 230°C)

• Develop a catalyst that is tolerant to 3-4 parts per million volume (ppmv) H2S in reformate
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

357

Introduction

The water-gas shift (WGS) reaction, 

CO + H2O CO2 + H2,

is used to convert the bulk of CO in the raw 

reformate to carbon dioxide (CO2) and additional 

hydrogen (H2). In the chemical process industry, 

e.g., in the manufacture of ammonia, the shift 

reaction is conducted at two distinct temperatures. 

The high-temperature shift (HTS) is carried out at 

350-450°C using an iron-chrome (Fe-Cr) catalyst. 

The low-temperature shift (LTS) is carried out at 

160-250°C with the aid of a copper/zinc oxide 

catalyst (Cu/ZnO).

The commercial HTS and LTS catalysts require 

activation by careful pre-reduction in situ and, once 

activated, lose activity very rapidly if they are 

exposed to air. Further, the HTS catalyst is inactive at 

temperatures <300°C, while the LTS catalyst 

degrades if heated to temperatures >250°C. The 

automotive application, because of its highly 

intermittent duty cycle, requires alternative water-gas 

shift catalysts that (1) eliminate the need to sequester 

the catalyst during system shutdown; (2) eliminate 

the need to activate the catalyst in situ; (3) increase 

tolerance to temperature excursions; and (4) reduce 

the size and weight of the shift reactors. Another 

desirable property for an automotive WGS catalyst is 

tolerance to ppm levels of sulfur in the feed stream 

because sulfur species are present as contaminants or 

additives in conventional fuels (30 parts per million 

weight [ppmw] in future gasoline gets converted to 3 

ppmv H2S in reformate).

Approach

We are investigating bifunctional catalysts in 

which one component of the catalyst adsorbs or 

oxidizes CO and the other component dissociates 

water. Our present research is focusing on metalsupport combinations to promote this bifunctional 

mechanism. The metallic component is chosen to 

adsorb CO at intermediate adsorption strengths 

(platinum [Pt], Ru, palladium [Pd], PtRu, PtCu, 

cobalt [Co], ruthenium [Ru], silver [Ag], iron [Fe], 

copper [Cu], and molybdenum [Mo]). The support is 

chosen to adsorb and dissociate water, typically a 

mixed-valence oxide with redox properties or oxygen 

vacancies under the highly reducing conditions of the 

reformate.

Tests of the candidate catalysts' activities were 

conducted with simulated reformate using a microreactor. The micro-reactor was operated as a 

differential reactor for determining kinetic 

parameters and as an integral reactor for overall CO 

conversions. The concentrations of reactant gases 

were chosen to simulate the composition and 

concentrations of gases exiting an auto-thermal 

reformer ("High CO", dry composition: 10% CO, 

13% CO2, 43% H2, balance diatomic nitrogen [N2]) 

and exiting an HTS stage ("Low CO", dry 

composition: 5% CO, 15% CO2, 45% H2, balance 

N2. A steam-to-dry gas ratio of 0.45 was chosen to 

simulate the additional amount of water necessary to 

cool the autothermal reforming gases to 400°C. 

Sulfur tolerance testing was conducted using 

simulated reformate containing 11% CO, 7.5% CO2, 

45.5% H2, 6 ppmv H2S, balance N2, and a steam-todry gas ratio of 0.45.

Results

Last year a copper/mixed oxide catalyst was 

identified as a potential WGS catalyst with several 

desirable properties. As opposed to copper/zinc 

Figure 1. ANL's copper/mixed oxide catalyst can be 

activated in air rather than dilute hydrogen 

with no loss of WGS activity (within the 

error of the measurement). GHSV = 

200,000 hr-1, "High CO" reformate
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

358

oxide, this catalyst can operate above 260°C without 

loss of activity, does not have to be reduced in situ 

(Figure 1) and does not lose activity upon exposure 

to air up to 300°C (Figure 2). This catalyst also does 

not lose activity upon exposure to water condensate. 

It does lose activity when cooled down to room 

temperature in reformate; however, the activity can 

be regenerated by heating the catalyst to reaction 

temperature in air or to 400°C in reformate (Figure 

3).

A WGS bed composed of the copper/mixed 

oxide catalyst powder was tested for its ability to 

reduce the CO in reformate from an inlet 

concentration of 10.2% (dry basis) to an outlet 

concentration of 1% (dry basis). This was 

accomplished in two steps, by first reducing the CO 

concentration to 5% and then to <1%. Figure 4A 

shows that the copper/mixed oxide bed can achieve 

5% CO out (dry basis) at a temperature of 400°C and 

a gas hourly space velocity (GHSV) of 158,000 hr-1

compared with 45,000 hr-1 for the commercial ironchrome catalyst. A dry outlet CO concentration of 

<1% can be achieved by the copper/mixed oxide 

catalyst at a temperature of 322°C and a GHSV of 

23,000 hr-1 compared with 230°C and 25,000 hr-1 for 

the commercial copper/zinc oxide (Figure 4B). The 

temperature of the copper/zinc oxide bed was held at 

230°C in order to avoid the deactivation of the 

catalyst that occurs above 260°C. Therefore, the 

copper/mixed oxide catalyst can achieve an outlet 

Figure 3. ANL's copper/mixed oxide catalyst does not 

lose WGS activity when exposed to water 

condensate in hydrogen/helium and reversibly 

loses activity when cooled to room 

temperature in wet or dry reformate. GHSV = 

200,000 hr-1, "High CO" reformate

Figure 2. ANL's copper/mixed oxide catalyst does not 

lose WGS activity with multiple cycles 

between reformate and air at temperatures up 

to 300°C. GHSV = 200,000 hr-1, "High CO" 

reformate

Figure 4. ANL's copper/mixed oxide catalyst can 

achieve CO conversions from (A) 10.2% in to 

<5% out at 400°C and 158,000 hr-1 (vs 45,000 

hr-1 for Fe-Cr) and (B) 5% in to <1% out at 

322°C and 23,000 hr-1 (vs 25,000 hr-1 at 

230°C for Cu/ZnO).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

359

CO concentration of <1% (90% conversion) at an 

overall GHSV of 20,000 hr-1 whereas a combination 

of iron-chrome and copper/zinc oxide requires a 

lower GHSV of 16,000 hr-1.

The higher GHSV that can be achieved with the 

Argonne National Laboratory (ANL) copper/mixed 

oxide translates into a 20% reduction in the WGS 

catalyst volume compared with the commercial 

catalysts. The projected size, weight, and cost of 

copper/mixed oxide catalyst for an automotive fuel 

processor are 0.15 liter/kilowatt electric (L/kWe), 

0.14 kg/kWe, and $0.9/kWe. The projected size and 

weight fall short of the DOE goals. Iprovements are 

needed in the catalyst's activity. Improvements are 

also needed in the sulfur tolerance of the catalyst, as 

it showed total deactivation after 45 hours on a 

stream of 4.5 ppmv H2S in reformate.

We improved the WGS activity of cobalt- and 

ruthenium-based catalysts while suppressing the 

methanation activity by adding a promoter. As 

shown in Figures 5 and 6, these catalysts are more 

active than commercial iron-chrome at temperatures 

>300°C. Our results indicate that the cobalt and 

ruthenium catalysts would be suitable replacements 

for iron-chrome as an HTS catalyst.

Conclusions

We further developed a temperature-stable 

copper/mixed oxide catalyst by fabricating it in a 

structured form that has the same activity as the 

powder. This catalyst can be activated in air and 

does not lose activity after exposure to air at 

temperatures up to 300°C. The ANL copper/mixed 

oxide catalyst has the potential to reduce the volume 

of the WGS reactor by 20% compared with the 

commercial catalysts. The copper catalyst showed 

susceptibility to poisoning by H2S in the reformate 

feed. We have also developed cobalt and ruthenium 

catalysts with higher activity than commercial ironchrome (325-400°C) by using a promoter to suppress 

methane formation.

FY 2002 Publications/Presentations

1. D. J. Myers, J. F. Krebs, J. D. Carter, R. Kumar, 

and M. Krumpelt, "Metal/Ceria Water-Gas Shift 

Catalysts for Automotive Polymer Electrolyte 

Fuel Cell Systems," Presentation, Abstract, and 

Presentation Record, American Institute of 

Chemical Engineers, 2002 Spring Meeting, Fuel 

Processing Session III, New Orleans, LA, March 

10-14, 2002.

2. D. J. Myers, J. F. Krebs, J. D. Carter, R. Kumar, 

and M. Krumpelt, "Metal/Ceria Water-Gas Shift 

Catalysts for Automotive Polymer Electrolyte 

Fuel Cell Systems," Presentation and Preprint, 

224th American Chemical Society Fall National 

Meeting, Boston, MA, August 18-22, 2002.

Figure 6. The addition of a promoter (P) to ANL's 

cobalt/oxide catalyst improves its WGS 

activity at temperatures below 350°C to give 

it higher activity than commercial ironchrome (Fe-Cr). GHSV = 30,000 hr-1, "High 

CO" reformate 

Figure 5. The addition of a promoter (P) to ANL's 

ruthenium/mixed oxide catalyst diminishes 

the conversion of CO to methane while 

maintaining WGS activity higher than 

commercial iron-chrome (Fe-Cr). GHSV = 

30,000 hr-1, "High CO" reformate
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

360

IV.C.14 Transition Metal Carbide Water Gas Shift Catalysts

Levi Thompson (Primary Contact)

University of Michigan

Department of Chemical Engineering

3026 H.H. Dow Building

Ann Arbor, MI 48109-2136

(734) 647-7150, fax: (734) 763-0459, e-mail: ltt@umich.edu

DOE Technology Development Manager: Nancy Garland

(202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

ANL Technical Advisor: William Swift

(630) 252-5964, fax: (630) 972-4473, e-mail: swift@cmt.anl.gov

Subcontractors: Süd Chemie, Louisville, KY; Catalyte LLC, Arlington, MA; Union Miniere Inc., New 

Brunswick, NJ 

Objectives 

The objective of the project is to demonstrate water gas shift (WGS) catalysts with:

• Rates in the absence of sulfur that are twice those for Cu-based shift catalysts,

• Activities in the presence of sulfur that are >85% of activities in the absence of sulfur,

• Projected stabilities and durabilities that are compatible for use in automobiles, and

• Costs that are competitive with Cu-based catalysts.

Approach

Tasks devised to accomplish the program objectives included:

• Develop monolith washcoat procedure.

• Optimize carbide formulation, microstructure and pretreatment.

• Fabricate prototype catalyst.

• Evaluate and model catalyst performance.

• Demonstrate performance in prototype fuel processor.

• Access commercial potential.

Accomplishments

• Methods were demonstrated to washcoat the carbide catalysts onto cordierite monoliths and ceramic 

foams. The adhesion of the carbides to the substrates was very good.

• Our best performing carbide catalysts outperformed the commercial Cu-Zn-Al catalyst by a factor of 

more than 2. Ninety percent CO conversion was achieved with an hourly space velocity in excess of 

70,000 hr-1, exceeding the present DOE WGS catalyst performance target.

Future Directions

• Evaluate carbide catalysts in the presence of sulfur.

• Produce >1 kg of catalyst for prototype work and third-party testing.

• Produce monolith supported prototype catalysts.

• Assess cost competitiveness via evaluations by an established fuel processor developer.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Introduction

Fuel cells are being developed to enable the 

commercialization of cleaner, more fuel efficient 

vehicles. The fuel cell technology favored by many 

vehicle manufacturers is proton exchange membrane 

(PEM) cells operating with H2 from hydrocarbon 

steam reforming and/or partial oxidation. The water 

gas shift (WGS) is a critical step during fuel 

processing, and the associated reactor constitutes 

about a third of the mass, volume and cost of the fuel 

processor. While presently available catalysts work 

well in industrial petroleum refining and chemical 

plants, significantly improved catalysts are required 

to meet the transient operation and size constraints 

imposed by vehicular applications. Rather than 

seeking incremental improvements through the 

modification of existing formulations (e.g., Fe-Cr 

and Cu-Zn catalysts), we are developing new WGS 

catalysts based on transition metal carbides. 

Significant reductions in the WGS reactor size and 

cost are anticipated as a consequence of high 

activities, durabilities and sulfur tolerance.

The focus of Phase II of this project is to 

optimize formulations for the carbide catalysts and 

produce monolith supported prototype catalysts that 

substantially out-perform the commercial catalysts. 

In addition, we will evaluate the cost competitiveness 

of the monolith supported carbide catalysts. The 

performance of new monolith supported catalysts 

demonstrated in this effort will be confirmed by 

independent evaluations by established fuel 

processor developers.

Approach

The carbide catalysts were synthesized and 

washcoated onto substrates using a proprietary 

method. Water gas shift rates and product 

selectivities for the carbide powders were measured 

in a plug flow reactor using a feed gas that simulates 

the exhaust from the partial oxidation of gasoline. 

The individual gas phase constituents were delivered 

by mass flow controllers, and H2O was added by 

bubbling the dry gas mixture through a heated 

saturator vessel. The CO was passed through a bed 

of alumina to remove any carbonyls. The resulting 

reactant contained 38.6% H2, 15.9% N2, 5.7% CO, 

6.3% CO2, and 30.0% deionized H2O. The WGS 

rates were measured at 175-240°C and atmospheric 

pressure with CO conversions that typically ranged 

up to 30%. Prior to the rate measurements, the 

catalyst bed was pretreated either in H2 or a mixture 

of 15% CH4 in H2 for 4 hours at 400-590°C.

Results

The reaction rates reached steady-state after 

approximately three hours on-stream and were 

reproducible to within 10% during subsequent runs. 

Small amounts of methane were produced over some 

catalysts; however, there was no evidence of 

methanation activity at steady-state.

The performance of selected catalysts that were 

pretreated at 450°C in the CH4/H2 mixture is 

illustrated in Figure 1 (the Cu-Zn-Al catalyst was 

pretreated at 200°C in a mixture of 2% H2 in N2 for 4 

hours as recommended by the manufacturer). 

Several of the formulations substantially 

outperformed the commercial Cu-Zn-Al catalyst.

The performance of the carbide catalysts was a 

function of the pretreatment conditions employed. 

For example, pretreatment in the CH4/H2 mixture 

typically resulted in catalysts that were more active 

than those same catalysts pretreated in pure H2 

(Figure 2). For some materials, increasing the 

pretreatment temperature also resulted in significant 

improvements in the performance. The improved 

activities appear to be linked to the production of 

Figure 1. Comparison of Reaction Rates for the Carbide 

and Cu-Zn-Al Catalysts
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

362

additional carbide sites based on the results of in situ

x-ray photoelectron spectroscopic characterization.

We recently compared characteristics of the 

carbide catalysts to the DOE targets. As one can see 

from Table 1, the performance of one of our best 

catalysts, UM-3, exceeded important DOE targets.

We demonstrated that the carbide catalysts could 

be washcoated onto cordierite monoliths and ceramic 

foams. Details regarding the methods are 

proprietary and were not disclosed. Examples of the 

monolith and foam supported catalysts are illustrated 

in Figures 3 and 4.

Characteristic Target Cu-Zn-Al UM-3

GHSV (hr-1) 30,000 30,800 >70,000

CO Conversion (%) >90 76 89

H2 Selectivity (%) >99 >99 >99

Volume (L/kWe) <0.1

Weight (kg/kWe) <0.1

Durability (Hrs.) 5000

Cost ($/kWe) <1

*Rates measured at 240°C. The equilibrium CO conversion 

under these conditions is 96.5%.

Table 1. Progress Against DOE Performance Targets*

Figure 2. Effects of Pretreatment Gas and Temperature 

on Rates for the Carbide Catalysts

Figure 3. Carbide Washcoated Cordierite Monolith

Figure 4. Carbide Washcoated Ceramic Foam
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

363

Conclusions/Future Work

The carbides have been demonstrated to be 

highly active WGS catalysts and are able to be 

washcoated onto monolith and foam substrates. To 

further differentiate the carbide catalysts and enhance 

their commercial potential, we will demonstrate that 

they are:

• more durable than the Cu-Zn-Al catalysts 

that are used commercially,

• much more tolerant to sulfur than other types 

of WGS catalysts, and

• cost effective.

Future work will focus on producing larger 

quantities (>1 kg) of the most active carbide 

catalysts, preparing and evaluating monolith 

supported prototype catalysts, and determining the 

cost competitiveness of the catalysts.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

364

IV.C.15 Development of Novel Water-Gas-Shift Membrane Reactor 

W.S. Winston Ho (Primary Contact)

Department of Chemical Engineering

The Ohio State University

140 West 19th Avenue

Columbus, OH 43210-1180

(614) 292-7907, fax: (614) 292-3769, e-mail: ho@che.eng.ohio-state.edu

DOE Technology Development Manager: Nancy Garland

(202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

ANL Technical Advisor: Thomas G. Benjamin

(630) 252-1632, fax: (630) 252-4176, e-mail: benjamin@cmt.anl.gov

Objectives

• Develop a mathematical model for the novel water-gas-shift (WGS) membrane reactor with a carbon 

dioxide (CO2)-selective membrane to elucidate the effects of system parameters on the reactor and to 

show the feasibility of achieving hydrogen (H2) enhancement via CO2 removal and carbon monoxide 

(CO) reduction to 10 parts per million (ppm) or lower from the modeling study.

• Synthesize CO2-selective membranes for the reactor.

• Develop the membrane reactor for achieving H2 enhancement and <10 ppm CO.

Approach

• Develop a non-isothermal model for the novel WGS membrane reactor by taking material and energy 

balances and reaction into account.

• Use the model to study the effects of system parameters on the reactor, to carry out the technical 

analysis of the reactor for synthesis gases from steam reforming and autothermal reforming, and to 

guide/minimize experimental work.

• Synthesize and characterize of CO2-selective membranes containing amino groups.

• Incorporate the membrane synthesized in the reactor to demonstrate H2 enhancement via CO2 removal 

and CO reduction to 10 ppm or lower.

Accomplishments

• Developed a one-dimensional non-isothermal model for the novel WGS membrane reactor with a 

CO2-selective membrane in the hollow-fiber configuration using air as the sweep gas. 

• Elucidated the effects of system parameters on the membrane reactor for synthesis gases from steam 

reforming and autothermal reforming.

• Showed the feasibility of achieving H2 enhancement via CO2 removal and CO reduction to 10 ppm or 

lower based on the modeling study.

Future Directions

• Analyze the effects of feed pressure on the membrane reactor for synthesis gases from steam reforming 

and autothermal reforming.

• Synthesize and characterize CO2-selective membranes for the reactor.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

365

• Conduct the proof-of-concept demonstration using the laboratory membrane reactor. 

• Carry out the prototype membrane reactor demonstration for a 50 kilowatt (kW) fuel cell.

Introduction

A WGS reactor for the conversion of carbon 

monoxide and water to hydrogen and carbon dioxide 

is widely used in chemical and petroleum industries. 

The reactor is also critically needed for the 

conversion of fuels, including gasoline, diesel, 

methanol, ethanol, natural gas, and coal, to hydrogen 

for fuel cells. Since the WGS reaction is reversible, 

the reaction is not efficient, resulting in a high 

concentration of unconverted CO (about 1%) in the 

H2 product and a bulky, heavy reactor. 

The WGS reaction can be enhanced significantly 

through a CO2-selective membrane, which removes 

the reaction product, CO2, in order to beat the 

reaction equilibrium and shift the reaction towards 

the product side. The CO2-selective WGS 

membrane reactor has advantages including (1) a 

high-purity H2 product is recovered at the high 

pressure (feed gas pressure) and (2) air can be used as 

the sweep gas to remove the permeate, CO2, on the 

low-pressure side of the membrane to have a high 

driving force for the separation. These advantages 

are especially important for fuel cell vehicles. The 

first advantage eliminates the need for an unwanted 

compressor. With the second advantage, the high 

driving force created by the air sweep can result in 

low CO concentration and high H2 purity and 

recovery.

We have developed a mathematical model for the 

countercurrent WGS membrane reactor with a CO2-

selective membrane in the hollow-fiber configuration 

using air as the sweep gas. With this model, we have 

elucidated the effects of system parameters on the 

novel WGS membrane reactor for synthesis gases 

from steam reforming and autothermal reforming. 

The modeling results show that H2 enhancement via 

CO2 removal and CO reduction to 10 ppm or lower 

are achievable. For comparison and the 

completeness of the modeling work, we have also 

developed a similar model for the cocurrent WGS 

membrane reactor. 

Results

Development of Mathematical Model

We have developed a one-dimensional nonisothermal model for the countercurrent WGS 

membrane reactor with a CO2-selective membrane in 

the hollow-fiber configuration using air as the sweep 

gas. Figure 1 shows the schematic of each hollowfiber membrane with catalyst particles in the reactor. 

The modeling study of the membrane reactor is based 

on: (1) the CO2 / H2 selectivity and CO2 permeance 

reported by Ho [1, 2] and (2) low-temperature WGS 

reaction kinetics for the commercial catalyst copper 

oxide, zinc oxide, aluminum oxide (CuO/ZnO/

Al2O3) reported by Moe [3] and others [4]. In this 

modeling study, the model that we have developed 

has taken into account critical system parameters 

including temperature, pressure, feed gas flow rate, 

sweep gas (air) flow rate, CO2 permeance, CO2 /H2

selectivity, CO concentration, CO conversion, H2

purity, H2 recovery, CO2 concentration, membrane 

area, water (H2O)/CO ratio, and reaction 

equilibrium. 

For a 50 kW fuel cell system, two types of 

synthesis gases, one from the steam reforming of 

methane and the other from the autothermal 

reforming of gasoline with air, have been considered. 

The syngas from steam-reforming of methane 

consists of 18.63% CO (theoretical maximum value), 

58.23% H2, 0.78% CO2, and 22.36% water (24% 

CO, 75% H2, and 1% CO2 on a dry basis). The 

syngas from autothermal reforming of gasoline with 

air consists of 18.63% CO (maximum), 20.96% H2, 

Figure 1. Schematic of a Countercurrent CO2 Selective 

Membrane Reactor Containing Catalyst 

Particles
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

366

0.78% CO2, 37.27% diatomic nitrogen (N2), and 

22.36% water (24% CO, 27% H2, 1% CO2, and 48% 

N2 on a dry basis). 

Modeling for Syngas from Steam Reforming of 

Methane

For the syngas at 3 atm from steam reforming of 

methane, the modeling of the membrane reactor 

containing 20,500 hollow fibers was conducted. 

Figure 2 shows the profile of the CO concentration in 

the H2 product in the reactor with an inlet feed 

temperature of 180o

C for a total reactor length of 61 

centimeters (24 inches). The syngas flow on the 

high-pressure side of the membrane (3 atmospheres 

[atm]) was countercurrent to the flow of air sweep at 

1 atm on the low-pressure permeate side of the 

membrane (with 22oC inlet air). The molar flow rate 

ratio of the air sweep to the syngas was 0.75. As 

shown in this figure, the CO concentration in the H2

product at the exit of the reactor was 7.8 ppm, which 

was better than the desired concentration of 10 ppm 

for fuel cells. The H2 recovery was very good at 

90.3%. A CO conversion of 99.997% was achieved.

Figure 3 depicts the profiles of the H2 mole 

fraction in the H2 product both on a dry basis and on 

a wet basis in the same membrane reactor. A high H2

concentration of 99.99% on a dry basis resulted in 

the H2 product, which was significantly higher than 

the original concentration of 75% in the syngas. In 

other words, the novel membrane reactor has given 

not only significant H2 enhancement but also a H2

product with a CO concentration of less than 10 ppm.

For the same membrane reactor, the effects of 

inlet feed temperature and sweep-to-feed molar ratio 

on CO and CO2 concentrations and H2 recovery were 

studied. For the inlet feed temperatures ranging from 

160o

C to 220oC at a sweep-to-feed molar ratio of 

0.75, the CO concentrations in the H2 product were 

all below 10 ppm, and the H2 recoveries were about 

90%. As the sweep-to-feed molar ratio increased 

from 0.5 to 1.25 at an inlet feed temperature of 

180oC, the CO concentration in the H2 product 

decreased from 12.5 ppm to 2.2 ppm as a result of a 

more favorable equilibrium at a lower outlet feed 

temperature. As shown in Figure 4, the H2 recovery 

decreased significantly as the ratio increased. The 

H2 loss to the sweep gas was a result of the higher H2

driving force created from the higher ratio. 

Figure 3. Profiles of Hydrogen Mole Fractions in the 

Hydrogen Products on Dry and Wet Bases 

Along the Countercurrent Membrane 

Reactors for the Synthesis Gases with (1) 

18.63% CO from Steam Reforming And (2) 

5% CO from Autothermal Reforming

Figure 2. Profiles of Carbon Monoxide Mole Fractions 

in the Hydrogen Products Along the 

Countercurrent Membrane Reactors for the 

Synthesis Gases With (1) 18.63% CO from 

Steam Reforming and (2) 5% CO from 

Autothermal Reforming 
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367

However, the CO2 concentration (~100 ppm) in the 

H2 product hardly changed with either the ratio or the 

inlet feed temperature since the CO2 concentration 

was nearly equivalent to that in the sweep gas. 

Modeling for Syngas from Autothermal Reforming 

of Gasoline with Air

Similarly, significant H2 enhancement and a H2

product with 10 ppm CO or lower were also obtained 

for the synthesis gases at 3 atm from the autothermal 

reforming of gasoline with air containing CO at 

concentrations of 18.63%, 10%, 5%, and 1%. As the 

CO concentration of the feed gas decreased, the 

temperature rise in the membrane reactor due to the 

WGS reaction decreased. At the feed gas CO 

concentration of 5% or lower, there was no 

temperature rise. For the feed gas CO concentration 

of 5% (5% CO, 37% H2, 11% CO2, 33.5% N2, and 

13.5% water), Figure 2 illustrates the profile of the 

CO concentration in the H2 product for the reactor 

containing 20,000 hollow fibers with an inlet feed 

temperature of 180o

C. The molar flow rate ratio of 

the air sweep to the syngas was 1. As shown in this 

figure, the CO concentration in the H2 product at the 

exit of the reactor was 7.7 ppm. The H2 recovery 

was excellent at 98.4%.

Figure 3 depicts the profiles of the H2 mole 

fraction in the H2 product both on a dry basis and on 

a wet basis in the same membrane reactor. A H2

concentration of 55.22% on a dry basis resulted in 

the H2 product, which was significantly higher than 

the original concentration of 42.8% in the syngas. 

Comparison with Cocurrent WGS Membrane 

Reactor

For comparison and the completeness of the 

modeling work, we have also developed a similar 

model for the cocurrent WGS membrane reactor. 

Figure 5 illustrates the comparison between the 

cocurrent and countercurrent WGS membrane 

reactors in terms of the profiles of CO mole fractions 

in the H2 products along the reactors under the same 

conditions. As shown in this figure, the CO 

concentration in the H2 product was 7.8 ppm for the 

countercurrent reactor whereas that was 0.77% 

(7,700 ppm) for the cocurrent reactor. Thus, the 

countercurrent reactor was much more effective than 

the cocurrent one. Future work will be on the 

countercurrent reactor only. 

Conclusions

We have developed a one-dimensional nonisothermal model for the countercurrent WGS 

membrane reactor with a CO2-selective membrane in 

the hollow-fiber configuration using air as the sweep 

gas. With this model, we have elucidated the effects 

of system parameters, including feed CO 

concentration, feed temperature, and sweep-to-feed 

molar ratio, on the reactor for synthesis gases from 

steam reforming and autothermal reforming. The 

Figure 4. Effect of Sweep-To-Feed Molar Flow Rate 

Ratio on Hydrogen Recovery for the 

Countercurrent Membrane Reactor With the 

18.63% CO Syngas From Steam Reforming

Figure 5. Comparison Between Cocurrent And 

Countercurrent Membrane Reactors in Terms 

of the Profiles of Carbon Monoxide Mole 

Fractions in the Hydrogen Products along the 

Reactors 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

368

modeling results have shown that H2 enhancement 

(>99.9% H2 for the steam reforming of methane and 

>49% H2 for the autothermal reforming of gasoline 

with air on a dry basis) via CO2 removal and CO 

reduction to 10 ppm or lower are achievable for both 

synthesis gases investigated. For comparison and the 

completeness of the modeling work, we have also 

developed a similar model for the cocurrent 

membrane reactor. The countercurrent reactor is 

much more effective than the cocurrent one. 

References

1. W. S. Ho, “Membranes Comprising Salts of 

Aminoacids in Hydrophilic Polymers”, U. S. 

Patent 5,611,843 (1997).

2. W. S. Ho, “Membranes Comprising Aminoacid 

Salts in Polyamine Polymers and Blends”, U. S. 

Patent 6,099,621 (2000).

3. J. M. Moe, “Design of Water-Gas-Shift Reactors”, 

Chem. Eng. Progress, 58, 33 (1962).

4. N. E. Amadeo and M. A. Laborde, “Hydrogen 

Production from the Low-Temperature WaterGas-Shift Reaction: Kinetics and Simulation of 

the Industrial Reactor”, Int. J. Hydrogen Energy, 

20 (12), 949 (1995).

FY 2002 Presentations/Publications

1. Louei El-Azzami and W.S. Winston Ho, 

“Modeling of Water-Gas-Shift Membrane 

Reactors with a CO2-Selective Membrane for 

Fuel Cells”, AIChE Annual Meeting, Reno, NV, 

November 4 – 9, 2001.

2. W.S. Winston Ho, “Engineering Membranes for 

Environmental and Energy Applications”, Invited 

Talk at the Ohio State University, Columbus, OH, 

March 14, 2002.

3. W.S. Winston Ho, “Engineering Membranes for 

Environmental and Energy Applications”, Invited 

Talk at the Colorado State University, Fort 

Collins, CO, March 29, 2002.

Patent Filed

1. W.S. Winston Ho, “CO2-Selective Membranes 

Containing Amino Groups”, U. S. Patent 

Application Serial No. 10/145,297, filed on May 

14, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.D Fuel Cell Stack Subsystem and Components

IV.D.1 R&D of a 50 kW, High Efficiency, High Power Density, CO-Tolerant 

PEM Fuel Cell Stack System

Tim Rehg (Primary Contact), Nguyen Minh (Program Manager)

Honeywell International

2525 W. 190th Street, MS-36-1-93193

Torrance, CA 90504-6099

(310) 538-7220, fax: (310) 512-3432, e-mail: Timothy.Rehg@ ps.ge.com

DOE Technology Development Manager: Patrick Davis

(202) 586-8061, fax: (202) 586-9811, e-mail: Patrick.Davis@ee.doe.gov

ANL Technical Advisor: William Swift

(630) 252-5964, fax: (630) 972-4473, e-mail: swift@cmt.anl.gov

Objectives

• Research, develop, assemble, and test a 50 kW net polymer electrolyte membrane (PEM) fuel cell 

stack system comprised of a PEM fuel cell stack and the supporting gas, thermal, and water 

management subsystems. The PEM fuel cell stack system will be capable of integration with at least 

one of the fuel processors currently under development by Hydrogen Burner Technology (HBT) and 

Arthur D. Little, Inc.

Approach

This phased program includes the fabrication and testing of three 10-kW subscale PEM fuel cell stacks 

leading up to the final 50 kW system. Stack technology development and system analysis were conducted 

iteratively to identify pertinent technology advances to be incorporated into successive subscale stack 

builds. The final system analysis will define the 50 kW stack and system configuration.

Phase I:

• PEM stack R&D to demonstrate multi-fuel capability and CO tolerance

• PEM stack R&D to advance technologies toward DOE targets

Phase II:

• Subscale integration, electronic control system development, transient characteristics, and durability 

testing

Phase III:

• Testing of the 50 kW PEM fuel cell stack system

• Hardware delivery of 50 kW PEM fuel cell stack system to Argonne National Laboratory

Accomplishments

• Testing of the balance-of-plant with the integrated turbocompressor has been completed.

• A 3rd generation 10-kW class PEM stack with compression molded bipolar plates has been completed 

and tested, and anode stoichiometry of 1.15 has been demonstrated.

• The 50-kW class PEM fuel cell stack has been built and integrated into the brassboard system.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

370

Future Directions

• Conduct performance testing of the 50 kW net PEM fuel cell stack system brassboard at nominal load, 

peak load, and different intermediate partial loads and determine system efficiency.

• Deliver 50 kW net PEM fuel cell stack system brassboard to Argonne National Laboratory at the 

conclusion of the project (07/02).

Introduction

Fuel cell power plants will become viable 

substitutes for the internal combustion engine (ICE) 

in automotive applications only when their benefits 

of increased fuel efficiency and reduced emissions 

are accompanied by performance and cost 

comparable to the ICE. Meeting these requirements 

is a significant technical challenge that requires an 

integrated systems approach. This effort 

encompasses the technical and developmental 

activities required to incorporate innovations 

necessary to develop a 50 kW fuel cell stack system 

to meet the requirements set forth by the DOE. 

Approach and Results

Fuel Cell Stack System

The PEM fuel cell stack system consists of the 

fuel cell stack and supporting gas, thermal and water 

management systems as shown in Figure 1. Overall 

system performance depends on the careful 

integration of these subsystems. The system 

developed under this contract was designed to accept 

reformed gasoline from a fuel processor. 

Development of the fuel processor was not part of 

this program.

The 50 kW fuel cell stack brassboard system 

design has been completed. The three-dimensional 

layout including six hexagonally shaped stacks can 

be seen in Figure 2. During this reporting period, all 

major components have been procured, and the 

balance of plant has been assembled. A photograph 

of the system is shown in Figure 3. The brassboard 

has been designed for 50 kW electric power output, 

operating at high-efficiency on simulated gasoline 

reformate. It incorporates full integration and 

management of on-board thermal, water and air 

subsystems, and makes use of off-the-shelf 

components to minimize cost and assembly time. 

For air delivery, the fuel cell stack system is 

equipped with a Honeywell turbocompressor 

developed under separate DOE funding (see Figure 

4). The turbocompressor delivers enough air for the 

fuel cell stack system and the fuel processor at an 

Figure 1. PEM Fuel Cell Stack System Diagram

Figure 2. 50 kW Brassboard System Design
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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operating pressure of up to 3 atmospheres at peak 

condition. During this reporting period the balanceof-plant with the integrated turbocompressor and its 

controller has been tested to verify adequate 

performance. Six 10-kW class PEM fuel cell stacks 

have been built using compression molded bipolar 

plates. These stacks have been integrated into the 

balance-of-plant for final system performance 

testing.

10-kW PEM Fuel Cell Stack With Molded 

Bipolar Plates

For the fabrication of the 50-kW PEM fuel cell 

stack, compression-molded composite bipolar plates 

have been employed. These plates are made in a 

single step, which will help to reduce the 

manufacturing cost substantially in the future. 

During this reporting period, Honeywell has received 

final delivery of all molded bipolar plates and has 

completed the assembly and testing of six 10-kW 

size PEM fuel cell stacks. 

In order to test the performance of the 

compression-molded bipolar plates, a 63-cell 

subscale stack was built initially and tested. The 

performance of the subscale stack at the nominal 

power condition is shown in Figure 5. The test 

conditions are described in detail in Table 1. At a 

current density of 0.115 A/cm2

, the stack was able to 

stably operate at an anode stoichiometry of 1.15. The 

single cell voltage at this point was measured at 0.74 

V. This results in slightly higher performance than 

previously seen with machined bipolar plates. 

Figure 3. 50 kW Brassboard System

Figure 4. Honeywell Phase II Turbocompressor

Anode Cathode

Gas Reformate Air

Stoich 1.15 2.15

RH 100% 50%

Temperature 80°C 80°C

Pressure 1.25 atm 1.25 atm

Table 1. Test Conditions for 63-cell PEM FC Stack 

with Molded Composite Bipolar Plates

Figure 5. Performance of 63-cell PEM Fuel Cell Stack 

with Compression Molded Composite Bipolar 

Plates
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

372

After completion of the testing of the 63-cell 

stack, the first 10-kW size stack was built and tested. 

Figure 6 compares the performance of this stack with 

the conceptual design performance and the originally 

predicted performance for the 50-kW brassboard 

system. The results show that the single-cell voltage 

remains slightly below the desired performance for 

the conceptual design, but has improved over the 

predicted brassboard performance for the lower 

power conditions. At the higher power conditions, 

including peak power, the voltage is identical to the 

prediction. In addition, the results show that the stack 

was able to operate at an anode stoichiometry of 1.25 

for all power settings above 12.5 kW. At the nominal 

power setting, the overall pressure drop through the 

anode flowfield of the molded bipolar plates at flows 

below 1.35 stoichiometry is too low to remove liquid 

water. Anode stoichiometry below 1.25 at the 

nominal condition were demonstrated in later testing 

by reducing the anode relative humidity to 50%. 

After successful testing of the first 10-kW size 

stack with molded bipolar plates, five more stacks 

were assembled and tested. Successively, all six 

stacks were integrated into the balance-of-plant, and 

the system is ready for performance testing.

Conclusions

In this reporting period Honeywell has 

completed the assembly and testing of the balanceof-plant with the turbocompressor and fuel cell 

stacks. Our attention is now focussed on the final 

performance testing of the 50 kW brassboard system 

and delivery to Argonne National Laboratories. 

Results from a 63-cell sub-scale PEMFC stack test 

with compression-molded composite bipolar plates 

demonstrated a low anode stoichiometric flow of 

1.15 at nominal conditions. A full size 10-kW PEM 

fuel cell stack demonstrated stable performance at all 

system power points for an anode stoichiometric 

flow of 1.25.

The current projected brassboard system nominal 

efficiency is 45% (assuming 1.25X stoichiometric 

flow of reformate), and the projected power densities 

are ~0.2 kW/kg and ~ 0.15 kW/L, versus the CY 

2002 DOE targets established for this project of 55%, 

0.35 kW/kg and 0.35 kW/L. It should be noted that 

the above numbers include contributions from offthe-shelf components for the brassboard, i.e. 

oversized heat exchangers and valves. The main 

contributers to the loss of efficiency are increased 

flow stoichiometry and parasitic loads. Some of the 

key reasons for increased parasitic loads are 

compressor motor power and increased pressure drop 

for some components (heat exchangers, valves, etc.).

Figure 6. PEM Fuel Cell Stack Performance at 

Different System Operating Points
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.D.2 Development of Comprehensive Computer Models for Simulation of Fuel 

Cell Systems

Hongtan Liu

Department of Mechanical Engineering

University of Miami, Coral Gables, FL 33214

(305) 284-2019, fax: (305) 284-2580, e-mail: hliu@miami.edu

DOE Technology Development Manager: Donna Lee Ho 

(202) 586-8000, fax: (202) 586-9811, e-mail: Donna.Ho@ee.doe.gov

ANL Technical Advisor: William Swift

(630) 252-5964, fax: (630) 972-4473, e-mail: Swift@cmt.anl.gov

Objectives

• Develop comprehensive computer model for Polymer Electrolyte Membrane (PEM) fuel cells.

• Demonstrate the feasibility of unified model approach to eliminate errors due to approximate boundary 

conditions at various interfaces.

• Develop reliable tools for design and optimization of fuel cells, fuel cell stacks, and fuel cell energy 

systems (long-term).

Approach

• Develop general mathematical models valid in different elements of a fuel cell .

• Eliminate boundary conditions at the various interfaces between different elements of a fuel cell.

• Develop models with flexibility, adaptability and different levels of complexity, so that they can be 

used for different purposes. The model must be easy to update and revise to incorporate custom code.

• Develop independent packages (not based on any CFD package) that are economical, robust and highspeed.

Accomplishments

• Demonstrated the feasibility of the unified approach.

• Developed sub-model A: 2D single-phase flow model – down the channel and across the FC 

sandwich.

• Developed sub-model B: 2D single-phase flow model – across the channel and across the FC 

sandwich.

• Developed a 3-D model for hydrogen feed with constant over-potential across the catalyst layer.

• Developed a 2D two-phase flow model with variable over-potential across the catalyst layer.

• Substantially extended and improved the 3-D single phase model, including the variation of overpotential across the catalyst layers.

• Developed a 3-D single-phase model for reformate feed in the anode.

• Developed a preliminary fuel cell stack model.

• Performed systematic experimental tests to calibrate and improve the models.

• Worked closely with industry to customize and improve the models.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Future Plans 

• Further develop the 3-D single-phase model: improve on reformate feed and for different flow fields. 

• Improve the fuel cell stack model. 

• Couple the stack model with a system model.

• Extend the models to other types of fuel cells. 

• Further interactions with industry.

Introduction

A fast, reliable, and specialized CFD model for 

PEM fuel cell simulation can be very useful in fuel 

cell design optimization and operation control. In this 

project, a unified PEM fuel cell simulation model has 

been successfully established. This project started in 

FY 2000 with 2-D single-phase models. In FY 2001, 

the 2-D models were successfully transformed into a 

unified 3-D model for hydrogen feed. In FY 2002, 

this established 3-D model was extended to include 

reformate feed, accounting for the poisonous effect 

of carbon monoxide as well as the dilution effect of 

the reformate gas stream on the anode side. Based on 

this 3-D model with the geometry of a single fuel 

cell, a preliminary stack model was established. 

Extensive experiments in our lab and industry 

interactions were carried out to improve and calibrate 

the computation model. 

Approach

The geometry of a single fuel cell is shown in 

Figure 1. The PEM fuel cell is divided into 9 regions 

according to the material properties and flow 

characteristics. In FY 2000, this project started with 

2-D single-phase models that included 2 sub-models 

[1, 2]. One of the 2-D models has a geometry 

comprised of flow direction and the plane across the 

fuel cell sandwich (on the xy-plane). The other one 

includes the region across the channel and across the 

fuel cell sandwich (on the xz-plane). 

In FY 2001, a general 3-D model was developed 

[3]. This general mathematical model consists of the 

equations of continuity, momentum, energy, and 

species concentrations in different elements of the 

fuel cell sandwich, as well as the equations for phase 

potential in the membrane and the catalyst layer. 

This set of governing equations is coupled with 

chemical reaction kinetics by introducing various 

source terms. The generality of the model lies in its 

independence of chemical kinetic models, since the 

kinetics are incorporated in the source terms. One 

can choose any kinetics model, and any new 

development in the electrochemistry can easily be 

incorporated in this general model. To solve the 

mathematical model, an in-house computer code has 

been developed. Compared with some commercial 

CFD packages, this self-produced code was designed 

for a specific purpose so that the computation time 

could be significantly reduced. The output results 

from this 3-D model include oxygen concentration 

variations in different planes, local current density 

distributions, reaction rate, temperature distributions, 

water vapor distributions along anode and cathode, 

etc. Details about the model and results can be found 

in Zhou and Liu [3]. In FY 2001, a preliminary 2-

phase, 2-D model was also developed [4]. It was 

found that a single-phase model is sufficient when 

the current density is low, when the current density is 

larger and approaching the current density limit, 

phase changing of water becomes significant. 

In FY 2002, the 3-D single-phase model was 

significantly improved in several aspects. 

Specifically, instead of assuming constant 

overpotential across the catalyst layer, the variation 

Figure 1. Single Fuel Cell Geometry
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

375

of over-potential across the catalyst layer was added 

to the model [5]. Figure 2 shows the variation of the 

overpotential within the catalyst layer at different 

current densities. When the current density is low, 

variation of overpotential is not significant, but when 

the current density is high, the overpotential variation 

is significant and cannot be neglected. In order to 

reduce computation time and ensure the accuracy of 

the model, systematic analysis and reductions of the 

model have been conducted, some highlights of 

which can be found in [5]. 

Reformate feed is expected to be the viable 

intermediate fuel for fuel cell applications, and a 

PEM fuel cell operating on reformate gas has unique 

characteristics. Two of the characteristics are the 

dilution effect of the inert gases and the variation of 

hydrogen content at different locations of a fuel cell. 

The third is the poisoning effect of the carbon 

monoxide (CO) present in the reformate. The 

previous 3-D model has been extended and modified 

to account for these extra characteristics. The kinetic 

equations for CO poisoning effects that were 

presented by Springer et al. [6] were used. With those 

adjustments, the 3-D model now can successfully 

demonstrate some features not revealed by 1-D 

kinetic models in the literature [6]. The reduction of 

CO at larger current density due to reaction 

consumption is shown by the CO contours in Figures 

3 and 4. The model results of CO affecting PEM fuel 

cell performance is shown in Figure 5. Figure 6 

shows that the computation results compared very 

well with the test data available from the literature 

[7].

Based on the single fuel cell model, a 

preliminary stack model is set up as shown by Figure 

7. This modeled region includes 5 channels and 3 

cells. Cooling plates were inserted into the stack at an 

interval of 3 cells. (This choice is just used as an 

example.) The model can easily accommodate 

different numbers of cells and channels, and different 

stack designs can also be easily handled. With this 

stack model, computational investigations of the 

temperature distributions were carried out. Some 

sample temperature contours are shown in Figures 8 

Figure 2. Variation of Overpotential Inside the Catalyst 

Layer Figure 3. CO Concentration Along the Flow Direction

Figure 4. CO Concentration Across the Fuel Cell (Half of 

Z Over the Shoulder Plate)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

376

and 9. While the cooling plates and the convection 

along the border cool the fuel cells, some locations of 

the fuel cells inside the stack can experience very 

high temperature. The modeling results can be used 

to devise better ways for fuel cell stack thermal 

management. 

To calibrate the model, extensive experiments 

were conducted in our Fuel Cell Laboratory at the 

University of Miami [8]. Close interaction with the 

fuel cell industry was also carried out.

Conclusions

During the past 3 years, a generalized 3-D PEM 

fuel cell simulation model was developed at the 

University of Miami. This generalized model started 

from the basic fluid flow and electro-chemical 

principles. This generalization makes it easily 

adaptable to include choices of different flow fields, 

different fuel cell materials and flow design, and 

different fuels used. A computation code specifically 

designed for this mathematical model was produced 

and proved accurate and efficient. In FY 2002, the 3-

D model has been significantly improved by adding 

the variation of overpotential across the catalyst 

layer. It was also extended to include the reformate 

feed at the anode. Extension of this single-cell model 

to study various stack design choices has also been 

Figure 5. Polarization Curves at Different CO 

Figure 6. Comparison of Modeling Results With 

Experimental Data for CO Poisoning

Figure 7. Geometry for the Fuel Cell Stack Model

Figure 8. Temperature Contours Across the Flow 

Channels
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

377

proven feasible. The great potential of the models for 

industrial applications has been demonstrated, 

especially through the close collaborations with 

industry partners. Our future research plans include 

extending this generalized 3-D model to other types 

of fuel cells and coupling the stack model to a fuel 

cell system model. 

References

1. Gurau, V., Liu, H.T. and Kakac, S., AIChE, Vol. 

44, pp. 2410-2422, 1998.

2. Kazim, A., Liu, H.T. and Forges, P., J. Applied 

Electrochem., Vol. 29, pp. 1409-1416, 1999.

3. Zhou, T. and Liu, H.T., Int. J. Transport 

Phenomena, Vol. 3 (3), pp. 177-198, 2001.

4. You, L. and Liu, H.T., Int. J. Heat and Mass 

Transfer, Vol. 45, pp. 2277-2287, 2002. 

5. Zhou, T. and H.T. Liu, 6th Biennial Conf. on 

Engineering Systems Design and Analysis, 

Istanbul, Turkey, July 8-11, 2002.

6. Springer, T.E., Rockward, T., Zawodzinski, T.A., 

J. Electrochemi. Soc., Vol.148 (1), pp. A11-A23, 

2001 . 

7. Divisek, J., Oetjen, H.-F., Schmidt, V.M. and 

Stimming, U., Electrochem. Acta., Vol. 43, pp. 

3811-3815, 1998.

8. Wang, L., Husar, A., Zhou, T., and Liu, H., Zhou, 

T, “Parametric Study of PEM Fuel Cell 

Performances,” to be presented at ASME 

Congress, New Orleans, November 17 – 22, 2002. 

FY 2002 Publications and Presentations

1. Zhou, T. and Liu, H.T., “A General Three 

Dimensional Model for PEM Fuel Cells,” in Int. J. 

Transport Phenomena, Vol. 3 (3), pp. 177-198, 

2001.

2. You, L. and Liu, H.T., “A Parametric Study of the 

Cathode Catalyst Layer of PEM Fuel Cells Using 

a Pseudo-Homogeneous Model,” Int. J. Hydrogen 

Energy, Vol. 26, pp. 991-999, 2001.

3. Liu, H.T., Zhou, T. and You, L., “CFD Modeling 

of Proton Exchange Membrane Fuel Cells,” in 

Proc. 9th Annual Conference of the CFD Society 

of Canada, Kitchener, Ontario, Canada, May 27-

29, 2001.

4. Zhou. T. and Liu, H.T., “Numerical Simulation Of 

Performance Of PEM Fuel Cells,” in Proc. of the 

2nd Int. Conference on Computational Heat and 

Mass Transfer, COPPE/UFRJ – Federal 

University of Rio de Janeiro, Brazil, October 22-

26, 2001.

5. You, L. and Liu, H.T., “A Two-Phase Flow And 

Transport Model For The Cathode Of PEM Fuel 

Cells,” Int. J. Heat and Mass Transfer, Vol. 45, 

pp. 2277-2287, 2002. 

6. Zhou, T. and Liu, H.T., “Heat Transfer 

Enhancement in Fuel Cells with Interdigitated 

Flow Field Design,” Int. J. Computer 

Applications in Technology, in publication, 2002.

7. Zhou, T. and Liu, H.T., “Development and 

Simplification of a Three-Dimensional PEM Fuel 

Cell Model,” 6th Biennial Conference on 

Engineering Systems Design and Analysis, 

Istanbul, Turkey, July 8-11, 2002.

8. Zhou, T. and Liu, H.T., “Effects of Heat and Mass 

Transfer Enhancements on PEM Fuel Cell 

Performances,” 12th International Heat Transfer 

Conference, France, August 18-23rd, 2002. 

Figure 9. Temperature Distribution Within the 3 Cells 

Along the Flow Direction
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

378

9. Zhou, T. and Liu, H.T., “Simulation of 

Performance of PEMFC Operated by Reformed 

Gas,” accepted for the 2002 Fuel Cell Seminar, 

Palm Springs, California, November 18-21, 2002.

10. Wang, L., Husar, A., Zhou, T., Liu, H., and Zhou, 

T, “Parametric Study of PEM Fuel Cell 

Performances,” accepted to the ASME Congress, 

New Orleans, November 17 - 22, 2002. 

11. Higier, A., Husar, A., and Liu, H., “Design of a 

Fuel Cell Fixture with Precise Compression 

Control and Preliminary Experimental Results,”

accepted for the 2002 Fuel Cell Seminar, Palm 

Springs, California, November 18-21, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

379

IV.D.3 High Performance, Matching PEM Fuel Cell Components and Integrated 

Pilot Manufacturing Processes

Mark K. Debe (Principal Investigator), Judith B. Hartmann (Primary Contact)

3M Company

3M Center, Building 0201-01-C-30

St. Paul MN 55144-1000

(651) 736-1772, fax: (651) 575-1187, e-mail: jbhartmann@mmm.com

DOE Technology Development Manager: Valri Lightner

(202) 586-0937, fax: (202) 586-3237, e-mail: Valri.Lightner@ee.doe.gov

DOE Technology Development Manager: JoAnn Milliken

(202) 586-2480; fax: (202) 586-9811; e-mail: JoAnn.Milliken@ee.doe.gov

ANL Technical Advisor: Thomas Benjamin

(630) 252-1632, fax: (630) 252-4176, e-mail: benjamin@cmt.anl.gov

Subcontractor: GM - GAPC, Rochester, NY

Objectives

• Develop a set of high performance, matched proton exchange membrane (PEM) fuel cell components 

and pilot manufacturing processes to facilitate high volume, high yield stack production.

• Demonstrate the matched component performance in a 1-kW fuel cell stack.

Approach

• Phase 1 

- Increase surface area of the 3M-patented, nanostructured, thin film catalyst support system 

consistent with high volume manufacturing process.

- Develop anode catalyst compositions and structures with higher reformate tolerance and/or a nonprecious metal replacement for Ru, using a catalyst deposition process that easily generates new 

compositions and structures.

- Investigate binary and ternary catalyst compositions and structures to produce higher activity 

cathodes.

- Develop carbon electrode backing (EB) media, optimized for performance with the catalyst system 

and flow field.

- Optimize the fuel cell flow field design for optimized water management and air bleed utilization 

with the catalyst and EB components.

- Define pilot manufacturing scale-up of the processes for fabrication of catalysts, catalyst coated 

membrane (CCM) assemblies, and electrode backing media.

• Phase 2 

- Optimize pilot scale manufacturing of roll-good fabricated catalyst support films and catalyst 

deposition. 

- Specify membrane electrode assembly (MEA) component parameters and conduct final pilot scale 

runs to generate process statistics. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

380

- Fabricate, test, and deliver a 1-kW stack to subcontractor for evaluation using optimized flow field 

and matched MEAs fabricated by pilot processes.

Accomplishments

• Developed a new Pt ternary cathode catalyst that gives the same performance with one-half the amount 

of Pt, producing 0.4 A/cm2

 at 0.8 V under 30/30 psig H2/air with 0.2 mg/cm2 total precious metal per 

MEA.

• Identified a non-precious metal replacement for Ru on the anode for reformate tolerance, which, with 

air bleed, gives equivalent performances within ±10-20 mV. 

• Integrated multiple process steps for generating the nanostructured catalyst support films into a single 

pass, dry web-coating, pilot plant process. Completed MEA fabrication cost model based on existing 

pilot production process and equipment. 

• Developed a unique flow field design via modeling and basic principles of gas transport that optimizes 

the uniformity of hydrogen and air mass flow velocities for the matched EB media and increases high 

current density performance over conventional designs.

• Developed a roll-good processed electrode backing/gas diffusion layer component having matched 

properties to the nanostructured thin film catalyst and flow field; generated pilot scale production 

quantities for statistical analysis of variance and demonstration of process capability.

Future Directions 

• Complete pilot scale fabrication of multiple lots of roll-good, nanostructured support films, anode and 

cathode catalyst deposition on those substrates, and roll-good CCM fabrication to generate statistical 

process and performance data.

• Complete fuel cell testing of statistically sampled, roll-good fabricated, coated EB materials and 

CCMs having matched properties for optimum performance.

• Complete evaluation of roll-good fabricated MEAs from pilot processed material lots in 1-kW stacks 

at 3M and subcontractor facilities.

Introduction

The membrane electrode assembly (MEA) is the 

core component set of a PEM fuel cell (PEMFC) 

stack. An MEA consists of five basic components: 

anode and cathode catalysts, ion exchange polymer 

membrane, and anode and cathode gas diffusion 

layers. The functions of these basic components are 

intimately related, and their properties must be 

matched for optimum performance. For large-scale 

volume fabrication at the cost and quality targets 

required by transportation applications, very high 

yields and in-line process control of integrated 

processes based on cost effective materials are 

required. This project is directed towards 

demonstrating high performance, matching PEM fuel 

cell components manufacturable by integrated pilot 

processes, utilizing a patented nanostructured thin 

film catalyst support system.

Approach

Our approach to developing high performance, 

matching PEMFC components and integrated pilot 

manufacturing processes has several facets. These 

include optimization of the individual components, 

such as the anode and cathode catalysts and their 

supports, and electrode backing and gas diffusion 

layers, all made by processes consistent with high 

volume manufacturing methods.

For the anode and cathode catalyst development, 

the unique nanostructured support and catalyst 

coating methods offer many combinations of 

materials and process conditions to generate new 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

381

catalyst compositions and structures. The major 

focus areas have been generating higher surface area 

supports, fabricating and testing new PtxMy binary 

and ternary constructions for anodes and cathodes, 

and reducing air bleed - all with goals of increasing 

performance and stability and reducing precious 

metal loading. 

Development of carbon electrode backing (EB) 

media has included evaluation of different types of 

electrode backing materials, coatings, coating 

configurations, and coating processes. Evaluation 

involves measurement of a variety of physical 

properties and of fuel cell performance under a broad 

range of controlled conditions using nominally 

identical catalyst coated membranes (CCMs). 

The flow field is an integral component of the 

MEA system. Matching it to the EB material is 

particularly important in order to obtain uniform gas 

flow velocity and pressure distributions that in turn 

will yield the most uniform current density 

distributions. The gas permeability properties of the 

various electrode backing and gas diffusion layers 

were key inputs for fluid dynamic modeling used to 

devise a unique flow field design that gives 

optimized mass flow uniformity while enhancing 

performance at high current densities and matching 

pressure drop specifications supplied by the 

subcontractor.

Scale-up and integration of the processes for 

producing the nanostructured catalyst support films 

via a single pass, dry web process with on-line 

monitoring has been a major focus during the past 

year to demonstrate process control, determine the 

pilot production equipment limits, increase material 

yields, and reduce costs. The catalyst coating 

processes have also been scaled up to give the 

required cross-web uniformities and apply the new 

multi-element catalysts. A detailed cost model for 

several different final integrated process scenarios 

was developed. 

Results

Cathode Catalysts

In the past year, screening of a wide range of 

binary PtxMy catalysts to find a cathode catalyst with 

greater mass activity and/or stability than pure Pt was 

completed. The process for fabricating the 

nanostructured catalysts allows a wide range of new 

constructions to be easily made and tested.

Figure 1 compares the performance of three 

different Pt binaries and two different Pt ternary 

constructions with the pure Pt cathode catalyst. The 

test uses high-pressure hydrogen/oxygen to best 

reflect the oxygen reduction reactivity of the cathode 

catalysts. As can be seen, all the combinations 

outperform the pure Pt catalyst. All the samples 

contained 0.1 mg/cm2

 of precious metal, except for 

the second ternary, PtAB-2, which contained 0.15 

mg/cm2. PtAB-2 was selected for scale-up during 

Phase 2 and became the focus for 50-cm2

 fuel cell 

testing.

As discussed in Reference 1, it is well 

documented that, with our standard nanostructured 

support particles, the baseline pure Pt catalyst has a 

mass specific surface area of about 7 m2

/g. For our 

standard loadings of 0.22 mg/cm2

, this corresponds 

to an effective surface roughness factor (or SEF, 

surface enhancement factor) of 12-15 cm2

/cm2. 

Figure 2 shows duplicate measurements (Series A, 

Series B) of the SEF for the PtAB-2 ternary catalyst 

at three different loadings compared to the standard 

Pt at 0.22 mg/cm2

. It is seen that the ternary has the 

same surface area with half the amount of Pt as the 

standard pure Pt catalyst. This doubling of the mass 

Figure 1. Comparison of the oxygen reduction activity 

of various binary and ternary catalysts with 

pure Pt, using 30-psig oxygen test conditions 

to enhance the differentiation.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

382

specific surface area to ~ 15 m2/g allows the same 

fuel cell performance to be obtained with half the 

precious metal content.

This is best shown by comparing polarization 

curves for the same MEA, taken in two orientations. 

The first orientation has the PtAB-2 catalyst, with 0.1 

mg/cm2 Pt, as the cathode and the standard Pt 

catalyst, with 0.2 mg/cm2

, as the anode. In the 

second orientation, the hydrogen, air, and voltage 

leads are reversed so the ternary becomes the anode 

and the standard Pt is on the cathode. Figure 3 

compares potentiodynamic (PDS) constant flow 

polarization curves at ambient pressure for these two 

MEA orientations and clearly indicates the improved 

kinetic behavior of the ternary over the standard Pt 

catalyst. 

Figure 4 shows two types of polarization scans 

from an MEA having a total of 0.2 mg Pt/cm2

/MEA. 

This MEA has the same PtAB-2 catalyst on the 

cathode as in Figure 3, but the standard Pt on the 

anode reduced to 0.1 mg/cm2. In Figure 4, the single 

potentiodynamic scan (PDS) polarization curve was 

obtained with constant flow (CF) conditions at 75oC, 

while the lower four galvanodynamic scan (GDS) 

curves were obtained with constant stoichiometric 

flow (CS) conditions and varying humidification at 

80oC. All were obtained with H2/air at 30/30 psig 

inlet pressures. The 30-psig constant flow conditions 

can achieve close to the DOE technical target of 0.4 

A/cm2 at 0.8 V for MEAs on hydrogen/air. This 

performance with this total loading of 0.2 mg/cm2/

MEA of Pt corresponds to the 2005 target of 0.6 g/

kW at 0.8 V and 0.3 g/peak kW of precious metal.

Anode Catalysts

Screening for better or less costly anode catalysts 

is also a major task area. Finding a replacement for 

Figure 2. Comparison of the measured surface area, 

using hydrogen adsorption-desorption cyclic 

voltammetry, from pure Pt and the PtAB-2 

ternary containing varying amounts of Pt.

Figure 3. Comparison of PDS polarization curves from 

a single MEA tested in two orientations, first 

with the PtAB-2 ternary (with 0.1 mg/cm2

 Pt) 

as a cathode and the pure Pt (0.21 mg/cm2

) as 

the anode (5589-223), and second with the 

PtAB-2 as the anode and the pure Pt as the 

cathode (5589-354). The ternary with half 

the amount of Pt outperforms the pure Pt.

Figure 4. PDS-CF and GDS-CS polarization curves at 

30 psig inlet pressure from an MEA having a 

total of 0.2 mg/cm2

/MEA of total precious 

metal (Pt).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

383

Ru was a primary goal, along with reducing the 

amount of Pt required for adequate reformate 

tolerance. To facilitate the rapid screening of many 

new catalyst constructions having different 

compositions and structures, anode over-potential 

(AOP) and AC impedance measurements were used. 

Reference 1 discussed results from two new binary 

anode catalysts containing 0.1 mg/cm2 of Pt and nonprecious metal replacements for Ru, which had less 

AOP than the PtRu control. This past year led to 

development of still another PtM binary, where M is 

a non-precious metal replacement for Ru, which was 

down-selected for scale-up during Phase 2. Figure 5 

compares 75oC, 30 psig, constant flow polarization 

curves under H2/air, reformate with 2% air bleed, 

and reformate with 4% air bleed from an MEA 

having this binary as the anode (0.20 mg/cm2 Pt) and 

a standard Pt cathode (0.21 mg/cm2). There is little 

difference between 2% and 4% air bleed and about a 

35 mV loss compared to pure hydrogen at 0.5 A/cm2. 

The curves suggest the DOE reformate target of 125 

mA/cm2

 at 0.83 V and 9 psig are close to being met, 

but the rated power targets under reformate of 500 

mA/cm2

 at 0.75 V and 30 psig fall short by about 35 

mV.

Roll-Good Electrode Backing Media

The EB materials and configurations 

demonstrating the highest potential for meeting 

project goals were selected for optimization. This 

past year, the work focused on demonstrating the EB/

GDL process capability. Rolls of EB material were 

processed and the EB coatings applied in multiple 

pilot scale coating runs. Two types of on-line 

measurements were successfully used for 

characterization of two key physical properties. All 

lots were characterized off-line as well for these two 

plus a third critical property. All three parameters 

were demonstrated to be in process control. Analysis 

of variance within and between rolls did show some 

statistically significant differences, but total 

variability was small. Fuel cell characterization of 

MEAs having EB/GDL samples taken across all the 

produced rolls are underway using CCMs having 

standard Pt anodes and cathodes. Fuel cell tests of 

EB/GDL media sampled from one 450-lineal-yard 

roll are also underway with CCMs having the new 

PtAB-2 ternary cathode catalyst. This matched 

CCM/EB combination is giving the best performance 

to date and excellent statistical reproducibility, as 

shown in Figure 6. This shows the galvanodynamic, 

constant stoichiometry polarization curves from the 

first seven tested MEAs of 12 statistically sampled 

EB/GDLs from the fully processed 450-lineal-yard 

roll-good.

Flow Field

The flow field and EB/GDL must be matched for 

optimum performance and durability. Designing for 

the most uniform gas flow distributions and effective 

water management should translate into the most 

Figure 5. GDS-CF polarization curves under hydrogen 

and reformate with 2% and 4% air bleed, 

from an MEA having a PtM binary on the 

anode containing no Ru and 0.2 mg/cm2 of 

total precious metal (Pt).

Figure 6. Seven GDS-CS polarization curves of EB/

GDL samples taken from a pilot-scale 

processed 450-lineal-yard roll. The excellent 

reproducibility also reflects uniformity of the 

CCM. The galvanostatic (GSS) current 

density between scans was 0.95 A/cm2

.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

384

uniform current distributions. This year, 

computational fluid dynamics (CFD) modeling at 3M 

has led to a unique flow field design targeted for the 

EB roll-good materials discussed above. This design 

was refined as well to meet the desired in-cell 

pressure drops for the pressure-flow rate curves 

suggested by our subcontractor. Figure 7 shows a 

series of comparison polarization curves from 

different MEAs, each tested first in a cell having a 

commercially available quad-serpentine flow field, 

and then after transferring to a cell having the 

optimized flow field. By design, the gas flow 

distributions should be significantly more uniform in 

our new optimized flow field. As Figure 7 shows, 

there is also better performance in the high current 

density regime, as expected due to the operating 

principle of the new flow field.

Nanostructured Catalyst Process Scale-Up

A key aspect of demonstrating an integrated 

MEA manufacturing process has been development 

of a single pass, dry web coating process for 

generating the nanostructured catalyst support films 

with their catalyst coating. This overall process 

involves several separate sub-processes, which 

previously were done individually. Reduced cost 

and improved yields are greatly facilitated by 

sequentially carrying out these individual process 

steps during a single web coating run. This year 

significant progress was made on demonstrating a 

single pass pilot process with online control of the 

nanostructured support films. Scanning electron 

microscopy (SEM) imaging allows off-line 

characterization of the catalyst coated support films 

to document the nanostructured element feature 

dimensions, number density, and geometric surface 

area as a function of cross-web and down-web 

position. Figure 8 shows SEM cross-sectional and 

plan view images of Pt-coated nanostructured 

features at 50, 125, and 240 ft respectively, downweb of a single pass 250-lineal-ft coating run. The 

nanostructured support whiskers are essentially 

identical both cross-web and down-web. Twelve 

nominally identical coating runs have been 

completed for statistical characterization of this 

integrated process.

Stack Testing

The MEAs fabricated with the matched 

components and integrated manufacturing processes 

are to be evaluated in a 1-kW stack at the 

subcontractor’s facilities. Development of the stack 

with the proprietary flow fields is being done at 3M 

Figure 7. Comparison of PDS-CF polarization curves 

from three MEAs, each evaluated first in the 

standard quad-serpentine flow field, and 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

385

with consultation from the subcontractor. The first 

H2/air tests with 200-cm2

 MEAs incorporating the 

new cathode ternary catalysts and optimized EB/

GDL were started on June 28, 2002, in this first stack 

and currently show excellent cell-to-cell uniformity. 

Conclusions

Significant progress has been made in all aspects 

of the objectives of developing high performance, 

matched PEM fuel cell components and integrated 

pilot manufacturing processes. Results to date 

indicate that, with the new ternary cathode catalyst, 

the potential is good for meeting the project 

performance objectives on hydrogen air in a 1-kW 

stack while exceeding the precious metal loading 

targets. Similarly, the progress on development of 

the integrated manufacturing processes indicates the 

potential for meeting volume and quality objectives. 

Future work includes finishing the generation of 

multiple lots of roll-good fabricated CCM and 

subsequent characterization and fuel cell testing to 

determine the statistical variance of the processes, 

completion of a similar fuel cell evaluation of the 

EB/GDL roll-good media, and completion of the 1-

kW stack development and testing of the pilot 

manufactured MEAs at the subcontractor facilities.

References

1. FY 2001 Progress Report for Fuel Cells for 

Transportation, page 113.

Figure 8. Scanning electron micrographs of the 

nanostructured catalyst support films at 

beginning (50 ft), middle (125 ft) and end 

(240 ft) locations of a 250-lineal-ft pilot scale 

run in which the support films were produced 

in a single pass, dry process.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

386

IV.D.4 Design and Installation of a Pilot Plant for High-Volume Electrode 

Production

James Arps (Primary Contact)

Southwest Research Institute

P.O. Drawer 28510

San Antonio, TX 78228-0510

(210) 522-6588, fax: (210) 522-6220; e-mail: jarps@swri.org

DOE Technology Development Manager: JoAnn Milliken 

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

DOE Technology Development Manager: Valri Lightner

(202) 586-0937, fax: (202) 586-3237, e-mail: Valri.Lightner@ee.doe.gov

ANL Technical Advisor: Thomas Benjamin

(630) 252-1632, fax: (630) 252-4176, e-mail: Benjamin@cmt.anl.gov

Subcontractors: General Motors, Warren, MI; W.L. Gore and Associates, Inc., Elkton, MD

Objectives

• Demonstrate proofs of concept for the large-scale preparation of high performance electrodes for 

membrane electrode assemblies (MEAs) and assess electrode and MEA architecture against 

FreedomCAR cost targets.

• Design, build, and install equipment for a high-volume pilot plant capable of catalyzing tens of 

thousands of square meters of electrode material per year.

• Complete process development and qualification of the pilot plant.

• Benchmark MEAs fabricated at SwRI against commercially available products.

• Incorporate MEAs into two ”short stack” fuel cells built by General Motors and deliver to Argonne 

National Laboratory for testing and evaluation.

Approach

• Prepare MEAs using ultra-low load Pt and Pt-alloy deposition technologies that exceed DOE 2005 

precious metal loading targets, and test the MEAs under hydrogen-air and reformate-air operating 

conditions.

• Determine the impact of large-scale catalyzation methods on MEA performance, if any, and develop 

approaches to minimize them.

• Establish in situ process control methods for catalyst deposition and demonstrate high-efficiency metal 

recovery approaches.

• Complete equipment shakedown and initiate regular operations at the pilot plant.

• Fabricate sufficient ultra-low load MEAs from catalyzed electrode material for incorporation into two 

short stacks.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

387

Accomplishments

• Completed construction, acceptance testing, installation, and shakedown of pilot manufacturing 

system at SwRI.

• Catalyzed several thousand square feet of anode and cathode electrode materials at feed rates up to 40 

feet per minute using the pilot system.

• Confirmed that materials manufactured using the pilot system exhibit similar performance to 

electrodes catalyzed on a laboratory scale.

• Developed robust, off-line methods for spot-checking loading and uniformity of catalyzed material. 

• Fabricated more than fifty 800-cm2

 MEAs to date as part of the development effort for the GM stacks.

Future Directions

• Complete trials to optimize electrode catalyzation rates, catalyst utilization, material throughput, and 

production yield.

• Continue efforts to optimize catalysts for improved CO tolerance and long-term durability.

• Complete fabrication of hydrogen-air and reformate-air MEAs for GM stacks.

• Assemble, test, characterize, and deliver stacks to Argonne National Laboratory.

Introduction

Broad commercial acceptance of fuel cell 

technology for use in automotive applications is 

expected to require a fuel cell stack that meets 

FreedomCAR target costs of $35/kW by 2010. One 

of the most critical components impacting overall 

system performance and economics is the membrane 

electrode assembly (MEA). It is anticipated that the 

MEA must be available for less than $10/kW in order 

to meet these overall cost targets. Central to 

achieving these economics is the reduction of the 

amount of precious metal catalyst in the MEA, 

specifically platinum (Pt) and related alloys such as 

Platinum Ruthenium (Pt-Ru), without degrading 

power density or system longevity. To this end, a 

target of 0.2 g per rated kW or approximately 0.1 mg/

cm2

 total platinum loading in the MEA has been 

established for 2010.

Work at Southwest Research Institute (SwRI) has 

been directed at addressing this issue through the 

development of large-area, high-throughput, 

vacuum-based coating technologies to reduce the 

overall precious metal content of finished electrodes. 

Specifically, “ultra-low” Pt and Pt-Ru catalyzed 

electrodes with loadings of 0.10 mg/cm2 or less have 

been fabricated using state-of-the art electrode 

substrates procured from W.L. Gore and Associates. 

A pilot manufacturing facility has now been 

completed which has the capability to catalyze more 

than 100,000 square meters of electrode material per 

year on a two-shift basis − enough to allow the 

fabrication of MEAs for potentially several thousand 

fuel cell-powered vehicles. 

Approach

The centerpiece of this project, a highly 

automated system for catalyzing fuel cell electrode 

materials, was installed in April; acceptance testing 

was completed in May 2002. A photograph of the 

system in operation is shown in Figure 1. In general, 

the system has performed to design specifications, 

with material feed rates up to 40 feet per minute 

having been demonstrated in recent trials at precious 

metal deposition rates of ~0.02 mg/cm2

/sec. Cycle 

time from loading of a roll of electrode material to 

catalyzation and removal is typically less than 2 

hours. Additional features of note include the ability 

to account for and adjust to changes in the material 

such as splices, wrinkles, and edge shifts, and the 

incorporation of removable, recyclable shielding that 

should allow for the recovery of more than 90% of 

any unused catalyst.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

388

One of the control screens developed for the 

system is illustrated in Figure 2. Notable data 

acquisition and control features include fully 

computerized, touch-screen control of the entire 

process sequence, including one-touch pump down, 

automated run, and vent cycles. 

Data logging of all critical deposition and 

vacuum system parameters is available to ensure 

optimal run-to-run quality control, correlate material 

and system performance, and assess long term 

machine stability.

Several thousand linear feet of additional 

intermediate electrode material has been supplied by 

Gore over the past year for use with this system 

during extensive production optimization trials. Pilot 

quantities of catalyzed electrode material, up to 500 

linear feet per run, have been prepared and evaluated 

using standardized test methods. A hand-held 

spectrophotometer has also been implemented for 

rapid inspection of catalyst loading and uniformity 

(few seconds per point). A section of electrode 

material intentionally catalyzed at different platinum 

loadings from approximately 0.01 to 0.10 mg/cm2 is 

presented in Figure 3. The catalyst uniformity is 

better than +/-10% both parallel and perpendicular to 

the machine direction.

Small scale (25-100 cm2 active area) MEAs have 

been fabricated using electrode materials with the 

pilot system. Sample MEAs have been test 

evaluated in both hydrogen-air and simulated 

reformate-air with 10-50 ppm CO at H2/air 

stoichiometries of 1.2/2.0 and 2.0/3.5 at pressures 

ranging from ambient to 30 psig. MEAs tested on 

hydrogen-air have produced beginning-of-life 

performance in the range of ~200 mA/cm2 at 0.8 V 

and ~700 mA/cm2 at 0.7 V at a total loading of ~0.1 

mg Pt/cm2. MEAs tested on reformate (40% H2)-air 

have generated initial current densities in the range of 

up to ~150 mA/cm2 at 0.8 V and ~500 mA/cm2 at 0.7 

V at a total loading of ~0.2 mg Pt/cm2

. Given the 

particularly good performance on neat H2 at ultralow loadings, it was agreed that two smaller stacks, 

~10 kW each, optimized to run on neat hydrogen and 

Figure 1. Photograph of Pilot System

Figure 2. Sample Control Screen 

Figure 3. Catalyst Loading Contour Plot at Different 

Deposition and Feed Rates
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

389

reformate, respectively, would be constructed with 

MEAs fabricated at SwRI as the final deliverables for 

the project. Figure 4 is a photograph of a GM stack 

similar to the ones scheduled for construction.

Conclusions

The primary objective, construction and 

demonstration of a pilot-scale system for catalyzing 

ultra-low load electrodes for polymer electrolyte fuel 

cells, has been achieved. The system has nominally 

met major design targets for material feed rates and 

catalyst deposition rates. It is estimated that, in twoshift operation, the system is capable of catalyzing 

sufficient electrode material to fabricate stacks for as 

many as 10,000 vehicles. MEAs fabricated with 

electrodes produced by this system significantly 

exceed 2005 FreedomCAR targets for catalyst 

loading and approach the requirements set for 2010. 

Continued work is planned to further optimize 

material throughput, yield, and catalyst utilization on 

the pilot system. Additional efforts to evaluate the 

performance of SwRI-manufactured MEAs at higher 

CO concentrations and over longer durations are also 

anticipated.

Figure 4. Photograph of a General Motors “Short” 

Stack that Will Utilize SwRI-Manufactured 

MEAs
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

390

IV.D.5 Integrated Manufacturing for Advanced Membrane Electrode Assemblies

Emory S. De Castro

De Nora N.A., E-TEK division

39 Veronica Ave

Somerset, NJ 08873

(732) 545-5100 ext 114, fax: (732) 545-5170, e-mail: emory.decastro.etek@denora.com

Mark G. Roelofs

DuPont Company

Chestnut Run

Wilmington, DE 

(302) 695-7342, fax: (302) 695-2503, e-mail: mark.g.roelofs@usa.dupont.com

DOE Technology Development Managers: 

Valri Lightner: (202) 586-0937, fax: (202) 586-3237, e-mail: Valri.Lightner@ee.doe.gov

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

ANL Technical Advisor: Thomas Benjamin 

(630) 252-1632, fax: (630) 252-4176, e-mail: Benjamin@cmt.anl.gov

Subcontractors: DuPont Company, Wilmington, DE; Nuvera Fuel Cell, Cambridge, MA; 

Northeastern University, Boston, MA

Objectives

• Create improved cathode structures and catalysts for proton exchange membrane fuel cells (PEMFCs) 

at temperatures <100°C that allow a significant reduction of precious metal without loss in 

performance

• Discover and develop proton exchange membranes (PEMs) capable of extended fuel cell operation at 

higher temperatures of 120 to 150°C, at low relative humidity (RH), and without leachable 

components

• Incorporate the advances of the efforts described above with advanced MEA fabrication processes that 

are amenable to mass production

Approach

• Fabricate highly controlled gas diffusion layers through fine gradient machine coating methods; 

exploit a new structure-function approach to designing improved catalysts and catalyst alloys

• Investigate additives to extend the stable performance of Nafion7 membranes to 120°C; create a new 

class of ionizable materials that enable proton transport in the absence of water (150°C operation)

• Develop new machine-based or ion beam coating methodologies to create very low loaded precious 

metal MEAs

Accomplishments

• Identified a preparation for platinum on carbon black catalyst that provides ~60% reduction in 

precious metal grams/kW compared to current commercial preparations

• Established “proof of principle” for catalyst structure-function approach
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

391

• Set up basis for constructing fine-gradient ELAT7 materials

• Developed a new base material into a gas diffusion layer (GDL) with lower resistance and improved 

mass transport at high current density

• Synthesized and screened approximately twenty electrolyte and monomer compounds for high 

temperature membranes

• Identified several model liquid electrolytes with >100 mS/cm conductivity at 150°C and low RH

• Fabricated a candidate composite membrane with 60% increase in conductivity vs. Nafion7 N117 at 

120°C and low RH

Future Directions

• Further develop catalyst structure-function approach and implement to create designed catalysts with 

anticipated reduced metal loads

• Link ink morphology to GDL structure; establish relationship between GDL structure and FC 

performance; build fine gradient ELAT7 with increased precious metal (PM) utilization

• Continue exploration of alternate polymeric backbones and acid groups (high temperature membrane)

• Create and test hypotheses as to required functionality and utilize these to narrow and focus the 

synthetic effort (high temperature membrane)

• Evaluate FC lifetime and performance of benchmark Nafion7 and candidate membranes (high 

temperature membrane)

Introduction

A significant challenge for PEMFC technology 

is precious metal thrift and creating new ion 

exchange membranes that are capable of stable 

operation at temperatures exceeding 120°C and 

preferably 150°C. The greatest barrier to reduction 

of platinum metal in the MEA is due to the cathode 

half reaction. For membranes to operate at over 

120°C, a new class of materials employing 

alternative proton transport mechanisms is necessary. 

Current platinum or alloy catalysts have a 

distribution of crystal facets, and some of these 

crystal planes exhibit higher activity for oxygen 

reduction. If one could selectively synthesize 

catalysts with a greater number of the desired planes, 

a more potent catalyst would result. However, 

advances in catalyst structure are not enough; the 

utilization of the catalyst and also proton and oxygen 

transport must improve to realize the full potential of 

the activity and ultimately reduce PM loading. 

Proton and oxygen transport may be improved 

through the realization of a fine gradient structure for 

the GDL. A satisfactory answer to these technical 

challenges would reduce the barrier to 

commercialization by reducing precious metal cost, 

allow a significant reduction in heat exchangers, and 

provide a vast simplification for systems operating 

with hydrogen derived from hydrocarbon sources.

Approach

A series of innovative catalyst preparation 

techniques has been identified. Each technique is 

surveyed, and the resulting catalyst is subjected to 

electrochemical and spectroscopic evaluation. 

Spectroscopic data are reintegrated in a sophisticated 

computer model that allows detailed bulk structural 

information to be derived. For this modeling, the 

methods are ranked according to the likelihood of 

selectively fabricating highly active crystal faces. 

Thus, the model provides a link to design catalysts 

based on a structure-function approach.

For the fine-gradient ELAT7, we first establish 

the relationship between ink formulation parameters 

and how they impact key architectural quantities 

such as pore size distribution and hydrophobicity. 

Next, the architectural quantities are linked to actual 

fuel cell test results. Finally, fine gradients of 

porosity and hydrophobicity are constructed using 

the relationship(s) previously established.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

392

For high temperature membranes, three avenues 

are being pursued: a) synthesis of new ionomers, b) 

covalent modification of Nafion7, and c) polymerinorganic composites. Some of the approaches aim 

to increase the attractive forces holding water within 

the membrane, enabling operation at low RH. Others 

seek to embody Brønstead bases as an alternative to 

water, which allow for proton mobility in the absence 

of water. This mechanism is exemplified by proton 

conductivity in e.g. H3PO4 or CsHSO4, in which the 

protons hop and the protonated base need not move 

macroscopic distances.

Results

A summary of catalyst synthesis methods 

investigated for both activity and potential to control 

the crystal face population(s) is shown in Table 1. Of 

these, the methodology indicated as “Shows 

Promise” appears to provide a wide range of 

structures over only a moderately small range of 

tested parameters. Due to this unexpected result, 

additional efforts were directed to this method.

Table 2 summarizes some preliminary results in 

testing these new platinum catalysts. Using our rapid 

catalyst screening protocol (70°C, 43 psig cathode, 

36 psig anode), we record a reduction in precious 

metal usage of around 60% as measured by power.

In developing the fine-gradient ELAT7, one 

activity is incorporating new carbon cloth or paper 

materials as the support web for the microporous 

carbon black/catalyst coatings. Figure 1 shows the 

consequences of converting a new type of web to the 

ELAT7 configuration. We were able to build an 

assembly with lower overall electrical resistances 

that can facilitate transport at high current density.

An example of the process behind building a 

GDL is shown in the metrics of Figure 2. Here we 

are evaluating a 2 x 2 matrix of formulation (1 and 2) 

vs. coating method (A and B), and plotting the total 

solids deposited on the web versus the position of the 

layer. In addition to the differences in deposition rate 

listed here, most notable is the instability induced at 

the fifth position for Formulation 1, Coating method 

Catalyst Pt on 

carbon

Alloys on 

carbon

Organic Method XXX XX

Controlled 

Environment ⊕ ---

Simultaneous vs. 

Sequential NA XX

New Carbons ⊕ ---

Temperature ⊕ ---

Key Symbol

Preliminary Evaluation ⊕

Shows Promise XXX

Interesting Results XX

No Potential X

Not Evaluated to date ---

Not Applicable NA

Table 1. Methods Evaluated to Control Crystal Face 

Population

Preparation 

Method

“High 

Efficiency 

Hydrogen” 

at 0.8V

“Reformate 

Target” at 

0.75V

Commercial 4.25 g/kW 2.84 g/kW

Organic Method 1.76 g/kW 1.02 g/kW

Percent 

Reduction in PM

59% 64%

Table 2. Comparison of “Organic Method” Platinum on 

Carbon Black vs. Commercial Catalyst (cathode 

metal only)

Figure 1. Evaluation of Alternative Web (Cathode/

Anode: 1.5 Bar A, 70°C; Anode hydrator T = 

Cathode hydrator T = Cell: 70°C)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

393

A: instead of a linear increase in solids, we actually 

start to remove solids under these conditions. In 

addition to solids, we also measure through-plane 

conductivity, permeability, and numerous other 

characteristics as a function of the position in the 

gradient. The correlation of these characteristics to 

the formulation morphology is the goal of these 

experiments.

A series of model electrolyte compounds and 

monomers has been synthesized with the aim of 

understanding which functionalities can engender 

conductivity at low RH for high temperature 

membranes. The working hypothesis is that 

ionomers are in general less conductive than their 

constituent monomers, so that chemistries may be 

screened using model compounds prior to investment 

in polymer synthesis and membrane fabrication. A 

cell was constructed of quartz, ceramic, PTFE, and Pt 

materials, allowing measurement of the conductivity 

of 800 microliter liquid samples at temperatures up to 

200°C. Conductivities of several liquid organic 

electrolyte model compounds are shown in Figure 3, 

with a few samples attaining 50 to 200 mS/cm at 

150-180°C. The water contents indicated are the 

starting compositions and are chosen to correspond 

to significantly lower water contents (acid:water 

mole:mole) than is required by Nafion7. Though 

water vapor pressure was not explicitly controlled, 

the cell was not pressurized and the water vapor 

partial pressure was less than 1 atm. The maximum 

conductivity, followed by a decrease in conductivity 

at higher temperatures, observed for some samples is 

believed to be due to evaporation of water. 

Compound U is one of the very few electrolytes 

investigated in which the neat liquid without added 

water generates appreciable conductivity. For 

comparison, the conductivity of Nafion7 117 

membrane was measured as 7 mS/cm at 150°C and a 

water vapor partial pressure of 1.1 atm (23% RH).

The electrolytes investigated so far cover a range 

of aliphatic and aromatic compounds, fluorinated and 

non-fluorinated, with sulfonic and non-sulfonic acid 

groups. Our challenge now is to learn to incorporate 

these acid functionalities into ionomers without 

losing the conductivity as they are diluted and 

immobilized with polymer scaffolding.

Another potential method for achieving a high 

temperature membrane utilizes composites of 

ionomers with hydrophilic inorganic compounds. 

The desire is for the inorganic compounds to alter the 

microstructure of the ionomer, perhaps by holding 

open the ionic pores or by increasing the attractive 

force with which the water is held in the membrane. 

A further function of the filler is to decrease the creep 

of the ionomer and prolong membrane life. The most 

promising results have been obtained with an 

ionomer/inorganic composite membrane, where the 

conductivity at 120°C, 23% RH has been increased 

from ~5 mS/cm for N117 to ~9 mS/cm (Table 3). 

The goal resistance of 0.1 ohm cm2 would, however, 

require 50 mS/cm, assuming a 50 micron thick 

membrane. Thus, we still need a much larger 

increase in conductivity to achieve very thin 

membranes.

Figure 2. Comparison of Formulations and Coating 

Parameters Figure 3. Conductivity vs. Temperature
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

394

Conclusions

Although quite early in our program, the use of 

the structure-function approach for catalyst design 

has yielded great improvements to the platinum on 

carbon black design. The further development of this 

methodology, when combined with the anticipated 

increase in performance of the fine-gradient ELAT7, 

should result in greatly enhanced cathode structures 

for normal temperature operation (up to 100°C).

For the high temperature membrane, achieving 

high conductivity at low relative humidity is one of 

the most challenging requirements. However, given 

that low resistance is the germane need, low 

conductivity may be ameliorated with very thin 

membranes. If such a compromise proves necessary, 

it will then place the onus back on achieving 

excellent puncture, creep, and fuel permeation 

properties. Our future path includes work to further 

increase conductivity and to incorporate the existing 

liquid electrolyte leads into ionomers without losing 

the conductivity as they are made into solid 

membranes.

Membrane Conductivity (mS/cm)

@ 80°C, 

95% RH

@ 80°C, 

20% RH

@ 120°C, 

23% RH

N117, sample 1 86 3.3 4.5

N117, sample 2 85 5.5 6.1

Candidate V, 

sample 1

89 5.8 10.0

Candidate V, 

sample 2

105 4.3 8.4

Table 3. Conductivities measured with AC-impedance, 

4-point probe for N117 and a candidate 

composite membrane. Metered dry air and 

water are mixed in a vaporizer then fed to a 

pressurized flow cell in an oven. The 80°C, 

95% RH data are for membranes which had 

been previously exposed to low RH. Freshlyboiled expanded membranes which have not 

been exposed to low RH give much higher 

conductivities of the order of 180 mS/cm 

@80°C, 95% RH.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

395

IV.D.6 Development of High Temperature Membranes and Improved Cathode 

Catalysts 

Dr. Shari Bugaj (Primary Contact)

UTC Fuel Cells

195 Governor's Highway

South Windsor, CT 06074

(860) 727-2808, fax: (860) 727-2750, e-mail: Shari.Bugaj@utcfuelcells.com

DOE Technology Development Manager: Valri Lightner 

(202) 586-0937, fax: (202) 586-3237, e-mail: Valri.Lightner@ee.doe.gov

Main Subcontractors: 

High Temperature Membrane

Virginia Polytechnic Institute and State University (Virginia Tech), Blacksburg, Virginia

Pennsylvania State University, University Park, Pennsylvania

Stanford Research Institute International, Menlo Park, California

IONOMEM, Marlborough, Connecticut

Princeton University, Princeton, New Jersey

Cathode Catalysts

Northeastern University, Boston, Massachusetts 

University of South Carolina, Columbia, South Carolina

United Technologies Research Center, East Hartford, Connecticut

Case Western Reserve University, Cleveland, Ohio

 Objectives

• Develop and demonstrate an advanced polymeric membrane able to operate at near ambient (1-1.5 

atmospheres) pressure in the temperature range of 120~150o

C and able to meet DOE's program goals 

for performance.

• Develop and demonstrate improved high-concentration platinum (Pt) cathode catalysts that will enable 

the reduction of Pt loading to 0.05 milligrams per centimeter squared (mg/cm2

) and meet DOE's goals 

for performance.

Approach

• Phase 1: High Temperature Membranes (HTMs) and improved Pt catalysts will be synthesized, 

characterized and compared with issued specifications.

• Phase 2: Laboratory-scale catalyst-coated membranes (CCMs) will be fabricated, optimized and 

tested using the Phase 1 down-selected membranes and catalysts.

• Phase 3: Full-size CCMs with the down-selected and optimized HTMs and catalysts will be fabricated 

and tested in two individual multi-cell stacks.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

396

Accomplishments

• This project was initiated during the first quarter of 2002. Eight out of the nine subcontractors have 

initiated membrane and catalyst synthesis. Technical accomplishments for the four months since the 

initiation are given below.

• At Virginia Tech., high yields (>80%) of 3,3'-disulfonate, 4,4'-dichlorodiphenylsulfone were obtained 

by sulfonating commercially available monomers. Films (>40,000 molecular weight) drawn from 

these co-monomers showed negligible degradation in boiling water and acceptable proton conductivity 

at room temperature in water. 

• United Technologies Corporation Fuel Cells (UTCFC) has developed and applied a new and novel insitu electrochemical technique to quantify hydrogen crossover in membranes. 

• High-concentration (40 weight percent [wt%]) ternary Pt alloy samples prepared using the 

carbothermal technique have yielded surface area and activity values comparable to commercial Pt 

samples. Platinum/Carbon (Pt/C) prepared by pulse-electrodeposition showed superior surface area 

and activity when compared to direct current deposited Pt/C electrodes. 

Future Directions

• Continue polymer synthesis and evaluation of the fabricated films per membrane screening 

specifications. Initiate the fabrication of initial promising candidates into CCMs.

• Continue evaluation of Pt catalysts being synthesized using the colloidal sol, carbothermal and the 

electrodeposition techniques and compare results against catalyst screening specifications. Debug 

rotating disk electrode technique.

Introduction

Two main challenges in the PEMFC arena are 

the reduction of cathode Pt loading and development 

of membranes that can operate over 120o

C. 

Surmounting these two challenges will directly affect 

the cost, performance and the size of PEMFC stacks. 

On the HTM project, new polymeric materials with 

negligible thermal degradation and acceptable proton 

conductivity in the 120-150oC range are required. 

On the improved catalyst project, a combination of 

higher activity catalysts and thinner catalyst layers is 

required to achieve the aggressive DOE performance 

targets. 

Approach

To develop HTMs, UTCFC has teamed with 

research groups that possess competencies in the 

fields of polymer chemistry and engineering. The 

subcontractors on the HTM project are investigating 

modified Nafion and new non-Nafion based 

membrane systems (see Table 1). The subcontractors 

on the improved catalyst project and their individual 

approaches are given in Table 2. 

Table 1. High Temperature Membrane Program 

Approach

Results

This project was initiated during the first quarter 

of 2002. Since then, all the subcontractors have hired 

appropriate personnel and initiated membrane/

catalyst synthesis. A majority of the required 

processes are in place, and eight of the nine

Group

Principal 

Investigator Approach

IONOMEM Mr. Leonard 

Bonille

Hygroscopic solid ion conductor (e.g., zirconium phosphate, 

etc.) filled Nafion

Penn State 

University

Prof. Digby 

Macdonald

Sulfones and sulfoxides of aromatic PPBP and aliphatic PVA. 

Covalent sulfonic acid bonded 

PEEK, PBI and PPBP

Princeton 

University

Prof. Andrew 

Bocarsly

Layered sulfonated Polystyrene/Fluoropolymer system

Stanford 

Research 

Institute

Dr. Susanna 

Ventura

Sulfonated PEEK-PBI-PAN

Virginia 

Tech

Prof. James 

McGrath

Sulfonated Poly(arylene ether 

sulfone)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

397

Table 2. Advanced Cathode Catalyst Program Approach

subcontractors have reported preliminary results. At 

Case Western, the catalyst modeling work will start 

in September 2002, when Dr. Jerome Roques will 

start as a post doctoral associate. Some of the 

preliminary results obtained during the past four 

months are presented here.

High Temperature Membranes

To measure the gas crossover in HTMs, UTCFC 

developed a new in-situ electrochemical test. The 

test involves oxidizing the hydrogen that is 

transported across the membrane and measuring the 

limiting currents. Typical crossover limiting currents 

for two membranes of different thicknesses are 

depicted in Figure 1.

 At VirginiaTech, 3,3'-disulfonate, 4,4'-

dichlorodiphenylsulfone co-monomers with varying 

degrees of sulfonation were prepared from 

commercially available monomers. Nuclear 

magnetic resonance (NMR) spectroscopy was 

conducted on selected polymeric films to investigate 

the level of sulfonation. The NMR results showed 

that the sulfonation levels could be quantified very 

accurately. The water uptake of bi-phenol sulfone 

(BPSH) films increased with an increase in the 

degree of sulfonation. The membrane samples 

drawn from BPSH40 with 20, 30 and 40 K molecular 

weights showed proton conductivity values on the 

order of 0.09 S/cm. To evaluate the thermal 

degradation of the polymers, BPSH40 films were 

exposed to boiling water extractions using the 

Soxhlet technique in conjunction with Fourier 

transform infrared (FTIR) spectroscopy. The spectra 

were collected as a function of exposure time (see 

Figure 2). As seen from the figure, there is 

negligible change in the spectra up to 3,500 hours, 

Group

Principal 

Investigator Approach

North 

Eastern 

University 

(NEU)

Prof. Sanjeev 

Mukerjee

Micellar Pt nano cluster synthesis, colloidal sol synthesis of 

binary Pt alloys

University 

of South 

Carolina 

(USC)

Prof. Branko 

Popov

Pulse electro-deposition of Pt 

and Pt alloys on Carbon [Pt and 

Pt-X, X=Fe, Ni, Co, Mn, Cu]

UTC Fuel 

Cells

Dr. Shari 

Bugaj

Carbothermal synthesis of ternary Pt alloys [Pt-Ir-X and PtRh-X, [X=Ni, Co and V]]

Case 

Western 

Reserve 

University 

(CWRU)

Prof. Al 

Anderson

Quantum chemical modeling of 

Pt alloys and ORR

UT 

Research 

Center 

(UTRC)

Dr. Ned 

Cipollini

Reproducible and stack size 

CCM fabrication

Figure 1. In-situ Limiting Hydrogen Crossover 

Currents for Two Membranes of Different 

Thicknesses

Figure 2. Influence of Hot Water Soxhlet Extraction 

on the FTIR of Sulfonated Poly(arylene 

ether) Copolymers BPSH40
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

398

indicating that the hydrolytic stability of the films is 

excellent. No noticeable change in the nature or the 

ion exchange capacity of the membrane was noted 

during the Soxhlet experiment. 

Penn State has modified electrochemical 

instrumentation that operates above 100o

C. The 

accuracy of the instrumentation was confirmed by 

Nafion 117 characterization. Princeton has initiated 

the synthesis of laminar membranes and anticipates 

initial characterization results on these materials over 

the next quarter. IONOMEM possesses a HTM that 

was shown to operate at 120oC prior to the start of 

this program. Since the initiation of this program, 

IONOMEM's efforts have been focused on electrode 

structure and catalyst modifications to establish a 

performance base.

Advanced Cathode Catalysts

UTCFC has modified the carbothermal synthesis 

process (U.S. Patent 4,677,092, US 4,806,515, US 

5,013,618, US 4,880,711, US 4,373,014, etc.) to 

prepare 40 wt% ternary Pt alloy catalysts. Various 

high-concentration Pt catalyst systems were 

synthesized and the electrochemical surface area 

(ECA) and electrochemical activity values compared 

to commercially available catalysts (see Table 3). 

The UTCFC catalysts showed ECA and activity 

values comparable to the commercial catalysts. A 

rotating disk electrode technique for catalyst activity 

measurements has been developed and is currently 

being debugged at UTCFC. 

Table 3. Preliminary ECA and Activity Data of 

Synthesized Pt Alloys

At the University of South Carolina, Pt/C 

electrodes were fabricated by using direct current 

(DC) and pulse current electrodeposition methods. 

With the use of current pulses rather than DC, a 

higher deposition current density could be used and 

Pt deposits with a higher surface area were possible. 

Figure 3 compares the polarization performance of 

electrodes prepared by pulse electrodeposition 

(current density=50 mA/cm2 and duty cycle=0.25) 

and DC deposition. Electrodes fabricated under 

pulse deposition conditions display better 

performance than the DC-plated electrode. The best 

performance is obtained when the ON time is 100 ms 

and OFF time is 300 ms. 

At NEU, a series of electrocatalysts were 

synthesized based on classical colloidal sol synthesis 

techniques. These included platinum nickel/carbon 

(PtNi/C), platinum chromium/carbon (PtCr/C), and 

platinum cobalt/carbon (PtCo/C) together with the 

control Pt/C. All of the above electrocatalysts were 

prepared with 20% metal loading on carbon support 

(Vulcan XC-72, Cabot Corp). Ohmic corrected Tafel 

Catalysts

Catalysts ECA 

(m2/Pt)

Catalyst 

Activity

 (A/gPt)

Commercial 50% 

Pt/C

98 25.1

Comercial 50% 

PTFE/C alloy

63 37.7

40% PT/Carbon C 110 27

40% Pt50Ir23Co25 75/62 33

40% Pt50Ir23Ni25 60 23

Figure 3. Polarization Curves at 50 milliamps/cm2 and 

Duty Cycle of 0.25
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

399

plots for PtCr/C, PtCo/C, PtCoCr/C and PtNi/C are 

shown in Figure 4. As seen from the figure, the alloy 

catalysts are inherently more active than the Pt/C 

control. The data shows a lowering of the 

overpotential for oxygen reduction by up to 50 

millivolts. At a potential of 0.9 volts, this translates 

to an eight-fold enhancement in oxidation-reduction 

reaction (ORR) activity. Stability and surface 

analysis of the Pt alloys was also performed using xray techniques.

Conclusions

The project is in its early stages and processes 

are in place for making progress. Preliminary results 

show that the HTM team is ramping up by initiating 

polymer synthesis processes and also by modifying 

instrumentation to perform high temperature 

measurements. On the advanced catalyst program, Pt 

and Pt alloys prepared using the colloidal sol, 

carbothermal and pulse electrodeposition processes 

are being characterized and compared with 

commercial Pt catalysts. 

References

1. S. Kocha, P.Plasse, L.Onishi, D. Wheeler, J. Bett, 

AIChE Spring Meeting Proceedings- Fuel Cell 

Technology: Opportunities and Challenges, 

March 10-14, 2002, New Orleans.

Figure 4. Ohmic Corrected Tafel Plots for Oxygen 

Reduction on Pt and Pt Alloy 

Electrocatalysts Prepared at Northeastern 

(note that PtCr/C is a system being 

considered only for ORR fundamentals; it 

will not be under consideration for downselection)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

400

IV.D.7 High-Temperature Membranes

Thomas A. Zawodzinski (Primary Contact), Hayley Every

Department of Chemical Engineering 

Case Western Reserve University

Cleveland, OH 44106

(216) 368-5547, fax: (216) 368-3016, e-mail: taz5@po.cwru.edu

Michael Eikerling, Lawrence Pratt, Antonio Redondo, Tom Springer, Judith Valerio, Francisco Uribe, 

Michael Hickner and Tommy Rockward

Los Alamos National Laboratory

Electronic and Electrochemical Materials and Device Research Group

Los Alamos, NM 87545

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• To develop new membranes and membrane electrode assemblies (MEAs) for operation at temperatures 

substantially in excess of 120°C

Approach

• Simultaneously carry out R&D on:

- Physical chemistry of polymer electrolytes

- New polymeric electrolytes

- New approaches to proton transport in polymer electrolytes

- Development of MEAs based on new polymer electrolytes

Accomplishments

Physical Chemistry

• Computational studies revealed key intermediate states in proton transfer processes; showed that 

water plays a role in ‘bridging’ and organizing acid groups to facilitate proton transfer 

New Membranes

• Synthesized new polymers with higher acidity

• Developed several strategies targeting ‘water replacements’

Catalyst-Coated Membranes (CCMs)/Electrodes

• Successfully fabricated MEAs for one class of new membrane materials; achieved performance 

comparable to that of Nafion-based MEAs 

Industrial and Other Collaborative Interactions

• Worked directly with several university partners in developing and testing high-temperature 

membranes

• Assisted DOE industry partners in CCM development for high-temperature membranes
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

401

• Developed draft Roadmap for High Temperature Polymer Membranes

• High-Temperature Polymer Membrane Working Group (HTPMWG) was expanded and strengthened 

through several meetings

Future Directions

• Perform more extensive computational studies on novel systems

• Continue to develop methods for screening new membrane concepts at a higher rate; test new 

electrolytes in fuel cells on a 4 month cycle starting in the fall of 2002

• Expand initial tests on enhancing electrode performance; develop capability for probing oxidation 

reduction reaction (ORR) at temperature ex situ; develop understanding of interactions at buried 

interfaces within electrodes

- Develop reliable CCM fabrication approaches

- Continue to develop means for scale-up of polymers, film-making and CCM production to modest 

scale

• Industry and Other Collaborations

- Continue to make industrial and academic contacts from Case Western Reserve University (CWRU) 

to enable technology transfer and dissemination of ideas

- Organize the HTMWG (streamline funding mechanism, improve meeting scheduling); evolve 

toward a discussion group format, idea exchange

Introduction

The need to operate at temperatures exceeding 

100°C presents difficult new challenges for the 

polymer electrolytes used in fuel cells. This difficulty 

stems from the decrease in water content of the 

polymer electrolytes in the desired temperature 

range. There is a need for detailed understanding of 

the impact of poor or zero hydration on membrane 

and electrode processes in the fuel cell. Water plays 

a key facilitating role in proton transport; thus, lower 

water content leads to lower conductivity. Lack of 

water also has important negative consequences for 

electrode behavior. 

Approach

At this point, we do not know which of several 

approaches is most promising. Thus, our membrane 

development efforts involve (1) a full-fledged effort 

to explore approaches involving polymer synthesis 

and development, as well as implementation of new 

“carrier” media to replace the function of water in 

Nafion, and (2) a study of proton transfer dynamics. 

We are using theoretical approaches to explore 

specific possibilities for new acid group types or for 

acid-base interactions that could lead to progress in 

proton transfer media. We are also working to 

establish better understanding of the energetics of 

proton transfer to inform synthetic efforts. We also 

are working to incorporate new polymers in fuel cells 

by developing catalyst-coated membranes from the 

new materials. Finally, we have assisted DOE in 

setting up a range of polymer electrolyte 

development efforts, involving several universities 

and with significant industrial input.

Results

Physical Chemistry

As a starting point for our efforts, proton 

solvation and transfer in water-containing polymer 

electrolytes will provide some clues on critical steps 

in the approach. We are studying the energetics and 

dynamics of these processes. The tools we develop 

allow us to compare strengths of various target acids 

and assess the efficacy of water ‘replacements.’ We 

continue to expand the range of acid types studied as 

hydrates using density functional computational 

methods. These studies give us insight into the 

relative importance of solvation and dissociation 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

402

processes for various highly delocalized anions. The 

most interesting work this year used a sophisticated 

ab initio/molecular dynamics method to identify 

some surprising aspects of the proton transport 

dynamics. Specifically, we found that sidechain-tosidechain hopping of protons could occur, albeit with 

the ‘cooperation’ of certain water configurations 

bridging between sidechain groups. This finding is 

highly suggestive regarding possible water 

replacements and their structural requirements for 

facilitating proton transport. 

Additional work is underway to use 

computational methods to (i) tailor bases to mimic 

water, perhaps using substituted imidazoles or other 

proton carriers; (ii) understand proton transport in 

phosphoric acid/basic polymer systems; and (iii) 

augment other experiments on new polymers and 

additives of various types.

New Membranes

Three classes of membrane materials are 

presently in preparation and testing. These are (i) 

polymers and inorganic materials with controlled 

pore size to be modified with acid groups lining 

pores, (ii) polymeric systems with intrinsically 

stronger acid groups, and (iii) polymer systems 

swollen or imbibed with tailored proton acceptors. 

These are useful both intrinsically and as test or 

model systems. At least two more types of materials 

are ‘on the drawing board.’ Details of our ideas and 

approaches will be provided as the materials are 

tested later this year. 

CCMs

We are forming CCMs from new polymers, often 

with radically different properties than those to 

which we are accustomed. Observed difficulties in 

achieving good performance with new CCMs stem 

from processes occurring at several different length 

scales: 

• Macro scale (CCM level): adhesion 

phenomena, polymer segregation in catalyst 

layer, mechanical properties of electrode and 

membrane

• Meso scale (agglomerate level): mass 

transport of gases, continuous proton and 

electron conducting pathways

• Nano scale (local level): proton accessibility 

to site, electrocatalysis, polymer adsorption, 

polymer mobility

We have successfully catalyzed the Virginia Tech 

membranes and obtained performance comparable to 

that obtained with Nafion membranes of comparable 

thickness. Results are shown in Figures 1 and 2. The 

importance of these results lies in our ability to 

overcome difficulties inherent in catalyzing many of 

the emerging new membranes. Achieving good 

performance required some treatment of the CCM 

under operating conditions in the cell. The cells thus 

prepared appear to be robust in lifetests over 

hundreds of hours. 

A more fundamental problem that arises in the 

high temperature regime is the necessity of good 

proton accessibility to electrodes. Many new 

polymer types proposed involve a sulfonated 

aromatic polymer. Microelectrode studies of the 

ORR on such materials indicate a significant loss of 

activity with decreasing water content in the 

polymer, far exceeding that observed with Nafion. 

This is likely due to the lower acidity of the aromatic 

sulfonates compared with that of the perfluorinated 

material. Our best results to date have been obtained 

using Nafion as the ionomer in the cathode catalyst 

layer.

We are actively studying the impact of the range 

of environments local and corresponding different 

Figure 1. Polarization curves showing comparison of 

performance at 80o

C of CCMs prepared from 

Nafion 112 and biphenyl sulfone (BPSH-30, 

2.6 mil thick) membranes. Catalyst loading: 

0.2 mg/cm2

 Pt anode, 0.4 mg/cm2 cathode.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

403

degrees of proton access to surface. Given the 

constrained dynamics of the polymer system, acid 

access to the catalyst surface is a key issue. Various 

additives, such as low molecular weight acids, have 

been and are being used to augment catalyst layer 

acidity and the mobility of acidic groups. Results to 

date have been inconclusive.

Industrial and Other Collaborative Interactions

We are engaged in a series of collaborative 

efforts with industry, national laboratories, and 

universities to facilitate efforts to achieve the targets 

for high-temperature polymer membranes. We have 

organized the High-Temperature Polymer Membrane 

Working Group, which has met four times to date. 

Bi-annual meetings allow us to assess progress and to 

communicate issues and needs to the hightemperature membrane community at large.

Conclusions

The development of new polymer electrolytes 

for operation at elevated temperature is under way. 

However, this is a long-term project. Replacement of 

water is the most difficult problem, but adequate 

stability and cathode activity are not trivial objectives 

to achieve. We have developed several different 

approaches to address this problem. Fundamental 

work, including computational and experimental 

studies of new acid-functionalized materials, can 

provide useful insights into the conduction process to 

guide synthetic efforts. The first polymers geared for 

temperatures in excess of 100°C are emerging, and 

testing is showing that, although promising, there are 

definite shortcomings. Work on making viable new 

materials continues.

Figure 2. Polarization curves showing comparison of 

performance at 120oC of CCMs prepared 

from Nafion 112 and BPSH-30 (2.6 mil thick) 

membranes. Catalyst loading: 0.2 mg/cm2

 Pt 

anode, 0.4 mg/cm2

 cathode.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.D.8 Bacterial Cellulose Membranes

Hugh O’Neill (Primary Contact), Barbara R. Evans, and Jonathan Woodward

Chemical Sciences Division, Oak Ridge National Laboratory

P.O. Box 2008

Oak Ridge, TN 37831-6194

(865) 574-5004, fax: (865) 574-1275, e-mail: oneillhm@ornl.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail:JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

ORNL Technical Advisor: David Stinton 

(865) 574-4556, fax: (865) 241-0411, e-mail: stintonp@ornl.gov

Objectives

• To synthesize a low cost proton conductive membrane from bacterial cellulose for polymer electrolyte 

membrane (PEM) fuel cells.

- This membrane must be stable at temperatures greater than 120o

C.

- It must maintain the conditions conducive to proton conductance from the anode to the cathode 

through the polymeric medium, while operating at high temperatures. The area specific resistance 

must be no greater than 0.1 ohm-cm2

.

Approach

• Bacterial cellulose has several properties that have been identified as useful for PEM fuel cell 

development, including thermal stability and low hydrogen crossover characteristics.

• Bacterial cellulose membranes were modified with acid groups to produce a proton conductive 

membrane without compromising the structure of the cellulose membrane. 

Accomplishments

• Different strategies to confer ion-exchange properties on bacterial cellulose were investigated. The 

synthesis of a cellulose phosphate membrane was the most successful.

• Several properties of the cellulose phosphate membrane were evaluated, including hydrogen 

crossover, ion-exchange capacity and thermal stability.

Future Directions

• Complete the characterization of phosphate membranes, especially the determination of the proton 

conductivity of the membranes.

• Test the performance of ion-exchange membranes in a membrane electrode assembly (MEA).

• Revisit and evaluate other strategies for chemical modification of cellulose.

• Modify cellulose in vivo by using activated glucose monomers.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

405

Introduction

Bacterial cellulose is produced by 

Gluconoacetobacter sp. bacteria during growth on 

carbohydrate sources. Nascent cellulose strands, 

synthesized by the bacteria, are secreted and form 

layers at the air-liquid interface (Figure 1A, 1B). This 

network of cellulose fibrils resembles a sponge and is 

called a pellicule. After cleaning to remove cellular 

debris, the pellicule typically contains greater than 

99% H2O, the remainder being cellulose. On drying 

the pellicules to remove water, the layers of cellulose 

collapse on top of each other to produce a very thin 

membrane (< 50 μm thick). 

Of particular interest to the DOE fuel cell 

program is the development of thermostable 

membranes that will facilitate the transfer of protons 

from the anode to the cathode during operation of a 

PEM fuel cell at high temperatures (>120oC). At 

higher operating temperatures, the electrode kinetics 

is improved, resistance to poisoning by carbon 

monoxide is increased, and the catalyst cost is 

minimized. In addition, higher operating 

temperatures would facilitate the thermal 

management of the system and stack.

Bacterial cellulose has several unique properties 

that potentially make it a valuable material for the 

development of PEM fuel cells (Reference 1): (1) it 

is an inexpensive and non-toxic natural resource; (2) 

it has good chemical and mechanical stability; (3) it 

is very hydrophilic; and (4) it doesn’t re-swell after 

drying. Additionally, its thermal stability and gas 

crossover characteristics are superior to Nafion 117®, 

a material currently widely used as a proton 

conductive membrane in PEM fuel cells.

Approach

There is a wealth of data, both in the scientific 

and patent literature, on the chemical modification of 

plant cellulose. All of these methods are equally 

applicable to bacterial cellulose given that the two 

types of cellulose are chemically identical. However, 

it is the physical structure of bacterial cellulose 

membranes that make them a potential material for 

PEM fuel cells. Therefore, the aim is to modify 

bacterial cellulose pellicules in a manner that retains 

the structure of the cellulose and does not 

compromise the physical properties, such as thermal 

stability, gas crossover characteristics, and resistance 

to re-swelling after drying. 

Results

Several different strategies were employed to 

modify bacterial cellulose with ion-exchange groups. 

Of the methods attempted, modification of native 

bacterial cellulose with phosphate groups was the 

most successful (Figure 2). The properties of the 

Figure 1. SEM Micrographs of Freeze Dried Bacterial 

Cellulose (A: transverse section, B: top view)

Figure 2. Synthesis of Cellulose Phosphate
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

406

native and modified membrane compared with 

Nafion 117® are presented in Table 1. 

Thermogravimetric analysis of cellulose 

phosphate in an oxygen atmosphere indicated that it 

started to degrade at 245°C, compared to less than 

90°C for Nafion 117®. This marked increase in the 

thermal stability of cellulose phosphate over native 

cellulose was not unexpected given that this material 

was first developed as a flame retardant. Cellulose 

phosphate has only 13% of the H2 permeability of 

Nafion. Unlike Nafion, cellulose phosphate is prone 

to swelling in H2O. However, at temperatures 

greater than 120o

C this may not pose a problem 

during operation of the fuel cell. The density of ionexchange groups available for proton transport is 

similar in both materials. The superior mechanical 

properties of Nafion are most probably due to the 

difference in thickness between the materials. 

The acid stability of the cellulose phosphate 

membrane was determined at 95o

C in 1N sulfuric 

acid. After 45 hours cellulose phosphate lost 39% of 

its original weight. This increase in sensitivity to 

acid attack is most probably an artifact of the reaction 

conditions employed in the synthesis. Modifications 

on the reaction procedure will be investigated to 

minimize this unwanted side reaction.

Conclusions

Several properties of cellulose phosphate have 

been evaluated. The material has good thermal 

stability and low hydrogen crossover, two 

requirements that are important to meet DOE fuel 

cell program targets. Further characterization of the 

material is required, especially the determination of 

proton conductivity. In addition, testing of the 

material in an MEA will allow the effect of acid 

stability and swelling properties of cellulose 

phosphate be evaluated under typical PEM fuel cell 

operating conditions. 

References

1. O’Neill, H., Evans, B.R., and Woodward, J. 

(2001) in Fuels Cells for Transportation Annual 

Progress Report pp 141-145

Publications/ Presentations

1. Evans, B.R., O’Neill, H., Malyvanh, V.P., 

Woodward, J. “Palladium-bacterial cellulose 

membranes for fuel cells” Biosensors and 

Bioelectronics, submitted

Membrane Characteristics Native 

Cellulose

Cellulose 

Phosphate Nafion 1177

Physical Properties Dry membrane thickness (mm) 0.010 0.023 0.199

Wet membrane thickness (mm) 0.032 0.081 0.225

H2O content / g dry membrane (g/g)1 3.47 3.16 0.31

Thermal stability (oC) 130 245 <90

Ion exchange capacity (mequiv/g) 0 1.3 0.9

H2 crossover (nmol.mil/h.cm2.atm)2 n.d. 267.2 2039.4

Mechanical stability Resistance to crease/crack: dry Yes No Yes

 hydrated Yes Yes Yes

Resistance to tearing: dry No No Yes

 hydrated Yes Yes Yes

Resistance to gas pressure (dry) n.d. 30 psi >50 psi

Chemical stability Acid stability (% weight loss)3 12 39 2.5

Table 1. Comparison of the Properties of Cellulose Phosphate with Native Bacterial Cellulose and Nafion 1177
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

407

2. O’Neill, H., Evans, B.R., and Woodward, J. 

(2002) “Bacterial Cellulose in Energy 

Conversion Applications” A poster presentation 

at the 24th Symposium on Biotechnology for 

Fuels and Chemicals, April 28th to May 1st, 

Gatlinburg, TN.

3. O’Neill, H., Evans, B.R., and Woodward, J. 

(2002) “Micro-fuel cell development based on 

bacterial cellulose” An oral presentation at the 

14th World Hydrogen Conference, June 9th- 13th, 

Montréal, Canada. 

Special Recognitions & Awards/Patents 

Issued

1. Evans, B.R., O’Neill, H., Malyvanh, V.P., and 

Woodward, J. (2001) “Metallization of bacterial 

cellulose for electronic and electrical devices” 

Patent Pending ID 0869, S-96, 631

2. O’Neill, H., Evans, B.R., and Woodward, J. 

(2002) “Synthesis of a novel ion-exchange/

proton conductive membrane” Invention 

disclosure, submitted ID 1099, S-99, 279
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

408

IV.D.9 Nano-particulate Porous Oxide Electrolyte Membranes (POEMs) as 

Proton Exchange Membranes

M. Isabel Tejedor, Marc A. Anderson, and Walt Zeltner

Environmental Chemistry and Technology Program, University of Wisconsin 

Room 109, 660 North Park Street, Madison, WI 53706 

(608) 262-2674, fax:(608) 262-0454, e-mail: nanopor@facstaff.wisc.edu 

Mark A. Janney and James O. Kiggans

Metals and Ceramics Division, Oak Ridge National Laboratory

P.O. Box 2008, MS 6087, Oak Ridge, TN 37831-6087

(865) 574-8863, fax:(865) 574-8271, e-mail: kiggansjo@ornl.gov

DOE Technology Development Manager: JoAnn Milliken 

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

ORNL Technical Advisor: David Stinton 

(865) 574-4556, fax: (865) 241-0411, e-mail: stintondp@ornl.gov

ANL Technical Advisor: Thomas Benjamin

(630) 252-1632, fax: (630) 252-4176, e-mail: benjamin@cmt.anl.gov

Objectives

• Develop microporous inorganic oxide-based membranes of TiO2 with high proton conductivity that 

can operate at above 100°C with minimal water management problems.

• Develop processes to fabricate porous nickel or graphite paper electrodes that support the membrane.

• Demonstrate fuel cell behavior in porous oxide electrolyte membrane- (POEM-) based membrane 

electrode assemblies (MEAs).

Approach

• Phase 1: (a) Determine conditions under which nanoparticle sols of candidate oxides yield 

microporous gels; (b) Measure proton conductivities of these gels as a function of temperature and 

relative humidity; (c) Chemically adsorb anionic or cationic functional groups onto oxide particles 

contained in xerogels or membranes in order to enhance proton conductivity.

• Phase 2: (a) Develop methods for depositing platinum on asymmetric mesoporous electrodes; (b) 

Deposit crack-free films of POEMs on mesoporous electrodes; (c) Characterize permeabilities of H2

and O2 through the resulting supported membranes under desired conditions of relative humidity and 

temperature; (d) Fabricate and test an entire inorganic MEA containing a POEM deposited on 

mesoporous electrodes. 

Accomplishments

• Demonstrated proton conductivity of 0.022 S/cm in POEMs (membranes <1 μm thick) at temperatures 

up to 135oC at a relative humidity (RH) of 81%.

• Better defined the effects of pore size and pH on proton conductivity in POEMs.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

409

• Collected initial data concerning open circuit potential and current-voltage relationships for an oxidebased anode/POEM configuration (i.e., 2/3 of an MEA). (Pt loading in anode = 0.003 mg/cm2)

Future Directions

• Develop a better understanding of the relationships and interactions among the various layers in the 

MEA (particularly the cathode layer) and how they control the performance of the overall fuel cell 

system. 

• Characterize and subsequently optimize the performance of fuel cells that contain POEMs.

• Develop testing techniques for measuring proton conductivity at temperatures approaching 150°C at ≥

40% RH.

• Investigate POEMs using the nickel substrate as the support for the cathode instead of the anode in an 

inorganic MEA.

• Further develop graphite fiber paper supports as a potential substitute for nickel substrates.

Introduction

Nano-particulate porous oxide electrolyte 

membranes (POEMs) are being developed as a 

radical alternative to polymeric proton exchange 

membranes (PEMs) for fuel cells. These new 

membranes can operate at temperatures over 100°C, 

retain water at these elevated temperatures, and 

provide proton conductivities of the same order of 

magnitude as the presently employed Nafion 

membranes. In addition, inorganic membrane 

electrode assemblies (MEAs) that incorporate 

POEMs should reduce the cost of fuel cells by 

substantially reducing the amount of Pt catalyst 

required to operate the fuel cell, and by minimizing 

CO poisoning of the Pt and facilitating heat rejection 

when operating at elevated temperatures.

One constraint in using POEMs is that they must 

be supported on a structural substrate because the 

membranes are thin (≤ 500 nm), porous (~40 vol% 

void space), and brittle (an inherent property of 

ceramic membranes). The porous substrate provides 

both electrical conductivity and gas distribution. 

Because the POEM itself is composed of 5-10 nm 

particles, an intermediary sandwich layer (particle 

diameter 50 to 500 nm) is required to provide 

geometric compatibility.

These membranes are made of nanoparticle 

oxides, which represent hydrophilic, higher 

temperature alternatives to polymeric proton 

exchange membranes (PEMs). These membranes 

are supported on either tape cast porous nickel or 

porous graphite paper electrodes n to date, we have 

only examined the porous nickel supports.

Approach

The objective of this effort is to develop MEAs 

for H2 fuel cells based on POEMs. These membranes 

are made of nanoparticle oxides such as TiO2, SiO2, 

ZrO2, or Al2O3 that are hydrophilic and offer higher 

temperature stability and operation than polymeric 

PEMs. These membranes are supported on tape cast 

porous nickel.

The POEM MEA is a complex materials system, 

not just a collection of individual components. This 

oxide-based MEA (anode / membrane electrolyte 

(separator) / cathode) is a composite material that 

simultaneously performs a variety of operations. One 

cannot consider any particular aspect of this 

materials system in isolation; all functions must 

operate in concert with one another. The anode must 

conduct electrons and at the same time convert 

hydrogen gas to protons at one interface with the 

POEM. The POEM itself must conduct protons but 

not electrons, which would cause a short, while also 

preventing crossover of hydrogen and oxygen across 

the POEM. Lastly, the cathode must convert gaseous 

oxygen to O-2 ions that then combine, at the other 

interface with the POEM, with protons that have 

migrated through the POEM. This cathode reaction is 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

410

a four-electron-transfer reaction that is quite difficult 

to perform efficiently. More will be said about the 

cathode layer and reasons for improving its 

performance later in this report.

Results and Discussion

Membrane Development – pH Effects

Proton conductivity in fluid-filled, hydrophilic, 

mesoporous, inorganic membranes such as these 

POEMs derives from the movement of H+ ions (1) 

by hopping along surface sites from particle to 

particle, (2) by migrating through the electrical 

double layer in the pores near the surface of the 

particles, or (3) by migrating through the bulk pore 

fluid. As shown in Figure 1, proton transport and the 

resulting conductivity drastically change with the pH 

at which the membrane is equilibrated. Note that 

“Nafion” type membranes are often soaked in strong 

acids to protonate their acid groups. In this regard 

POEMs are similar, although full protonation of the 

surfaces of these inorganic membranes may be 

reached at higher pH values than required for Nafion.

This behavior also greatly depends upon the 

nature of the oxide as shown in Figure 2. Note that at 

lower relative humidities, TiO2/ZrO2 and Al2O3

membranes have conductivities that are two to three 

orders of magnitude higher than SiO2 even though 

the silica membranes are more acidic. The reason for 

this behavior is that these membranes were 

preequilibrated at pH 1.5. This pH is very close to the 

isoelectric pH (i.e., the pH at which the surface of the 

oxide is electrically neutral) of SiO2, which is ≈ 2-3, 

but 4 to 7 pH units more acidic than the isoelectric 

pH values of TiO2/ZrO2 and Al2O3, respectively. As 

a result, the SiO2 membranes are NOT highly 

protonated at pH 1.5 whereas the other two 

membranes have almost achieved maximum 

charging and therefore maximum proton 

conductivity. 

Membrane Development – Pore Size Dependence

The conductivity of a particular membrane 

depends on the conditioning of the surfaces within 

the pores as well as the relative humidity. These two 

factors interact to determine how much water resides 

inside the pores. In the as-fired condition, the pore 

surfaces are poorly protonated. Conditioning the 

membrane material by exposing the membrane to an 

aqueous solution tends to increase the degree of 

protonation depending on the pH of the solution, as 

noted above. However, as can be seen in Figure 3, 

proton conductivity for TiO2 at 40oC also depends 

upon pore size, increasing one order of magnitude at 

low RH values as pore diameter decreases from 35 to 

25 Angstroms. We can lower the pore size in this 

membrane even further to ca. 15 Angstroms, which 

may further enhance its proton conductivity.

Initial Evaluation of an Inorganic MEA

Because these POEMs are not self-standing 

materials like organic polymer membranes such as 

Figure 1. Dependence of Proton Conductivity on pH at 

40oC

Figure 2. Proton Conductivity (in S/cm) for Various 

Oxides as a Function of Relative Humidity at 

80oC [diamonds are TiO2/ZrO2, ovals are 

Al2O3, triangles are SiO2 (20-60 A), squares 

are Si02 (9-15 A)]
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

411

Nafion, an MEA cannot be fabricated unless the 

membranes are cast on a rigid but porous support. 

Furthermore, the support must be electrically 

conducting and must already be coated with a porous 

catalyst layer before the membrane is cast. The 

resulting composite MEA will be activated by 

imbibing an acid solution into the MEA before it is 

used. 

Enable Fuel Cell Corp. (Middleton, WI) 

fabricated a passive test chamber to evaluate the 

performance of the materials. For these initial room 

temperature tests, we fabricated 2/3 of an inorganic 

MEA (i.e., porous nickel support / nanoparticle TiO2

membrane loaded with Pt catalyst to serve as one 

electrode / TiO2 POEM). We used a carbon fabric 

loaded with Pt as the second electrode. We ran the 

inorganic MEA as either an anode or a cathode 

depending on the polarity of the test circuit. When 

hydrogen contacted the inorganic MEA (i.e., the 

MEA was operated as a working anode), we 

achieved open circuit voltages between 0.74 and 1.02 

V. When the inorganic MEA was operated as a 

cathode, we obtained slightly lower voltages (0.76 –

0.88 V).

Unfortunately, it was difficult to seal the cell to 

prevent hydrogen leaks. In addition, it was difficult 

to test individual layers of the MEA system because 

the carbon fabric glued itself to the inorganic MEA 

and could not be detached without delaminating the 

MEA. To resolve these issues, we built a new test 

cell, as shown in Figure 4. As shown, the MEA is 

now sealed in a metal “O” ring using ceramic 

cement. This cell proved to be easily sealed without 

hydrogen leaks and, furthermore, it could be readily 

disassembled. However, we still need to improve the 

ohmic contacts to the anode and cathode layers. We 

utilized copper wool to provide contacts in this 

apparatus. However, copper wool easily oxidizes 

when in contact with acids and does not provide a 

uniform contact with the electrodes.

Test Performance

Shown in Figure 5 are initial current-voltage 

curves for the 2/3 of an inorganic MEA system 

described above versus a similar Nafion-based 

system in tests at room temperature. As can be seen, 

the Nafion system performs somewhat better than 

our initial prototype when the inorganic MEA 

operates as an anode. When we invert the contacts so 

that the inorganic MEA operates as a cathode, the 

inorganic MEA system performs much worse. A 

positive side to this performance is that the Pt content 

of the inorganic MEA is 0.003 mg/cm2

.

Figure 3. Dependence of Proton Conductivity on RH 

for Various Pore Size TiO2 Membranes Figure 4. Teflon Test Cell and the Inorganic MEA 

System

Figure 5. Current-Voltage Curves for the Inorganic 

MEA versus a Nafion System
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

412

Cathodes and the Total MEA

Shown in Figure 6 is a diagram of a nickel 

support and a Pt-loaded nanoparticulate oxide acting 

as a porous cathode. Organic-based fuel cell cathodes 

often have some Nafion added to improve proton 

conductivity but at the cost of electrical conductivity. 

However, we have the reverse problem – we have 

excellent proton conductivity in the inorganic 

cathode, but the oxides are electrical insulators. We 

need to boost the electrical conductivity of the 

cathode in order to fabricate a total inorganic MEA. 

This is a major objective of our future work.

Conclusions/Future Directions

• We have successfully fabricated and tested 2/3 of 

an inorganic MEA consisting of a porous nickel 

support, a nanoparticle TiO2 membrane 

containing platinum catalyst that served as an 

effective anode, and a nanoporous TiO2 porous 

oxide electrolyte membrane. A novel test cell 

was built to facilitate testing, but additional 

modifications are needed. Although the 

performance of this prototype inorganic MEA 

was not as good as a corresponding Nafion-based 

system at room temperature, the inorganic MEA 

required only a small amount of platinum to 

function. In order to prepare this inorganic MEA, 

a novel method had to be developed for applying 

a ceramic sandwich layer to the porous, 

electrically conducting nickel substrate. This 

method should be useful in other membrane 

applications.

• Efforts will continue to fabricate a full inorganic 

MEA and to test these systems at high 

temperatures. It appears that a functional 

inorganic MEA will require a cathode with 

higher electrical conductivity than available in 

our initial tests. In addition, we are attempting to 

develop a graphite fiber-based substrate having 

the requisite chemical compatibility with the 

PEM environment. As part of this development, 

POEM fuel cell assembly using standard, 

multilayer manufacturing technologies will be 

investigated.

FY 2002 Publications/Presentations

1. Results were presented at the national meeting of 

the American Institute of Chemical Engineers in 

New Orleans in March 2002.

Figure 6. Diagram of an Inorganic Fuel Cell Cathode
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

413

IV.D.10 Low-Platinum Catalysts for Oxygen Reduction at PEMFC Cathodes

Karen Swider Lyons (Primary Contact), Gregory B. Cotten, and Jason A. Stanley

Naval Research Laboratory

Code 6171

4555 Overlook Ave, SW

Washington, DC 20375-5342

(202) 404-3314, fax: (202) 767-3321, e-mail: karen.lyons@nrl.navy.mil

Wojtek Dmowski and Takeshi Egami

Department of Materials Science and Engineering

University of Pennsylvania

3231Walnut Street

Philadelphia, PA 19104

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objective

• Decrease the platinum content of the oxygen reduction reaction catalysts in fuel cell cathodes to meet 

the DOE 2010 precious-metal-loading goals of 0.2 g/rated kW. 

• The new catalysts must cost less than $35/kW and be stable for at least 5000 hours.

Approach

• Low-platinum catalysts are prepared in combination with amorphous, hydrous transition-metal oxides. 

The catalysts are dispersed in carbon inks, and their electrocatalytic activity is screened in half-cell 

measurements. 

• The physical properties of the catalysts are determined from thermal analysis, surface-area 

measurements, X-ray photoelectron spectroscopy, and transmission electron microscopy.

• Atomic pair-density function analysis of X-ray diffraction patterns is used to resolve the local structure 

of the catalysts from 0.15 to 2 nanometers (nm).

• Catalyst performance is confirmed by testing in fuel cells in collaboration with Los Alamos National 

Laboratory (LANL). 

Accomplishments

• Half-cell measurements on catalysts of a Pt-doped iron-oxide phase have approximately 20 times the 

activity of the standard 10 weight % Pt on Vulcan carbon. 

• Pair-density function analysis of X-ray diffraction patterns shows that active iron oxide (FeOx) 

catalysts are disordered at the nanoscale by the platinum and also have micropores, while inactive 

catalysts do not share these features. 

• Platinum supported on niobium oxide phases also exhibits high activity for oxygen reduction, despite a 

50 to 150 fold decrease in platinum compared to the standard 10 weight % platinum on Vulcan carbon. 

• The Pt-loading goals for the DOE 2008 program will be met if the half-cell performance of the new 

catalysts is matched in fuel cell measurements and the catalysts prove to be stable.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

414

Future Directions

• Correlate the half-cell catalysis results to fuel cell performance.

• Improve corrosion resistance of catalysts.

• Improve activity and test stability of platinum-niobium oxide catalysts. 

• Develop Pt-free catalysts by using transition-metal oxide mixtures that mimic Pt performance.

• Develop fuel-cell testing capabilities at the Naval Research Laboratory (NRL). 

Introduction

State-of-the-art proton exchange membrane fuel 

cells (PEMFCs) contain high loadings of Pt, making 

the fuel cells costly and subject to fluctuations in the 

market availability of the noble metal. The cost of 

the fuel cells and imports of noble metals can be 

drastically reduced by using little or no Pt in fuel cell 

cathodes. This would improve the 

commercialization potential of fuel cells. 

The catalytic activity of the oxygen reduction 

reaction (ORR) at the fuel cell cathode is known to 

be relatively slow, presumably because it is a 4-

electron (e-

) mechanism:

O2 + 4H+ + 4e-

 = 2 H2O

*Note: O2 = Oxygen gas, H+ = proton, H2O = water

The cathode must be catalytically active, and the 

catalyst site must have a supply of oxygen, protons, 

and electrons, and must be able to transport away 

water. The reaction above becomes limited when the 

transport of any of these four species is slow. 

We are designing new low-Pt electrocatalysts for 

oxygen reduction at PEMFC cathodes. Catalysts are 

targeted based on their ability to transport the 

following species: (1) molecular oxygen, (2) 

protons, (3) electrons, and (4) water. We have 

selected “amorphous” hydrous oxides with low 

amounts of platinum to fulfill these transport criteria. 

All catalysts are transition-metal oxide based, 

because hydrous transition-metal oxides are good 

proton and water conductors. Oxides are also less 

prone to poisoning (electro-chemical activity 

degradation) than metals, and some mixed-oxide 

catalysts also have the ability to mimic Pt. Some 

oxide catalysts may also be resistant to dissolving 

under the highly corrosive conditions at the PEMFC 

cathode. 

Although the catalysts are termed amorphous, 

they can have nanoscale order in their atomic 

structures that can have a significant bearing on their 

activity and transport properties. These nanoscale 

structural properties are not easily discerned with 

conventional materials science tools, but can be 

elucidated using an emerging technique: atomic 

pair-density function analysis of X-ray diffraction 

(PDF-XRD).1,2 

We analyzed the physical and structural 

properties of hydrous oxide materials having high 

ORR activity to determine the factors leading to 

high-performance PEMFC cathode catalysts. Last 

year, we reported 20 times the ORR activity per 

weight Pt when Pt-iron oxide (Pt-FeOx) catalysts are 

compared to 10 weight % Pt/Vulcan carbon 

standards. The nanoscale structural properties that 

lead to this high activity are reported here. 

Approach

Catalyst powders are prepared from aqueous 

solutions in ambient conditions and then heated at 

various temperatures to adjust their water contents. 

The water content of the final materials is determined 

via thermal analysis. 

The catalytic activity of the catalysts for the 

ORR is screened using a rotating-disk electrode 

(RDE) method.3

 The activity of the new transition 

metal oxide catalysts is estimated by comparison to a 

standard RDE of 10 weight % platinum/Vulcan 

carbon, XC-72 (Pt/VC) catalyst (Alfa). The 

electrocatalytic activity of the catalysts are compared 

in Tafel plots of potential vs. current, calculated from 

the electrochemical data as described in the 

literature.

Because conventional structural analysis 

methods (e.g., X-ray diffraction and transmission 

electron microscopy) are not effective on amorphous 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

415

materials, the nanoscale structures are best resolved 

via atomic pair-density function (PDF) analysis of 

the X-ray diffraction patterns of the catalysts. Highenergy X-ray diffraction is carried out at beamline 

X7-A of the National Synchrotron Light Source. 

Results

As reported last year, Pt-FeOx catalysts have the 

same ORR activity with 20 times less Pt than a 10 

weight % Pt/VC standard. These results of an active 

catalyst are shown in a Tafel plot of current vs. 

voltage in Figure 1. 

The Pt-FeOx samples with the highest ORR 

activity are heated at 150°C in air. Samples heated at 

higher or lower temperatures, or under oxygen, argon 

or hydrogen have lower electrocatalytic activity. The 

procedures for adding the Pt to the FeOx also have a 

significant impact on their activity.

Conventional XRD measurements show that all 

of the active and inactive samples are strongly 

disordered (i.e, amorphous solids or dispersed 

nanocrystals). However, the PDF-XRD 

measurements show significant differences between 

the active and inactive catalysts. When 3% Pt is 

added to the FeOx, it distorts the entire FeOx

structure. The PDF-XRD data for a 3% Pt-FeOx

sample is compared to a pure FeOx sample in Figure 

2. The atomic structure of the best performing PtFeOx sample is best described as glassy corner linked 

polyhedral (CLP) network. A schematic of this 

structure is shown in Figure 3. The iron (Fe) atoms 

are coordinated in a tetrahedral oxygen cage. In 

comparison, the inactive samples do not have this 

nanoscale structure and are partially crystalline. 

The most active samples have only local order 

(to 1.0 nm) and also have cage-like structures, or 

ones with micropores. The micropores (sized on the 

order of 0.4 to 1.0 nm) are likely filled with water or 

hydroxyl groups and are therefore conducive for 

proton conduction. The iron in the active samples 

also exists in mixed valence states, which is likely to 

contribute to the electrochemical activity of the PtFeOx. Furthermore, the Pt atoms are uniformly 

distributed throughout the structure.

Figure 1. Tafel plot of standard 10% Pt on Vulcan 

carbon compared to the new catalysts of 20% 

Pt (~5% Pt-Fex) on Vulcan carbon (0.6 weight 

% Pt total). 

 Conditions: sweep rate = 10 millivolts; 

electrolyte: 0.1 M sulfuric acid (H2SO4); 

rotation rate = 1000 rpm; temperature = 60°C. 

Data from argon gas sweep subtracted from 

that of O2 sweep. 

Figure 2. PDF-XRD of 3% Pt-FeOx vs. FeOx. The 

addition of 3% Pt to the FeOx structure causes 

four significant changes: (1) an increase in 

the distance between the iron and oxygen 

atoms, (2) a decrease between the platinum 

and iron atoms, (3) disruption of the bridging 

oxygen, and (4) disorder to the network 

beyond 0.4 nm. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

416

The Pt-FeOx catalysts are not stable to corrosion, 

as has been confirmed in our laboratory and during 

fuel cell testing at LANL.

However, we can use our understanding of the 

Pt-FeOx materials to design new, stable catalysts. Ptniobium oxide (Pt-NbOx) catalysts are currently 

under development. Preliminary studies show that 

despite having 150 times less Pt than the 10% Pt/VC 

standard, the Pt-NbOx samples have high activity. 

NbOx is a more stable oxide than FeOx, and studies 

are underway to confirm its long-term activity. 

Conclusions

The ORR activity of Pt is greatly enhanced by 

dissolving it in a matrix that is a good protonic 

conductor. PDF-XRD structural measurements show 

that the addition of low amounts of Pt (~3%) to FeOx

can lead to a material with high ORR activity and a 

unique structure. Active materials are disordered 

beyond ~1.0 nm and also have micropores. 

Disruption of the microporous structure causes a 

decrease in catalyst activity. Although the Pt-FeOx

catalysts are not stable to corrosion, new niobiumbased catalysts are being investigated and already 

show higher stability. 

Other transition-metal oxide systems having 

little or no Pt will continue to be developed. A fuel 

cell test station is also being acquired by NRL, so 

that new materials can be tested rapidly and 

effectively. 

If the results from the half-cell measurements are 

matched in the actual fuel cell operation, the DOE 

goals to reduce the Pt loading of the fuel cell by 10X 

by 2008 will be met. The decreased amount of Pt in 

the fuel cell will also result in a significant decrease 

in the cost of the PEMFCs.

References

1. K. E. Swider-Lyons, K. M. Bussmann, D. L. 

Griscom, C. T. Love, D. R. Rolison, W. 

Dmowski, and T. Egami, in Solid State Ionic 

Devices II Ceramic Sensors, E. D. Wachsman, W. 

Weppner, E. Traversa, P. Vanysek, N. Yamazoe, 

M. L. Liu, Editors, The Electrochemical 

Proceedings Series, Pennington, NJ , 2000, 

PV2000-32, p. 148.

2. T. Egami, Mater. Trans., 31 (1990) 163.

3. S. Lj. Gojkovic, S. K. Zecevic, and R. F. Savinell, 

J. Electrochem. Soc., 145 (1998) 3713.

FY 2002 Publications/Presentations

1. K. E. Swider-Lyons, “Mixed-Conducting Oxides 

in Electrochemical Power Sources,” in High 

Temperature Materials In Honor of the 65th

Birthday of Professor Wayne L. Worrell, ed. S. 

Singhal, The Electrochemical Proceedings Series, 

2002, PV 2002-5, p. 124. 

2. K. E. Swider-Lyons, “Mixed-Conducting Oxides 

in Electrochemical Power Sources,” Symposium 

on High Temperature Materials In Honor of the 

65th Birthday of Professor Wayne L. Worrell, 

100th Meeting of the Electrochemical Society, 12-

17 May 2002, Philadelphia, PA. 

3. W. Dmowski, T. Egami, K. E. Swider-Lyons, and 

C. T. Love, “Nanocrystalline or Amorphous? 

Structure of Hydrous RuO2 from X-ray 

Scattering” Conference on Crystal Chemistry of 

New Materials and Soft Matter Studied by 

Figure 3. Schematic of a CLP framework. The 

micropores in the structure are ideal for 

proton conduction. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

417

Synchrotron and Neutron Diffraction and 

Scattering. August 2002, Grenoble, FRANCE. 

4. Karen E. Swider-Lyons, Jason A. Stanley, 

Gregory B. Cotten, Wojtek Dmowski, and 

Takeshi Egami, “Low-Platinum Oxide-Based 

Electrocatalysts For Oxygen Reduction In Proton 

Exchange Membrane Fuel Cells,” Symposium on 

Recent Advances in Fuel Cells and Fuel 

Processing, 224th National Meeting of the 

American Chemical Society,18-22 August 2002, 

Boston, MA. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

418

IV.D.11 Low Platinum Loading Catalysts for Fuel Cells

Radoslav Adzic (Primary Contact), Jia Wang, Stanko Brankovic, Kotaro Sasaki

Brookhaven National Laboratory, Bldg. 555

Upton, NY 11973-5000

(631) 344-4522, fax : (631) 344-5815, e-mail: adzic@bnl.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov 

Objectives

• Develop a new catalyst with a considerably lower Pt loading, to reach the 2004 DOE target of 300 μg/

cm2 total noble metal loading (150 μg/cm2 for anode) and improved carbon monoxide (CO) tolerance 

compared with the commercial platinum Ruthenium (Pt-Ru) catalysts. 

• Characterize Pt/Ru electrocatalysts prepared by a new method involving a spontaneous deposition of 

Pt on Ru nanoparticles. 

Approach

• Synthesize electrocatalysts having a submonolayer Pt loading on Ru nanoparticles by spontaneous 

deposition of Pt on a Ru surface.

• Determine the catalytic properties of the new catalyst for hydrogen (H2) and H2 + CO oxidation and 

improve the thin layer rotating disk electrode method.

• Characterize new electrocatalysts by high-resolution transmission electron microscopy (HRTEM), insitu fourier transform infrared (FTIR) spectroscopy and extended x-ray absorption fine structure 

(EXAFS) techniques. 

• Test the new electrocatalyst in the membrane electrode assembly (MEA) at Los Alamos National 

Laboratory.

• Explain the catalytic activity and function of the new electrocatalyst.

Accomplishments

• Electrocatalysts with a 1/8 of monolayer Pt loading on Ru nanoparticles have been synthesized by 

spontaneous deposition of Pt on a Ru surface, each of which have at least three times larger massspecific activity for H2 oxidation than two commercial catalysts and a larger CO tolerance, as 

determined by thin film rotating disk electrode measurements.

• The carbon-supported catalysts with 1% Pt on 10% Ru (18 μg Pt/cm2

) tested in the MEA at Los 

Alamos National Laboratory by Dr. Francisco Uribe exhibited a high CO tolerance and the same 

activity for H2 oxidation as commercial catalysts with 10 times larger Pt loadings. This catalyst has the 

noble metal loading close to the 2004 DOE target (200 vs. 150 μg/cm2

 ), which can be reached by a 

small decrease of Ru content.

• The possibility of having a catalyst for diatomic oxygen (O2) reduction with a monolayer of Pt on Ru 

that approaches the activity of carbon-supported Pt has been demonstrated.

• A method of synthesizing carbon-supported W nanoparticles has been developed with D. Mahajan 

from Brookhaven National Laboratory (BNL). These nanoparticles will be tested as the core for new 

catalysts containing low coverages of noble metals in the shell. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

419

Future Directions

• Further optimization of the catalyst prepared by spontaneous deposition of Pt and further catalyst 

characterization with electrochemical and EXAFS techniques.

• Further testing of the catalyst in the MEAs. 

• Investigation of possibilities to reduce or replace Ru in the catalyst by non-noble metals.

• Investigations of low Pt loading catalysts for O2 reduction.

Introduction

In June 2001 we initiated this project to explore 

the possibilities of decreasing the Pt loading in Pt-Ru 

catalysts for H2/CO oxidation in the polymer 

electrolyte membrane fuel cells (PEMFCs). We have 

demonstrated a new method for the preparation of the 

Pt-Ru catalysts involving spontaneous deposition of 

Pt on Ru nanoparticles that we explored first with 

single crystal Ru surfaces. The resulting catalysts 

have a high CO tolerance with considerably lower Pt 

loading than the commercial catalysts. 

Approach

Pt is deposited only at the surface of Ru 

nanoparticles rather than throughout the Pt-Ru 

nanoparticles. The method facilitates tuning of the 

electronic and catalytic properties of Pt-Ru catalysts 

by controlling the Pt cluster size. In contrast to the 

Pt-Ru alloy catalysts, this structure has all the Pt 

atoms available for the catalytic reaction, which 

decreases the Pt loading.

Results

Characterization of the Electrocatalyst

HRTEM has been used to investigate the type of 

Pt deposited on Ru nanoparticles. For the PtRu20 

catalyst, the dominant features, both in symmetry and 

lattice spacing, are consistent with the hexagonally 

close-packed Ru single crystal structure. An example 

of the images with different resolutions obtained with 

the help of Y. Zhu (BNL) is shown in Figure 1. 

Figure 1e is a pattern Fourier transferred from the 

boxed area in Figure 1d, where the particle is viewed 

along the (101) direction.

 The distribution of the lattice spacing and the 

lattice fringes obtained from 170 particles fit well 

with the low index spacings of the hexagonally closepacked Ru single crystal. Pt is selectively deposited 

Figure 1. Upper panel: model of Pt islands on a Ru 

cubooctahedron nanoparticle. Lower panel: 

Electron micrographs of the PtRu20 catalyst. 

(a) Low magnification morphology of the 

metal particles (black dots, average size 2.5 

nm) on carbon spheres (average size 50 nm). 

(b-d) High-resolution images showing atomic 

resolved lattice structures. (e) Diffractogram 

obtained from the high-resolution image 

shown in (d).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

420

on Ru nanoparticles and not on carbon because a 

metallic Ru surface acts as a reducing agent for Pt 

deposition. For low Pt:Ru atomic ratios the small Pt 

clusters are expected, and these probably acquire the 

Ru lattice spacing upon small contraction. 

In-situ EXAFS data obtained with the help of M. 

Subramanian and J. McBreen (BNL) are shown in 

Figure 2. The radial structure functions of Pt foil and 

Pt/Ru catalysts are compared. The spectrum for the 

Pt/Ru catalyst is dominated by Ru. The analysis 

shows that the smaller peak can be fitted by the one 

Pt atom coordinated to four Ru atoms. The Pt-Ru 

bond length is 2.69Å, as in the Pt-Ru alloys. The PtPt coordination is being analyzed. First results 

indicate that the Pt islands on Ru are very small, 

which is consistent with the HRTEM data. 

Catalytic Activity

The thin-film rotating disk electrode has been 

used for determination of the catalytic activity. The 

catalyst was attached to the glassy carbon electrode 

by careful deposition from aqueous dispersion and no

Nafion® film was used to cover the deposit. This can 

significantly improve the tests of supported 

electrocatalysts. Kinetic parameters for the oxidation 

of H2 and H2 + CO have been determined by 

nonlinear fitting of the entire polarization curve. 

Mass-specific activities of the catalysts were 

determined by finding the minimum Pt loading 

needed to obtain the Tafel slope, exchange current 

density, and the Levich slope comparable to those 

found for the polycrystalline Pt electrode. In this 

way, a full utilization of the catalyst is verified. 

Figure 3 shows H2 oxidation on the PtRu20 catalyst; 

the curve is the fit to the experiment (points) for j0 = 

1.3 millamps per centimers squared (mA/cm2

) and b 

= 29.6 millivolt (mV), which are the values for 

polycrystalline Pt. The insert shows the calculated 

kinetic current in the absence of diffusion control.

For the PtRu20, PtRu10, and PtRu5 samples 

prepared by spontaneous deposition of 1/9 to 4/9 

Figure 2. In situ EXAFS data for the PtRu20

electrocatalyst at 0.05 V vs. reversible 

hydrogen electrode in 0.5 M H2SO4 solution. 

The curve for a Pt foil is given for 

comparison. 

Figure 3. Polarization curves for H2 oxidation on 

PtRu20/C prepared by spontaneous Pt 

deposition in 0.5 M H2SO4 solution. The 

parameters of the best fits are given in the 

graph. Insert: Calculated kinetic current vs. 

potential with b=29.6 mV and j0=1.30 mA/

cm2

. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

421

monolayer Pt on Ru, the minimum Pt loading is 5 

nmol/cm2 (1 μg Pt/cm2

). This is only 1/3 of that for 

Pt or PtRu (Commercial A) catalysts and only twice 

of the atomic density of a Pt(111) surface, indicating 

that the high activity of Pt metal for hydrogen 

oxidation is retained when the atomic assemblies are 

reduced to submonolayer levels on Ru. The enhanced 

CO tolerance was studied at low potentials by 

correlating the loss of activity in 0.1% CO/H2 and the 

CO coverage on Pt and Ru sites.

Figure 4 displays a mass-specific activity of 

PtRu20 catalyst in comparison to Commercial A’s 

PtRu 1:1 alloy and Commercial B’s Pt3Ru2

electrocatalysts for the oxidation of H2 in 0.5M 

H2SO4. A considerably higher mass-specific activity 

of the PtRu20 electrocatalyst has been observed. 

CO Tolerance

Figure 5 displays a comparison of the CO 

tolerance of three catalysts based on the current as a 

function of time for the oxidation of H2 with 1095 

ppm of CO at 60o C for the PtRu20, Commercial A’s 

PtRu and Commercial B’s Pt3Ru2 catalysts with the 

loadings indicated in the graph obtained with rotating 

disk electrode at 2500 rpm. A considerably larger CO 

tolerance is seen for the PtRu20 electrocatalyst.

Conclusions

The new electrocatalyst has higher mass-specific 

activity and CO tolerance than commercial 

electrocatalysts with several times larger Pt loadings. 

The Pt islands on Ru have lower CO coverage than 

that of the Pt-Ru alloy, as inferred from the CO 

stripping charges. Lower Pt-CO bond strength and an 

efficient CO spillover to RuOH are the likely causes 

of enhanced CO tolerance. The new catalyst 

facilitates reaching the limiting value for Pt 

dispersion, and thus, full catalyst utilization becomes 

possible.

For Pt, the loading of the new catalyst is below 

the DOE target (150 μg/cm2

) for precious metals for 

2004. For Ru, it is at the present level of the state-ofthe-art catalysts. 

Preliminary data for O2 reduction on 1⁄2 

monolayer of Pt on Ru nanoparticles (not shown) 

indicates that a very active catalyst for O2 reduction 

can be designed with low Pt loadings. 

FY 2002 Publications 

1. S. R. Brankovic, J.X. Wang, and R.R. Adzic, 2. Pt 

submonolayers on Ru nanoparticles - a novel low 

Pt loading, high CO tolerance fuel cell 

electrocatalyst , Electrochem. Solid State Lett., 4, 

A217-A220 (2001).

Figure 4. Mass-specific activities of the three 

electrocatalysts for the oxidation of H2 at 0.05 

V in 0.5M H2SO4 at 25 and 60o C at 2500 

rpm.

Figure 5. CO tolerance of the three electrocatalysts 

from a time dependence of the current for the 

oxidation of H2 with 1095 ppm CO in 0.5M 

H2SO4 at 60o C at 2500 rpm.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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3. S.R. Brankovic, J McBreen, R.R. Adzic, 

Spontaneous Deposition of Pt on a Ru(0001) 

Surface, J. Electroanal. Chem., 503, 99-104 

(2001).

4. S.R. Brankovic, J. McBreen, R.R. Adzic, 

Spontaneous deposition of Pd on a Ru(0001) 

Surface, Surf. Sci., 479, L363-L368 (2001).

5. S.R Brankovic, J.X Wang, R.R. Adzic, Metal 

monolayer deposition by replacement of metal 

adlayers on electrode surfaces, Surf. Sci., 477, 

L173- L179 (2001).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.D.12 Development of High-Performance, Low-Pt Cathodes Containing New 

Catalysts and Layer Structure

Paolina Atanassova (Primary Contact), David Dericotte, Paul Napolitano, Rimple Bhatia, Jim 

Brewster, Mark Hampden-Smith (SMP), Cynthia Lundgren, Lin Wang (DuPont) and Sandip 

Mazumder (CFDRC)

Superior MicroPowders, LLC

3740 Hawkins Dr. NE

Albuquerque, NM 87109

(505) 342-1492, fax: (505) 342-2168, e-mail: paolina@smp1.com

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Valri Lightner: (202) 586-0937, fax: (202) 586-3237, e-mail: Valri.Lightner@ee.doe.gov

Contractor: Superior MicroPowders, LLC, Albuquerque, NM

Subcontractors: DuPont, Wilmington, DE; CFDRC, Huntsville, AL

Objectives 

• Develop and apply combinatorial powder synthesis platform based on spray pyrolysis for discovery of 

high-performance low-Pt cathode electrocatalysts.

• Develop engineered cathode layer structures containing the new electrocatalysts.

• Demonstrate enhanced performance of membrane electrode assemblies (MEAs) with low Pt content 

towards the DOE goals of 0.6 g Pt/kW in automotive applications for the year 2005.

Approach 

• Design and build a combinatorial powder synthesis system (CPSS) capable of generating a large 

number of electrocatalyst powders with variable composition and microstructure.

• Test benchmark catalysts with half-cell rapid screening technique for their activity in the oxygen 

reduction reaction (ORR) and compare ranking of catalysts with their performance in polymer 

electrolyte membrane MEAs.

• Synthesize binary and ternary Pt-alloy electrocatalysts by spray pyrolysis and test their performance in 

MEAs.

• Optimize the MEA structure with benchmark Pt-based supported catalysts with various Pt loadings in 

the catalysts and in the cathode layer.

• Improve the software for modeling the operation of fuel cells to account for the effect of liquid water 

on the performance of the cell, and perform validation studies.

Accomplishments 

• Combinatorial Powder Synthesis System (CPSS) designed and assembled on schedule.

• Half-cell rapid screening technique for screening electrocatalysts for their ORR activity in place and 

benchmarked for various Pt-based electrocatalysts.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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• Various binary and ternary Pt-alloy catalysts synthesized by spray pyrolysis and improved 

performance demonstrated in terms of lower g Pt/kW at 0.8 V n up to 40% reduction of Pt loading 

demonstrated for ternary Pt-alloy catalysts compared to supported Pt catalysts.

• Strategy and workflow for future combinatorial synthesis in place.

• MEA structure and printing approach improvements demonstrated in comparison with initial test data.

• Improvements in the fuel cell performance modeling developed and validation studies in progress.

Future Directions 

• Install and apply the CPSS for production, in a combinatorial mode, of a large number of 

electrocatalyst powders with variable composition and microstructure.

• Increase capacity of half-cell rapid screening technique to match the screening needs of CPSS powder 

generation capability.

• Continue to improve the structure and performance of the cathode layer and test the performance of 

newly discovered electrocatalyst compositions in MEA configuration that are identified by the rapid 

screening technique to have enhanced kinetic performance.

• Use modeling to predict trends in the MEA performance as a function of variables in the electrode 

structure and operating conditions.

• Demonstrate the performance of combined features derived from the best performing low-Pt 

electrocatalyst and the optimal MEA structure in a short stack fuel cell.

Introduction 

One vital issue delaying mass production of 

PEMFCs is the availability of a low-cost, highperformance oxygen reduction catalyst. Superior 

MicroPowders (SMP) has developed a spray-based 

process for low-cost, high-volume manufacturing of 

high-performance, highly reproducible 

electrocatalyst powders for PEMFC applications (1). 

This powder production process serves as the 

platform for this project to achieve the aggressive 

low-Pt DOE targets of 0.6 g Pt/kW by the year 2005.

The project goals are to significantly improve 

both the kinetic performance of the electrocatalyst 

powder at low noble metal loading and its utilization 

in the cathode layers through layer structure 

development. Limitations in the catalyst performance 

will be addressed through combinatorial discovery of 

supported catalyst compositions and microstructures. 

The discovery of these new catalyst formulations will 

be carried out under conditions that have been scaled 

for commercial powder production. A large variation 

of binary, ternary and quaternary noble metal - 

transition metal alloys and mixed metal-metal oxide 

catalyst compositions will be screened. To improve 

the utilization/performance of the catalyst in MEAs, 

the electrocatalyst-containing formulations will be 

applied to proton-conductive membranes where the 

chemical composition of the formulation and the 

nature of the coating will be varied to uncover the 

optimum cathode layer performance. 

Approach 

Effort 1: Combinatorial discovery of low Pt 

compositions with microstructure optimization using 

spray based catalyst manufacturing. This effort is 

focused on the combinatorial discovery of new low 

Pt electrocatalyst formulations. A large variation of 

multi-component catalysts will be produced by SMP 

in a combinatorial discovery mode. Initially, the 

powder synthesis will be performed with existing 

equipment and then on a new system designed and 

built at SMP. Samples generated at SMP, will be 

tested by DuPont in a half-cell rapid screening device 

for their electrochemical performance. The optimum 

compositions will be scaled up for testing in single 

MEAs and stacks. 

Effort 2: Development of engineered particles 

and layers. This effort is focused on the ability of the 

spray-based generation approach to tailor 

electrocatalyst structure to minimize polarization 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

425

losses. SMP will engineer and produce novel 

composite particles and MEA structures and test 

them in single 50 cm2

 cell MEA configuration to 

optimize the cathode layer structure and 

performance. In parallel, Computational Fluid 

Dynamics Research Corporation (CFDRC) will 

model MEA processes on microscopic (primary and 

secondary particle structure) and macroscopic (layer, 

MEA) scales. Using the results from the single cell 

testing and the data from the CFDRC model, SMP 

will further optimize the MEA structure to obtain 

maximum performance with a focus on highthroughput manufacturing and cost reduction.

Stack testing. Ultimately, MEAs designed and 

fabricated by SMP that combine the best scaled up 

novel catalysts (Effort 1) and the optimal cathode 

structure (Effort 2) will be tested in full scale short 

stack operation modules. The stack building and 

testing will be performed by leading automotive 

PEMFC developers, such as General Motors. The 

end-users will also provide valuable feedback in 

terms of performance and cost targets from a 

perspective of commercial implementation in the 

market.

Results 

In order to execute a combinatorial approach for 

discovery of novel electrocatalyst materials, several 

key workflow components need to be in place, 

including the ability to generate a large number of 

electrocatalyst powders with variation in the 

composition and microstructure and to test their 

activity in the ORR by a rapid screening technique. 

Combinatorial Synthesis. The conceptual design 

of the CPSS was completed during the current report 

period and its installation is on schedule. Figure 1 

illustrates the overall configuration of the CPSS, 

which is based on current R&D scale unit at SMP. 

Rapid screening of the electrochemical 

performance. DuPont has developed rapid half-cell 

screening techniques to evaluate catalyst activity for 

methanol oxidation, CO tolerance and oxygen 

reduction. These measurements are performed in 

liquid sulfuric acid electrolytes, and up to 32 

electrodes can be screened in parallel using a variety 

of electrochemical techniques in a 3-electrode 

configuration. A picture of the experimental setup is 

shown in Figure 2. With this capability, DuPont can 

rapidly evaluate many electrocatalyst samples and 

map their activity for electrochemical reactions. 

Using this set-up, DuPont evaluated a series of 

benchmark Pt-based catalysts supplied by SMP for 

the oxygen reduction reaction using linear 

polarization techniques in a sulfuric acid medium. 

The catalysts were tested at various loadings in the 

electrodes, and the normalized currents at various 

voltages were compared to the current densities 

observed in the kinetic region for MEAs made and 

tested at SMP. We have been able to correlate the 

ranking of the activity by the rapid screening 

approach and the MEA performance for different 

classes of catalysts. Further optimization of the 

electrode formulation is needed for accurate ranking 

of catalysts supported on different types of carbons.

Figure 1. Combinatorial Powder Synthesis System 

Figure 2. DuPont’s Experimental Set-Up for Rapid 

Half-Cell Screening of Electrocatalysts
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

426

Binary and ternary Pt alloys. A large variety of 

Pt-based catalysts were tested for their performance 

in test conditions relevant to automotive applications 

and to benchmark their performance for further 

comparison with the newly discovered 

electrocatalyst compositions. Significant effort was 

placed on finding alternative platinum precursors to 

support the synthesis of complex alloy and metalmetal oxide electrocatalyst compositions, where 

metal precursor compatibility becomes important. 

Several platinum precursors were identified as 

yielding high performance Pt-based catalysts and 

being compatible with a variety of alloying metal 

precursors. The precursors are also more costeffective for large-scale production.

In order to establish a baseline for our systems 

and methodologies, several binary and ternary 

compositions supported on Vulcan XC-72 were 

evaluated. Among these were PtxRuy, PtxCoy, 

PtxCry, PtxPdy, PtxCryCoz, and PtxNiyCoz. Initial 

efforts were directed towards variation of the spray 

conversion processing conditions to ensure 

conversion of metals, crystallite size and alloying. 

Post processing of the powders was attempted in 

several cases and consisted of annealing the 

electrocatalysts in varying H2/N2 atmospheres, 

temperatures and times. Conversion of the metal 

precursors and alloying of different species were 

monitored via x-ray diffraction (XRD). Figure 3 

illustrates the effect of various processing conditions 

on the structural characteristics of PtxNiyCoz/Vulcan 

XC-72 electrocatalysts. A selected ternary alloy, 20 

and 40 wt.% PtNiCo/Vulcan XC-72 electrocatalysts 

were tested in MEAs at identical total metal loadings 

and test conditions and compared to pure Pt 

supported catalyst. Improvement of up to 40% in 

terms of g Pt/kW at 0.8 V was observed when 

alloyed catalysts were compared to pure Pt ones. 

Figure 4 compares the performance of 40 wt.% 

PtNiCo/Vulcan XC-72 catalysts prepared at different 

conditions and 40 wt.% Pt/Vulcan XC-72 catalyst 

deposited at the same total metals loading of 0.45 mg 

Me/cm2 (Me – total metals loading) in the MEA. 

Test conditions. For the evaluation, 50 cm2

 test 

MEAs with Nafion 112 (DuPont) membrane were 

used. The MEAs were tested at 80°C, with flows 

corresponding to 1A/cm2 at 1.5 stoichiometry for 

hydrogen and 2.5 stoichiometry for air on the anode 

and cathode, respectively. Humidified H2 (100%) 

and air were used, at 30 psig pressure on both the 

anode and cathode sides. 

MEA structure development. The development 

of the electrode structure was focused on finding 

optimal combinations of electrocatalyst loadings, 

layer thicknesses and ionomer-to-catalyst ratios. 

Figure 5a shows the polarization curves for MEAs 

with 60 wt.% Pt/Carbon used as cathode catalyst at 

Pt loadings in the range of 0.25 to 0.65 g Pt/cm2. 

Figure 5b compares the performance of these MEAs 

in terms of g Pt/kW at 0.8 V. For all these 

benchmark Pt loadings, a performance around 2 g Pt/

kW was demonstrated.

Figure 4. Performance Comparison of Ternary 40 wt.% 

PtxNiyCoz/Vulcan XC-72 and 40 wt.% Pt/

Vulcan XC-72 Electrocatalysts

Figure 3. Synthesis of Ternary Pt-alloy 

Electrocatalysts: Effect of Composition and 

Processing Conditions on Structural 

Parameters 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

427

Various types of Nafion membranes and gas 

diffusion layers were compared as well. The 

electrode deposition technique was optimized to 

achieve performance comparable to the “state-of-theart” for ink deposition approach. Several deposition 

techniques were investigated for printing the 

electrode layers, Figure 6 compares the performance 

achieved with two MEAs, printed by method A and 

method B with otherwise identical composition. 

Improved Method B yields performance of 1.9 g Pt/

kW at 0.8 V and the above stated test conditions. 

Further optimization of the electrode structure is in 

progress for catalysts with various loadings on highsurface-area carbon supports.

Modeling effort. CFDRC has made several 

generic improvements to their existing software for 

modeling fuel cells and performed several validation 

studies. These are listed below:

• A comprehensive water transport model was 

developed to account for effect of liquid 

water on the performance of the cell. This 

involved solution of an additional transport 

equation for liquid water saturation. Effects 

of convection, surface tension, electroosmotic drag, gravity and surface tension are 

taken into account in this model.

• Several new models to compute effective 

diffusivity in porous regions were 

implemented.

• Several validation studies were performed 

against data reported in the literature.

Validation of the code against data generated inhouse at SMP is underway. Upon completion of 

these validation studies (expected by September, 

2002), much of the focus will be on using the model 

as a predictive tool to identify better MEA designs. 

Further development of the model to account for 

variables in the structure on a microscopic level is in 

progress.

Conclusions 

Significant progress has been made in 

implementing all necessary components for 

successful execution of both the combinatorial 

Figure 5a. Effect of Pt Loading on Performance Using 60 

wt.% Pt/Carbon as Cathode Catalyst

Figure 5b. Performance of MEAs with 60 wt.% Pt/

Carbon Cathode Electrocatalyst at 0.8 V

Figure 6. Effect of Deposition Method on the MEA 

Performance
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

428

discovery approach and electrode structure 

optimization. Results on the synthesis of benchmark 

alloy catalyst compositions demonstrate the ability of 

the SMP’s spray approach to generate complex 

electrocatalyst formulations with improved 

electrochemical performance. Future work will 

expand on the compositions screened according to a 

combinatorial strategy in place. The advances in the 

two parallel efforts, i.e. improvements in kinetic 

performance and MEA structure optimization, will 

be combined to reveal the overall achievements in 

performance at reduced Pt loadings.

References

1. Kodas, T.T., M.J. Hampden-Smith, J. Caruso, D.J. 

Skamser, and Q.P. Powell, Metal-carbon 

composite powders, methods for producing 

powders and devices fabricated from same. 2000, 

Superior MicroPowders: US 6,103,393.
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429

IV.D.13 New Electrocatalysts for Fuel Cells

Philip N. Ross, Jr. (Primary Contact), Nenad Markovic

Lawrence Berkeley National Laboratory

Materials Sciences Division

1 Cyclotron Rd., MS 2-100

Berkeley, CA 94720

(510) 486-6226, fax: (510) 486-5530, e-mail: pnross@lbl.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202)586-2480, fax: (202)586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Conduct research on the kinetics and mechanism of electrode reactions in low temperature fuel cells. 

Develop new electrocatalysts using a materials-by-design approach.

Approach

• Study the kinetics of fuel cell electrode reactions on well-characterized model electrodes and high 

surface area fuel cell electrocatalysts using modern electroanalytical methods. Study the mechanisms 

of the reactions using state-of-the art in-situ spectroscopes. 

• Use ultra-high vacuum methods of surface preparation and surface analyses to form tailored surfaces. 

Synthesize nanoclusters to have the tailored surface. 

• Characterize the microstructure of the nanoclusters by high-resolution electron microscopy. 

• Transfer technology to catalysts developers/vendors.

Accomplishments 

• Proof-of-principle experiments demonstrated that a Au-Pd alloy with <50 wt. % Pd can replace Pt as 

the hydrogen electrode catalyst without any loss in performance.

• Proof-of-principle experiments demonstrated that “Pt skin” structures with a non-precious metal core 

can be stable under PEMFC air cathode operating conditions

Future Directions

Cathode side 

• Create “skin” nanostructures of Pt on non-noble substrates and determine their activity and stability as 

novel low-Pt air cathode electrocatalysts. Select the most promising substrate for synthesis as high 

surface area catalyst.

• Develop and optimize a new class of non-Pt model catalysts. Synthesize and test new non-Pt high 

surface area catalysts at fuel cell conditions.

Anode side

• Synthesize and characterize Pd-Au bimetallic nanoparticles and conduct preliminary testing of these 

nanoparticles as anodes in PEMFC hydrogen-air cells.

• Determine CO-tolerance of tailored electrodes consisting of thin films (1-10 monolayer) of Pd on the 

close-packed single crystal surfaces of Ta, Re, and W.
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430

Introduction

It is known from the theory of surface 

segregation in bimetallic alloys that, in certain 

systems, preferential surface enrichment in one 

element is so strong that it leads to a “skin” structure, 

i.e. the outermost layer is a “skin” of one element. 

Theoretically, for nanoparticles, such a segregating 

alloy system could form particles having a “grape” 

microstructure, a skin of one element over a core of 

the other. In principle, one could use this 

thermodynamic property to replace the “buried” 

atoms in Pt nanoparticles with a non-precious metal, 

e.g. Fe or Co, resulting in 100% Pt dispersion (all Pt 

atoms are surface atoms) without the need to create 

extremely small particles, e.g. <2 nm. For example, 

if a standard pure Pt catalyst consists of particles 

having on average a dispersion of 20%, replacement 

of the buried atoms in those particles with a base 

metal would enable the Pt loading to be reduced by a 

factor of 5, all other factors being the same. This is 

the basic strategy we are currently pursuing to reduce 

Pt loading in PEMFC cathodes.

Approach

Pt3Ni and Pt3Co are classical examples of alloys 

of Pt having a skin surface structure, a pure Pt skin. 

In this case, enrichment occurs by interchange of Pt 

and Co atoms between the first two atomic layers, the 

subsequent layers having the bulk composition (75% 

Pt). The thermodynamic driving force in this case is 

for the larger atom to be at the surface, since, in facecentered cubic metals, the surface is generally 

relaxed outward and the second layer contracted. 

The Pt3Ni and Pt3Co systems do not represent cases 

of extreme segregation we need for replacing buried 

Pt atoms, but they do serve as a useful test case for 

the concept of a skin structure, and there may be, by 

serendipity, a beneficial electronic effect. The most 

important aspect of the study of this system was the 

stability of the skin structure when used as an oxygen 

reduction electrode under PEMFC conditions.

Results

Cathode Catalysts

Pt3Ni and Pt3Co solid electrodes were prepared 

using conventional metallurgy and pre-treated in a 

surface analytical vacuum chamber equipped with 

various instruments for surface preparation and 

analysis. For each alloy, either a pure Pt skin or a 75 

at.% Pt surface was prepared and tested as an oxygen 

reduction catalyst. The resulting activity for oxygen 

reduction as a function of composition is shown in 

Figure 1. The Pt skin structure is both more and less 

active than the pure Pt reference surface, depending 

on whether the subsurface is Co or Ni, suggesting 

there is an electronic effect that can be either 

beneficial or deleterious. The most important result 

represented in Figure 1 is the stability of the skin 

structure under the conditions of use as an oxygen 

reduction electrode, e.g. continuous cycling between 

0.1 – 1.0 V under 1 bar O2 in acid electrolyte (1 M 

trifluoromethane sulfonic acid) at 60o

C produced no 

change in the curves. 

Anode Catalysts

The catalytic activity of Pd for the hydrogen 

oxidation reaction (HOR) can be modified by 

preparing the Pd in the form of an ultrathin film, e.g. 

1 monolayer (ML). This result is summarized in 

Figure 2. A 1 ML film of Pd on Pt(111) has about 5 

times the catalytic activity of a multilayer of Pd. 

Pt(111) was chosen for the substrate because of the 

lattice match with Pd. Preliminary results with a 

Re(0001) substrate look equally promising. 

According to thermodynamic predictions, Pd should 

form a pure monatomic skin on the surface of a 

Re3Pd (25% Pd) alloy. If this Pd skin has the same 

catalytic activity as the monolayer shown in Figure 2, 

then the Pd loading in the hydrogen anode of a H2-air 

PEMFC can be as low as 0.05 g per kW, e.g. about 

the same as in current conventional gasoline vehicle 

catalytic converters.

Conclusions

Proof-of-principle experiments indicate that 

synthesis of Pt as surface enriched nanoparticles 

could enable Pt loadings in the PEMFC air cathode 

to be lowered by as much as a factor of 5 from 

present (optimized) levels, e.g. from 1 g per kW to 

the DOE target of 0.2 g per kW. Comparable 

experiments with Pd thin films indicate an even 

greater reduction in Pt Group Metal (PGM) loading 

is possible for the hydrogen electrode, comparable to 

the PGM content of the catalytic converter in current 

conventional gasoline vehicles.
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431

Figure 1. (top) Current-potential curve for a rotating 

disk electrode (1600 rpm) under 1 bar O2 in 

0.1 M HClO4 for different disk electrodes: Pt 

skin on Pt3Ni, Pt skin on Pt3Co, and pure Pt. 

(bottom) Steady-state current densities (per 

unit geometric area) at 0.85 V (vs. reversible 

hydrogen electrode [RHE]) for the five 

different electrodes: pure Pt, Pt skin on Pt3Ni 

and Pt3Co, the 75% Pt surfaces on Pt3Ni and 

Pt3Co. 333 K.

Figure 2. (top) Current-potential curve for a rotating 

disk electrode (1600 rpm) under 1 bar H2 in 

0.1 M HClO4 for different disk electrodes as 

indicated in the labels. (bottom) Exchangecurrent densities in acid electrolyte (pH = 1) 

for the hydrogen oxidation reaction as a 

function of Pd coverage on the Pt(111) 

substrate. 293 K.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

432

Publications

1. Markovic, N. M. and P. N. Ross, 

“Electrocatalysts by Design: From the Tailored 

Surface to a Commercial Catalyst”, Electrochim. 

Acta, 45, 4101, 2000.

2. Markovic, N. M. and P. N. Ross, “New 

Electrocatalysts for Fuel Cells: From Model 

Surfaces to Commercial Catalysts”, CATTECH 4

(2000) 110.

3. V. Stamenkovi_, N. M Markovi_, P. N. Ross, 

“Structure-Property Relationships in 

Electrocatalysis: Oxygen Reduction and 

Hydrogen Oxidation Reactions on Pt(111) and 

Pt(100) in Solution Containing Chloride Ions”, J. 

Electroanal. Chem. 500 (2001) 43.

4. T.J. Schmidt, B. N. Grgur, N.M. Markovi, and 

P.N. Ross, “Oscillatory Behavior in the 

Electrochemical Oxidation of Formic Acid on 

Pt(100): Rotation and Temperature Effects”, J. 

Electroanal. Chem. 500 (2001) 43.

5. N. M Markovic, T.J. Schmidt, V. Stamenkovic, 

P.N. Ross, “Oxygen Reduction Reaction on Pt 

and Pt Bimetallic Surfaces: A Selective Review”, 

Fuel Cells-From Fundamentals to Systems , 1 

(2001)105-116.

6. T.J. Schmidt, V. Stamenkovic, C.A. Lucas, N.M. 

Markovi, and P.N. Ross, “Surface Processes and 

Electrocatalysis of the Pt(hkl)/Bi –Solution 

Interface”, Physical Chemistry Chemical Physics 

3 (2001)3879.

7. T.J. Schmidt, P.N. Ross, N.M. Markovi, 

“Temperature-Dependent Surface 

Electrochemistry of Pt Single Crystal Surfaces in 

Alkaline Solution” Part I. CO Oxidation”, J. 

Phys. Chem, B 105 (2001)12082.

8. U.A. Paulus, A. Wokaun, G.G. Scherer, T.J. 

Schmidt, V. Stamenkovic, V. Radmilovic, N.M. 

Markovi, and P.N. Ross, “Oxygen Reduction on 

Carbon Supported Pt-Ni and Pt-Co Alloy 

Catalysts”, J. Phys. Chem. B 106 (2002) 4181.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.D.14 Electrodes for Polymer Electrolyte Membrane Fuel Cell Operation on 

Hydrogen/Air and Reformate/Air

Francisco A. Uribe (Primary Contact), Tom Zawodzinski, Judith Valerio, Guido Bender, Fernando 

Garzon, Andrew Saab, Tommy Rockward, Peter Adcock, Jian Xie, Wayne Smith

Los Alamos National Laboratory

PO Box 1663, MS D429

Los Alamos, NM 87545

(505) 667-3964, fax: (505) 665-4292, e-mail: uribe@lanl.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov 

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Optimize existing polymer electrolyte membrane (PEM) fuel cell technology for use with H2 and 

reformed hydrocarbons. 

• Improve overall PEM fuel cell operating efficiency.

• Improve the efficiency of the fuel cell cathode while lowering the dependence on precious metal 

loading.

• Achieve 0.4 amps per centimeters squared (A/cm2

) @ 0.8 volt (V) on hydrogen (H2) with <0.25 

milligrams platinum per centimeters squared (mg Pt/cm2) on cathode

• Demonstrate 0.4 A/cm2 @ 0.8 V on Reformate with <0.40 mg Pt/cm2 on cathode

• Initiate Cooperative Research & Development Agreement with Donaldson for studying the effect of 

ambient air impurities on fuel cell performance.

• Establish the effect of 50 parts per billion hydrogen sulfide on anode performance

Approach

• Investigate the use of a reconfigured anode to improve fuel cell performance in the presence of trace 

levels of carbon monoxide (CO) impurities.

• Evaluate new anode catalysts for CO tolerance.

• Study the effect of other potential reformate impurities on fuel cell performance.

• Evaluate new cathode catalyst and materials for higher operating efficiencies at lower precious metal 

loadings.

• Evaluate new membrane electrode assembly (MEA) fabrication protocols to enhance catalyst 

utilization and overall fuel cell efficiency.

Accomplishments

• Demonstrated the effectiveness of using the reconfigured anode in reformate fuel streams containing 

up to 250 parts per million (ppm) CO impurity with air bleed.

• Obtained good performances with a new CO tolerant 90:10 ruthenium:platinum anode catalyst. 

• Determined the effects of hydrogen sulfide, a potential reformate impurity, on fuel cell performance.

• Screened potential cathode catalysts with reduced platinum loadings.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

434

• Developed new MEA fabrication protocols leading to enhanced catalyst utilization and overall fuel 

cell performance.

Future Directions

• Investigate alternative catalyst materials for use in reconfigured anodes.

• Evaluate new potential CO tolerant catalysts.

• Further study hydrogen sulfide fuel stream impurity effects and develop technologies to minimize 

associated performance reduction.

• Screen new potential cathode catalyst materials.

• Continue to develop modified MEA fabrication protocols.

Introduction

The reforming of hydrocarbon fuels is one of the 

leading processes under consideration for producing 

hydrogen to power PEM fuel cells. However, the 

hydrogen stream generated by the reforming process 

can contain volatile chemical compounds that 

significantly diminish the fuel cell performance. Two 

approaches to solving this problem are to lower the 

level of impurity resulting from the reformation 

process, or to modify the fuel cell itself to be more 

tolerant toward those compounds. This study has 

taken the latter approach; ways were investigated to 

improve the anode performance in the presence of 

anticipated reformate impurities. 

Fuel cell operation depends not only on 

hydrogen oxidation at the anode but also on oxygen 

reduction at the cathode. The oxygen reduction 

reaction plays a very significant role in limiting the 

operating efficiency of the fuel cell, and is very 

dependent on high precious metal loadings in the 

catalyst layer. Improving the efficiency of this 

reaction while lowering the precious metal loadings 

is critical to commercialization of fuel cell 

technology to automotive applications.

Approach

The predominant deleterious impurity 

anticipated in the reformate fuel stream is CO. This 

gas is more strongly absorbed on the surface of the 

catalyst than hydrogen, effectively blocking the sites 

where hydrogen oxidation should occur. One method 

to prevent this from happening is to remove the CO 

by oxidizing it to harmless carbon dioxide before it 

can reach and react with the anode surface. This can 

be accomplished by using the Los Alamos National 

Laboratory (LANL) reconfigured anode, shown 

schematically in Figure 1. The reconfigured anode 

has an outer, non-precious metal catalyst layer added 

to the standard MEA. Bleeding a low level of air into 

the fuel stream results in preferential oxidation of the 

CO at this outer layer.

A second approach to solving the CO problem is 

to use an anode catalyst that is intrinsically more CO 

tolerant and that may contain a lower percentage of 

precious metals. In a given period of time, we receive 

many new potential catalysts from both commercial 

and non-commercial sources. These materials are 

Figure 1. Fuel Cell Schematic with Reconfigured Anode
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

435

fabricated into MEAs, using a protocol established at 

LANL, then placed in fuel cells and tested under 

standard operating conditions.

A third approach to developing better fuel cell 

anodes is to study the kinetics and mechanisms 

associated with the reactions of suspected impurities 

in the reformate stream and various catalysts. The 

mechanism for CO poisoning of the anode catalyst is 

fairly well understood, but for other potential poisons 

that may not necessarily be the case. During this past 

year such a study has been initiated for hydrogen 

sulfide, a very likely by-product in reformed fuels 

initially containing sulfur bearing compounds.

An approach similar to that used to improve 

anode performance was also applied to the study of 

the cathode reaction and included the following:

• Develop new MEA fabrication methods to 

improve catalyst utilization.

• Work with vendors to develop and test new 

catalyst formulations.

• Study the dependence of performance on 

catalyst layer structure.

• Study the effects of suspected impurities 

present in air (sulfur dioxide, nitrogen 

oxides, particulates) on cathode 

performance.

Results

Results obtained with the LANL reconfigured 

anode and platinum anode catalyst are shown in 

Figure 2. The graph on the top shows the effect of a 

small amount of CO on the operating characteristics 

of the fuel cell, with pure hydrogen as a fuel source. 

There is an almost catastrophic loss of performance 

when 100 ppm of CO is added to the hydrogen. 

However, using the reconfigured anode and adding 

4% air to the mixture results in essentially complete 

CO oxidation and restores the performance of the 

fuel cell. The graph on the bottom shows similar 

results for a synthetic reformate fuel stream 

containing 40% hydrogen, 35% nitrogen and 25% 

carbon dioxide. In this case the effects of adding 250 

ppm of CO are fully mitigated with the addition of 

6% air.

The second approach of building CO tolerance 

directly into the anode catalyst has also been 

confirmed. The most promising results to date were 

obtained with a catalyst provided by R. Adzic from 

Brookhaven National Laboratory, composed of 10% 

ruthenium and 1% platinum on a carbon support. As 

shown in Figure 3, a significant fraction of the fuel 

cell performance is restored with the addition of 

small amounts of air to the fuel stream. Perhaps even 

more significant is that the total platinum loading of 

this catalyst is only 18 micrograms per square 

centimeter, approximately 1/10 that normally used in 

operating fuel cell anodes.

Figure 2. Fuel cell performance at 80oC with 

reconfigured anode containing a non-precious 

metal-based chemical catalyst. (0.2 mg Pt/cm2 

at each electrode)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

436

Preliminary data obtained with hydrogen sulfide, 

another anticipated reformed fuel impurity, show this 

compound has an even more serious effect on fuel 

cell performance than CO. Hydrogen sulfide appears 

to poison the platinum catalyst irreversibility.

Results obtained from studies on improving the 

cathode/oxygen reduction reaction are summarized 

in Figure 4. This figure shows the effect of changing 

the catalyst from pure platinum to a platinumchromium alloy, and of changing the MEA 

preparation method from the standard painted/decal 

method to using an automated doctor blade approach. 

The new catalyst and new preparation method both 

enhance fuel cell performance.

Figure 3. Low Pt Content Anode Catalyst for CO 

Tolerance (Anode: 0.2 mg Ru-Pt/cm2; 

Cathode: 0.2 mg Pt/cm2

)

Figure 4. Cathode Optimization: New Catalyst and 

MEA Preparation (0.2 mg Pt/cm2 at each 

electrode)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

437

Conclusions

The performance of fuel cells operating on 

reformed hydrocarbon fuels is seriously affected by 

the presence of trace impurities present in the fuel 

stream. However, a significant fraction of 

performance losses can be regained by using either a 

reconfigured anode design or an alternative anode 

catalyst material. This has been clearly demonstrated 

for a CO impurity level of up to 250 ppm in the fuel 

stream. Studies also indicate that using alternative 

cathode catalyst materials and new MEA preparation 

methods can still result in further fuel cell 

performance gains.

FY 2002 Publications\Presentations

1. F. Uribe, S. Gottesfeld and T. Zawodzinski, "The 

Effect of Ammonia as Potential Fuel Impurity on 

Proton Exchange Membrane Fuel Cell 

Performance", J. Electrochem. Soc., 149, A293 

(2002).

2. F. Uribe and T. Zawodzinski, "A Study of 

Polymer Electrolyte Fuel Cell Performance at 

High Voltages. Dependence on Cathode Catalyst 

Layer Composition and on Voltage 

Conditioning". Accepted in Electrochimica Acta. 

(2002).

3. P. A. Adcock, S. Pacheco, E. Brosha, T. 

Zawodzinski, and F. Uribe, "Maximization of CO 

Tolerance of PEMFC Systems Using 

Reconfigured Anodes". To be presented at the 

Electrochemical Society Meeting, Salt Lake City, 

UT (Fall 2002).

4. F. Uribe and T. Zawodzinski, "PEMFC 

Reconfigured Anodes for Enhancing CO 

Tolerance with Air Bleed", 201st Electrochemical 

Society Meeting, Philadelphia (2002). Abstract 

No. 806.

5. P. Adcock, F. Uribe, J. Valerio and T. 

Zawodzinski, "New Results for Maximization of 

CO Tolerance of Hydrogen and Reformate Fuel 

Cells", 201st Electrochemical Society Meeting, 

Philadelphia (2002). Abstract No. 814.

6. J. Xie, F. Garzon, T. Zawodzinski, "The 

Microstructure of the Cathode Catalyst Layer in 

PEFC's", 201st Electrochemical Society Meeting, 

Philadelphia (2002). Abstract No. 808.

7. J. Xie, S. Pacheco, K. Wilson, C. Zawodzinski 

and T. Zawodzinski, "Influence of Ionomer 

Content in the Cathode Catalyst Layer on the 

Performance of PEM Fuel Cells", 201st 

Electrochemical Society Meeting, Philadelphia 

(2002). Abstract No. 810.

8. E. Brosha, S. Pacheco, P. Zelenay, F. Uribe, F. 

Garzon and T. Zawodzinski, "Development of 

Freeze-Dried Catalysts for Hydrogen and Direct 

Methanol Fuel Cells", Electrochemical Society 

Meeting, San Francisco, CA (2001). Abstract No. 

322.

9. F. Uribe and T. Zawodzinski, "The Effects of Fuel 

Impurities on PEM Fuel Cell Performance", 

Electrochemical Society Meeting, San Francisco, 

CA (2001). Abstract No. 339.

Patent Applications

1. F. Uribe and T. Zawodzinski, "Fuel Cell Anode 

Configuration for CO Tolerance" (2001).

2. F. Uribe and T. Zawodzinski, "Method for 

Improving High Cell Voltage Performance for 

Polymer Electrolyte Membrane Fuel Cell". 2001/

0044040 (2001).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

438

IV.D.15 Nondestructive Study of the Water Transport Mechanism Inside 

Operating PEM Fuel Cells Using Neutron Imaging Techniques 

Muhammad Arif (Primary Contact), David Jacobson, Rahul Satija (now at Duke University)

National Institute of Standards and Technology

Gaithersburg, MD 20899

(301) 975-6303, fax: (301) 926-1604, e-mail: arif@nist.gov

DOE Technology Development Manager: Nancy Garland 

(202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

Neutron imaging may be the only technique available today that has the realistic possibility of mapping 

water distribution in flow channels and membranes inside operating PEM fuel cells. This information can 

be very important to fuel cell developers for designing more robust and efficient fuel cells. Our research 

objectives are as follows.

• Development of a neutron-imaging facility for studying PEM fuel cell water transport.

• Two-dimensional imaging of time-dependent bulk water distribution in an operating PEM fuel cell and 

quantification of the results.

Approach 

• Phase 1. Define neutron beam characteristics most sensitive to water distribution in fuel cells. Define 

spatial and temporal resolution parameters for visualization of water/vapor distribution. 

• Phase 2. Based on parameters defined in Phase 1, design a new beam line and a charge-coupled device 

(CCD)-based neutron imaging instrument at the National Institute of Standards and Technology 

(NIST) nuclear reactor. Make special considerations for easy accessibility and user friendliness of the 

facility for non-NIST fuel cell researchers.

• Phase 3. Carry out neutron measurements on a working 4-stack PEM fuel cell to define the operating 

parameters of the new setup and test the limits of achievable spatial and temporal resolution of water 

distribution and flow dynamics inside a working fuel cell. 

Accomplishments

• Designed a state-of-the-art new neutron imaging facility for fuel cell research. This facility will be 

used for critical water transport studies in the MEA and the flow channels, for the measurement of the 

hydrogen diffusion co-efficient across the MEA and water/vapor phase, and for evaluation of the 

integrity of various interfaces. The facility is expected to be operational in October, 2002.

• Using existing facilities, non-destructively imaged and quantified time-dependent water distribution in 

an operating fuel cell. A near 1 second time resolution was achieved. The total water content inside 

the fuel cell as a function of time was also quantified.

Future Directions

Three-dimensional imaging of the fuel cell is needed to allow independent measurement of water/vapor 

distribution parameters within any section or part of the fuel cell.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

439

• Develop neutron-imaging methods to accurately measure water gradients across a fuel cell PEM 

membrane.

• Determine diffusion coefficient and hydrophobic characteristics of the gas diffusion layer.

• Characterize two-phase flow mechanism in the fuel cell flow field.

• Study the time-dependent membrane-catalyst-gas diffusion layer interface integrity.

Introduction

Compared to most other forms of radiation, 

neutrons are highly efficient in probing complex 

structures because of their tremendous penetration 

capability in almost all known materials and due to 

their unique ability to distinguish different materials 

with very similar physical properties. They are 

particularly effective in detecting hydrogenous 

materials and other light elements. As a result, 

neutron imaging is ideally suited for non-destructive, 

in situ visualization and quantification of water 

transport phenomena in operating PEM fuel cells.

Approach and Results

The new setup is being constructed at the BT6 

high intensity thermal beam line at the NIST Center 

for Neutron Research (NCNR) nuclear reactor 

(Figure 1) to non-destructively characterize water 

transport mechanism in single or multi-stack PEM 

fuel cells. The high neutron flux will allow 

attainment of a time resolution of about 1 sec and a 

nominal detector spatial resolution of about 30 μm. 

The imaging process consists of a neutron beam 

passing through a sample. The beam is attenuated by 

the presence of hydrogenous material (water vapor/

water) present in the sample (fuel cell as an 

example). Consequently, an image of the 

hydrogenous material is formed and recorded by a 

CCD camera (Figure 2). The digital image is then 

analyzed to determine the quantity and distribution of 

water/water vapor inside the fuel cell. 

At the imaging station, the largest fuel cell that 

can be imaged is about 20 cm x 20 cm. A sample of 

larger length can be imaged section by section 

through translation of the sample. The fuel cells also 

can be single- or multi-cell. The facility will operate 

as a user facility; a proposal will be required and will 

be reviewed for merit before allocating beam time. 

A generic fuel cell test station will be available for 

Figure 1. Schematic of New Fuel Cell Imaging Station

Figure 2. Schematic of Neutron Imaging Setup
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

440

general use, but users will be free to bring their own 

if needed. 

To establish operating parameters for the new 

imaging station, we rotated a 4-cell stack in a high 

intensity thermal beam at the NCNR reactor and 

obtained three-dimensional images of the fuel cell as 

normally done during a medical imaging CAT scan. 

The cell was imaged while operating with a typical 

output of about 2.5 A at 3.5 V, and the water (and 

water vapor) profile in the flow channels was 

recorded as a function of time (about 1 frame a 

second). A sample of the water distribution is shown 

in Figure 3. A graph of the total water content as a 

function of time is shown in Figure 4. The water 

content shows periodic behavior with time. From 

time-lapse images it appears that the water drains 

only when it reaches a certain volume. The periodic 

drainage also seems to be un-correlated with the 

temperature fluctuation and hydrogen flow variations 

(which were small and random; inconsistent with 

observed periodicity). The most likely explanation is 

surface adhesion of water and/or capillary action by 

the flow channels. We plan to repeat these 

experiments in a more controlled environment in the 

near future. The quantification of time-dependent 

water distribution like this can be very useful in 

theoretical modeling of fuel cell water transport 

characteristics.

Conclusions

• A new imaging facility for fuel cell research is 

expected to be operational in October, 2002. It is 

a user facility open to researchers from fuel cell 

manufacturers and automotive companies as well 

as academic institutions and national 

laboratories.

• We have been able to observe time dependent 

water distribution in an operating fuel cell. The 

result should be useful in modeling water 

transport mechanism and design of flow 

channels. We plan to collaborate with University 

of Miami (among others) in this regard. 

Figure 3. Water Distribution in Flow Channels

Figure 4. Total Water Content in the Fuel Cell as a 

Function of Time
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

441

IV.D.16 Direct Methanol Fuel Cells

Piotr Zelenay (Primary Contact), Eric Brosha, John Davey, Christian Eickes, Robert Fields, Michael 

Hickner, Don McMurry, Bryan Pivovar, Geraldine Purdy, John Ramsey, John Rowley, Mahlon 

Wilson, Christine Zawodzinski, Thomas Zawodzinski, and Yimin Zhu

Materials Science and Technology Division

Los Alamos National Laboratory

Los Alamos, New Mexico 97545

(505) 667-0197, fax : (505) 665-4292, e-mail : zelenay@lanl.gov

DOE Technology Development Managers: Nancy L. Garland and JoAnn Milliken

(202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Objectives

• Develop materials, components and operating conditions of direct methanol fuel cells (DMFCs) for 

transportation and portable applications optimizing power density, overall fuel conversion efficiency 

and cost. In particular:

• Design and optimize membrane-electrode assemblies (MEAs) to enhance cell performance.

• Advance electrocatalysis of methanol oxidation and oxygen reduction, thus allowing lower total 

precious metal loading and/or better cell/stack performance.

• Demonstrate viability of cell components in short- and long-term operation of single cells and stacks.

Approach

• Build and operate single cells and prototype DMFC stacks with different anode and cathode catalysts, 

membrane materials, flow patterns and optimized MEAs to maximize performance and demonstrate 

stability.

• Perform complete electrochemical and non-electrochemical testing to gain insight into key factors 

impacting performance and durability of direct-methanol fuel cells.

• Model, design and fabricate hardware components to optimize performance of single cells and short 

stacks.

Accomplishments

Catalyst Research

• Identified an alternative binary platinum- patent pending/Carbon (Pt-X/C) cathode catalyst allowing 

DMFC operation at a voltage 60-80 millivolts (mV) higher than state-of-the-art platinum/carbon (Pt/

C) catalysts.

• Established in-house catalyst fabrication capability, by which otherwise unavailable catalysts can be 

synthesized, e.g., 80 weight percent Pt/C catalyst for the DMFC cathode.

• Optimized composition of cathodes with significantly reduced Pt loading, thus achieving 0.15 watt per 

centimeter squared (W cm-2)with a total precious metal loading of 1.2 milligrams (mgs) cm-2 (80°C).

• Completed study of the effect of platinum-to-ruthenium (Pt-to-Ru) ratio on anode performance, 

demonstrating optimum performance with 55±5 atomic percent of Ru in the anode catalyst layer.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

442

Membrane Research

• Determined sulfonation level and processing method as key to the performance of new sulfonated poly 

(arylene ether sulfone) membranes (BPSH membranes).

• Developed fabrication techniques and demonstrated BPSH MEAs with relative in-cell selectivity up to 

2.5 times that of Nafion®-based MEAs.

Stack Research and Development

• Designed and fabricated components for a new 22 W stack for portable power applications and a new 

500 W stack for auxiliary power unit (APU) applications.

• Tested novel hardware designs in single cells and prototype stacks with very good results.

Future Directions

• Continue fundamental research and development of electrocatalysts for methanol oxidation and 

oxygen reduction.

• Improve performance by optimizing hydrophilic/hydrophobic properties of the cathode.

• Determine the effect of sulfonation on performance of BPSH membranes in DMFCs; narrow the gap 

between bench-top and fuel cell selectivity of alternative membranes.

• Demonstrate durability of Nafion®-based MEAs in short stacks for 500 hours and alternative MEAs in 

single cells for 100 hours.

• Investigate composition of the DMFC cathode exhaust at various operating conditions.

• Complete 500 W stack for auxiliary power applications.

Introduction

Direct methanol fuel cell research at Los Alamos 

National Laboratory (LANL) has focused on 

developing materials, components and operating 

conditions relevant to potential applications in 

portable power (commercial electronics, battery 

replacement for the military) and transportation 

(vehicular propulsion, on-board auxiliary power 

units). The main objective of the LANL research 

effort in the area of direct methanol fuel cells has 

been to demonstrate that DMFC-based systems stand 

a good chance of meeting power-density, overall 

energy-conversion efficiency and cost targets 

outlined in the DOE Hydrogen, Fuel Cells and 

Infrastructure Technologies Program.

Results

In our FY 2002 research, we have focused on the 

performance of carbon-supported cathode catalysts, 

especially at low Pt loading. A major achievement 

has been the introduction of a new binary catalyst, 

Pt-X (patent application pending). In addition to 

showing higher activity towards oxygen (concluded 

from hydrogen/air fuel cell testing), this catalyst 

appears to be less susceptible to the detrimental 

action of the crossover methanol than regular Pt/C 

catalyst. As a consequence of higher activity in the 

oxygen reduction reaction and improved methanol 

tolerance, the Pt-X/C catalyst allows DMFC 

operation at a voltage 60-8-mV high than the voltage 

achievable with a state-of-the-art commercial PT/C 

catalyst (De Nora) at the same Pt loading of 0.6 mg 

cm-2 (Figure 1).

We have found that cathodes with significantly 

reduced Pt loading seem to benefit from the use of 

carbon-supported catalysts. A comparison of the 

activity of unsupported Pt cathode catalyst with the 

activity of carbon-supported Pt catalyst (40% Pt by 

weight) indicates that carbon-supported catalysts 

outperform unsupported catalysts as long as Pt 

loading remains below ca. 1 mg cm-2. Also, carbonsupported Pt and Pt-X cathodes both require careful 

optimization of the ionomer content in the catalyst 

layer, with the best results obtained at a weight 

fraction of recast Nafion® between 30 and 40%. 

Once the anode and cathode catalyst layers are 

optimized, a very good DMFC performance can be 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

443

achieved with even moderate Pt loading. One of the 

highlights of our DMFC research in FY 2002 has 

been reaching 0.15 W cm-2 in aerial power density 

with a total (anode + cathode) Pt loading of only 1.2 

mg cm-2 (80°C).

Continuing our anode catalyst effort, we have 

completed a performance study of unsupported Pt-Ru 

catalysts, with a Pt-to-Ru atomic ratio ranging from 

9:1 to 1:2. This study, conducted in collaboration 

with Johnson Matthey, has shown that, regardless of 

the cell operating temperature, the highest activity 

towards methanol is achieved with catalysts 

containing 55±5 at% of Ru in the bulk phase (Figure 

2). Voltammetric stripping of surface CO has further 

revealed that the corresponding surface composition 

of the best-performing catalysts is approximately 30 

at% of Ru.

In the past year, we have come considerably 

closer to the introduction of new ionomeric 

membranes into direct methanol fuel cells. Most of 

our membrane/MEA research has focused on the 

BPSH polymer (collaboration with Virginia Tech). 

We have found that membrane processing, such as 

boiling in acidic aqueous solutions, greatly affects 

the polymer morphology, ability to partially block 

methanol crossover and, consequently, selectivity in 

DMFC operation. Once processed, membranes with 

somewhat lower sulfonation level, BPSH-35 rather 

than BPSH-40, have been found to perform better in 

an actual DMFC. A very significant accomplishment 

of the membrane research in FY 2002 has been 

successful fabrication and testing of BPSH-based 

MEAs in direct methanol fuel cells. As shown in 

Figure 3, these MEAs are capable of performing 

comparably, if not better, than state-of-the-art MEAs 

using Nafion®. In addition to offering good cell 

performance, BPSH MEAs has been found to reduce 

methanol crossover by as much as 58%, from ~0.12 

A cm-2 (Nafion® 117) to ~0.05 A cm-2 (processed 

BPSH-35), 

Although fundamental research has remained the 

focal point of the DMFC project at LANL, we have 

continued prototyping DMFC stacks for the portable 

power applications and auxiliary power units to 

prove practical viability of core technology 

developed at LANL, identify possible scale-up 

issues, and verify adaptability of the technology to 

complete systems developed by our partner, Ball 

Aerospace & Technologies Corporation. 

Cell components for a portable power stack have 

been optimized in single-cell and short-stack testing. 

The first twenty-two-cell 22 W stack has been built 

and tested, showing respectable performance at 

ambient cathode pressure (0.75 atmospheres [atm]), 

Figure 1. DMFC Performance of Pt-X/C and Pt/C 

Cathode Catalysts at 80°C - Cathode Pt 

Loading 0.6 mg cm-2.

Figure 2. Performance of unsupported Pt-Ru anode 

catalyst as a function of atomic content of 

ruthenium in the bulk catalyst phase; current 

density determined from the anode 

polarization plots at a potential of 0.35 V vs.

dynamic hydrogen electrode.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

444

low air flow (stoichiometry below 3) and relatively 

high voltage of 0.55 V/cell (Figure 4).

The first-generation APU hardware for MEAs 

with 100 cm2 in the active area has been based on 

high-conductivity graphite plates. The maximum 

power generated by a single APU cell has been 21 W 

at a total cathode pressure of 2.8 atm and air 

stoichiometry of 2.1 (Figure 5). The same cell has 

delivered ca. 11 W at a cathode pressure of 0.76 atm 

(ambient) and air stoichiometry of only 1.3 (without 

accounting for the air needed to handle methanol 

crossover).

Conclusions

DMFC research at LANL in FY 2002 has 

focused primarily on fundamental issues relevant to 

potential portable and transportation applications of 

direct methanol fuel cells, such as cathode and anode 

electrocatalysis, electrode composition and structure, 

membrane properties and MEA design. Substantial 

progress has been achieved in cathode research, 

Figure 3. Cell Polarization and Methanol Crossover 

Plots Obtained with BPSH-35 (preprocessed by boiling) and Nafion® 117 at 

80°C - Cell Polarization Data Taken at 

Ambient Cathode Pressure CMeOH=1.0 mol 

per liter

Figure 4. 22 W Portable Power DMFC Stack and 

selected Performance Data
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

445

which includes the introduction of a highly 

promising binary catalyst and optimization of 

catalyst layers at a low Pt loading. The most active 

composition of the unsupported Pt-Ru anode catalyst 

has been identified. Major progress has been made 

in membrane/MEA research, with alternative 

membrane materials exhibiting greatly reduced 

crossover rates and in-cell performance at the same, 

or higher, level as obtained with Nafion® 117. The 

core MEA technology and fuel cell hardware 

developed at LANL over the past few years has been 

incorporated into components for the prototype 22 W 

and 500 W DMFC stacks for prospective portable 

and APU use, respectively. The first 22 W stack has 

been built and tested at ambient cathode pressure and 

low flow of air, with results clearly demonstrating 

significant practical potential of DMFCs.

FY 2002 Publications/Presentations

1. Adsorption on Fuel Cell Nanoparticle Electrodes: 

A Radioactive Labeling Study,” P. Waszczuk, A. 

Wieckowski, P. Zelenay, S. Gottesfeld, C. 

Coutanceau, J.-M. Léger and C. Lamy, J. 

Electroanal Chem., 511, 55-64 (2001).

2. Direct Methanol Fuel Cells at Reduced Catalyst 

Loadings,” P. Zelenay, F. Guyon and 

S. Gottesfeld, in Direct Methanol Fuel Cells, S. 

R. Narayanan, S. Gottesfeld and T. Zawodzinski 

(Eds.), ECS Proceedings, Electrochemical 

Society, Pennington, New Jersey, vol. 2001-4, 

pp. 123-135 (2001).

3. 80 Watt Direct Methanol Fuel Cell Stack for 

Portable Power Applications”, X. Ren, J. Davey, 

H. Dinh, B. Pivovar, C. Rice, S. Gottesfeld, and 

P. Zelenay, in Fuel Cell Technology: 

Opportunities and Challenges, Topical 

Conference Proceedings, 2002 AIChE Spring 

National Meeting, March 10-14, 2002, New 

Orleans, Louisiana.

4. Direct Methanol Fuel Cell Performance Using 

Sulfonated Poly(arylene ether sulfones) Random 

Copolymers as Electrolytes”, B. Pivovar, M. 

Hickner, J. McGrath, P. Zelenay, and T. 

Zawodzinski, in Fuel Cell Technology: 

Opportunities and Challenges, Topical 

Conference Proceedings, 2002 AIChE Spring 

Meeting, March 10-14, 2002, New Orleans, 

Louisiana.

5. Influencing the Transport of Water, Methanol and 

Protons through a Fuel Cell Ion Exchange 

Membrane”, M. Hickner, F. Wang, Y. Kim, B. 

Pivovar, T. Zawodzinski and J. McGrath, in Fuel 

Cell Technology: Opportunities and Challenges, 

Topical Conference Proceedings, 2002 AIChE 

Spring Meeting, March 10-14, 2002, New 

Orleans, Louisiana.

6. Joint 200th Meeting of the Electrochemical 

Society and 52nd Meeting of the International 

Society of Electrochemistry, San Francisco, CA, 

September 2-7, 2001. Title: “Development of 

Freeze-Dried Catalysts for Hydrogen and Direct 

Methanol Fuel Cells”; E. L. Brosha*, S. Pacheco, 

F. Uribe, H. Garzon, T. A. Zawodzinski.

7. Joint 200th Meeting of the Electrochemical 

Society and 52nd Meeting of the International 

Society of Electrochemistry, San Francisco, CA, 

September 2-7, 2001. Title: “Problems with 

Membrane Electrode Assemblies for NonNafion® Based Membranes”; B. S. Pivovar*, 

M. Hickner, J. E. McGrath, P. Zelenay and T. A. 

Zawodzinski.

Figure 5. Development of 500 W DMFC stack for 

auxiliary power system: Single cell 

polarization and power plots. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

446

8. 4th Hawaii Battery Conference 2002, Waikoloa, 

HI, January 8-11, 2002. Title: “Direct Methanol 

Fuel Cell Research and Development at Los 

Alamos National Laboratory” P. Zelenay (invited 

lecture).

9. 2002 Spring National Meeting of American 

Institute of Chemical Engineers, New Orleans, 

LA, March 10-14, 2002. Title: “80 W Direct 

Methanol Fuel Cell Stack for Portable Power 

Applications”; X. Ren, J. Davey, B. S. Pivovar*, 

H. N. Dinh, C. Rice, S. Gottesfeld, P. Zelenay.

10. 2002 Spring National Meeting of American 

Institute of Chemical Engineers, New Orleans, 

LA, March 10-14, 2002. Title: “Direct Methanol 

Fuel Cell Performance Using Sulfonated 

Poly(arylene ether sulfone) Random Copolymers 

as Electrolytes”; B. S. Pivovar*, M. Hickner, F. 

Wang, J. McGrath, P. Zelenay, T. A. 

Zawodzinski.

11. MRS Spring Meeting, San Francisco, CA, April 

2, 2002. Title: “System and Material Issues in 

Direct Methanol Fuel Cells”; B. S. Pivovar 

(invited talk).

12. 223rd Meeting of American Chemical Society, 

April 7-11, Orlando, FL. Title: “Electrocatalysis 

in Direct Methanol Fuel Cells”; P. Zelenay 

(keynote lecture).

13. 223rd Meeting of American Chemical Society, 

April 7-11, Orlando, FL. Title: “DMFC Activity 

of Pt:Ru Blacks of Different Composition”; C. 

Eickes*, P. Zelenay, T. Morita and D. 

Thompsett.

14. 223rd Meeting of American Chemical Society, 

April 7-11, Orlando, FL. Title: “Novel Pt/Ru 

Catalyst for the DMFC Anode: Electrochemical 

Cell and DMFC Testing”; P. Waszczuk, H.-S. 

Kim, A. Wieckowski, Y. Zhu, P. Zelenay*.

15. 201st Meeting of the of the Electrochemical 

Society, Philadelphia, Pennsylvania, May 12-17, 

2002. Title: “DMFC Cathode Catalyst with 

Improved Methanol Tolerance”; Y. Zhu*, 

P. Zelenay.

16. Annex XI Meeting of International Energy 

Agency Meeting, May 17-18, 2002, Philadelphia, 

Pennsylvania, Title: “80 W DMFC Stack and 

Performance Data”; X. Ren, J. Davey, B. S. 

Pivovar, H. N. Dinh, C. Rice, S. Gottesfeld, 

P. Zelenay*.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

447

IV.D.17 Development of Advanced Catalysts for Direct Methanol Fuel Cells

S. R. Narayanan

Jet Propulsion Laboratory

California Institute of Technology

Pasadena, California 91109

(818) 354-0013, fax: ( 818) 393-6951, e-mail: s.r.narayanan@jpl.nasa.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Reduce catalyst cost for direct methanol fuel cells (DMFCs). 

• Demonstrate feasibility of reducing Pt-Ru catalyst loading to 0.5 mg/cm2 using thin film deposition 

techniques.

• Develop a low-cost manufacturing technique for MEA fabrication.

• Prepare and identify low-cost alternatives to Pt-Ru based on Ni, Zr, and Ti catalysts.

Approach

• Utilize direct current (DC) magnetron sputter-deposited multi-component catalyst layers.

• Employ reactive sputter-deposition of alloys and oxides.

• Characterize half-cells and full cell MEAs electrochemically.

• Characterize structural and electronic properties.

Accomplishments

• Platinum-Ruthenium alloy films of various compositions have been sputter-deposited and 

characterized in half-cells and full cells.

• Fuel cell performance has been improved from 100 mW/mg to 800 mW/mg at 0.1 mg/cm2

 of catalyst 

at the anode.

• Effect of reactive co-sputtering of RuOx has been studied and determined not to have any beneficial 

effect.

• A unique metal nanostructure has been developed by pretreatment of Nafion films.

Future Directions

• Prepare and characterize ternary Pt Mx My films by December 2002.

• Deposit corrosion resistant alloy films of base metals by June 2003.

• Demonstrate 2000 mW/mg by June 2003.

• Characterize metal/metal oxide systems by December 2003.

• Demonstrate 2500 mW/mg by June 2004.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

448

Introduction

Fuel cells offer the possibility of reduced 

emissions and high efficiency for transportation 

applications. Of the various fuel cells being 

considered, the direct methanol fuel cell (DMFC) is 

very attractive due to the key advantages of reducing 

system complexity and potentially improving 

transient response compared to reformate-air fuel cell 

systems. However, DMFCs currently require 

unsupported noble metal catalysts at high loadings of 

2.5 – 4.0 mg/cm2

, leading to a high catalyst cost of 

$100-150/kW. Also, to keep the overall fuel cell cost 

low, the preferred method of catalyst application 

must be designed for manufacturing. Thus, cost 

presents a major obstacle to commercialization of 

DMFCs. Enhancement of the efficiency of this fuel 

cell is also necessary to achieve the required weight 

and volume required for transportation applications. 

This research effort aims at addressing these key 

issues of cost and efficiency. 

The overall objective is to develop new methods 

of preparing electrocatalysts, novel electrode 

structures, and new-low cost electrocatalysts that will 

result in overall cost reduction and improved 

performance of direct methanol fuel cells. 

The specific objectives are: 

• Reduce the catalyst loading levels of Pt-alloy 

in DMFCs to 0.5 mg/cm2

 or less 

• Develop new low-cost methods of 

fabricating membrane-electrode assemblies 

• Prepare catalysts with enhanced activity for 

methanol electro-oxidation

• Develop non-noble metal methanol 

oxidation catalysts.

Approach

The Jet Propulsion Laboratory (JPL) has 

researched the stated objectives by investigating 

sputter-deposition (SD) of designed anode and 

cathode nanostructures of Pt-alloys, and electronic 

structures and microstructures of sputter-deposited 

catalyst layers. JPL has used the information derived 

from these investigations to develop novel catalysts 

and membrane electrode assemblies (MEAs) that 

will meet the DOE objectives of lower fuel cell cost 

and high performance. 

SD is routinely used to deposit thin films and has 

proven benefits from economies of scale in the 

metallization of plastics. The technique has already 

been used to create enhanced and unique MEAs for 

H2-air proton exchange membrane fuel cell 

(PEMFC) systems. In this project, JPL is pursuing 

the use of SD to create DMFC membrane electrode 

assembly structures with highly electro-active 

catalyst layers that will reduce the amount and cost of 

the Pt-alloy catalyst at the fuel cell anode. 

The research involves the development of 

techniques for deposition of porous catalyst layers by 

defining the conditions of pressure, sputter rates, and 

target configurations that will result in appropriate 

compositions and morphology for the catalyst layer. 

The effect of catalyst structure and composition on 

the activity of the catalyst layers will be 

characterized by x-ray diffraction (XRD), x-ray 

photoelectron spectroscopy (XPS), scanning electron 

microscopy (SEM), x-ray absorption spectroscopy 

(XAS), and electrochemical polarization studies in 

half cells and full cells. New base metal and noble 

metal alloys and oxides will also be studied with an 

aim to identify new compositions that will result in 

enhanced activity. The catalyst activity target is 2500 

mW/mg of anode catalyst.

Results

The main focus of this year’s effort has been on 

the deposition and characterization of platinumruthenium films of various compositions produced 

by co-sputtering of the individual elements. The 

effect of ruthenium deposited by reactive cosputtering has also been studied. The sputtering 

chamber was modified with a linear drive to be able 

to produce films on graphite foils, porous carbon 

structures, and on membranes. Thin films were 

deposited on graphite foil electrodes and 

characterized by XRD, XPS, SEM and polarization 

experiments. 

XRD results indicate that the alloy phase exhibits 

continuous change in lattice parameter and a change 

in structure from a face-centered cubic (fcc) to a 

hexagonal close pack (hcp) lattice consistent with the 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

449

formation of a solid solution. The alloy deposit 

exhibits fine grain characteristics with crystallite size 

of about 15-25 nanometers. These grain sizes are 

about 3 to 4 times smaller than those observed in 

chemically prepared materials. Electrochemical 

activity as measured in half-cells and full-cells 

increases with platinum content, and the lowest Tafel 

slopes were obtained for a bulk composition of 50/50 

atomic weight % of Pt/Ru. XPS analysis indicated 

small amounts of oxides of platinum and ruthenium 

on the surface. The oxide content was approximately 

30% and did not seem to depend on the metal 

composition. 

Cyclic voltammetric studies indicated that the 

activity of the Pt-Ru films increased with operating 

temperature just as in conventional catalyst layers 

produced from unsupported catalyst inks. Membrane 

electrode assemblies were fabricated from Pt-Ru 

films of the most active compositions, and a power 

density of 800 mW/mg was realized for anodes that 

were deposited with about 0.1 mg/cm2

 of Pt-Ru (see 

Figure 1). Applying the catalyst layers by sputter 

deposition on the electrode was found to yield better 

performance than applying them on the membrane. 

This was attributed to the enhanced electrical 

connectivity achieved when the catalyst layer is 

applied on the electrode. However, this is only true 

for very thin films. When thicker composite films 

are produced, such as those planned later in this 

project, good electrical connectivity may be achieved 

even with membrane deposition. 

SEM photographs of sputtered films show that 

the layers are fairly dense and appear to crack into 

platelets when subjected to MEA fabrication. The 

dense films do not lend themselves to high surface 

areas; therefore, there is substantial scope for 

enhancement of performance if the surface area can 

be increased. This may be achieved by producing 

porous 3-D Pt-Ru layered structures. One such 

method for creating such 3-D structures, that seem to 

be extremely promising, involves the pre-treatment 

of the membrane surface by ion-beam etching, which 

is then followed by sputter-deposition of the metal. 

This results in substantially enhanced surface area 

and very rough nanostructures. Next year’s effort 

will include characterization of such films. 

Electrodes were fabricated with catalyst layers 

containing platinum-ruthenium alloys and platinumruthenium oxide. Membrane electrode assemblies 

were fabricated with such cells, and the performance 

was evaluated in a full cell configuration. Although 

ruthenium oxide is a proton conductor and is 

expected to enhance the rate of proton transport from 

the interface during methanol oxidation, no 

noticeable improvement in activity of the catalyst 

layer was observed by addition of ruthenium oxide. 

The role of other metal oxides such as tungsten oxide 

will be investigated next year, along with evaluation 

of non-noble metal catalysts based on nickel, 

titanium, and zirconium.

Conclusions

High catalyst activity and utilization of sputtered 

thin films was demonstrated in operating fuel cells. 

Optimal sputter-deposition conditions for platinumruthenium alloys have been determined. The effect 

of composition on the performance of Pt-Ru films 

was studied, and optimal composition has been 

determined. Novel methods of enhancing surface 

area and improving porosity have been identified. 

Co-sputtered ruthenium oxide has been demonstrated 

not to have any significant beneficial effect on the 

activity of the catalyst layers. While cost presents a 

major obstacle to commercialization of DMFCs for 

mobile applications, this project demonstrates novel 

means to reduce the catalyst costs in DFMC fuel 

cells. Efficiency enhancements that are also 

necessary for DMFCs to be viable will be addressed 

Figure 1. Catalyst Utilization Curves for SputterDeposited (filled symbols), Carbon Supported 

(G, 1.0 mg/cm2

), and Conventional (∗, 8.0 

mg/cm2

) Pt-Ru
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

450

in the subsequent phases of the project under the 

development of new catalysts.

Publications and Presentations

1. C. K. Witham,T.I. Valdez, and S. R. Narayanan, 

“Nanostructured Catalysts for Direct Methanol 

Fuel Cells”, 200th Electrochemical Society 

Meeting, Philadelphia, May 2002

2. C. K. Witham, T. I. Valdez, and S. R. Narayanan, 

“Methanol Oxidation Activity of Co-Sputter 

Deposited Pt-Ru Catalysts”, Proceedings of the 

Symposium on Direct Methanol Fuel Cells, 

Electrochemical Society, PV 2001-4, p.123
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

451

IV.D.18 Carbon Composite Bipolar Plates

T. M. Besmann (Primary Contact), J.W. Klett, and J. J. Henry, Jr.

Surface Processing and Mechanics Group and Carbon and Insulating Materials Group

Oak Ridge National Laboratory, P.O. Box 2008, MS 6063, Bldg. 4515 

Oak Ridge, TN 37831-6063

(865) 574-6852, fax: (865) 574-6198, e-mail: besmanntm@ornl.gov 

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

ORNL Technical Advisor: David Stinton 

(865) 574-4556, fax: (865) 574-6918, e-mail: stintondp@ornl.gov

Objectives

• Develop a slurry molded carbon fiber material with a carbon chemical vapor infiltrated sealed surface 

as a bipolar plate. 

• Collaborate with potential manufacturers with regard to testing and manufacturing of such 

components.

Approach

• Fabricate fibrous component preforms for the bipolar plate by slurry molding techniques using carbon 

fibers of appropriate lengths.

• Fabricate hermetic plates using a final seal with chemical vapor infiltrated carbon.

• Develop commercial-scale components for evaluation.

Accomplishments

• Developed carbon composite material with graphite particulate filler to control pore size and speed 

surface sealing.

• Further characterized and measured mechanical properties of carbon composite plate material.

• Significantly improved wetting of bipolar plate surface.

• Determined surface roughness of finished bipolar plate components.

• Supported scale-up efforts at licensee Porvair Fuel Cell Technology.

Future Direction

• Develop bipolar plate materials/configurations to meet various users’ unique requirements.

• Improve wetting properties of carbon surfaces.

• Decrease component thickness.

• Transfer technology and aid in scale-up with Porvair.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

452

Introduction

In FY 2002, the Oak Ridge National Laboratory 

(ORNL) carbon composite bipolar plate effort has 

achieved several programmatic goals in measuring 

plate properties and improving wetting. It is 

necessary to have accurate mechanical property 

information for the bipolar plates in order to assure 

they will survive handling, assembly, and service. 

These measurements need to go beyond simple 

tensile or flexure strength, since the relatively thin 

plates will be subjected to combined tension-torsion 

loading in assembly and to potentially high rates of 

stress during handling and service. Thus, torsion 

behavior and fracture toughness are particularly 

important to understand. Measurements of these 

properties, along with methodologies to demonstrate 

material uniformity through thermal imaging, have 

been developed.

Approach

Fibrous component preforms for the bipolar plate 

are prepared by slurry molding techniques using 100-

μm carbon fibers (e.g., Fortafil) in water containing 

phenolic resin followed by curing. Molds are used to 

impress channels and other features into the preform, 

and the surface of the preform was sealed using a 

chemical vapor infiltration (CVI) technique in which 

carbon is deposited on the near-surface fibers 

sufficient to make the surface hermetic. In the 

current work, differing amounts of carbon flake filler 

were used and the effects on properties determined. 

Infrared imaging to identify defects and 

inhomogeneities was performed by heating one side 

of the samples and imaging the opposite side. Shear 

stress is a good measure of torsion behavior. Thus, 

the Iosipescu method was used to measure shear 

properties, whereby the shear strength of one of the 

different material shear planes of a composite may be 

determined by loading a coupon in the form of a 

rectangular flat strip with symmetric centrally 

located V-notches using a mechanical testing 

machine and a four-point asymmetric fixture. 

Failure of the specimen occurs by shear between the 

V-notches. The efforts to improve wetting of the 

carbon surface consisted of briefly heating the 

components to 1000°C in air.

Results

Slurry-molded preforms 2.5 mm in thickness 

were produced and cut into 5-cm squares. 

Illustrative results of the thermal imaging are seen in 

Figure 1. The relative uniformity indicates little 

density difference within the plates and between 

plates. There is some indication of delamination 

along the edges, although this is likely due to cutting 

of a larger plate into the 5 cm samples.

The Iosipescu torsion measurement results are 

given in Table 1, with an example stressdisplacement curve shown in Figure 2. These values 

are indicative of a relatively torsion-resistant 

material, particularly given the low density of the 

carbon composite. The stress-displacement curves 

indicate little delamination or other failures until 

ultimate failure.

The dramatic improvement in wetting of the 

carbon composite surface with treatment is seen in 

Figure 3. Whereas, prior to oxidative treatment, 

water appeared to have a small wetting angle on the 

surface of the carbon composite, water readily spread 

Sample (% Filler) Strength Measurement

PMP10R (0%) 25.9"9.9 MPa

PMP10T (0%) 19.3 MPa (1 test)

PMP09K (15%) 24.4"11.8 MPa

PMP11E (30%) 43.3"2.7 MPa

PMP11G (30%) 17.1"1.1 MPa

PMP11H (30%) 18.7"4.7 MPa

Table 1. Measurements of Shear Stress by the Iosipescu 

Method for Carbon Composite Samples with 

Differing Amounts of Carbon Flake Filler

Figure 1. Infrared Images of Carbon Composite Bipolar 

Plate Material Samples
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

453

on the surface after treatment with an apparent large 

wetting angle. 

Conclusions

During this period, the mechanical properties of 

the carbon composite bipolar plate material were 

assessed, including measurements of uniformity and 

defect distribution by infrared imaging. The results 

indicate good material uniformity and substantial 

resistance to torsional stresses. Significant 

improvement in the wetting of the material was 

demonstrated after a simple oxidation treatment.

FY 2002 Publications/Presentations

1. T. M. Besmann, J. W. Klett, J. J. Henry, Jr., and 

T. D. Burchell, “Carbon Composite Bipolar 

Plates for PEMFC,” 26th Annual International 

Conference on Advanced Ceramics and 

Composites, January 13-18, Cocoa Beach, FL.

2. T. M. Besmann, J. W. Klett, J. J. Henry, Jr., and 

E. Lara-Curzio, “Carbon/Carbon Composite 

Bipolar Plate for PEM Fuel Cells,” National 

Meeting of the American Institute of Chemical 

Engineers, March 10-14, New Orleans, LA.

3. T. M. Besmann, J. W. Klett, J. J. Henry, Jr., and 

T. D. Burchell, “Carbon Composite Bipolar Plate 

for PEMFC,” Future Car Congress, June 3-5, 

Arlington, VA.

Figure 2. Typical Stress-Displacement Curve for the 

Iosipescu Torsion Measurement of the Carbon 

Composite Bipolar Plate Material

Figure 3. Water Illustrates a Much Larger Wetting 

Angle on the Carbon Composite after 

Oxidative Treatment
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454

IV.D.19 Cost-Effective Surface Modification for Metallic Bipolar Plates 

M.P. Brady

MS 6115, Oak Ridge National Laboratory

P.O. Box 2008, Oak Ridge, TN 37831-6115

(865) 574-5153, fax: (865) 241-0215, e-mail: bradymp@ornl.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, email: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

ORNL Technical Advisor: David Stinton 

(865) 574-4556, fax: (865) 574-6918, e-mail: stintondp@ornl.gov

Objective

• Develop a low-cost metallic bipolar plate alloy that will form an electrically conductive and corrosion 

resistant nitride surface layer during thermal nitriding to enable use in a PEM fuel cell environment. 

Approach

• Conduct a study of the nitridation behavior of a series of model Ni-X and Fe-X base alloys (X = nitride 

forming elements such as Cr, Nb, Ti, V) that can potentially meet DOE bipolar plate cost goals.

• Identify the most promising combination of X additions, ternary and higher order alloying addition(s), 

and nitridation reaction conditions that result in the formation of an adherent, dense nitride surface 

layer. 

• Evaluate corrosion behavior in 80°C sulfuric acid solutions to simulate PEM fuel cell environments (in 

collaboration with K. Weisbrod and C. Zawodzinski of Los Alamos National Laboratory and I. 

Paulauskas and R.A. Buchanan of the University of Tennessee)

• Characterize nitride layer microstructure and composition by x-ray diffraction, electron probe 

microanalysis, scanning electron microscopy, and transmission electron microscopy. Use this 

information in a feedback loop to modify alloy chemistry and nitridation processing conditions to 

optimize the protectiveness of the nitride surface layer.

• Measure electrical conductivity of select nitrided alloys by D.C. four-point probe. 

• Down-select model Ni-Fe-X alloy for in-cell performance evaluation and begin modification and 

optimization of alloy composition/nitridation conditions for commercial scale up and/or identify 

nitridation conditions suitable for commercially available alloys (if feasible).

Accomplishments

• A model nitrided Ni-50Cr wt% alloy exhibited no discernible degradation after 1 week immersion in 

pH 2 sulfuric acid at 80°C and a corrosion current density of less than 1 x 10-6 A/cm2 up to ~ 0.9 V vs. 

standard hydrogen electrode (SHE) in pH 3 sulfuric acid at 80°C. This level of corrosion resistance is 

in the range of the goal for metal bipolar plates and warrants scale-up to in-cell testing and evaluation. 

Further, the Cr-nitride layers formed on the Ni-50Cr alloy grow in a very robust manner such that lack 

of coverage over features such as stamped flow fields does not appear to be a major issue. Preliminary 

measurement of electrical properties of a nitrided coupon indicated an electrical conductivity in the 

104Ω-1cm-1 range, which is two orders of magnitude greater than the DOE target. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

455

• Coupons of nitrided Ni-50Cr were delivered to Los Alamos National Laboratory for further corrosion 

testing and evaluation. Preliminary feedback from ongoing exposure in the Corrosion Test Cell 

indicate stable electrical resistance (collaboration with K. Weisbrod). 

• A United States provisional patent disclosure was submitted in April 2002 for nitrided Ni-Cr and 

related base alloys.

Future Directions

• Pursue in-cell testing of nitrided Ni-50Cr to determine if the promising corrosion resistance translates 

to in-cell performance.

• Optimize nitridation conditions and reduce the level of Cr to below 40-42 wt.% in order to improve the 

cold formability of the alloy and reduce processing and raw material costs (based on input from 

commercial alloy producers).

• Investigate the nitriding characteristics of existing commercial high-Cr-, Ni- and Fe- base alloys to 

determine if a similar corrosion resistant Cr-nitride layer can be formed in order to facilitate scale-up 

and transfer of this technology. 

• Establish partnerships with alloy producers and fuel cell manufacturers.

Introduction

The bipolar plate is one of the most expensive 

components in proton exchange membrane (PEM) 

fuel cells. Thin metallic bipolar plates offer the 

potential for significantly lower cost than 

conventional machined graphite bipolar plates and 

reduced weight/volume and better performance than 

developmental carbon fiber and graphite bipolar 

plates currently under consideration. However, 

inadequate corrosion resistance can lead to high 

electrical resistance and/or can contaminate the 

proton exchange membrane. Metal nitrides (e.g. 

TiN or Cr2N) offer electrical conductivities up to an 

order of magnitude greater than that of graphite and 

are highly corrosion resistant. Unfortunately, most 

conventional coating methods for metal nitrides are 

too expensive for PEM fuel cell stack 

commercialization or tend to leave pin-hole defects, 

which result in accelerated local corrosion and 

unacceptable performance. 

Approach

The goal of this effort is to develop a bipolar 

plate alloy that will form an electrically conductive 

and corrosion resistant nitride surface layer during 

thermal (gas) nitriding. There are three advantages 

to this approach. First, because the nitriding is 

performed at elevated temperatures, pin-hole defects 

are not expected because thermodynamic and kinetic 

factors favor complete conversion of the metal 

surface to nitride. Rather, the key issues are nitride 

layer cracking, adherence, and morphology (discrete 

internal precipitates vs. continuous external scales), 

which can potentially be controlled through proper 

selection of alloy composition and nitridation 

conditions. Second, thermal nitridation is an 

inexpensive, well-established industrial technique. 

Third, the alloy can be formed into final shape by 

inexpensive metal forming techniques such as 

stamping prior to thermal nitridation. 

Results

A series of model Ni-base alloys with additions 

of (5-15)Ti, (5-10)Nb, (10-15)V, (5-10)Nb + (5-15)V 

and (35-50)Cr wt%, to form external Ti, Nb, V, 

Nb+V, or Cr based nitride layers, was studied (Table 

1). Ni was selected as the initial alloy base because it 

is relatively inexpensive ($2-4/lb), has good ductility, 

doesn’t compete with Cr during thermal nitridation, 

and exhibits a relatively low permeability to 

nitrogen, which favors external nitride layer 

formation. 

Corrosion behavior was screened by a 1 week 

immersion in pH 2 sulfuric acid at 80°C in order to 

optimize alloy composition and nitridation 

conditions. Anodic polarization testing was then 

conducted on the most promising nitrided alloys in 

aerated pH 3 sulfuric acid at 80°C to quantify 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

456

corrosion resistance. A corrosion current density of 

less than 1 x 10-6 A/cm2

 up to a range of 

approximately 0.9 V vs. standard hydrogen electrode 

(SHE) was considered indicative of sufficiently 

promising behavior to warrant further development 

and future in-cell stack testing. 

Nitrided Ni-(5-10)Ti base alloys (to form an 

external TiN base layer) exhibited relatively low 

corrosion currents (Figure 1). However, regions of 

through thickness local attack of the TiN surface 

layer were evident in most of the coupons. Nitrided 

Ni-(5-10)Nb + (5-15)V wt% base alloys formed 

external Ni-Nb-V-N and Nb-V-N scales which 

resulted in good corrosion resistance in the 1 week 

immersion screening in pH 2 sulfuric acid at 80°C 

(weight loss <-0.05 mg/cm2) but exhibited high 

corrosion currents in the anodic polarization testing 

(10-5– 10-4 A/cm2 range at 0.9 V vs. SHE). The Ni-

(10-15)V wt% alloys formed external V-N layers 

after the nitridation treatment, but exhibited 

relatively high weight losses in the sulfuric acid 

immersion screenings (3-5 mg/cm2

 loss after 1 

week). External Nb-N layers could not be formed on 

Ni-(5-10)Nb wt.% alloys under the nitridation 

conditions used in the present work (Table 1).

Of the nitrided alloys examined, Ni-50Cr wt.% 

exhibited the most corrosion resistance and met the 

target corrosion current of less than 1 x 10-6 A/cm2

up to ~ 0.9V vs SHE in pH 3 sulfuric acid at 80°C 

(Figure 1 and Table 1). The post-nitridation 

microstructure of all the Ni-Cr alloys (35Cr, 45Cr, 

50Cr wt.%) examined, nitrided for 1-2 h at 1100°C in 

nitrogen, consisted of external Cr2N overlying a 

mixed zone of Cr-depleted Ni(Cr) and a ternary NiCr-N subscale nitride (Figure 2) (occasional 

examples of internal Cr2N were also observed in the 

lower Cr alloys). The degree of continuity, and 

hence protectiveness, of the external Cr2N improved 

with increasing alloy Cr content, with a dense nearly 

continuous or continuous layer formed on Ni-50Cr. 

Optical analysis after testing revealed no evidence of 

significant corrosion or breaching of the nitride layer 

Alloy Base 

(wt.%)

Nitridation Conditions 

(high-purity nitrogen)

Nitrogen 

Uptake 

(mg/cm2)

Temperature Time (h)

Ni-(5-15)Ti 1000-1100°C 8-48 0.1-1

Ni-(5-10)Nb 900-1100°C 1-48 0.1-2

Ni-(10-15)V 1100°C 24-48 0.5-1

Ni-(5-10)Nb-

(5-15)V

1100°C 24-48 0.5-1

Ni-(35-50)Cr 1100°C 1 1.5-2

Table 1. Summary of Nitriding Conditions Figure 1. Anodic polarization data in aerated pH 3 

sulfuric acid at 80°C (scan rate of 0.1 mV/s) 

Figure 2. Scanning electron microscopy cross-section 

of Ni-50Cr wt% nitrided for 2 h at 1100°C in 

N2. point 1- external Cr2N scale: 69Cr-30N1Ni atomic percent (at.%), point 2- Crdepleted Ni(Cr) metal (light): 68Ni-32Cr 

at.% (71Ni-29Cr wt%), point 3- subscale 

ternary Ni-Cr-N phase (dark): 52Cr-14N34Ni at.%. Compositions determined by 

electron probe microanalysis using pure 

element standards for Ni, Cr and a Cr2N 

standard for nitrogen. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

457

formed on the Ni-50Cr. Uncoated Ni-50Cr metal 

also exhibited relatively low corrosion currents 

(Figure 1) but showed evidence of pitting after the 

test exposure. 

The nitridation of the Ni-50Cr alloys was very 

robust, with no evidence of inadequate coverage at 

sharp corners or edges. Figure 3 shows a coupon of 

Ni-50Cr that was hand stamped with the letters 

“ORNL”, nitrided, and then immersed in pH 2 

sulfuric acid at 80°C for 1 week; there was no attack 

evident in the stamped regions. These results suggest 

that the present approach is amenable to coverage 

and protection of stamped flow field features in a 

bipolar plate. Bulk electrical conductivities were in 

the range of 1-2 x 104 Ω-1cm-1 after nitriding, which 

surpasses the DOE electrical conductivity target by 

two orders of magnitude.

Conclusions/Future Work

These results indicate that nitrided Ni-Cr base 

alloys show potential for use as bipolar plates in 

PEM fuel cells. Future work will focus on in-cell 

testing of nitrided Ni-50Cr to determine if the 

promising corrosion resistance demonstrated in the 

anodic polarization testing translates to good in-cell 

performance. From a cost and alloy processing 

perspective, lower levels of Cr are needed, ≤ ~ 40-42 

wt% range [1], particularly in terms of the rate of 

work hardening during cold rolling, to allow the 

economical production of alloy sheet. The critical 

level of Cr needed to form an external nitride layer 

on binary Ni-Cr alloys is in the range of 30-40 wt% 

Cr [2], so a reduction below 50 wt% Cr appears 

feasible with proper adjustment of nitridation 

conditions (e.g. temperature, N2 vs. NH3

environments, initial surface condition) to form a 

sufficiently continuous and dense Cr2N (or possibly 

CrN) layer. Reduction in Cr level may also be 

achievable through ternary alloying additions that 

form nitrides of intermediate thermodynamic 

stability between those of Cr and Ni, ie. secondary 

gettering [e.g. 3]. For example, the level of Al 

needed to form an external alumina layer on Cu-Al 

alloys can be significantly reduced by additions of Zn 

[e.g. 3]. It may also be possible to form similar 

corrosion resistant nitride layers on Fe-Cr or Ni(Fe)-

Cr base alloys, which would also further reduce alloy 

cost. Investigation of the nitriding characteristics of 

existing commercial Ni-Fe-Cr alloys will also be 

performed. Emphasis in the next year will be placed 

on establishing collaborations with commercial alloy 

producers and fuel cell manufacturers to facilitate 

technological assessment (particularly in-cell testing) 

and scale-up of this approach.

References

1. G. Smith and M. Harper, Special Metals Corp., 

private communication (2002)

2. R.P. Rubly and D.L Douglass, Oxid. Met., 35, 

259 (1991)

3. M.P. Brady, B. Gleeson, I.G. Wright, JOM, 52(1) 

16 (2000).

FY 2002 Publications

1. “Assessment of Thermal Nitridation to Protect 

Metal Bipolar Plates in PEM Fuel Cells”, M.P. 

Brady, K. Weisbrod, C. Zawodzinski, I. 

Paulauskas, R.A. Buchanan, and L.R. Walker, 

submitted to Electrochemical and Solid State 

Letters.

Patents

1. “Metallic Bipolar Plate Alloys Amenable to 

Inexpensive Surface Modification for Corrosion 

Resistance and Electrical Conductivity”, M.P. 

Brady, J.H. Schneibel, B.A. Pint, and P.J. 

Maziasz, United States Provisional Patent 

Disclosure, April 2002.

Figure 3. Macrograph of stamped and nitrided Ni-50Cr 

coupon after 1 week exposure in pH 2 

sulfuric acid at 80°C (coupon dimensions 1” 

X 1⁄2”).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

458

IV.D.20 Scale-Up of Carbon/Carbon Composite Bipolar Plates

David Haack (Primary Contact), Ken Butcher, Earl Robert Torre

Porvair Fuel Cell Technology, Inc.

700 Shepherd Street

Hendersonville, NC 28792

(800) 843-6105, fax: (828) 697-7960; e-mail: dhaack@pamus.com

DOE Technology Development Manager: Donna Ho 

(202) 586-8000, fax: (202) 586-9811, e-mail: Donna.Ho@ee.doe.gov

ANL Technical Advisor: Thomas Benjamin

(630) 252-1632, fax: (630) 252-4176, e-mail: Benjamin@cmt.anl.gov

Main Subcontractor: UTC Fuel Cells, Inc., South Windsor, Connecticut

Objectives

• Develop carbon/carbon composite materials for bipolar plates that meet or exceed target property 

criteria

• Evaluate the performance of the bipolar plate materials through fuel cell stack testing

• Design and construct a research-scale production line for materials development efforts

• Design and construct a pilot-scale production line to demonstrate high volume, low-cost bipolar plate 

manufacturing

Approach

Phase I

• Design, construct and install material forming, pressing and thermal treatment equipment

• Systematically investigate material forming techniques and composition ingredients

• Systematically investigate material processing variables and test material properties

• Perform fuel cell testing to evaluate plate performance at UTC Fuel Cells

• Investigate forming techniques aimed at rapid, low-cost production

Phase II

• Design, construct and install a pilot-scale production line for 300 plates per hour capacity

• Design and implement quality assurance system for pilot line

• Evaluate pilot line performance and estimate pilot and mass bipolar plate production costs

• Evaluate pilot line bipolar plates for fuel cell performance and deliver fuel cell stack

Accomplishments

• Developed two-sided embossed bipolar plates with excellent material properties, exhibiting the 

potential for low-cost production

• Designed, constructed and installed research material forming and processing equipment

• Developed improved bipolar plate materials, exhibiting improved material properties and low-cost 

ingredients
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

459

• Began investigation into rapid-forming techniques

• Began fuel cell testing at UTC Fuel Cells

Future Directions

• Continue material development efforts for improved material properties and reduced raw materials

• Continue rapid-forming investigations

• Continue fuel cell testing

Introduction

In April 2001, Porvair Fuel Cell Technology, Inc. 

(PFCT) licensed a carbon/carbon composite bipolar 

plate formation technology from Oak Ridge National 

Laboratory (ORNL). The goal of PFCT is to transfer 

this technology from the laboratory to full-scale, 

low-cost mass production to meet the emerging need 

of the rapidly developing fuel cell industry. This 

program is directed at further developing the carbon/

carbon bipolar plate material to meet the 

performance, durability and cost demands of the fuel 

cell industry, and to demonstrate a pilot-scale 

manufacturing line to produce this material in 

reasonable pilot quantities (300 plates per hour).

The process involves formation of a carbon 

perform by a low-cost slurry molding process. The 

pre-form is pressed and a flow field pattern is 

embossed in the surfaces. The porosity of the plate is 

then filled to the desired density by chemical vapor 

infiltration.

Approach

The path to final production demonstration is 

split into two major parts in this program. Phase I 

focuses upon material and composition refinement to 

satisfy the fuel cell property and performance 

requirements. Also in Phase I, investigations and 

demonstrations of research-scale rapid material 

formation techniques will be performed. 

The approach in material development is to 

systematically perform statistically designed 

experiments. Techniques include fractional factorial 

designs, Grecko-Latin squares, and self-directed 

optimization. Data collected is statistically evaluated 

to determine primary and combined effects of the 

variables of investigation. Properties of importance 

will be measured using standard techniques; they 

include material electrical conductivity, strength, 

flexure, hydrogen permeability, and corrosion rate. 

Our commercial partner in this endeavor, UTC Fuel 

Cells, will measure bipolar plate performance in outof-cell testing and in-cell testing (both single and 

multiple cell stacks).

Phase II focuses upon process development to 

result in a pilot production line capable of producing 

300 bipolar plates per hour. Our goal is a complete 

functional pilot line, including all relevant quality 

assurance, failure mode and effects analysis, and 

statistical manufacturing characterization processes. 

This will be completed by transferring the most 

promising mass-production technique to larger-scale 

and continuous equipment operation in a dedicated 

production line. 

Results

The project to this point has focused primarily 

upon process design and equipment installation, 

although some material and process development has 

been performed. A laboratory space has been 

arranged for the bipolar plate development activities. 

A research vacuum forming system (Figure 1) has 

been installed for use in manufacturing experimental 

material. Material pressing equipment, material 

property testing equipment, and thermal processing 

equipment has also been installed. Figure 2 shows 

the laboratory-scale CVI furnace used for 

preliminary materials development efforts. Because 

the capacity of this furnace limits productivity, a 

larger furnace has been designed and installed 

(Figure 3) to provide capacity suitable to produce an 

average of 10 plates per hour (a Phase I productivity 

goal). 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

460

Materials development activities have focused 

upon improving material properties and reducing the 

costs of the raw materials composing the bipolar 

plate. The original work done at ORNL focused 

primarily upon the use of short graphite fibers as the 

backbone of the bipolar plate. The fiber material 

utilized, however, is quite expensive (projected high 

volume costs of ~$5/lb) and may limit the 

achievement of desirable material properties. A twolevel fractional factorial design investigating fiber 

type and content was undertaken to reduce the 

quantity of fiber in the product or to displace the 

expensive fiber material with lower cost alternatives. 

Results showed that much of the fiber within the 

material could be displaced, resulting in a lower-cost 

product with superior material properties. 

The potential of embossing flow field patterns in 

the preform materials has also been investigated. A 

two-sided proprietary flow field pattern has been 

successfully transferred to the carbon/carbon 

material yielding near-net-shape bipolar plates. 

Subsequent materials property testing has confirmed 

adequate material properties. 

Table 1 shows preliminary materials properties 

measured on non-optimized bipolar plate materials 

produced through initial development work at PFCT. 

Comparisons with published DOE goals are made in 

the table. Sealing of the plate through - through plate 

permeability is accomplished through the application 

of a thin non-permeable layer on the exterior surface 

of the material. Figure 4 is an SEM micrograph of 

such a surface. Permeability testing with nitrogen 

gas at room temperature has been performed (ASTM 

D1434), showing no detectable permeability. The 

experimental setup to allow testing with hydrogen is 

still under development.

Table 1. Carbon/Carbon Material Properties 

Figure 1. Photograph of carbon/carbon composite 

vacuum forming equipment.

Property Value

DOE 

Target

Electrical Conductivity (S/

cm) (ASTM C611)

> 300 > 100

Density (g/cc) 1.00 - 1.30 -

Flexural Strength (psi) 5700 > 600 (crush)

Flexibility (%)

(deflection at mid-span)

1.5 - 3.5 3 - 5

Nitrogen Permeability (cc/

cm2/sec)

 (ASTM D1434)

Not detected < 2x10-6

(Hydrogen)

Figure 2. Photograph of laboratory-scale chemical 

vapor infiltration (CVI) furnace
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

461

Some material trends have been established 

through continued experimental investigation. 

Figure 5 is a chart of material conductivity as a 

function of material density. Figure 6 is a similar 

chart showing material flexure strength. The process 

and material developed to date shows considerable 

flexibility to tailor material properties to desired 

levels. As seen in Figures 5 and 6, a trade-off exists 

between material density and material properties - a 

lightweight material will not be as strong or 

conductive as a heavier material. However, material 

properties measured appear to be well above the 

DOE targets, even with low-density materials. 

Further material optimization is continuing.

UTC Fuel Cells, Inc. is testing both machined 

and pattern-embossed materials in single fuel cell 

operation. Initial results, although not ready for 

publishlication, appear promising.

Conclusions

Preliminary work completed in this project 

includes laboratory and equipment setup and 

installation, and preliminary rounds of material 

optimization and process development. Full size 

bipolar plate prototypes have been produced with full 

double-sided flow patterns, demonstrating the 

potential of the manufacturing process. Process and 

material development has resulted in the 

characterization of material properties under a 

variety of composition levels. Material properties 

meeting or exceeding DOE targets have been 

measured, and bipolar plates, both machined and 

pattern-embossed, have been submitted to UTC Fuel 

Cells for in and out of cell testing. Phase I work will 

Figure 3. Photograph of Phase I development CVI 

furnace in assembly.

Figure 4. SEM micrograph of a molded carbon/carbon 

composite material. Figure shows thin skin 

coating on plate exterior to provide plate 

sealing.

Figure 5. Density influence on through-plane electrical 

conductivity from an array of experimental 

compositions.

Figure 6. Density influence on flexural strength from 

an array of experimental compositions.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

462

continue this year in the optimization of the material 

composition for cost and performance, in the 

development of potential mass-production 

techniques, and in expanded in-cell testing.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

463

IV.D.21 Carbon Foam for Fuel Cell Humidification

J. W. Klett (Primary Contact), Nidia Gallego, April McMillan, Lynn Klett

Carbon Materials Technology Group

Oak Ridge National Laboratory, P.O. Box 2008, MS 6087, Bldg. 4508 

Oak Ridge, TN 37831-6087

(865) 574-5220, fax: (865) 576-8424, e-mail: klettjw@ornl.gov 

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy.Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov 

ORNL Technical Advisor: David Stinton 

(865) 574-4556, fax: (865) 241-0411, e-mail: stintondp@ornl.gov 

Objectives

• Determine how graphite foams can be used to enhance the humidification of the fuel cell inlet air.

• Determine what characteristics of the foam require optimization to allow the combination of power 

electronics cooling with humidification of the inlet air.

Approach

• Design and construct a humidification test cell to utilize different foam structures to aid evaporation of 

water.

• Perform tests to characterize the humidification potential of the foam and develop optimized designs to 

minimize pumping power while maximizing humidification with heat generated from power 

electronics.

Accomplishments

• Foam was demonstrated to successfully humidify dry inlet air to 87% saturation at 60°C using a 

simulated power electronic device. 

• Optimization of foam density uniformity, batch consistency, and thermal properties was performed and 

showed that a foaming rate of 3.5°C/min and a graphitization rate of 1°C/min produced the best foam 

structures.

• A mathematical model for heat transfer in foams was developed, which can simulate power electronics 

cooling by fluid flow through the foam.

Future Directions

• Apply optimized foam structures to humidification systems to show improvement in humidification 

potential. 

• Apply mathematical model to design optimized humidification systems (i.e., lowest pressure drop, 

highest humidity, and lowest heater temperature).

• In collaboration with a fuel cell manufacturer, develop a full-scale prototype humidifier for fuel cell 

applications.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

464

Introduction

The efficiency of the automotive proton 

exchange membrane (PEM) fuel cell is dependent on 

many factors, one of which is the humidification of 

the inlet air. If the inlet air is not sufficiently humid 

(saturated), then the stack can develop dry spots in 

the membrane and efficiency and voltage will drop. 

Therefore, it is necessary to ensure that humid inlet 

air at the proper elevated temperature is supplied to 

the stack. Current methods involve utilizing a spray 

nozzle to atomize water droplets onto a cloth or wire 

mesh substrate. As the ambient inlet air passes over 

the cloth it picks up moisture; however, the relative 

humidity drops as the air is heated in the fuel cell. If 

heat could be supplied to the water efficiently, the 

system would become independent of the ambient 

conditions, the inlet air could become more humid at 

the proper temperatures, and the overall stack could 

maintain a high level of efficiency. Previous work 

with power electronic heat sinks and automotive 

radiators has demonstrated the high efficiency of 

carbon foam for heat transfer. Utilizing the carbon 

foam in the PEM fuel cell may reduce the inlet air 

humidification problems. 

The unique graphite foam, shown in Figure 1, 

has a ligament conductivity greater than 1500 W/

m⋅K, equivalent to artificial diamond. The high 

thermal conductivity of the foam combined with the 

very high surface area (>4 m2/g) result in heat 

transfer coefficients that are two orders of magnitude 

greater than those of conventional heat exchangers. 

Therefore, we believe that graphite foam can be 

effectively utilized to capture waste heat from power 

electronics to heat and humidify ambient air entering 

the fuel cell. To characterize the behavior of the 

foam in a humidification system, a test chamber 

normally used for evaluating heat sinks is utilized 

(see Figure 2). A block of carbon foam is brazed 

onto an aluminum plate and placed in a cavity 

through which cooling air flows. A simulated power 

inverter capable of generating up to 800 W, or 30 W/

cm2

, is mounted to the back of the aluminum plate. 

As cooling air passes through the system, the 

temperature of the heater and the inlet and outlet air 

can be measured.

Several tests were run to determine the efficacy 

of using waste heat from power electronics to heat 

and humidify ambient inlet air. Testing was initiated 

by flowing 5 SCFM of ambient (~20°C) air through 

the heat sink (test system) that was dissipating 10 W/

cm2

 of heat. The temperature of the outlet air 

increased to about 104°C. The test was repeated with 

the addition of 10 cm3/min of water to not only heat 

but also humidify the air. The temperature of the 

outlet air increased to 73°C at a relative humidity of 

24%. The test was repeated a second time with the 

addition of 20 cc/min of water for humidification. 

The temperature of the outlet air increased to ~59°C 

at a relative humidity of 87%. 

Figure 1. ORNL Graphite Foam

Figure 2. Schematic of Test Rig to Evaluate Heat Sink 

Geometries
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

465

The successful operation of a fuel cell vehicle 

will likely require about 4.5 m3/min or 160 SCFM of 

inlet air at a temperature of about 80°C. Our 

calculations show that there should be sufficient heat 

generated by the power electronics to adequately heat 

and humidify this volume of air. Unfortunately, very 

large quantities of water would be required to 

humidify this large volume of air. In fact, a hybrid 

electric vehicle would consume more water per mile 

or per hour than gasoline. In order to make 

humidification systems practical, very efficient 

systems that recycle moisture from the exhaust 

stream will be required. Hence, understanding the 

structure-processing relationship of the foam as a 

means of tailoring the foam properties will be 

required to optimize the humidification system. In 

addition, developing a model that can predict heat 

transfer and developing better joining methods to 

reduce thermal resistance will be critical to the 

success of this project. Therefore, efforts were 

initiated in several of these areas. 

Approach and Results

Foam Optimization

For many carbon materials the heat treatment 

rate during graphitization is critical to optimizing the 

material properties. Commercial heating rates of 

approximately 0.1°C/minute to 2800°C are typically 

used for graphitization. Because graphitization takes 

so long, it is expensive and energy intensive; thus, 

finding the maximum heating rate which yields the 

desired properties is critical to minimizing costs. 

Therefore, the influence of heating rate during 

graphitization on key properties of the foam such as 

density, thermal diffusivity and crystalline 

parameters was examined in this research. 

Density Uniformity: The first characterization of 

the foams was the measurement of the density 

uniformity after carbonization. Several billets of 

foams were made with two different foaming rates: 

3.5°C/min and 10°C/min. Test billets were heat 

treated in the top and bottom positions in the furnace, 

as illustrated in Figure 3. This provides an 

understanding of the temperature uniformity within 

the furnace and its effects on the resulting foam. 

Table 1 reports the density uniformity for the billets 

processed at different foaming rates and positions in 

the furnace. The density of samples heat treated at 

the top of the furnace is much more uniform than 

samples heat treated at the bottom of the furnace. 

While there appears to be a slight effect on density 

uniformity due to the foaming rate, this effect is 

small comared to the effect of the position of the pan 

in the furnace. This implies that the temperature at 

the bottom of the furnace (most likely a lower 

temperature) during the foaming is not sufficient to 

produce uniform temperature profiles in the foam, 

thereby leading to non-uniform foam density plots.

Thermal Properties: Cubes cut from each billet 

were separated into groups of four and fired to 

Figure 3. Furnace Diagram with Locations of Billets of 

Foam

Table 1. Density (in g/cc) Uniformity of Billets
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

466

2800°C at five different heating rates (0.5, 1, 5, 10, 

and 15°C/min). The thermal properties of the 

samples were then measured in x, y, and z directions 

with a Xenon flash diffusivity apparatus. The 

thermal conductivity of the samples was calculated 

from their thermal diffusivity. Table 2 lists the Zdirection thermal conductivity values for each 

graphitization heating rate and position within the 

furnace. From these data, it is clear that the thermal 

conductivity is directly related to the graphitization 

heating rate. A similar trend was observed in the 

crystal properties of the foams determined from Xray diffraction (not shown here for brevity). 

However, it is not understood why there is a 

maximum at 1°C/min. 

The effect of the location of the samples in the 

foaming furnace on the final thermal properties is 

also noteworthy. It is clear that in the Z-direction 

(the direction with the highest conductivity), both 

billets that were located in the top of the furnace 

exhibited the highest overall thermal conductivity, 

irrespective of foaming rate. However, it is also 

evident that the foaming rate does affect the final 

thermal properties, with the lower foaming rate 

yielding graphitized foam with the higher thermal 

conductivity. While these trends are also true for the 

x and y directions, the effects are less pronounced 

due to the lower thermal conductivities in these 

directions.

Modeling of Heat Transfer

A mathematical model was developed to predict 

the thermal transfer in the foams. This is critical to 

developing engineered structures which provide both 

humidification and electronic cooling. This model 

uses the equations of energy, motion, and continuity 

to develop a finite element solution with a 

commercial package, FLEXPDE. For the 

hypothetical model, heat is assumed to be added to 

the top of the foam (simulating a heater), and the 

fluid flows perpendicular to the heat flow (see Figure 

4). The following equations were input to the model:

Darcy-Forcheimer Equation for flow through porous 

media

Equation of Continuity

Heat Equation in Fluid

Heat Equation in Foam

Model heat transfer from foam to fluid as a source/

loss term - q

The results were exceptional, as shown in Table 

3. The model adequately predicts the output fluid 

temperature and heater temperatures for various 

conditions in power input and flow rates. Now that 

the model is validated, it can be applied to 

engineering concepts to easily predict and design the 

optimum configurations to produce humid inlet air 

while cooling devices such as power electronics.

Figure 4 illustrates the results of the simulations. 

First, the model can predict the flow field of the 

fluid, in this case a plug flow, which is optimum for 

heat transfer. Next, the model predicts the isotherms 

of the foam and water, giving the designer important 

visualization of the system, thereby allowing easier 

engineering of optimum designs.

Graphitization 

Heating Rate

Bottom Pan Top Pan

Foaming Rate Foaming Rate

3.5°C/

min

10°C/

min

3.5°C/

min

10°C/

min

0.5 118.6 85.8 132.9 109.4

1.0 134.7 111.9 148.9 115.5

5 130.7 104.3 133.9 114.1

10 123.7 96.6 126.4 112.7

15 98.7 88.4 125.1 115.3

Table 2. Z-direction Thermal Conductivity (in W/m⋅K) 

after Graphitization

0 v v v

κ

μρ

κ

μ = −∇p − +

0 v v ( ) v

2  ∇⋅ 

 



 = −∇ − − κ

μρ

κ

μ P

( ) w Tw CpDT qgained 0 = ∇ ⋅ − k ∇ − ρ + 

( ) f Tf qloss 0 = ∇⋅ − k ∇ − 

( ) qloss qgained hloc Aspec Tf −Tw  =  = − ⋅ ⋅
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

467

Conclusions

It was shown that carbon foam is beneficial to 

humidification systems for fuel cells. The foam has 

demonstrated the ability to utilize waste heat from 

power electronics to both heat and humidify ambient 

inlet air to ~80°C and 80% relative humidity. 

The foaming process was characterized to 

optimize both the foaming rate and the graphitization 

rate of the foams. It was found that the temperature 

uniformity of the foaming furnace is critical to the 

density uniformity and batch consistency of the foam 

billets. It was found that a foaming rate of 3.5°C/min 

produced foams with more uniform densities and 

higher thermal conductivities than a higher foaming 

rate. It was also found that a graphitization rate of 

less than 1°C/min produces foams with the highest 

thermal conductivities. 

Last, a mathematical model was developed 

which accurately predicts heat transfer from the foam 

to a fluid flowing through the pores of the foam. 

This is critical to developing optimized designs for 

humidification devices that both humidify and 

provide cooling potential.

Power Input (W) 300 300 600 600 

Water Flow Rate [gph] 25 45 25 45

Pressure Drop [psi] 3.5 7.0 3.5 7.0

Measured Base Plate 

Temperature [C] 300.3 296.8 308.7 303.4

Predicted Base Plate 

Temperature [C] 299.6 297.2 308.4 303.6

Measured Outlet Water 

Temperature [C] 293.8 292.6 296.3 293.9

Predicted Outlet Water 

Temperature [C] 293.7 292.4 295.8 293.9

Table 3. Heat Transfer Model Results

Figure 4. Model and Results of Simulated Heat 

Transfer from Foam to Fluid Flowing through 

Foam
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

468

IV.D.22 Carbon Monoxide Sensors For Reformate Powered Fuel Cells

Fernando Garzon (Primary Contact), Eric Brosha and Rangachary Mukundan

MS D429, MST-11 Group

Los Alamos National Laboratory

Los Alamos, New Mexico, 87545

(505) 667-6643, fax: (505) 665-4292, e-mail: garzon@lanl.gov

DOE Technology Development Managers:

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Objectives

• Hydrogen reformate gas powered fuel cell systems require sensors for carbon monoxide level 

monitoring and feedback control.

- Develop a high temperature sensor for measurement of 0.1 to 2% carbon monoxide in reformate gas 

for fuel processor control.

- Develop a low temperature sensor for measuring 10-100 ppm range concentrations for stack 

poisoning control.

Approach

• Two electrochemical sensor types are being investigated for high and low temperature carbon 

monoxide sensing:

- An oxide solid electrolyte device based on the kinetics of the electrode reactions is being developed 

for the high temperature application.

• Yttria-doped zirconia and gadolinia-doped ceria oxygen ion conductors and strontium yttrium 

zirconium oxide proton conductors are being investigated as the solid electrolyte.

• Several metals including Pt, Pd, Au, Ru and Ni are being evaluated as the sensing and reference 

electrodes.

- A amperometric device based on carbon monoxide inhibition of hydrogen oxidation kinetics using 

either a perfluorosulfonic acid polymer electrolyte or an inorganic acid electrolyte is being evaluated 

for the low temperature application.

Accomplishments

• A cerium oxide based high temperature sensor has been developed. The sensor responds well to 10-

500 parts per million of carbon monoxide in air.

• Strontium zirconate proton conducting thin film electrolytes have been successfully synthesized and 

characterized.

• Amperometric low temperature carbon monoxide sensors have been developed and tested under a 

variety of conditions. These devices respond well at ambient temperature to carbon monoxide in 

hydrogen streams.

Future directions

• Modify the electrodes in the cerium (or zirconium) oxide devices to detect CO in the presence of 

hydrogen.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

469

• Increase the operating temperature of the low temperature devices from room temperature to 

approximately 80oC.

• Optimize low temperature amperometric devices for fast response time.

• Evaluate catalyst composition, loading and particle size effects on sensor performance.

• Investigate alternative electrolytes.

• Test the sensor prototypes in actual reformate gas streams.

Introduction

The detection and measurement of carbon 

monoxide in high temperature reformate streams is 

of vital importance to the successful implementation 

of fuel cells for transportation. Much research is 

being performed to optimize low-cost fuel reformer 

systems that convert liquid hydrocarbon fuels to 

hydrogen gas containing fuel streams. This 

hydrogen gas typically feeds a polymer electrolyte 

membrane (PEM) fuel cell utilizing a platinum based 

anode. It is well known that low concentrations of 

carbon monoxide (~10-100) ppm impurities in 

hydrogen can severely degrade the performance of 

PEM fuel cell anodes. This performance degradation 

is due to strong adsorption of carbon monoxide on 

the electro-active platinum surface sites where 

hydrogen is normally oxidized to protons. 

The proper design of fuel reformer systems must 

pay careful attention to the minimization of carbon 

monoxide before the processed fuel stream enters the 

fuel cell stack. Many reformer systems use a 

secondary preferential oxidation reactor that 

selectively oxidizes the carbon monoxide present in 

reformate streams. In most transportation 

applications the steam reformer and the selective 

oxidation reactors do not operate under steady state 

conditions; large transients may occur which produce 

relatively large amounts of carbon monoxide. It is 

highly desirable to have a low-cost real-time carbon 

monoxide measurement system that provides 

feedback control to the fuel processing system in 

order to protect the PEM fuel cells from performance 

degrading concentrations of carbon monoxide.

Current fuel cell systems use air-bleeding 

methods to reduce the carbon monoxide poisoning of 

the Pt anode. Since this method involves the mixing 

of 2-6% air with the fuel stream, it results in a 

decrease in the energy efficiency of the fuel cell 

system and thus should only be used for carbon 

monoxide transients. Hence, a CO sensor that 

measures the CO content of the anode stream can be 

used for feedback control of the air-bleeding system 

thus allowing these systems to operate at maximum 

energy efficiency. We are designing and developing 

solid-state electrochemical sensors meeting these 

criteria, including the demonstration of prototype 

sensors.

Approach

High temperature carbon monoxide sensors

Los Alamos is developing high temperature 

zirconia- and ceria-based electrochemical sensors to 

measure 0.1-2% CO in hydrogen streams. These 

sensors would operate at 400-600oC and can be used 

for feedback control of the reformer system. We 

have successfully developed novel mixed-potential 

sensors that are capable of measuring ppm levels of 

CO in air1

. We are currently working on modifying 

the electrodes of these devices to enable them to 

work in a hydrogen atmosphere. We are also 

exploring the possibility of using proton-conducting 

electrolytes and using these sensors in an 

amperometric mode.

Low temperature carbon monoxide sensors

Low temperature carbon monoxide sensors 

based on the reversible carbon monoxide adsorptive 

poisoning of precious metal electrodes are also being 

developed by Los Alamos National Laboratory. The 

addition of metals such as ruthenium to the platinum 

electrode material greatly improves the hydrogen 

oxidation kinetics in the presence of CO. An 

amperometric sensor that senses the CO inhibition of 

the hydrogen oxidation can be fabricated from a 

platinum electrode, a proton conductor and a 

platinum ruthenium alloy electrode. While the 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

470

current density of the platinum electrode will be 

influenced by the surface coverage of carbon 

monoxide, the current density at the Pt/Ru alloy 

electrode should be relatively unaffected. This 

difference in the electrode current density in the 

presence of CO can be used to fabricate a low 

temperature CO sensor.

Results

During FY 2002 we prepared several low 

temperature sensors based on a Nafion® electrolyte 

and various metal electrodes. We evaluated the CO 

response of Pt, Pt/Ru and Ru metal electrodes at 

various loadings. Figures 1 and 2 illustrate the 

current vs. voltage curves from two sensors using 

precious metal loadings of approximately 0.2 mg/

cm2

. These electrodes were carbon supported 

electrodes and were prepared using a decal technique 

similar to typical fuel cell electrodes. Figure 1 

illustrates that the Pt and Pt/Ru electrodes are 

poisoned by CO at room temperature, and the 

hydrogen-oxidation current is greatly decreased. 

However, this process was found to be difficult to 

reverse and the original current vs. voltage curves 

could not be obtained even after the CO was removed 

from the gas stream. It is seen from Figure 2 (inset) 

that the CO poisoning of the Ru electrode is 

reversible, and the CO can be cleaned by the 

application of a voltage <-0.5 V. However, due to 

the low hydrogen-oxidation kinetics of this electrode, 

a sensor based on this electrode would have very 

little sensitivity to CO.

In order to improve the reversibility of the CO 

adsorption, several electrodes with higher catalyst 

loadings were evaluated. Pt, Ru and Pt/Ru black 

catalysts mixed with Nafion® and without carbon 

support were painted onto Nafion® membranes at 

approximately 10 mg/cm2 loadings. The current vs. 

voltage curves of a “Pt/ Nafion®/ Pt-Ru ” device are 

shown in Figure 3, where the Pt/Ru alloy electrode is 

relatively unaffected by the presence of 100 ppm of 

CO while the Pt electrode is poisoned. Moreover the 

CO from the Pt electrode can be easily cleaned by the 

application of a voltage >0.4 V. Therefore, this 

device, when biased at a voltage <0.4 V can be used 

as a CO sensor. The CO response obtained from this 

device at a bias of 0.3 V is illustrated in Figure 4. 

Figure 5 illustrates the current vs. voltage curve 

of a “Pt/ Nafion® /Ru” device and indicates that the 

CO poisons both the Pt and the Ru electrodes in a 

reversible manner. The poisoning of the Ru 

electrode can also be used to yield a sensor response 

when the bias is >-0.6 V. Figure 6 illustrates the 

Figure 1. Current-Voltage Characteristics of a “0.22 

mg/cm2 Pt/C // Nafion® // 0.25 mg/cm2 Pt/

Ru/C” sensor at room temperature.

Figure 2. Current-Voltage Characteristics of a “0.22 

mg/cm2 Pt/C // Nafion® // 0.12 mg/cm2

 Ru/

C” sensor at room temperature.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

471

response of this device to CO when the bias is set at –

0.5 V. This sensor shows excellent sensitivity to CO 

and can be used to measure CO concentration in the 

10-100 ppm range in a hydrogen stream. Although 

the CO desorption is fast at most CO levels, a bias of 

–0.8 V was found to restore the baseline of the sensor 

upon removal of the CO.

Conclusions

We have successfully developed low temperature 

sensors for the monitoring of carbon monoxide gas in 

a hydrogen stream. The sensors can detect parts per 

million concentrations of carbon monoxide in either 

a pure hydrogen or a hydrogen/carbon-dioxide 

Figure 3. Current-Voltage Characteristics of a “10 mg/

cm2

 Pt // Nafion® // 10 mg/cm2 Pt/Ru” sensor 

at room temperature.

Figure 4. Response of the “10 mg/cm2 Pt // Nafion® // 

10 mg/cm2

 Pt/Ru” sensor to 0, 50, 100, 150, 

200 ppm of CO in H2.

Figure 5. Current-Voltage Characteristics of a “10 mg/

cm2

 Pt // Nafion® // 10 mg/cm2 Ru” sensor at 

room temperature.

Figure 6. Response of the “10 mg/cm2 Pt // Nafion® // 

10 mg/cm2 Ru” sensor to 0, 50, 100, 150, 200 

ppm of CO in H2.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

472

stream. Future work includes the raising of the 

operating temperature of the sensor to approximately 

80o

C (fuel-cell operating temperature) and the 

optimization of the sensor response time and 

sensitivity.

References

1. R. Mukundan, E. L. Brosha, D. R. Brown, and F. 

H. Garzon. A mixed potential sensor based on a 

Ce0.8Gd0.2O1.9 electrolyte and platinum and gold 

electrodes. Journal of the Electrochemical 

Society, V 147(4), 1583-1588 (2000)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

473

IV.D.23 Electrochemical Sensors for PEMFC Vehicles

Ai-Quoc Pham (Primary Contact)

Lawrence Livermore National Laboratory

P.O. Box 808, L-350

Livermore, CA 94550

(925) 423-3394, fax: (925) 422-6892, e-mail: pham2@llnl.gov

DOE Technology Development Managers: JoAnn Milliken and Nancy Garland

(202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

(202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Develop a hydrogen safety sensor operating at 500°C or below, having 1s response time and being 

insensitive to humidity and hydrocarbons.

• Develop a hydrogen sensor for reformate fuel monitoring for hydrogen concentrations ranging 

between 10 to 100%.

• Develop a carbon monoxide (CO) sensor for reformate fuel monitoring.

Approach

• Use proven technology, i.e., solid state electrochemical sensors similar to the well-know oxygen 

sensor used in automobile exhaust gas

• Use mixed potential signal to eliminate the need for a reference gas compartment

• Use nanocrystalline electrode material for faster response time

• Develop micro-sensors for minimum power consumption

Accomplishments

• Data were obtained on temperature effect on sensor response

• Sensors with nanocrystalline electrodes were fabricated and tested

• Sensors with response time of a few seconds at 500°C were demonstrated

• Preliminary testing indicated no baseline drifting over several hundred hours

Future directions

• Complete characterization of hydrogen safety sensor

• Investigate limiting current type hydrogen fuel sensors

• Develop mixed potential CO sensors

• Develop micro-sensors with incorporated self heating device

• Transfer to industrial partners

Introduction

Proton exchange membrane fuel cells (PEMFCs) 

are among the most promising clean power system 

technologies being developed for transportation 

applications. The introduction of this new 

transportation technology implies important changes 

in vehicle design as well as incorporation of new 

features that do not currently exist in internal 

combustion engine automobiles. For example, the 

use of hydrogen, in particular, and combustible gases 

in general, requires additional safety devices to 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

474

prevent fire and explosion hazards. In addition, if 

hydrogen fuel is supplied by an on-board fuel 

reformer that delivers a hydrogen stream containing 

several other gases, additional control and 

monitoring devices are needed in order to protect and 

to efficiently operate the PEMFCs. 

The purpose of this project is to design, develop, 

and demonstrate solid state electrochemical sensors 

for the various controls and monitoring on PEMFC 

vehicles. During this first phase of the project, we 

focus on the development of a hydrogen safety 

sensor. 

Approach

A number of hydrogen and combustible gas 

sensors are commercially available. However, none 

of them appears to straightforwardly satisfy all the 

stringent requirements for automobile applications. 

In particular, the commercial hydrogen safety 

sensors suffer from significant long-term drifting as 

well as cross-sensitivity. Our approach is to use 

solid-state electrochemical sensor technology which 

has proven to be robust and reliable in automobile 

applications. Our sensor consists of an oxygenconducting electrolyte membrane sandwiched 

between two electrodes, one serving as reference and 

one as working electrode. The working electrode has 

mixed potential response when exposed to an 

atmosphere containing hydrogen, i.e., due to the 

competing oxidation-reduction reactions of hydrogen 

and oxygen on the electrode surface, the potential of 

the mixed potential electrode departs from the actual 

thermodynamic value. The reference electrode, 

which is designed to reach thermodynamic 

equilibrium, will thus have a different potential. The 

potential difference between the two electrodes is 

thus the sensor voltage. This sensor voltage is 

dependent on the hydrogen concentration. This type 

of sensor does not require a separate reference gas 

compartment.

Accomplishments

This project started in January 2001. During 

FY01, we successfully developed a mixed potential 

type sensor with response time as fast as 1 second. 

However, a fairly high operating temperature (600°C 

or higher) was needed in order to have fast reaction 

kinetics. While this high operating temperature is not 

a major issue if a micro-sensor with enough 

insulation is used, the power consumption to 

maintain that temperature could still be fairly high. 

Therefore, our goal was to lower the operating 

temperature to 500°C or below.

We studied the effect of temperature on the 

sensor response. It was found that the lower the 

temperature, the higher was the signal amplitude 

while the response time became longer. We also 

found that the smaller the particle size of the 

electrode material, the faster was the sensor response. 

It was then concluded that using nanocrystalline 

material would be beneficial to accelerate sensor 

response, especially at low temperatures. Figure 1 

shows the scanning electron microscopy picture of 

such a porous nanocrystalline electrode. The 

electrode was deposited using the colloidal spray 

deposition technique. The average particle size is less 

than 100 nm. At 500°C, the sensor response to 

hydrogen in air was 2 seconds for a flow rate of 2 

liters per minute. A fast response to hydrogen was 

also observed at 400°C, however, the signal tended 

to overshoot before stabilizing at steady state.

Some of the characteristics of the new sensor are: 

no humidity effect on sensor response, high 

selectivity versus methane (see Figure 2) and 

virtually no baseline drifting over several hundred 

hours of operation. However, some issues still need 

to be improved, including the over-shooting that was 

Figure 1. Micrograph of the Porous Nanocrystalline 

Electrode
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

475

observed at time and the slow recovery upon removal 

of hydrogen from ambient air.

Conclusion and Future Work

We have demonstrated the possibility to reduce 

the sensor operating temperature from 600°C to 

500°C. The sensor has some highly viable 

characteristics such as stability and selectivity.

Further work is needed in order to demonstrate a 

commercially viable device. For practical use, we 

will develop a self-heated micro-sensor for reduced 

power consumption as well as for minimum heat 

generation. 

Figure 2. Sensor Response to Methane and Hydrogen
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

476

IV.D.24 Development of Sensors for Automotive Fuel Cell Systems

Brian A. Knight (Primary Contact)

United Technologies Research Center

411 Silver Lane Mail Stop 129-30

East Hartford, CT 06108

(860) 610-7293, fax: (860) 610-7669, e-mail: knightba@utrc.utc.com

DOE Technology Development Manager: Nancy Garland 

(202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Main Subcontractors: ATMI, Inc., Danbury, Connecticut; Illinois Institute of Technology, Chicago, 

Illinois; NexTech Materials, LTD, Worthington, Ohio

Objectives

• Develop technology and a commercial supplier base capable of supplying physical and chemical 

sensors required to optimize the operation of proton exchange membrane (PEM) fuel cell power plants 

in automotive applications. 

Approach

• Obtain representative samples of physical parameter sensors currently available. 

• Determine the suitability of state of the art physical parameter sensors for the extreme environment of 

a PEM fuel cell power plant by testing them in a combination of laboratory and simulated fuel cell 

flow stream environments.

• Assist the sensor manufacturers, where necessary, to modify the sensors to achieve the requisite 

performance, cost, and durability goals.

• Modify baseline chemical sensing technology to create sensors capable of making the measuring the 

parameters of Table 3.2 in a PEM fuel cell operating environment. 

• Validate and document the performance and durability of the developed sensors by exposing them to a 

combination of laboratory and simulated fuel cell flow stream environments.

• Install the developed sensors on a breadboard PEM fuel cell at United Technologies Company fuel cell 

(UTCFC) for final testing.

Accomplishments

• This contract is still under negotiation; there has been no technical progress to date.

Introduction

The present state of the art in fuel cell 

powerplant sensor technology is embodied in the 

UTCFC PAFC PC 25 and PEM S200 powerplants. 

However, none of the chemical sensors, and only a 

very few of the physical sensors are "on-board" the 

powerplant. Furthermore, only temperature and stack 

differential pressure, in the S200, are measured 

continuously for control purposes. Production 

automotive fuel cell powerplants require all of these 

sensors to be on-board the powerplant, and to 

provide data signals on a continuous basis to 

optimize fuel cell operation and protect the cell stack 

from damage.

The measurement technology used by the PC 25 

and S200 "off-line" chemical analyzers cannot be 

adapted to provide the basis for on-board, 

continuously measuring chemical sensors. IFC and 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

477

its team members have identified three candidate 

technologies that have the potential to achieve these 

goals. 

Approach

Table 1 identifies the two technologies and the 

specific parameters the technologies will be targeting 

during the development effort. The sections below 

discuss each technology that we plan to use to 

develop the required capability. 

Table 1. 

CO = carbon monoxide, H2 = hydrogen, SO2 = sulfur dioxide, 

H2S = hydrogen sulfide, NH3 = Ammonia, O2 = diatomic oxygen

Electrochemical 

Electrochemical sensing is based on the 

interaction of an electrically conductive film with a 

molecular species in its environment. Typically an 

inorganic film is deposited on a semiconducting film, 

which, in turn is deposited over a series of 

interdigitated electrodes. The temperature of the 

device is maintained at a predetermined temperature 

to facilitate the desired interaction. As the target 

compound adsorbs to the sensing film, a change in 

the conductance of the semiconducting film between 

the interdigitated electrodes is produced, sensed and 

a signal is generated for external use. 

NexTech Materials is pursuing the development 

of low-cost electrochemical carbon monoxide (CO) 

sensors that will meet the requirements of the fuel 

cell application. NexTech has recently demonstrated 

detection of parts per million (ppm) CO in a 50% 

hydrogen stream using copper/chlorine (CuCl) thick 

films. Figure 1 shows the response of NexTech's 

sensor when cycling between 50:50 vol% nitrogen/

hydrogen (N2/H2) and 1000 ppm CO in N2/H2. The 

hydrogen content was varied between 25 and 75 

vol% (balanced with nitrogen) with no change in the 

baseline resistance noted. The sensing approach is 

based on the change in electrical resistance that 

occurs when carbon monoxide is selectively 

adsorbed by an inorganic film of a semiconducting 

material. The sensing material is deposited onto a 

substrate with interdigitated electrodes, with 

temperature being controlled by a thick-film heater 

deposited on the underside of the substrate, as shown 

in Figure 2. NexTech's results have demonstrated 

that this resistance change occurs rapidly (with either 

increasing or decreasing CO content), varies with the 

amount of CO from the gas stream, is insensitive to 

the presence of hydrogen, and can be used to detect 

low carbon monoxide levels. This type of sensor has 

the potential to be manufactured at a cost of $5 to 

$10 in volume. However, these sensors were used at 

a single temperature and CO concentration in the 

range of 100 -1500 ppm. More work is needed to 

determine the capability of this material for sensing 

CO at higher temperatures and/or higher CO 

concentration. Effort to explore the range of 

operation of the sensors will accelerate under this 

project.

Technologies CO H2 SO2 H2S NH3 O2

Electrochemical X X X X X

MEMS X X X X

Figure 1. Effect of carbon monoxide (1000 ppm) on 

resistance of NexTech sensor in a baseline gas 

composition of 50% hydrogen and 50% 

nitrogen.

Figure 2. Sensor Construction Detail
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

478

Micro Electro Mechanical Systems (MEMS)

MEMS is a method to produce microscopic 

three-dimensional sensor arrays from a solid 

substrate. Sensing mechanisms such as the 

hydrogen-induced transition from a metallic dihydride to a semiconducting tri-hydride can be 

deposited on a MEMS substrate. The reduced size, 

mass, subsequent thermal rise and fall times of the 

tiny devices, often called microhotplates, makes it 

possible to pulse the sensor to a desired operating 

temperature in milliseconds, make a measurement, 

and step to another measurement condition. Power 

consumption of such devices can be brought to very 

low values, response times can be in the sub second 

range, and sensitivity can be controlled by the actual 

reaction taking place in the uppermost sensing film. 

The micro-hotplate gas sensor is a 

conductometric MEMS-based sensor that uses the 

change in conductance of the sensing layer as a 

function of temperature and time to measure the 

gases present. A critical step in developing these gas 

sensors is the selection of a specific chemi-resistive 

reactive layer for each target gas. ATMI has 

demonstrated the development of a high 

performance-low cost MEMS based H2 gas sensor, 

(U.S. Patent, 09/231277, Allowed 2000) using 

palladium (Pd) alloy coated metal hydrides as the gas 

sensitive layer.

Figure 3 shows a typical unit of this design and 

the response to 0.25% hydrogen in dry air. These 

sensors have shown over a 100% change in 

resistivity to 0.25% H2 in air, at speeds of response of 

less than 0.5 second. 

UTCFC and its team members will investigate 

each of these platforms as a technology for part of 

the chemical-sensing requirement. No single 

platform is believed capable of addressing the entire 

chemical sensing requirement; therefore, each of the 

team members will develop its platform toward the 

requirement indicated in Table 3 1. The goal is to 

develop at least one applicable technology for each 

species and demonstrate them on an on-line S300 

system

Current Technology for Physical Sensing

The state of development of physical sensor 

technology is dramatically different from that of the 

chemical sensors. Demand for high performance 

temperature, humidity and pressure sensors by the 

automotive and heating, ventilating, air conditioning 

and refrigeration (HVAC) industries have resulted in 

a large variety of different sensors. Consequently, 

the primary goal of this section of the effort will be to 

evaluate and modify, as necessary, commercial offthe-shelf sensors to fill the need. The physical 

sensors used by the PC 25 and S200 physical 

powerplants can be used as the basis of on-board 

continuously measuring sensors. Additionally, it is 

possible that more recently developed sensors for 

measuring the same parameters may be a better 

starting platform than the PC25/S200 sensors. The 

team will continually monitor the evolution of new 

physical sensors during the performance of this 

project. 

Figure 3. MEMS Hydrogen Sensor
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

479

The UTCFC team will select a baseline device 

for each sensor and to confirm its ability to fully 

meet the DOE specification. If there are deficiencies, 

we will work with the manufacturer to modify the 

sensor to conform. Table 2 identifies current sensors 

and the properties expected to limit their application. 

The potential limitations will be carefully evaluated 

in lab testing and subsequent on-line testing if they 

successfully complete the lab-testing phase. 

Table 2.

UTCFC will evaluate these sensors in the 

appropriate test facilities, supplying a synthesized 

gas stream of known inlet gas composition, and 

determine the response accuracy of each sensor at the 

required operating temperature. By controlling the 

inlet gas composition and mass flow, a fixed 

reference will be established to which the sensor 

response will be compared as a function of time. 

This effort will be conducted in United Technologies 

Research Center (UTRC), IIT and UTCFC facilities. 

Baseline sensor technology taken from a 

combination of production PC25, S200 and fuel cell 

development laboratory applications will be 

subjected to a series of performance, durability and 

cost reduction studies. Concurrent with this portion 

of the task, a detailed review of alternate sensors will 

be conducted. Appropriate sensors will be ranked 

according to probability of successful test outcome. 

This ranking will be used to identify replacement 

candidates should any baseline sensor fail the full 

suite of evaluations. Initial qualification tests will be 

conducted by IIT in the PEM Fuel Cell Benchmark 

Facility. These tests will consist of installation and 

exposure of baseline sensor technology to precisely 

controlled temperature, humidity, pressure, and gas 

mixture conditions. Sensor response versus these 

parameters will be logged.

Second level testing will be conducted at UTRC. 

During these tests, the sensors will be installed in a 

chamber through which gases simulating an ATR 

exhaust stream (created by mixing gases, heating, 

and humidifying as necessary to obtain the desired 

composition) will flow. The sensors will be 

evaluated for accuracy, speed of response, cross 

sensitivity to non-target parameters and test gas 

parameters. The tests will operate continuously for 

40 hours, during which time a PC utilizing National 

Instruments LabView software will control and log 

all test parameters, including gas composition, sensor 

output, and control safety systems.

It is assumed that repetition of the above testing 

cycle will be required due to non-performance of 

some sensors. If baseline sensors cannot 

demonstrate superior performance, alternates will be 

selected.

References

1. J.N. Huiberts, et al, Nature 380 231(1996). 

Physical 

Sensor

Current 

Manufacturer

Operating 

Range

Items to be 

Confirmed in 

Testing

Temperature Gulf Sensors 

Inc.

0 - 1900o

F Corrosion 

resistance; 

repeatability

P Cell Stack Atmos 

Engineering

1-3 atm; 

-50oC to 

+100oC

Survivability in 

gas stream; 

linearity; drift; 

accuracy, cost

Relative 

Humidity

General 

Eastern

0 to 100% 

RH; -10oC 

to 100o

C 

gas stream

Corrosion

resistance; 

sensor drift; 

repeatability, 

cost

Mass 

Flowmeter

Sierra 

Instruments

30 - 300 

SLPM @ 

80oC

Accuracy, 

corrosion 

resistance; 

repeatability, 

cost
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

480

IV.D.25 Design and Development of New Glass-Ceramic Proton Conducting 

Membranes 

Steve W. Martin (Primary Contact), Steven A. Poling, Jacob T. Sutherland 

Iowa State University, Materials Science and Engineering Department

3053 Gilman Hall

Ames, Iowa, 50011

(515) 294-0745, fax: (515) 294-5444, e-mail: swmartin@iastate.edu

DOE Technology Development Manager: Roxanne Danz 

(202) 586-7260, fax: (202) 586-9811, e-mail: Roxanne.Danz@ee.doe.gov

Objectives 

• Investigate a new class of proton conducting membranes using thio-acids for hydrogen fuel cell 

applications.

• Produce anhydrous solid membranes having minimal fuel crossover capability and address many of 

the problems associated with current hydrogen fuel cell technologies.

• Optimize thio-acid membranes to yield high proton conductivities (10-6 to 10-3 Siemens per centimeter 

[S/cm]).

• Demonstrate performance, thermal stablility, and chemical stability with exposusre to water (H2O) and 

diatomic oxygen (O2) in a typical fuel cell setup.

Approach

• Synthesize new thio-acids.

• Synthesize membrane materials from thio-acids; final product may be a glass, glass/ceramic, or 

ceramic structure with stable sulfur-hydrogen groups.

• Measure the proton conductivity between -70oC and 500o

C.

• Determine thermal stability.

• Determine chemical stability with respect to H2O and O2.

• Determine electrochemical properties, including reduction and oxidation potentials, and cyclic 

voltammetry.

• Cooperatively fabricate and test membrane electrode assembly (MEAs) using the most promising 

membranes. This is to be done in partnership with an external company specializing in fuel cells.

Accomplishments 

• Two new thio-acids have been synthesized, a thiogermanic acid and a thiomolybdic acid. 

Additionally, the synthesis route is able to produce hydrosulfides and sulfides from many different 

hydroxide and oxide precursors.

• Thiogermanic acid, dihydrogen tetragermanium sulfide (H2Ge4S9), is the thermally stable form of 

nanostructured tetrahydrogen tetragermanium sulfide (H4Ge4S10). Tetrahydrogen tetragermanium 

sulfide with n molecules of H2S (H4Ge4S10.nH2S) has a measurable conductivity of 10-5S/cm at room 

temperature; at higher termperatures it decomposes to H2Ge4S9 with a reduced conductivity and 

greater thermal stability.

• Thiomolybdic acid H2MoS4 appears to conduct both protons and electrons. Possible catalytic 

behavior, electrode application, and storage capability of this acid are undetermined at this time.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

481

• Thermally and chemically stable membranes have been synthesized from thio-acids. Conductivities of 

10-7 S/cm at ~ 352oC were achieved with materials thermally stable to at least 500oC and chemically 

stable with H2O for prolonged exposures.

Future Directions 

• Reaction kinetics involving liquid hydrogen sulfide (H2S) solution are being studied for the 

germanium oxide (GeO2) and germanium sulfide (GeS2) systems. This study is exploring the effects 

of water, temperature, time, and pressure on the kinetics of these types of reactions. At this point, it is 

clear that hydration by water speeds the reaction. A high pressure phase, which is more thermally 

stable, is also realized from long reaction times.

• Investigation into new thio-acid compounds from oxide, hydroxide, and sulfide precursors is being 

excuted. One new compound has recently demonstated 10-3S/cm at 100o

C.

• Efforts to thermally stabilize these thio-acids with large alkali metal cations are underway. This may 

also produce primitive rotating phases with higher proton conduction values.

• Work is now underway to produce thermally and chemically stable membranes from these thio-acids. 

This involves bonding thio-acid units to known chemically and thermally durable compounds.

Introduction

Hydrogen-based fuel cells are becoming 

increasingly popular as an alternative to petroleumfueled internal combustion engines. Specifically, 

hydrogen can be converted to electricity through the 

use of a (H2-O2) fuel cell. The by-product of this 

type of a fuel cell is water, making this a "green" or 

environmentally friendly technology. At the heart of 

the fuel cell is the proton exchange membrane 

(PEM), which transports the proton from the anode 

to the cathode while providing electronic insulation 

between them. There are many types of PEMs, each 

with specific limitations [1].

With current PEMs, there remains a temperature 

region between ~200o

C and ~700oC that currently no 

one membrane can provide for optimum 

performance. We propose the use of chalcogenide 

glass-ceramic proton conducting membranes to help 

fill this temperature performance regime. These 

membranes are being developed to be highly 

conducting to protons, anhydrous in nature, 

thermally stable up to ~500oC, and chemically stable 

with respect to H2O and O2. Being solid in nature, 

these membranes are not expected to exhibit fuel 

cross-over problems. Proton conductivities of these 

membranes are expected to be orders of magnitude 

higher than their oxide counterparts, assuming they 

follow the trend exhibited by alkali cations such as 

lithium (Li) and silver (Ag) in chalcogenide verses 

oxide host materials [2].

Approach

Oxide, hydroxide, and sulfide compounds 

capable of forming thio-acids in liquid H2S solution 

are being identified. As an example, the reaction of 

GeO2 with liquid H2S at room temperature produces 

the thio-acid (H4Ge4S10.xH2S). Membranes may be 

produced by bonding thio-acid units with known 

thermally and chemically stable sulfide or oxide 

compounds. Taking a glass or ceramic material that 

has one or more thio-acid analogs and reacting it in a 

liquid H2S solution is one way to accomplish this.

Proton conductivity in the glasses and glassceramics is being determined through impedance 

measurements as a function of temperature and 

frequency. Direct current polarization experiments 

have been used to determine the electronic verses 

ionic conductivity of the samples. Physical 

properties of the glass-ceramic proton conducting 

materials have been determined, including 

decomposition, sublimation, crystallization, and 

glass transition temperatures. Structural comparisons 

have been used to examine stability with exposure to 

H2O and O2.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

482

A cooperative effort to fabricate and test MEAs 

using our most promising membranes is being 

carried out in partnership with an external company 

specializing in fuel cells.

Results

Proton conduction has been demonstrated for our 

anhydrous thio-acid materials. Figure 1 shows the 

resulting proton conductivity values for 

nanostructured H4Ge4S10.nH2S produced by 

reacting GeO2 with liquid H2S for four weeks. The 

data is presented in the temperature range of 61oC to 

300o

C; a conductivity of 10-5S/cm is realized at 

room temperature before the nanostructured 

H4Ge4S10 material decomposes to the thiogermanic 

acid H2Ge4S9. Effort is currently underway to 

stabilize the nanostructured H4Ge4S10 material, 

thereby increasing the conductivity and useable 

temperature range.

Figure 2 illustrates thermogravimetric analyzer 

(TGA) spectra of the thiogermanic acid H2Ge4S9. 

Longer reaction times, i.e. eight weeks versus two 

weeks, with liquid H2S appears to produce a more 

thermally stable crystal phase.

Figure 3 demonstrates proton conduction for one 

of our thermally and chemically stable thio-acid 

membranes. A conductivity of 10-7S/cm at ~ 352oC 

as achieved in the 0.14 gallium sulfide (Ga2S3) + 

0.86 GeS2 + H2S system. This material is thermally 

stable to at least 500o

C and chemically stable with 

prolonged H2O exposures.

Figure 4 presents preliminary proton conduction 

for one of our new thio-acid compounds. 

Conductivity of 10-3S/cm at ~100o

C was achieved 

(this is close to the commercial PEM Nafion7

 ~ 

Figure 1. Proton Conductivity Values for the 

Thiogermanic Acid between -61oC and 300oC

Figure 2. TGA Scan at 10oC/min of the Thiogermanic 

Acid

Figure 3. Proton Conductivity Values of the 0.14 

Ga2S3 + 0.86 GeS2 + H2S System between 

110oC and 500oC
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

483

10-2 S/cm). Beyond 100oC this compound 

decomposes. Effort is currently underway to 

thermally stabilize this new thio-acid compound, and 

to increase its proton conductivity and useable 

temperature range.

Conclusions

• A synthesis route for producing thio-acids, 

hydrosulfides, and sulfides has been 

identified; effort to decrease production time 

is underway.The structure, conductivity, 

thermal and chemical stability of many 

potential thio-acids have been investigated; 

many more are being pursued.

• Two new thio-acids have been identified and 

synthesised for the first time, namely 

thiogermanic acid and thiomolybdic acid.

• Preliminary ionic conductivity as high as 

10-3S/cm at ~100oC has been realized from 

one new compound; this is close to the 

commercial membrane material Nafion7.

• Structural modifications to thio-acid 

compounds and thio-acid membranes are 

underway to increase thermal stability and 

conductivity.

References

1. Martin, S.W., Poling, S.A., Sutherland, J.T., 

"Design and Development of New Glass-Ceramic 

Proton Conducting Membranes." DOE Hydrogen 

Program Annual Review, Proceedings (2002): 

NREL/CP-610-32405.

2. Angell, C.A. 1992. "Mobile Ions in Amorphous 

Solids." Annual Review of Physical Chemistry, 

43:693-717.

FY 2002 Publications/Presentations

1. “Design and Development of New Glass-Ceramic 

Proton Conducting Membranes,” Steve W. 

Martin, Steven A. Poling, and Jacob T. 

Sutherland, DOE Hydrogen Program Annual 

Review, Proceedings (2002): NREL/CP-610-

32405.

2. “Synthesis and Structure of Thiogermanic Acid 

H2Ge4S9,” Steven A. Poling, Steve W. Martin, 

and Jacob T. Sutherland, to be submitted.

3. “Design and Development of New Glass-Ceramic 

Proton Conducting Membranes,” Steve W. 

Martin, Steven A. Poling, and Jacob T. 

Sutherland, DOE Hydrogen Program Annual 

Review, Golden, CO, May 6-10, 2002.

4. “Synthesis and Characterization of a New Class of 

Ceramic Proton Conducting Solid Electrolytes,” 

Steve W. Martin, Steven A. Poling, and Jacob T. 

Sutherland, 201st Meeting of The Electrochemical 

Society, Philadelphia, PA, May 12-17, 2002.

5. Invited Talk, "Preparation and Characterization of 

New Proton Conducting Chalcogenide Glasses 

and Glass-Ceramics," University of Muenster, 

Muenster, Germany, July, 2002.

6. Invited Talk, "Preparation and Characterization of 

New Proton Conducting Chalcogenide Glasses 

and Glass-Ceramics," University of Dortmund, 

Dortmund, Germany, July, 2002.

7. “Invited Talk, "Preparation and Characterization 

of New Proton Conducting Chalcogenide Glasses 

and Glass-Ceramics,” University of Montepellier 

II, Montepellier, France, July, 2002.

Figure 4. Preliminary Conductivity Values for a Newly 

Synthesized Compound between -31o

C and 

136oC
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

484

8. “Protonated Chalcogenide Materials for Fuel Cell 

Electrolyte Membranes,” poster at the104th 

Annual Meeting and Exposition of the American 

Ceramic Society, Steve W. Martin, Steven A. 

Poling, and Jacob T. Sutherland, St. Louis, MO, 

April 29-May 1, 2002.

Special Recognitions & Awards/Patents

1. Provisional Patent: “Synthesis and Uses of Thio 

Acids” Steve W. Martin, Steven A. Poling, Jacob 

T. Sutherland, Iowa State University, ROI ISURF 

2894, February 8, 2002. Provisional filing date of 

July 26, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

485

IV.D.26 Fuel Cell System Durability

Rod Borup (Primary Contact), Michael Inbody, Troy A. Semelsberger, Francisco Uribe, and José 

Tafoya

P.O. Box 1663

Los Alamos National Laboratory

Los Alamos, NM 87545

(505) 667-2823, fax: (505) 665-9507, e-mail: Borup@lanl.gov

DOE Technology Development Managers: 

JoAnn Milliken: (202) 586-2480, fax: (202) 586-9811, e-mail: JoAnn.Milliken@ee.doe.gov

Nancy Garland: (202) 586-5673, fax: (202) 586-9811, e-mail: Nancy.Garland@ee.doe.gov

Objectives

• Achieve DOE system durability target of 5,000 hours on reformate.

• Quantify fuel cell component durability

- Fuel processor durability reforming liquid hydrocarbons (gasoline)

- Fuel cell durability on reformed gasoline

- Fuel cell durability on hydrogen

• Quantify fuel reformate effects on fuel cell system (fuel processor and fuel cell stack) durability

- Determine stack durability limits of operation with reformed fuel 

• Determine reformate effect on electrocatalyst durability

• Determine reformate effect on proton exchange membrane durability

- Determine fuel and fuel impurity effects on fuel processor catalyst durability

- Identify reformate species which limit fuel cell anode durability

Approach

• Measure single cell fuel cell performance with hydrogen and gasoline reformate

- Measure stack component durability with hydrogen

- Measure stack component durability with gasoline reformate from fuel processor

• Operate modular fuel processor system with liquid hydrocarbons to generate real reformate

- Measure fuel processor operation and reformate composition over long operational period (1000 hrs)

• Analyze fuel processor catalysts to determine structural and elemental changes

• Analyze reformate to determine low level of impurities

- Characterize membrane electrode assemblies (MEAs) during operation

• Electrochemical polarization curves, high frequency measurements

• Hydrogen adsorption/desorption

Accomplishments

• Operated fuel processor system with liquid hydrocarbon fuels for over 1000 hrs

- Measured fuel reformate impurities

• Near-zero NH3 formation (<0.5 ppm) with normal operating conditions
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

486

- Measured catalyst surface area after extended operation (~1,200 hours)

• Decrease of 20% to 90% observed in autothermal reforming (ATR) and preferential oxidation 

(PrOx) catalysts, including loss in activity and CO conversion in PrOx

• Improved fuel processor subsystem (carbon formation and fuel processor hydrocarbon breakthrough)

- Carbon formation limited by precious metal steam reforming catalysts, high steam-to-carbon (S/C) 

ratio (1.3), and high reforming temperature (>725o

C)

- Hydrocarbon breakthrough limited by additional S/C and reforming catalysts (<20 ppm C2

compounds)

• Measured hydrogen proton exchange membrane (PEM) performance

- Operated single cells with reformate and hydrogen B low performance observed with reformate

Future Directions

• Improve fuel processor conversion to eliminate high molecular weight hydrocarbon formation

• Study stack operation on reformed petroleum-based fuels to evaluate reformate effects:

- Pure fuel components and components blends

- Real fuels such as reformulated gasoline

• Measure fuel cell stack durability with hydrogen and reformate for direct comparison of reformate 

effects

Introduction

This report describes our FY02 technical 

progress in examining the durability of fuel cell 

systems to support the DOE target for 5,000 hour 

durability of these systems. The goal of this research 

is to identify the factors limiting the durability of fuel 

cells and fuel processors. This includes PEM fuel 

cell durability issues for operating on pure hydrogen, 

as well as those that arise from the fuel processing of 

liquid hydrocarbons (e.g., gasoline) as a function of 

fuel composition and impurity content. Benchmark 

comparisons with the durability of fuel cells 

operating on pure hydrogen are used to identify 

limiting factors unique to fuel processing. 

We describe the design, operation and 

operational results of the durability system, including 

the operating conditions for the system, fuel 

processor subsystem operation over 1000 hours, 

post-mortem characterization of the catalysts in the 

fuel processor, and single cell operation. 

Approach: Durability Gasoline Reformate 

Production and Single Cell Fuel Cells

Our approach to identify the limiting factors on 

fuel cell system durability is, first, to develop and 

operate a modular fuel processor system to examine 

the fuel composition and impurity effects on fuel 

processor durability and to generate reformate for 

testing the durability of fuel cell components. 

Second, we examine the effects of the reformate on 

the fuel cell components, primarily the membrane 

electrode assembly (MEA), by testing MEAs in 

single-cell fuel cells operating on both reformate and 

pure hydrogen. Third, we use a combination of fuel 

processor gas analysis, fuel processor catalyst 

characterization, and MEA characterization during 

and after operation to quantify performance losses 

and to identify limiting factors on durability such as 

poisons. The modular fuel processor subsystem, 

shown in Figure 1, was designed and constructed to 

simulate conventional methods of hydrogen 

generation for PEM fuel cell stacks. The fuel 

processor consists of a sequence of reactors: a partial 

oxidation/steam reformer (POx/SR) or autothermal 

reformer (ATR), sulfur removal, high-temperature 

shift (HTS), low-temperature shift (LTS), and 

preferential oxidation reactor (PrOx). Typical 

commercial and semi-commercial noble metal 

oxidation catalysts and noble metal or non-noble 

metal steam reforming catalysts are used in the ATR. 

Conventional commercial catalysts also are used in 

the HTS, LTS, and PrOx to allow full 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

487

characterization of the catalysts without violating 

proprietary concerns. The ATR atomic O/C (oxygen/

carbon - O from air only) is 0.8 to 0.85, while typical 

S/C (steam/carbon) is from 1.0 to 1.25. Additional 

downstream liquid water injection increases the 

overall S/C ratio to a typical S/C of 2.5 to 3.0. A 

slipstream of the reformate flow from the fuel 

processor is routed to the fuel cell test station. 

Figure 2 shows the fuel cell test station and 

single cells coupled with the fuel processor. The fuel 

cell test station can operate 3 single-cell fuel cells 

with either pure hydrogen or with the gasoline 

reformate. The direct comparison of pure hydrogen 

and reformate feeds to the single cells is used to 

identify the effects that fuel processing reformate has 

on the fuel cell durability. Currently, 50 cm2 single 

cell components are being tested. Performance 

during the durability test is measured with continual 

monitoring of the voltage/current performance along 

with periodic polarization curve, AC Impedance, and 

hydrogen adsorption/desorption (HAD) 

measurements to monitor the anode catalyst surface 

area. Following the durability testing, MEAs will be 

characterized to evaluate degradation mechanisms.

Results: Fuel Processor Operation

The fuel processor subsystem was operated with 

pure iso-octane to verify its performance. Figure 3 

shows 800 hours of the fuel processor operation on 

iso-octane, showing the temperatures in the different 

stages, and the CO outlet concentration. The 

temperature in the partial oxidation stage is about 

800 – 825o

C, and the outlet temperature of the steam 

reforming section is 775o

C. The average residence 

time for the ATR section is about 0.5 sec (GHSV ~ 

10,000), which should be sufficient for complete 

hydrocarbon conversion.

The HTS is operated at 400o

C, the LTS is 

operated at 250o

C, and the PrOx is controlled to a 

temperature of 125oC. The outlet CO concentration 

Figure 1. Fuel Processor System Showing the Stages 

for POx/SR, HTS, LTS and PrOx

Figure 2. Fuel Processor Coupled with Fuel Cell Test 

Station and Two PEM Fuel Cell Single Cells

Figure 3. Temperature and PrOx Outlet CO 

Concentration of Fuel Processor System 

during ~ 800 hrs Operation with Isooctane
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

488

from the ATR was typically about 10%; the outlet 

CO concentration from the LTS was <1%; and the 

outlet CO concentration from the PrOx varied 

initially from 0 to 150 ppm, with improved controls 

keeping the CO concentration below 100 ppm and 

typically below 40 ppm.

Figure 4 shows operation of the fuel processor 

subsystem on iso-octane for 11 days, after which the 

fuel was switched to a simulated gasoline of 74% 

iso-octane, 20% xylene, 5% methylcyclohexane and 

1% 1-pentene. After only two days of operation on 

this simulated gasoline, the pressure drop between 

the ATR and HTS increased due to carbon formation. 

Post characterization of the carbon formed showed 

that a high concentration of solidified hydrocarbons 

were present in the carbon (30% by weight). To 

prevent carbon formation between these reactor 

sections, the HTS water injection was moved from 

the inlet to the HTS to the outlet of the steam 

reformer section.

After extended operation, the catalysts present in 

the fuel processor were characterized to observe any 

potential degradation of the catalysts. The relative 

catalyst surface areas of the ATR, HTS, LTS and 

PrOx catalysts all decreased after extended 

operation. The initial portion of the ATR catalyst, 

where the fuel oxidation occurs, showed a large 

decrease in surface area, over an order of magnitude 

decrease from about 3 m2/g to <0.2 m2

/g (note that 

the surface area is low because the support material is 

included in the measurement). Other portions of the 

ATR catalyst did not show as big a decrease in 

surface area. The LTS catalyst surface area 

decreased about 50%, which appears to be 

independent of the catalyst location in the LTS 

section. The measured PrOx catalyst surface area, 

shown in Figure 5, decreased as a function of the 

axial location in the reactor catalyst volume. The 

measured PrOx catalyst surface area shows a high 

decrease in the upstream section, while in 

downstream sections of the PrOx, approximately 

75% of the original surface area is maintained.

Current results indicate operational issues for the 

fuel processor subsystem to meet the DOE durability 

target of 5000 hours due to carbon formation and 

catalyst surface area. Upon post-analysis of the fuel 

processor, carbon formation was observed regardless 

of fuel composition and operating condition. When 

aromatics were present in the fuel, carbon formation 

was a much a larger issue, such that the amount of 

carbon formed caused increases in the system 

pressure drop. Various improvements in the ATR 

design, including the water injection for the HTS, 

decreased the amount of carbon formation. In 

addition, elimination of any nickel steam reforming 

catalysts has helped decrease carbon formation.

Results: Single Cell Operation

Figure 6 shows a single cell operation for Nafion 

112 MEAs on pure hydrogen, and with reformate 

produced from the fuel processor. The steady state 

performance of the MEA on pure hydrogen was 

about 0.9 A/cm2 at 0.62 V. At hour 48, the pure 

hydrogen feed was switched to the gasoline 

Figure 4. Operation of fuel processor with isooctane 

and simulated fuel. Inlet pressures and 

pressure drops are shown, demonstrating the 

build-up of carbon in between the ATR and 

HTS.

Figure 5. PrOx Catalyst Surface Area after Total OnStream Time of ~1200 hrs of Operation
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

489

reformate. Even though the CO content of the fuel 

processor was below 50 ppm, and air injection was 

used for the anode of the fuel cell, the performance of 

the fuel cell was poor, as shown by the rapidly 

dropping current density of the MEA. As the 

reformate was switched back to pure hydrogen, the 

performance recovered quickly, within a few 

minutes.

Analysis of the fuel processor condensate 

showed that hydrocarbons were present. The 

hydrocarbons found in the condensate include 

hydrocarbons with molecular weights higher than 

those present in the original fuel, over 150. This 

could mean that some polyaromatic hydrocarbons are 

formed. Changes to the catalyst used in the fuel 

processor ATR section have been made to reduce the 

hydrocarbon output of the fuel processor section to 

improve performance of the fuel cells.

Hydrocarbon breakthrough from the fuel 

processor appears to have limited the durability of 

the PEM fuel cell anode. The loss of MEA 

humidification has also been observed to limit MEA 

durability. Hydrocarbon breakthrough has been 

eliminated by using small amounts of nickel catalyst 

in the ATR portion of the fuel processor; however, 

this resulted in carbon formation, which limited the 

fuel processor operational durability. Increasing the 

ATR S/C ration, adding precious metal steam 

reforming catalyst, and increasing the steam 

reforming temperature has also eliminated the 

hydrocarbon breakthrough. Modification of the 

MEA humidification should eliminate loss of gas 

feed humidification. These improvements should 

greatly improve the PEM MEA durability. 

Conclusions

Fuel processor operation producing hydrogen 

with low carbon monoxide content has been 

demonstrated for over 1000 operational hours. 

Current results indicate difficulties in operating the 

fuel processor subsystem continuously for the DOE 

target of 5000 hours due to carbon formation and 

reduced catalyst surface area. The catalyst surface 

decreased in all the stages of the fuel processor, with 

the amount of decrease depending on the catalyst and 

its axial location in the catalyst volume. Although 

the carbon monoxide concentration in the outlet of 

the fuel processor is low, the performance of the 

single cells is poor, apparently due to small amounts 

of hydrocarbons present in the reformate stream. 

Carbon formation over relatively long periods of 

time was also an issue between the ATR and HTS 

stages when fuels containing aromatics were used.

Future work is being conducted to examine fuel 

processor durability, PEM cell durability on 

reformate, and operation of PEM fuel cells on 

hydrogen. The durability of fuel processor catalysts 

and reactor materials will be examined with 'real' fuel 

blends with operation and design modified to help 

prevent carbon formation. This work will evaluate 

the fuel processor catalyst durability, carbon 

formation, and changes to the mechanical properties 

of ATR materials. PEM cell durability studies will 

concentrate on the operation and causes of 

degradation of the MEA portion of the fuel cell.

Presentations/Publications 

1. Fuels for Fuel Cells for Transportation 

Applications, Rod Borup, Lee Perry, Mike 

Inbody, Byron Morton, Troy Semelsberger and 

Jose Tafoya, AIChE Meeting, Spring 2002, New 

Orleans, LA, Los Alamos National Laboratory 

publication, LAUR-02-1207, March 2002.

Figure 6. Single Cell Operation on H2, Followed by 

Operation on Gasoline Reformate
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

490

IV.E Air Management Subsystems

IV.E.1 Turbocompressor for PEM Fuel Cells

Mark K. Gee

Honeywell Engines & Systems

2525 W. 190th Street, MS-36-2-93084

Torrance, CA 90504

(310) 512-3606, fax: (310) 512-4998, e-mail: mark.gee@honeywell.com

DOE Technology Development Manager: Patrick Davis 

(202) 586-8061, fax: (202) 586-9811, e-mail: Patrick.Davis@ee.doe.gov

ANL Technical Advisor: Bob Sutton 

(630) 252-4321, fax: (630) 252-4176, e-mail: sutton@cmt.anl.gov

Objectives

• Develop an optimum turbocompressor configuration by working with fuel cell system manufacturers 

and by improving upon previous project results.

• Reduce turbocompressor/motor controller costs while increasing design flexibility.

• Develop and integrate the turbocompressor/motor controller into a fuel cell system. 

Approach

• Use automotive and aerospace turbomachinery technology to reduce cost and weight/volume.

• Use VNT7 variable nozzle turbine inlet geometry to improve performance across the desired flow 

range.

• Use a mixed flow type compressor to improve low flow performance.

• Use contamination/oil free and zero maintenance compliant foil air bearings.

• Use a modular approach to improve design flexibility.

• Use a high efficiency, low cost two pole toothless motor.

• Use a low cost, no sensor required, variable speed motor-controller topology design. 

Accomplishments

• Accomplished numerous start/stop cycles with no appreciable wear.

• Continued demonstration of a modified turbocompressor with increased turbine inlet temperature 

(315o

C) capability and aerospace quality variable speed brassboard motor controller in the 50-kW 

DOE/Honeywell fuel cell brassboard system.

• Completed the analysis, design, and fabrication of the turbocompressor with a mixed flow compressor 

and VNT7

 variable nozzle turbine.

• Completed the analysis, design, and fabrication of a vehicle ready motor controller.

• Completed testing of the mixed flow compressor.

• Completed integration testing of the turbocompressor and vehicle-ready motor controller.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

491

Future Directions

• Complete testing of the turbocompressor VNT7 variable nozzle turbine.

• Complete analysis, design, fabrication, and testing of a reduced cost and enhanced performance 

turbocompressor.

• Complete analysis, design, fabrication, and testing of a reduced cost and enhanced performance motor.

• Complete analysis, design, fabrication, and testing of a reduced cost and enhanced performance motor 

controller with no sensor requirements.

Introduction

The objective of this work is to develop an air 

management system to pressurize a light-duty 

vehicle fuel cell system. The turbocompressor is a 

motor-driven compressor/expander that pressurizes 

the fuel cell system and recovers subsequent energy 

from the high-pressure exhaust streams. Honeywell 

designed and developed the motor driven 

compressor/expander and evaluated performance, 

weight and cost projection data. As compared to a 

positive displacement technology, the 

turbocompressor approach offers high efficiency and 

low-cost potential, in a compact and lightweight 

package. 

Approach

The turbocompressor design depicted in Figures 

1 and 2 consists of a compressor impeller, an 

expander/turbine wheel, and a motor magnet rotor 

incorporated onto a common shaft operating up to a 

speed of 110 krpm on compliant foil air bearings. A 

motor controller drives and controls the motor, which 

is capable of driving the turbocompressor to the 

maximum design speed. The air bearings are 

lubrication free in addition to being lightweight, 

compact, and self-sustaining. Thus, no pressurized 

air is required for operation. The current 

turbocompressor operates by drawing in ambient air 

through the motor/bearing cavities, where it is 

pressurized by the compressor, delivered to the fuel 

cell stack, used to oxidize any excess fuel in a tailgas 

combustor, then expanded through the turbine to aid 

in the overall turbocompressor/fuel cell system 

efficiency. 

Figure 1. Honeywell Fuel Cell Turbocompressor with 

Mixed Flow Compressor and VNT7 Variable 

Nozzle Turbine

Figure 2. Cross Section of Fuel Cell Turbocompressor 

with Mixed Flow Compressor and VNT7
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

492

Results

The current turbocompressor has operated for 

more than 450 hours at varying conditions. To date, 

a maximum speed of 110 krpm has been attained. 

To support the DOE/Honeywell fuel cell 

brassboard system testing, the turbocompressor was 

modified to handle increased turbine inlet 

temperatures. In addition, a modified aerospace 

quality motor/controller was assembled and used in 

the DOE/Honeywell fuel cell brassboard system, 

replacing a previously used motor/controller 

commercial unit. Testing of the DOE/Honeywell 

fuel cell brassboard system was initiated in late 2000 

and is expected to be completed in mid 2002. 

The turbocompressor and vehicle-ready motor 

controller was analyzed, designed, fabricated, and 

tested (see Figures 1, 2, and 3, and Table 1). The 

turbocompressor incorporates a mixed flow 

compressor and a VNT7 variable nozzle turbine. 

These features were incorporated to improve the lowflow performance while maintaining efficiency 

across the flow range. These changes included the 

following: the redesigned mixed flow compressor 

improved low flow performance with an improved 

surge line; however, the VNT7 variable nozzle 

turbine, which would have further improved 

performance and, consequently, lowered overall 

power consumption, was not tested due to program 

constraints. The vehicle-ready motor controller is of 

reduced size. Although its new technology requiring 

no sensors was not incorporated due to project 

constraints, the controller topology is configured to 

reduce production costs. Predicted performance of 

the turbocompressor and motor controller with the 

mixed flow compressor test results is presented in 

Figure 4. 

Conclusions/Future Work

The turbocompressor concept using selfsustaining compliant foil air bearings has 

demonstrated low power consumption and moderate 

pressure ratio at low flow rates in a compact 

lightweight package. Predicted power consumption, 

which includes the predicted effects of the VNT7

variable turbine nozzle can be further reduced if 

increased expander/turbine temperatures can be 

provided by the fuel cell system. The 

turbocompressor, capable of increased expander/

turbine temperatures, continues to be demonstrated 

in the DOE/Honeywell 50-kW fuel cell brassboard 

system. The latest turbocompressor with mixed flow 

compressor and variable inlet nozzle turbine 

technology, which, however, has not been utilized to 

date, demonstrated improved low-flow performance, 

DOE 

Parameters

DOE 

Guidelines

Honeywell 

Turbocompressor

Volume 4 liters total 

(w/o heat 

exchangers)

Turbocompr.: 6 liters

Controller: 13 liters

Weight 3 kg total 

(w/o heat 

exchangers)

Turbocompr.: 9 kg max

Controller: 6.5 kg max

Table 1. Fuel Cell Turbocompressor Physical Parameters

Figure 3. Fuel Cell Turbocompressor Motor Controller

Figure 4. Turbocompressor Shaft Power/Compressor 

Outlet Pressure Ratio vs. % Flow
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

493

while the latest variable speed motor/controller 

demonstrated reduced size, weight, reliability, and 

cost. Future work will investigate turbocompressor 

designs that incorporate flexibility to better meet the 

various vehicle fuel cell system developers’ needs in 

the rapidly changing vehicle fuel cell system market, 

while continuing to improve performance and reduce 

cost. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

494

IV.E.2 Development and Testing of a High Efficiency Integrated Compressor/

Expander Based on Toroidal Intersecting Vane Machine Geometry

Sterling Bailey (Primary Contact), Steve Chomyszak

Mechanology, LLC

453 South Main Street

Attleboro, MA 02703

(408) 356-5520, fax: (408) 358-4012, e-mail: sterling@mechanology.com

DOE Technology Development Manager: Patrick Davis

(202) 586-8061, fax: (202) 586-9811, e-mail: Patrick.Davis@ee.doe.gov

ANL Technical Advisor: Robert Sutton

(630) 252-4321, fax: (630) 252-4176, e-mail: Sutton@cmt.anl.gov

Objectives

• Develop a Toroidal Intersecting Vane Machine (TIVM)-based air management system that satisfies 

DOE’s 50-kWe automotive fuel cell system requirements and is readily adaptable to alternate user 

requirements.

• Select and demonstrate design features to assure adequate sealing, minimum porting pressure loss, and 

low friction operation.

• Measure the performance of the TIVM compressor/expander across the operating range.

• Fabricate and deliver a compressor/expander/motor prototype for independent testing.

Approach

• Test candidate materials for friction and wear using standard laboratory tribilogical methods. 

• Test candidate seal and port designs as well as low friction materials in simplified test configurations 

to select the best performing options for the TIVM compressor/expander.

• Optimize the vane surface solution methodology to provide a more efficient design process.

• Fabricate a TIVM compressor/expander prototype using seals, porting, and materials selected from the 

simplified feature tests and evaluations.

• Conduct performance tests of the prototype covering the full operating range.

• Refine the prototype features as necessary to obtain optimal performance.

• Integrate a high efficiency motor with the TIVM prototype and test the combined unit across the 

operating range.

• Deliver a TIVM compressor/expander/motor prototype to ANL for testing.

Accomplishments

• Initial friction and wear tests have identified one suitable material pair for the TIVM operating 

conditions and lifetime requirement. Additional tests are underway.

• A simplified single vane test rig has been designed for screening of seal and port designs and low 

friction materials. Hardware has been procured and assembly is in progress.

• CFD calculations have been initiated to guide seal and port designs.

• Analyses have been performed to determine port flow area and timing requirements.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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• Design optimization has reduced maximum speed from 4800 rpm to 3500 rpm with no increase in 

volume.

• A Linear Intersecting Vane Machine test device has been designed to allow simplified testing of vane 

interaction features. 

• Experimental expander vanes are being fabricated to potentially qualify a unique powder metallurgy 

process that provides net shape, finish, and hardness without secondary operations.

• A theoretical mathematical analysis of the surface solution methodology has been initiated.

• Initial thermal analyses have been performed to evaluate geometric changes caused by differential 

thermal expansion.

Future Directions

• Screening tests will be performed in the single vane test device using candidate seals and ports as well 

as low friction materials. Results will be evaluated to select the best options and to identify additional 

options to be tested.

• The Linear Intersecting Vane Machine test device will be fabricated and used with selected seals, 

ports, and low friction materials to provide basic performance data applicable to the TIVM and to 

further down-select options.

• The best performing design and material options will be implemented in a fully functional TIVM 

compressor/expander prototype, which will be tested across the operating range using Mechanology’s 

automated test stand.

• The TIVM prototype will be refined based on empirical and analytical data to optimize performance.

• A high efficiency motor will be integrated with the TIVM compressor/expander and a prototype 

compressor/expander/motor unit will be fabricated and delivered to ANL for independent testing.

Introduction

The Toroidal Intersecting Vane Machine (TIVM) 

is an innovative mechanical concept, invented and 

patented by Mechanology, that can be configured as 

an integrated, positive displacement compressor/

expander or compressor/compressor. In FY99 DOE 

investigated the TIVM concept for potential 

application to automotive fuel cell systems and 

determined that the inherent efficiency, compactness 

and thermodynamic attributes of this concept might 

be of significant benefit. Mechanology developed a 

prototype design specifically for the 50-kWe 

automotive system and evaluated its potential 

performance. Based on the encouraging results 

obtained, a first generation compressor/expander 

prototype was built and tested. Figure 1 illustrates 

this prototype partially assembled to show the 

compressor and expander. The compressor/expander 

prototype tests indicated that the TIVM runs 

smoothly with no mechanical problems; however, 

Figure 1. Partially Assembled First Generation TIVM 

Compressor/Expander Prototype
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

496

improvements are required to limit air leakage. 

Additional tests using the generic prototype with 

temporary seals demonstrated the capability of the 

TIVM to produce the necessary flow and pressure. 

The TIVM compressor/expander development plan 

was subsequently refocused on development and 

demonstration of seals, ports, and low friction 

materials. These are necessary to satisfy the 

functional performance requirements with low 

parasitic power. Although not the main focus of the 

current development program, the requirements for 

air management system packaging, noise, and cost 

are also considered critical for a successful TIVM 

based system and are carefully considered as 

development progresses.

Approach

The basic functions of the TIVM compressor/

expander (kinematics, pressure, flow) have been 

demonstrated; however, development and 

qualification of specific seals, flow ports, and low 

friction materials are required to meet the 

performance requirements. 

During 2002 Mechanology has focused on the 

use of simplified feature tests to allow rapid, efficient 

characterization of a broad range of design options 

for later inclusion in a full TIVM device. The initial 

simplified tests use a single vane test device to 

measure the leakage and friction characteristics of 

candidate vane seal designs and the effectiveness of 

alternate flow port designs. Computational Fluid 

Dynamics (CFD) analysis of the vane/housing/air 

interactions will be used to guide the design and 

testing of these features. Additional tests will be 

performed using a Linear Intersecting Vane Machine 

(LIVM) which introduces the vane interactions in 

simplified geometry. These tests will be used to 

further screen seal, port, and material candidates.

Definition of the vane surface configurations 

required for a specific TIVM can be accomplished 

through an iterative process developed by 

Mechanology. With sufficient iterations, a very good 

meshing surface solution can be obtained, as 

evidenced by the generic TIVM prototype vanes. 

However, this process is quite time consuming. 

Mechanology is exploring alternate mathematical 

approaches to develop a more efficient surface 

design methodology.

Low friction materials are necessary for the 

intersecting vanes to realize the predicted energy 

efficiency of the TIVM compressor/expander. 

Additionally, these materials must have sufficiently 

low wear under the TIVM operating conditions to 

perform acceptably during a 6,000-hour lifetime. 

Several candidate material pairs and potential 

coatings have been identified based on published 

data. To qualify materials for the TIVM, standard 

laboratory friction and wear tests are being 

performed. Successful materials will be tested in the 

single vane and LIVM devices, and the best materials 

will be used in a TIVM prototype.

One or more full TIVM compressor/expander 

prototypes will be fabricated by Mechanology and 

tested across the full operating range. Modifications 

will be made as necessary to optimize performance. 

Subsequently, a high efficiency electric motor will be 

integrated with the TIVM to form a complete 

compressor/expander/motor (CEM) component. 

This unit will be tested by Mechanology and then 

delivered to ANL for independent testing.

Results

ANL has constructed a tribology test rig that 

operates at the speed and interface pressure of the 

TIVM compressor/expander vanes at full power. 

This test rig is depicted in Figure 2. Initial dry 

friction and wear tests with stainless steel and low 

friction engineered polymer samples provided by 

Mechanology have indicated an acceptable friction 

coefficient at the TIVM operating conditions and 

wear rate consistent with the lifetime requirement. 

Additional tests are being conducted with high 

humidity and different material combinations. 

A simplified single vane test rig has been 

designed for screening of seal and port designs and 

testing of low friction materials with vanes traveling 

at speeds in the planned operating range. The single 

vane test device design with the pressure cover 

removed is illustrated in Figure 3. This device is 

designed to permit parametric variation of clearances 

and seal preloads as well as rapid change out of 

materials and seal designs. Test hardware and 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

497

instrumentation have been procured, and assembly is 

in progress. A computer control and data acquisition 

program has been written to allow testing at specified 

speeds and pressure differentials with automated data 

logging.

CFD calculations have been initiated at ANL 

using Mechanology’s single vane test configuration. 

These analyses will be used to understand the 

interaction of the vane/seal/air system as a function 

of operating conditions and to guide seal and port 

designs.

Optimization of the geometry detail has reduced 

the speed required for 100% flow from 4800 rpm for 

the first generation TIVM to 3500 rpm for later 

generations with no increase in the component 

overall dimensions. This has reduced the peak vane 

interaction speed by 25%.

A Linear Intersecting Vane Machine (LIVM) test 

device has been designed to allow simplified, rapid 

testing of vane interaction features. The LIVM 

design is shown schematically in Figure 4. The 

expander vanes in the LIVM, just as in the actual 

TIVM, drive the compressor vanes. The LIVM is 

instrumented to measure flows and pressures in the 

compression and expansion chambers as well as the 

force required as a function of time. Figure 5 shows 

an initial set of compressor vanes, with cutouts to 

accommodate various seal design inserts, to be tested 

in the LIVM. 

Conclusions/Future Work

Design and analysis of the first generation TIVM 

compressor/expander has shown that this concept has 

the potential to meet the DOE requirements for 

automotive fuel cell applications with better 

performance than many other options. Testing of the 

compressor/expander and generic TIVM prototypes 

Figure 2. ANL Tribology Test Equipment

Figure 3. Single Vane Test Apparatus Design

Figure 4. Linear Intersecting Vane Machine Design

Figure 5. Vanes for Linear Intersecting Vane Machine 

Testing
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has demonstrated correct kinematic functioning and 

the capability to produce the required pressure and 

flow. These tests have also highlighted the need for 

efficient seals and flow ports in the TIVM. 

Laboratory tribology measurements have indicated 

acceptably low friction and wear for one of the 

material pair candidates for the intersecting vanes. 

The ongoing development program is focusing on 

selection of seals, porting, and material options 

through simplified feature tests and then, 

sequentially, more prototypic TIVM tests. A full 

prototype TIVM compressor/expander/motor will be 

fabricated and tested to measure actual performance 

with the selected options. Subsequent work will 

include development and qualification of cost 

efficient manufacturing methods for high volume 

production and development of features to assure 

compliance with noise requirements. Additional 

testing will focus on the operating environment and 

reliability/endurance issues.

FY 2002 Publications/Presentations

1. Toroidal Air Management System Development 

and Testing Status, presented to the 

FreedomCAR Technical Team, April 17, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.E.3 Turbocompressor for Vehicular Fuel Cell Service

P. Fonda-Bonardi

Meruit, Inc.

1450 23rd Street,

Santa Monica, CA 90404-2902

(310) 453-3259, fax: (310) 828-5830, e-mail: fbarch@concentric.net

DOE Technology Development Manager: Patrick Davis 

(202) 586-8061, fax: (202) 586-9811, e-mail: Patrick.Davis@ee.doe.gov

ANL Technical Advisor: Dr. Robert Sutton

(630) 252-4321, fax: (630) 252-4176, e-mail: sutton@cmt.anl.gov

Subcontractors: MarNor Enterprises, Newport Beach, CA (instrumentation); FD Contours, Costa 

Mesa, CA; Prestige Mold, Santa Ana, CA (fabrication)

Objectives

• Test the design and performance of air bearings for turbocompressors.

• Test the performance of the expander and compressor for fuel cell system service.

• Test the endurance of Argonne National Laboratory’s (ANL’s) near-frictionless carbon (NFC) coatings 

in air bearings.

Approach

• Design, build, and test a specialized, instrumented test rig for measuring the performance of a new, 

high performance air bearing.

• Measure the performance of the DOE/Argonne near-frictionless carbon coating.

• Design, build, and test the prototype of a turbocompressor system supplying 76 g/sec of air for a fuel 

cell rated for 50-kWe output.

Accomplishments

• Demonstrated a mechanically simple (leafless) journal bearing for small (~1 kg weight, ~2 cm shaft 

diameter) rotors with lift-off and landing speeds of about 900 RPM, corresponding to a rubbing speed 

of about 1 m/s and a total rub of about 2 m per start-stop cycle. 

• Completed over 10,000 start-stop cycles with minimal NFC wear during NFC endurance testing; also 

demonstrated 3,700 start-stop cycles with DuPont Vespel journals and 1,300 start-stop cycles with 

DuPont Delrin journals.

• Demonstrated radial bearing take-off and landing without any low friction coatings (i.e. steel-on-steel 

surfaces) using a low-acceleration startup. 

• Demonstrated radial and thrust bearing rotordynamic stability to 27,000 RPM.

• Demonstrated a mechanically simple self-centering thrust bearing with a stiffness of 1.92 kiloNewton/mm (11.0 klb/in) at 20,000 RPM and 6 psig bearing feed pressure, increasing to 4.50 kn/mm 

(25.7 klb/in) at 20,000 RPM and 12 psig bearing feed pressure.

• Integrated prototype air bearing turbocompressor with commercial automotive positive-displacement 

compressor, instrumentation, and test bench. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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• Demonstrated turbocompressor expander, radial bearing, thrust bearing, and compressor performance 

to 33,000 RPM. 

Future Directions

• Complete performance testing of bearings and turbocompressor prototype to design speed. 

Introduction

Meruit Inc. has developed a novel air bearing for 

use in a small high-performance automotive fuel cell 

turbocompressor. A suitable air bearing must be 

inexpensive, durable, stable, and stiff enough to 

survive the automotive environment. Meruit has one 

main task: to validate its air bearing for automotive 

compressor/expander use. Development of an air 

bearing turbocompressor meeting DOE’s 

specifications was also pursued under the project.

Approach

A specialized test rig was designed, built and 

instrumented to investigate the radial (journal) liftoff and landing performance, radial bearing longevity 

with low-friction coatings, radial bearing 

rotordynamic stability, and thrust bearing stiffness. 

Meruit’s mechanically simple (i.e. cost effective) 

bearing demonstrated floating, non-contact 

operation, low lift-off and landing speeds, over 

10,000 start-stop cycles, high stiffness, and 

rotordynamic stability to the test rig limit of 27,000 

RPM.

A prototype turbocompressor using this air 

bearing system, designed to deliver the DOEspecified mass flows and pressure ratios, was built, 

integrated into an instrumented turbocompressor test 

bench simulating an automotive air system with an 

in-line positive-displacement compressor, and 

demonstrated to 33,000 RPM (35% of design speed).

Results

Radial (Journal) Bearing Lift-off

It was experimentally determined that while a 

large diameter (>75 mm) radial (journal) gas bearing 

would easily float a steel bearing in steel journals, the 

scaled-down (~20 mm) gas bearings intended for the 

DOE application would not lift off ("float") 

satisfactorily. This condition, present only when the 

shaft begins to turn from rest, could be remedied by 

lowering the coefficient of friction between the 

journal and gas bearing, and several low friction 

remedies were found to work: DuPont Vespel, 

DuPont Delrin, and ANL’s Near Frictionless Carbon

(NFC). Since the Meruit bearing only suffers wear 

on take-off or landing, the longevity of the bearing is 

measured in number of start-stop cycles (rather than 

operating hours). A bearing test rig was configured 

as an endurance tester to cycle the tested materials. 

For one start-stop cycle, the drive air is turned on, 

accelerating the rotor past the lift-off point; the air is 

turned off; and the coasting rotor floats until it lands 

and slows to a stop. Steel bearings with Vespel 

bushings in the journal were tested to 3,700 cycles; 

steel bearings with Delrin bushings were tested to 

1,300 cycles; and both bearings could have continued 

for more cycles.

ANL applied a NFC to the bearing shaft, which 

was tested with uncoated steel bushings. It was 

found that the bearing floated the ~1 kg rotor at just 

over 900 RPM with about 1 m of sliding contact and 

a rubbing speed of about 1 m/s. One NFC trial 

coating reached 5,800 cycles, and another reached 

10,200 start-stop cycles.

Modeling of the take-off process revealed that 

another way to achieve a clean take-off was to reduce 

angular acceleration (“slow start”). This was 

experimentally confirmed with bare steel bearings on 

bare steel journals.

Radial Bearing Rotordynamic Stability

It was determined that while the large diameter 

(>75 mm) three-lobe gas bearing could be 

accelerated to 30,000 RPM with no evidence of 

rotordynamic instability, the scaled-down ~20 mm 

bearing became unstable at about 14,000 RPM. This 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

501

instability was not a resonance that could be 

accelerated through; higher speed operation led to 

repeated bearing contact with the journal and 

eventual bearing destruction. CFD modeling 

suggested that at the smaller diameter, a four-lobe 

design would be stable over the entire design speed 

range. Several shafts with four lobes were designed, 

built, and tested with and without NFC coating. A 

~20 mm four-lobe shaft, otherwise identical to the 

three-lobe shaft, floated at a slightly higher (~950) 

RPM than the three-lobe shaft, but was shown to be 

stable to the test rig limit of 27,000 RPM (almost 

twice the critical speed of the three-lobe bearing). A 

23-mm shaft demonstrated stability to 33,000 RPM 

in the turbocompressor test rig. 

Axial (Thrust) Bearing Stiffness

Another aspect of the bearing test program was 

the experimental measurement of the thrust bearing’s 

stiffness, force, and damping properties. The thrust 

bearing’s stiffness is computed to increase with 

bearing feed air pressure, air temperature, and RPM; 

any increase in these values leads to a stiffer bearing 

with a more strongly damped response to shocks. 

Even a slight air flow through the bearing at zero 

RPM will center the bearing in its clearance and 

provide some stiffness. The test rig was configured 

with a thrust piston to apply controlled axial loads 

and instrumented to measure the resultant axial 

displacement as a function of bearing feed air 

pressure at speeds ranging from zero to 27,000 RPM. 

The measured stiffness at about 20,000 RPM was 

found to range from 1.92 kn/mm (11,000 lbs/in) at a 

feed pressure of 41.3 kPa (6 psig) to 4.50 kn/mm 

(25,700 lb/in) at 82.7 kPa (12 psig). The measured 

stiffness at a constant feed pressure of 6 psig at 

speeds of 21,000 and 27,000 RPM was found to be 

1.92 kn/mm (11,000 lb/in) and 2.24 kn/mm (12,800 

lb/in) respectively. These speeds are low compared to 

the design turbocompressor speed of 95,000 RPM, 

and yet the bearing still generates substantial and 

useful centering forces that resist thrust loads. 

Bearing air consumption was measured at about 0.08 

g/sec, which is negligible in comparison to the 76 g/

sec design air flow of the DOE turbocompressor.

Air System and Turbocompressor Design/

Performance Testing

To make up the difference between the expected 

expander returned power and the required 

compressor input power, Meruit designed an air 

system using a commercially available positivedisplacement compressor driven by an electric motor 

in tandem with Meruit’s turbocompressor. Meruit 

designed a family of compressor and expander 

wheels with varying characteristics (specific speed, 

dimensional ratios, etc.) representing different 

compromises in providing performance compatible 

with the DOE specifications. After extensive 

evaluation, a compressor wheel was chosen to 

provide a desired pressure curve over a wide range of 

mass flows, and a turbine wheel was matched to it. 

The chosen compressor wheel is intended to trade 

peak efficiency for extended turndown performance. 

The basic expander configuration comprises 

variable inlet vanes (nozzle segments) for the control 

of back pressure and mass flow for matching the 

performance of the compressor. Figure 1 presents the 

geometry of the inlet vanes and their relationship to 

the blades of the turbine wheel. The turbocompressor 

uses Meruit’s radial and thrust gas bearings with 

ANL’s NFC coating; the rotor is illustrated in Figure 

2, and the turbocompressor body without the 

expander and compressor housings is presented in 

Figure 3. 

Figure 1. Meruit Variable Nozzle Expander
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Using the valving of the test rig and the variable 

nozzles of the turbocompressor, the expander can be 

tested through a full range of nozzle openings from 

zero to 115% at various turbine feed pressures and 

mass flows. The compressor can be independently 

evaluated over a range of mass flows at each value of 

RPM. After the four-lobe bearing was demonstrated 

in the bearing test rig, the turbocompressor was fitted 

with a 23-mm four-lobe bearing. At the speeds 

tested to date (i.e. one-third of design speed), the 

compressor generates very little pressure (i.e. about 

one-ninth of design pressure), but all of the 

compressor performance data available so far 

indicate the designed pressure-to-mass flow 

performance with increases in mass flow at each 

speed.

Conclusions/Future Directions

Meruit’s leafless radial air bearing for small 

shafts has demonstrated low-speed lift-off and 

landing, trouble-free take-off, longevity, stiffness, 

and stability to moderate speeds. The leafless thrust 

bearing has demonstrated self-centering at zero speed 

and adequate stiffness at moderate speeds for 

automotive applications. Meruit’s turbocompressor 

using these air bearings has demonstrated the desired 

flat pressure performance to the speeds tested so far. 

Work continues to demonstrate rotordynamic 

stability and turbocompressor performance at higher 

speeds. 

References

1. Ajayi, O.O. et al. 2002. "Low Friction Coatings 

for Fuel Cell Turbocompressors", in DOE 2002 

Review OTT Fuel Cells Program, U.S. 

Department of Energy Office of Transportation 

Technology, May 2002. 

Figure 2. Meruit Turbocompressor Rotor

Figure 3. Meruit Turbocompressor Body
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IV.E.4 Motor Blower Technologies for Fuel Cell Automotive Power Systems

Thomas Clark (Primary Contact) and Michael Arner

UTC Fuel Cells

195 Governors Highway

South Windsor, CT 06074

(860) 727-2287, e-mail: tom.clark@utcfuelcells.com

DOE Technology Development Manager: Patrick Davis

(202) 586-8061, fax: (202) 586-9811, e-mail: Patrick.Davis@ee.doe.gov

Subcontractors: Phoenix Analysis and Design Technologies (PADT), Phoenix, AZ; R&D Dynamics, 

Bloomfield, CT

Objectives

• Develop small, lightweight, motor driven blowers to provide cathode air and fuel processor air for a 

near ambient pressure fuel cell operating on gasoline. 

• Demonstrate the performance of various types of air blowers via integration into a power plant.

• Evaluate both fuel processor air blower approaches, regenerative and centrifugal, and identify which 

technology is superior. 

• Identify and develop manufacturing methods that will allow the blowers to be produced at low cost in 

large production volumes. 

Approach

• Define performance requirements, flows, pressures, and temperatures, as well as cost and life targets, 

for both the cathode and fuel processor air blowers. 

• PADT will develop and build a mixed flow type blower to meet requirements for cathode air and a 

regenerative type blower to meet fuel processor air requirements. Prototypes will be used to evaluate 

aerodynamic performance as well as life and durability. 

• R&D Dynamics will develop and build a high-speed centrifugal machine supported by air bearings to 

meet the fuel processor air requirements. 

• UTC Fuel Cells will demonstrate operability and performance of both approaches by integrating the 

units into a power plant.

Accomplishments

• Requirements for both the cathode air blower and fuel processor air blowers have been defined and 

documented.

• PADT has completed design of the mixed flow axial cathode and regenerative fuel processor air 

blowers.

• PADT has developed and calibrated a regenerative wheel performance model.

• R&D Dynamics has completed design of a high-speed centrifugal machine for the fuel processor air 

blower utilizing air bearings.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

504

Future Directions

• Complete the prototype production of all three machines.

• Complete performance and endurance testing of all three blower types.

• Integrate blowers into a fuel cell power plant and test for operability.

Introduction

Near ambient pressure fuel cells running on 

gasoline require two sources of air, one for the fuel 

cell cathode and one for the gasoline fuel processor, 

which generates hydrogen. Due to the relative 

pressure differences required by the two applications, 

it is not energy efficient to fulfill the two air 

requirements with a single blower/compressor as is 

commonly utilized in pressurized type fuel cell 

systems. This project will define different types of 

machines to meet each air supply requirement; 

specifically, one type of machine will be evaluated 

for the low-pressure cathode air blower, and two 

other different types of machines will be evaluated 

for the higher-pressure fuel processor air blower. Air 

blower development targets are presented in Table 1.

Approach

For the near ambient pressure cathode air blower 

application, the best machine is clearly a mixed flow 

type of axial blower. This type of machine, illustrated 

in Figure 1, yields excellent overall efficiency in a 

very compact package and can be produced, in 

quantity, at a relatively low cost. Specific speed 

analysis indicates that a mixed flow machine will 

yield a high efficiency machine at reasonable 

rotational speeds. In this project, PADT will design, 

build, and test an optimized mixed flow blower 

which meets the performance requirements 

established and is readily producible using standard 

manufacturing processes.

For the higher pressure fuel processor air blower 

application, the optimal type of machine is not as 

clear. As part of the preliminary sizing, a variety of 

machines were evaluated, including rotary lobe, 

sliding vane, radial, centrifugal, and regenerative. 

Although the rotary lobe and sliding vane type 

machines could be developed to yield high overall 

efficiencies, they were eliminated as a result of other, 

Capabilities Cathode 

Air Blower

Fuel Processor 

Air Blower

Max Flow Rate (cfm) 170 70

Pressure Rise 1 psi 12 psi

Ambient Temperature 

(F)

-40 n 140 -40 n 140

Overall Efficiencya

 100% flow

 25% flow

60%

35%

50%

30%

Production Unit Costb

 @100,000 units/yr

$75 $75

Service Life (hrs) 5000 5000

Power Supply 200 Vdc 200 Vdc

a Includes motor, controller, mechanical and isentropic 

efficiency

b Includes motor controller and blower

Table 1. Blower Development Targets

Figure 1. Solid Model of PADT Designed Cathode Air 

Blower
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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non-aerodynamic requirements, primarily concerns 

regarding excessive size and weight, limited life 

capability due to wear, and higher production cost 

due to the need for more precise control of part 

dimensions and clearances. 

A radial type centrifugal machine was viewed to 

be an excellent overall choice because parts can be 

mass-produced at a low cost and life should be 

acceptable. However, in order to achieve peak 

efficiency and small size, the rotational speed needs 

to be high, far exceeding the capability of 

conventional low cost bearings. R&D Dynamics is 

presently working to develop a machine utilizing air 

bearings, thereby eliminating the life and speed 

limitation of conventional grease packed bearings. 

We believe that R&D Dynamics’s proprietary air 

bearing design can be mass produced at costs 

consistent with our overall goals and thus have begun 

development of a high speed (150,000 rpm) radial 

type, centrifugal machine as shown in Figure 2. 

Another equally viable approach to the fuel 

processing system (FPS) air blower is the 

regenerative type machine being developed by 

PADT. The regenerative machine as shown in 

Figure 3 allows for higher-pressure generation at 

lower rotational speed. This machine is presently 

being designed to run at 26,000 rpm and will utilize 

traditional, low cost, grease packed roller bearings. 

The theoretical maximum efficiency is not as high as 

the high-speed radial machine, but the low speed 

approach minimizes concerns with bearing life, 

thereby mitigating risk. Two critical tasks in the 

design of this machine will be to optimize the 

impeller geometry to obtain peak isentropic 

efficiencies while minimizing the number of critical 

clearances and tolerances, and to evaluate cooling 

schemes and their effect on the overall efficiency and 

cost of the machine. 

Results

Work to date has resulted in evolving designs for 

all three blowers, as shown in Figures 1, 2 and 3. All 

three designs utilized a typical turbo-machine design 

process that included tasks such as specific speed 

analysis, blade optimization, rotor-dynamic analysis, 

bearing analysis, thermal analysis, and motor 

optimization studies. Each machine has been 

designed to be small, yield high efficiency, and be 

manufacturable utilizing standard production 

methods commonly found in industry today.

Due to the low weight and small volume 

requirements dictated by a transportation application, 

power density is much higher in these machines than 

in equivalent performing, commercially available 

machines. Thus, removal of heat from the motor 

becomes a challenge. This issue of motor cooling has 

been a particularly troublesome task for all of the 

blower designs. Heat rejection in the PADT 

designed regenerative impeller FPS air blower has 

been particularly challenging, primarily due to the 

Figure 2. Solid Model of R&D Dynamics Designed 

Fuel Processor Air Blower

Figure 3. Solid Model of PADT Designed Fuel 

Processor Air Blower
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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relatively low efficiency of the pump head. This low 

efficiency requires the motor to produce more shaft 

power and thus results in a larger amount of motor 

waste heat that needs to be rejected. A thermal 

model has been developed and is being used as a tool 

to evaluate water cooling and a variety of air cooling 

techniques. Some of the output from this model, 

using conservative estimates for motor efficiency, is 

presented in Table 2. This data was evaluated and 

the following conclusions were made:

• Sustained operation at the maximum power 

condition may require water cooling. The 

water temperature will need to be less than 

40°C.

• Thermal isolation between the pump and 

motor housings will reduce motor winding 

temperature but increase the forward bearing 

temperature in excess of 140°C, which is 

detrimental to the bearing lube.

• Motor windings, which are thermally potted 

to the motor casing, will decrease the 

winding temperature and may allow air 

cooling if motor efficiency is 90%-92%.

• Motor efficiencies greater than 92% may 

allow air cooling without thermally potting 

the motor windings.

In the case of the R&D Dynamics machine, the 

isentropic efficiency of the machine is high; 

therefore, the shaft power required is lower than that 

required for the regenerative unit, and the amount of 

waste heat generated by the motor is lower. The 

predicted performance of this machine is presented in 

Figure 4. Because of this, placing fins on the motor 

casing and ducting air over the fins can cool the 

motor. The amount of cooling air is expected to be 

minimal and will be verified through thermal testing 

of the first prototype unit.

For the near ambient pressure PADT cathode air 

blower machine, depicted in Figure 1, heat rejection 

is accomplished by rejecting energy from the motor 

housing directly to the process air, utilizing the 

mixed flow cathode air blower design itself. This 

technique is possible for several reasons. The axial 

geometry of the blower lends itself to this type of 

approach; the amount of work done on the process 

fluid is fairly small and the volumetric flow rate 

relatively high; thus, the temperature rise of the 

process air is very small, and a large temperature 

differential exists between the motor housing and the 

process air.

Conclusions/Future Directions

PADT is presently building an aerodynamic 

development rig that will be used to validate a model 

that was developed to predict aerodynamic 

performance of their fuel processor blower. 

Prototype motors have been designed and will be 

Motor 

Winding 

Temp 

Motor 

Housing 

Temp 

Pump 

Head 

Temp 

Air Cooling 295EC 155EC 155EC

With thermal 

isolation

267EC 127EC 161EC

Thermal isolation 

& potted windings

197EC 127EC 160EC

Water Cooling 282EC 142EC 142EC

With thermal 

isolation

226EC 86EC 160EC

Thermal isolation 

& potted windings

156EC 86EC 160EC

Note: The above numbers presume a 90%-92% efficient motor and a 

pump head isentropic efficiency of 40%. These efficiencies are 

critical to selecting the proper cooling approach and will be validated 

by testing by the motor and pump head design.

Table 2. Results of PADT Fuel Processor Blower 

Thermal Analysis

Figure 4. Predicted Performance of R&D Dynamics 

Fuel Processor Blower
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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tested to establish “real-world” efficiencies. R&D 

Dynamics has manufactured blowers with both radial 

and thrust air bearings and is preparing to run these 

units in a test rig to determine the load capability of 

each bearing.

All three designs are nearly completed and 

production of parts for the prototype units has begun. 

Two prototype units for all three designs will be 

complete by November 2002. Performance testing 

of the units will commence immediately thereafter to 

verify aerodynamic performance and efficiency of 

each design.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.E.5 Hybrid Compressor/Expander Module

George E. Selecman (Primary Contact) and Paul E. McTaggart

TIAX LLC

Acorn Park

Cambridge, MA 02140-2390

(617) 498-6083, fax: (617)-498-7250, e-mail: selecman.g@tiax.biz

DOE Technology Development Manager: Patrick Davis 

(202) 586-8061, fax: (202) 586-9811, e-mail: Patrick.Davis@ee.doe.gov

ANL Technical Advisor: Robert D. Sutton 

(630) 252-4321, fax: (630) 252-4176, e-mail: sutton@cmt.anl.gov

Subcontractors: Concepts NREC, White River Junction, VT; Scroll Corporation, Carlisle, MA

Objective

• Based on the experience of two previous generations of scroll-based compressor/expander modules 

developed with DOE, design and build a hybrid compressor/expander module using both 

turbomachinery and scroll compression.

• Develop the algorithms and hardware to ensure stable and effective control of the hybrid system.

• Deliver a system with equivalent thermodynamic performance, at significantly lower weight and 

volume, when compared to previous generations of scroll compressor/expander modules.

Approach

• In the first year, develop system architecture and subsystem designs consistent with the overall goals 

of maintaining thermodynamic performance while reducing weight and volume relative to previous 

generations.

• In the second year, complete detailed engineering and initiate fabrication of subsystem components, 

and develop the control system hardware and algorithms.

• In the third and final year, complete fabrication of components and conduct subsystem assembly and 

test, followed by system integration and performance verification.

Accomplishments

• Defined basic system architecture, including preliminary allocation of performance requirements to 

subsystems.

• Initiated detailed design tradeoff studies for scroll machinery.

Future Directions

• Refine subsystem-level performance allocations.

• Initiate detailed design tradeoff studies for turbomachinery.

• Initiate breadboard scroll drive mechanism development and testing.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Introduction

Most current automotive fuel cell systems are 

designed for pressurized operation in order to reduce 

system size, boost stack efficiency, and improve 

water management. Applications for automobiles 

also require significant partial load capability, since 

the anticipated level of electrical energy storage is 

minimal. Due to the aggressive efficiency goals 

driving fuel cell development, the compressor must 

operate efficiently over a wide flow range, and 

efficient waste energy recovery in an expander or 

turbine is required to offset the compression load.

Traditionally, high-speed centrifugal technology, 

such as that used in automotive turbochargers, has 

resulted in a compact high-speed package that 

delivers high efficiency at the design point, but with 

performance that falls off dramatically under offdesign conditions. Scroll technology, a type of 

positive displacement machinery, provides high 

efficiency across a broad range of operating 

conditions, but results in a package that is 

significantly larger and heavier than that of highspeed centrifugal technology.

The objective of this project is to develop a 

hybrid compressor/expander module, based on both 

scroll and high-speed centrifugal technologies, which 

will combine the strengths of each technology to 

create a concept with superior performance at 

minimal size and cost. The resulting combined 

system will have efficiency and pressure delivery 

capability comparable to that of a scroll-only 

machine, at significantly reduced system size and 

weight when compared to scroll-only designs.

Approach

The design approach for the Hybrid TurboScroll 

Compressor/Expander Module (CEM) exploits the 

experience of developing the first two generations of 

scroll CEMs, in combination with the substantial 

experience of our turbomachine subcontractor, 

Concepts NREC. (Figure 1 shows the Second 

Generation Scroll CEM on its test stand.) By 

combining the performance attributes of a positive 

displacement scroll compressor (electrically driven) 

with those of a turbocharger (driven by fuel cell 

exhaust gases), we expect to be able to very closely 

match the pressure and flow requirements of the 

DOE guidelines in a package that is smaller and 

lighter than previous generations. Table 1 shows the 

weight and volume design goals for the program; 

with acknowledgement that these goals are still 

somewhat short of the DOE guidelines, they are 

clearly an improvement over the Second Generation 

Scroll.

Our first step was the construction and testing of 

a breadboard model of the system, as shown in 

Figure 2. In this configuration, a conventional 

automotive turbocharger (in the foreground) was 

coupled to the scroll compressor portion of the First 

Generation Compressor/Expander Module (in the 

Figure 1. Second Generation Scroll Compressor/

Expander Module

Table 1. Key Envelope Performance Goals for the 

Hybrid TurboScroll CEM
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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background). The results of that preliminary 

exploratory testing, while not delivering the desired 

efficiency, were sufficiently promising to justify the 

system concept.

Next, the development of an appropriate system 

architecture resulted in the block diagram shown in 

Figure 3. In this configuration, the turbocompressor 

draws in atmospheric air and compresses it to an 

intermediate pressure. (Note that the specification of 

this intermediate pressure is a key element in 

assigning performance requirements to the 

subsystems.) In order to reduce both the size and 

operating temperature of the scroll compressor, an 

intercooler is provided to reject at least part of the 

heat of compression to the atmosphere. The partially 

compressed gas, now cooler and denser, is then fed 

into the scroll compressor, which uses electrical 

power to achieve the final compression of the gas. 

Finally, the compressed air is fed into the fuel cell, 

which increases its temperature and reduces its 

pressure slightly. The exhaust gas from the fuel cell 

drives the turbine (through controllable inlet guide 

vanes) and, with the bulk of its energy extracted, is 

expelled to the atmosphere. The turbine provides the 

shaft power to drive the compressor by direct 

coupling.

This architecture offers some important 

advantages:

• The turbocompressor is powered only by the 

turbine, eliminating the issues associated 

with coupling power into a high-speed 

rotating shaft.

• Turbine inlet guide vanes provide both inlet 

control and control of fuel cell stack 

pressure.

• The scroll compressor provides pressure and 

flow characteristics that enable efficient 

operation across a broad range of flow rates.

Capturing these advantages entails overcoming 

certain challenges:

• Control of coupled turbomachinery and 

positive displacement machinery,

• Power and waste heat management,

• Isolation of lubricants from the process gas 

stream, and

• Reduction of size, weight and cost.

Starting with the turbocharger, pictured in Figure 

4, the approach to design involves balancing 

competing elements. Although clearly representing 

an increase in complexity and parts count, 

controllable inlet guide vanes for the turbine are 

considered a necessary minimum. Similar controls 

on compressor flow will be considered as part of the 

overall component design tradeoff study. In the 

interest of simplicity and conventionality, the initial 

design studies have focused on conventionally 

lubricated roller bearings. Management of the 

lubricant, though challenging, is considered more 

tractable at the present time that the integration of gas 

Figure 2. Breadboard Version of Hybrid TurboScroll 

CEM Configuration

Figure 3. System Architecture of Hybrid TurboScroll 

CEM
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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bearings or other technologies. The intercooler 

between the turbocompressor and the scroll 

compressor has conventional performance 

requirements, and indeed the preliminary approach is 

to select an available automotive intercooler of the 

appropriate size and integrate it into the system.

For the scroll, the design approach has involved 

the detailed evaluation of three competing 

configuration options, shown in Figure 5. The first 

alternative was a conventional crank-driven orbiting 

scroll, supported on a roller-Oldham bearing system, 

with grease lubrication. This configuration has the 

substantial advantage of conventionality, enabling 

the direct utilization of knowledge gained in dozens 

of scroll compressor design programs. In the second 

configuration, the two opposing elements of the 

scroll both rotate, on offset axes, coordinated in such 

a way that their relative motion is orbital. The 

primary advantage of this configuration lies in the 

relatively conventional bearing configuration, offset 

in part by a relatively unconventional drive 

mechanism requirement. The third design gangs 

multiple scrolls on a common drive mechanism, 

offering the possibility of reduced noise with the 

accompanying penalty of a relatively complex drive 

mechanism.

Each of the above alternatives was carried to the 

point of preliminary drive system sizing and overall 

subsystem layout. Based on that information, our 

evaluation of the alternatives has led to the selection 

of the conventional crank-driven orbital scroll as the 

primary design direction. This represents a 

conservative choice in the design of this system 

element, consistent with the overall need embodied 

in the program objectives to demonstrate the 

performance of the overall system concept.

The control and data management system 

configuration depends on both the data acquisition 

requirements and the control measurement and 

actuation means configured into the individual 

subsystems. Design of the hardware and algorithms 

are to commence following the completion of the 

preliminary subsystem designs. The test regimen for 

the subsystems, and ultimately the system as a whole, 

are anticipated to represent not merely a data 

acquisition phase, but an integration, test, and 

debugging phase.

Results

Having conducted a body of preliminary concept 

feasibility work, the design activities conducted in 

Figure 4. Concepts NREC Baseline Turbocharger 

Design Figure 5. Three Alternate Scroll Compressor 

Preliminary Design Configurations
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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the first active quarter of this project have focused on 

the system configuration and the definition of key 

subsystem requirements. Preliminary designs have 

been completed for three alternative scroll 

compressor configurations, and a down-select to the 

primary configuration has been accomplished. 

Upcoming work will involve the refinement of key 

system interface definitions and initiation of detailed 

design activity for the turbocharger.

Conclusions

Continued, and progressively more detailed, 

investigation of the Hybrid TurboScroll CEM 

concept indicates no issues that seem to threaten the 

viability of the selected system architecture. A 

substantial degree of additional detailed system and 

component design work is required to fully explore 

the issues of practicality and performance, but the 

design team still believes that the promise of 

thermodynamic performance substantially equal to 

that of the Second Generation Scroll CEM, at a 

substantially reduced weight and volume, is not only 

achievable, but within reach.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

513

IV.F Crosscutting Fuel Cell Analysis and Demonstration

IV.F.1 Precious Metal Availability and Cost Analysis for PEMFC 

Commercialization

Eric J. Carlson (Primary Contact) and Dr. Johannes H.J. Thijssen

TIAX LLC

Acorn Park

Cambridge, MA 02140-2390

(617) 498-5903, fax: (617) 498-7012, e-mail: carlson.e@tiax.biz

DOE Technology Development Manager: Arlene Anderson

(202) 586-3818, fax: (202) 586-9234, e-mail: Arlene.Anderson@ee.doe.gov

ANL Technical Advisor: Thomas Benjamin 

(630) 252-1632, fax: (630) 252-4176, e-mail: Benjamin@cmt.anl.gov

Objectives

• Assess current and projected demand for platinum group metals (PGMs) exclusive of fuel cell 

applications

• Estimate the relationships between supply capacity/reserves and long-term growth in demand for 

PGMs 

• Develop an econometric model to simulate the impact of fuel cell market growth scenarios on PGM 

supply and pricing 

• Perform a sensitivity analysis on supply and pricing to critical parameters in the model related to fuel 

cell markets and technology advances

• Obtain critical feedback from the important participants in the PGM value chain on the model 

assumptions and projections

• Develop a cost projection for the recycling of PGMs from fuel cells, and assess the impact on PGM 

supply and price

Approach

The project has been broken into five tasks as follows:

• Task 1: Collect historical PGM supply, demand, pricing and resource data

• Task 2: Develop fuel cell market commercialization scenarios

• Task 3: Develop PGM recycling scenarios including a high level PGM proten exchange membrane 

fuel cell (PEMFC) recycling cost model

• Task 4: Develop econometric model for the simulation of the impact of fuel cell introduction on PGM 

supply and price

• Task 5: Solicit feedback from PGM industry and automotive OEMs

Tasks 1 and 4 were scheduled for the fiscal years 2001 and 2002. The balance of the tasks will be 

completed in 2003.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

514

Accomplishments

• Completed PGM data collection with inputs from literature sources, PGM industry reports, precious 

metal trading companies, and geology experts

• Developed econometric modeling approach and presented to PGM industry for feedback

Future Directions

• During the balance of 2002, complete development of the econometric model

• During 2003, develop fuel cell market and recycling scenarios for input to PGM supply and pricing 

simulation

• Run simulation to project impact of fuel cell commercialization on platinum pricing and supply

• During 2003, obtain feedback from PGM industry and automotive OEMs 

Introduction

Platinum group metals are critical to the 

commercialization of fuel cells, but they also 

represent a significant contribution to overall system 

cost. Depending on operating design parameters, 

platinum would represent 10 - 20% of the cost of a 

gasoline fuel cell system produced in high volume. 

PGMs (primarily platinum and some ruthenium) are 

critical to catalyzing reforming/shift reactions in the 

fuel processor and electrochemical oxidation and 

reduction in the fuel cell, with the fuel cell 

requirements presently dominating the demand.

Successful adoption of fuel cells in 

transportation applications over the long-term could 

create markets on the order of ten million vehicles, 

leading to significant pressure on PGM suppliers to 

increase production capacity and supply. 

Consideration of stationary and portable applications 

for fuel cells further increases the demands on PGM 

supplies. Clearly, the combination of stationary, 

portable and transportation markets for fuel cells will 

create pressure on the PGM industry to increase 

supplies and might cause rapidly escalating prices 

(thereby threatening fuel cell market viability) unless 

action is taken to guide the process.

The commercialization of fuel cells will also 

depend on the amount of economically mineable 

PGM resources and the ability of the PGM value 

chain to supply the PGM materials in the needed 

forms at reasonable markups above the London 

Metals Exchange (LME) price.

The relationship between supply, demand, and 

price of the PGMs is complicated by several factors, 

including: the geographical concentration of ore 

bodies in South Africa and Russia, the control of 

production by a limited number of companies in 

these regions, the impact of politics, and the impact 

of the world economy on demand and price. 

Significant new demands for PGMs can lead to price 

increases in the short-term and potentially in the 

long-term if supply capacity does not increase.

The large layered intrusions that host all the 

world’s major PGM deposits can be easily identified 

even if covered to depths of a few kilometers by 

using regional gravity surveys. These rocks have 

high density and are easily recognizable in such 

studies. Hence, the likelihood of finding significant 

new deposits is not high. The discovery of new 

resources of PGM is likely to be limited to smaller 

intrusions that may provide small mining activities, 

but will not influence global production in a 

significant way.

Approach

The overall goal is not only to develop 

projections of PGM availability and cost, but also to 

identify and quantify the industry and market drivers 

influencing these parameters. On the demand side, 

we will break down the demand between existing 

markets and the potential applications of fuel cells. 

We will identify underlying trends in the industrial/

chemical and lifestyle markets with attention to 

growth of demand and potential for substitution of 

alternative materials. In the fuel cell markets, the 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

515

impact of technology on PGM demands will also be 

considered.

The modeling approach starts with construction 

of an econometric model based on historic supply, 

demand, and price data. A simulation will then be 

run to study the impact of introduction of fuel cell 

vehicles on the supply and price of platinum. Figure 

1 illustrates the steps in the modeling approach, and 

Figure 2 shows the structure and outputs of the 

econometric model.

Automotive catalysts and jewelry are the two 

dominant markets for platinum (approximately 80%) 

and are important elements in the econometric 

model. The investment industry consumes a minor 

amount of material but can exert significant influence 

on short-term price. However, over long periods of 

time, investment should have zero impact on supply 

and demand.

The model will be developed to provide at least 

the following information:

1. Price Elasticity of Demand: A measure of the 

sensitivity of quantity demanded to a change in 

the price of platinum. It provides a quantitative 

measure of the price responsiveness of quantity 

demanded along a demand curve. The greater 

the elasticity, the greater the effect that a price 

change will have on the quantity demanded.

2. Income elasticity: A measure of how responsive 

consumption of platinum is to a change in personal income when the price of platinum itself is 

not changed.

3. Price Elasticity of Supply: A measure of the 

responsiveness of quantity supplied to a change 

in price. It provides a quantitative measure of the 

price responsiveness of quantity supplied along a 

supply curve. The greater the elasticity, the 

greater the effect that a price change will have on 

the quantity supplied.

The validity of the model will be assessed first 

by examining it for theoretical consistency - that is, 

we will confirm that estimated coefficients have the 

correct signs as economic theory predicts. Second, 

we will examine the model’s “goodness of fit”. 

“Goodness of fit” refers to a quantitative measure of 

the extent to which the explanatory variables in the 

model “explain” the change in the dependent 

variables (i.e., the quantity of demand and supply of 

platinum). 

After completion and validation of the 

econometric model, future demand scenarios will be 

input into the econometric model to project the 

impact of fuel cell commercialization on supply and 

pricing. The scenarios for stationary, portable, and 

transportation applications of fuel cells will range 

from optimistic to pessimistic and contain volume 

and time estimates. Economic growth, catalyst 

technology development, and shifts in automotive 

powertrain technology will be some of the factors 

considered in development of the demand scenarios 

(see Figure 3). The model and the scenarios can be 

used to conduct sensitivity analyses to the various 

factors. Recycling will play a significant role as 

platinum consumption increases further. Recycling 

of automotive catalysts is now between 10 and 20% 

depending on the prices of platinum and palladium. 

Figure 1. Overview of Modeling Steps in Development 

of Future Projections of Supply and Price of 

Platinum

Figure 2. Structure of the Econometric Model and 

Outputs
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Results

Figure 4 summarizes the available resource data 

for PGMs and platinum. The assumptions and 

definitions underlying the reported data are critical to 

selection of values for the resource prediction. The 

increase in South African resources is based on the 

revised estimate by G. Cawthorn (2001). Technology 

advances now allow mining to greater depths, and 

Cawthorn’s increased resource amount assumes a 

depth of 2 kilometers in all areas of South Africa. 

The geology of the South African deposits is well 

characterized and can be extrapolated with 

confidence.

In contrast, the information about precious 

metals in Russia is considered a state secret, and 

much greater variation exists in reported values. Data 

from a variety of sources were compiled to arrive at 

the values for the other countries.

Model development started with analysis of the 

behavior of the real price of platinum over time. The 

nominal price was deflated by the consumer price 

index. Preliminary analysis indicates that the mean 

real price may be constant over a 100 year span; 

however, statistical tests are being performed to 

validate this result (see Figure 5). Excursions from 

the mean real price can be accounted for by specific 

events, for example, World War I and the U.S. 

regulations on automotive emissions. However, over 

time, the supply and demand come back into balance 

through increases in production or substitution of 

non-PGM materials.

Conclusions

• South Africa will continue to dominate supply of 

platinum and, in the estimate shown, has 80% of 

the projected resources.

• If statistical tests support the hypothesis of a 

constant real platinum price and historical 

behavior is repeated, then one could expect the 

introduction of fuel cells to increase the short 

term price of platinum; however, the platinum 

prices will then return to traditional values as 

supply increases.

Reference

1. Cawthorn RG (2001), “Global Platinum and 

Palladium Deposits,” August 2001 Presentation, 

copy from the author

Figure 3. Demand and Recycling Scenarios Will Input 

to the Econometric Model to Develop 

Projections of Supply and Price of Platinum

Figure 4. Platinum Resources Summary (Total PGM: 

181 million kg, Total Pt: 80 million kg)

Figure 5. U.S. Geological Survey Platinum Prices with 

Consumer Price Index (CPI) Deflator
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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IV.F.2 Assessment of Fuel Cell Auxiliary Power Systems for Onroad 

Transportation Applications

Dr. Carole J. Read (Primary Contact), Dr. Johannes Thijssen

TIAX, LLC

20 Acorn Park

Cambridge, MA 02140-2390

(617) 498-6162, fax: (617) 498-7054, e-mail: read.carole@tiax.biz

DOE Technology Development Manager: John Garbak

(202) 586-1723, fax : (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

Main Subcontractors: University of California-Davis, Institute of Transportation Studies

Objectives

• The objective of this cooperative study is to determine the viability of the use of proton exchange 

membrane fuel cells (PEMFCs) and electrode supported solid oxide fuel cells (SOFCs) as auxiliary 

power units (APUs) for on-road vehicles. The overall objectives of the program are:

• Assess viability considering:

- Fuel flexibility

- Start-up time

- Power level

- Duty cycle

- Overall vehicle efficiency

- Weight and volume

- Capital and operating & maintenance (O&M) cost

- Reliability, maintainability, "ease of repair"

• Determine research and development (R&D) needs and possible DOE roles 

• Project potential benefits to the Nation

- Barrels of oil displaced

- Criteria pollutants avoided

- Safety improvement & noise reduction benefits

Approach

• Task 1. Project kick-off Summarize the impact of system operating parameters on the design and 

performance of PEM and solid oxide fuel cells. 

• Task 2. Identify APU Requirements Finalize the segmentation of the vehicle APU market by vehicle 

class and application. For key segments, develop "straw-man" duty cycles, capital cost, O&M cost, 

and weight & volume targets. Confirm and adjust "straw-man" APU specifications via telephone 

interviews with industrial contacts. Choose 2 to 3 (total) PEM and SOFC APU applications to advance 

to Task 3. 

• Task 3. Develop Design Concepts Develop system layouts and conceptual designs for the 2 or 3 

options selected in Task 2. Conduct a trade-off analysis for the critical design and performance factors. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

518

Address vehicle integration issues. Compare the most promising fuel cell systems with other APU 

approaches (e.g. internal combustion engines, battery APUs, Stirling engines).

• Task 4. R&D Gap Analysis Determine the current gaps among fuel cell cost, performance and 

application requirements (look at 2005-2006 technology). Develop a timeline for technology 

development and commercialization, and extract R&D needs and opportunities for DOE involvement. 

Project benefits to the nation from technology introduction (e.g. oil displaced, emission reductions, 

noise reduction, and safety benefits)

• Task 5. Updatea Analysis Update the performance specifications and the implications on system 

design, after 6 months to a year from the delivery of the draft final report. 

Accomplishments

• Held kick-off meeting at Acorn Park headquarters of Arthur D. Little on January 23, 2002. 

• Refined scope of project.

• Finalized selection of fuel cell types for analysis. Determined that PEM and planar anode-supported 

SOFC are the most attractive fuel cell technologies to assess for onroad transportation APU 

applications.

• Initiated characterization and preliminary selection of fuel cell/APU applications. 

• Completed inventory of data gaps in promising APU applications (e.g. capacity, fuel capability, duty 

cycle).

• Selected long-haul heavy-duty truck cab load application using diesel fuel with a solid oxide fuel cell 

for conceptual design, layout and vehicle integration analysis.

Future Directions

• Incorporate 21st Century Truck Industry Working Group feedback on heavy-duty truck APU 

requirements and cost and performance targets.

• Conduct telephone interviews with interested industrial stakeholders on APU applications and their 

respective specifications for refrigeration applications, utility truck, police car applications, and future 

passenger car/light-duty vehicle applications.

• Commence design work on heavy-duty truck cab application using planar electrode supported solid 

oxide fuel cell and diesel fuel. Finalize specifications (e.g. capacity, duty cycle, volume and weight, 

vehicle integration issues).

• Finalize selection of remaining 1 to 2 systems for detailed study (leading candidates a refrigeration 

truck and a police car or contractor/utility truck application)

Introduction

Thus far, most of the interest in fuel cell 

transportation applications has focused on the use for 

propulsion, a very challenging task. Over the last two 

years, interest in the use of fuel cells for vehicle 

APUs has risen. The requirements of APU 

applications are thought to better match the initial 

performance and cost characteristics of fuel cells. 

APUs are also a possible initial fuel cell market 

application in the transportation sector and a step 

towards introduction of hybrid and fuel cell 

propulsion systems. The objective of this cooperative 

study is to determine the viability of the use of PEM 

and planar anode-supported SOFCs as APUs for onroad vehicles. In this context, the viability is defined 

in terms of achieving cost and performance targets.

Approach

Our team combines TIAX LLC and the Institute 

of Transportation Studies, University of California at 

Davis. We are concentrating on the application of 

PEM and anode-supported planar SOFC 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

519

technologies. With agreement of DOE, the scope has 

been refined to focus on technologies available in the 

2005-2006 timeframe. Applications will be those 

available from the present time to 2010. We will 

address applications that use existing fuel 

infrastructure (namely gasoline and petroleum 

diesel), alternative fuels (e.g. propane), and future 

fuel (hydrogen). 

We will look at passenger cars, class 1 and 2 

light-duty trucks and SUVs, class 3-8 trucks, 

recreational vehicles, transit buses, and specialized 

vehicle applications. Military applications are not 

part of the current scope of work.

Our project is being carried out in five tasks. 

This first task (completed) confirmed the scope and 

approach with DOE. Task 2, currently underway, is 

developing a list and ranking of promising current 

and future applications for APUs. Sources are 

publicly available data and input from industry and 

government contacts. Task 3 will produce conceptual 

designs and vehicle integration layouts of 2-3 fuel 

cell APU systems. Task 4 will identify the R&D gaps 

and possible roles for DOE. Benefits to the Nation 

will be projected including oil displacement and 

emission reductions. Task 5 will provide an update 6 

to 12 months from the submittal of the draft final 

report.

Results

Based upon current publicly available data, PEM 

and anode-supported SOFC technologies are the 

most promising technologies for transportation 

APUs, and thus will be the focus of this project. The 

performance specifications of fuel cell technologies 

are summarized in Figure 1. The key factors that 

influence fuel cell applicability as transportation 

APUs are power density, efficiency and system 

volume. Other important factors are fuel capability 

(and associated complexity of a fuel reformer), 

startup time and fuel cell stack life. A high-level 

ranking system yielded that PEM (both current and 

future high-temperature technology) and planar 

electrode-supported SOFC technologies appear to be 

the most applicable technologies for transportation 

APUs. These fuel cell technologies will be the focus 

of our study.

The team completed a high-level 

characterization of potential fuel cell APU 

applications. The overall process for this selection 

entailed four steps:

• Identify long list of potential fuel cell APU 

applications;

• Screen out options unlikely to be of interest 

based on DOE objective of achieving 

national benefits directly with APUs 

themselves or indirectly by facilitating 

introduction of fuel cells in vehicles for 

propulsion;

• Characterize applications at a high level; and

• Develop straw-man selection.

The types of loads considered were identified 

and classified in categories that represent increasing 

integration with the vehicle's propulsion system. 

These loads are summarized in Figure 2. The loads 

can be classified as those associated with hotel loads 

and telematics; refrigeration; loads during engine 

idling; aid to cold start; and integration with 

propulsion (e.g. complete vehicle electrification).

Figure 1. Fuel Cell Performance Characteristics

Figure 2. Potential Fuel Cell APU Loads
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

520

The complete list of APU applications 

considered included:

• Passenger Cars

- Minicompact

- Subcompact

- Compact

- Midsize (Luxury and Standard)

- Large (Luxury, Standard and Law 

Enforcement)

- 2-Seater

• Light-Duty Trucks

- Small pickup (<3,500 lbs.)

- Small van (<4,500 lbs.)

- Small utility (<3,500 lbs.)

- Large pickup (3,500-8,500 lbs.; Contractor 

vehicle and Standard)

- Large van (4,500-8,500 lbs.)

- Medium utility (3,500-4,799 lbs.; Luxury 

and Standard)

- Large utility (4,800-8,500 lbs.; Luxury and 

Standard)

• Medium-Duty Trucks (Class 3-6)

- PTO/Utility (e.g. lift, dump, wrecker, 

service)

- Delivery (Refrigerated and Standard)

- Recreational vehicle

• Heavy-Duty Trucks (Class 7-8)

- Local (Standard, Refrigerated and PTO/

Utility)

- Line-haul (Standard, Refrigerated, PTO/

Utility)

- Recreational vehicle

- Motor coach & transit buses

The characterization and selection of systems 

addressed the following aspects of fuel cell APU 

applications:

• Potential national benefits, which are the 

product of the achievable market and the 

benefit per vehicle:

- Economic (cost savings)

- Energy savings

- Environmental benefits (e.g. carbon 

dioxide, nitrogen oxides reduction)

- Noise reduction and safety improvement

• The possibility to either be introduced into 

the market in the near-term, i.e. an existing 

APU application (e.g. replacement of 

existing less-efficient APU technology), or 

have significant national and user benefits 

but require longer-term market introduction, 

e.g. future APU application that may require 

redesign of vehicle.

• Compatibility with either current or possible 

future fuel infrastructure.

Screening criteria were used to narrow the initial 

market analysis of possible APU applications for fuel 

cells:

• Duty cycle - the duty cycle of the vehicle 

should be suited to APU use, e.g. long idle 

times

• Market size - the market potential must be 

adequate to support investment in APU 

technology

• Vehicle cost - the initial cost of the vehicle 

must be high enough that an APU would 

likely represent a reasonably small portion of 

total vehicle cost (<15%, assuming a fuel 

cell APU cost of $5000) 

Figure 3. Potential Fuel Cell APU Applications - 

Vehicles Meeting Market and Cost Criteria
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

521

The vehicles meeting the initial criteria are 

shown in Figure 3.

Subsequent screening criteria used have both a 

short and long-term outlook:

• Energy savings 

• Emissions savings

• Cost savings 

• Acceleration of fuel cell introduction

Conclusions

Based on our first-pass APU application 

characterization and screening, hotel loads for longhaul heavy-duty truck / recreational vehicles, 

refrigerated trucks, police car and contractor utility 

trucks appear to be good candidates for further 

analysis. We will start detailed analysis of the longhaul truck cabin loads using petroleum diesel as a 

fuel. We will work with DOE to agree on the next 1 

to 2 applications for detailed study as part of Task 3.

References

1. Davis, Stacy C. (2001). Transportation Energy 

Data Book Edition 21—2001 ORNL-6966. Oak 

Ridge National Laboratory. October.

2. J.D Power and Associates (2001). “Luxury 

crossover SUVs Gaining Market Share at Expense 

of Midsize SUVs.” http://www.jdpa.com/pdf/

0143.pdf. August 15. Visited April 8, 2002. 

3. Kelly, K. (2001). “Battle for Police Market Heats 

Up.” WardsAuto.com. Website, 

http://industryclick.com/microsites/

newsarticle.asp?newsarticleid=269083&siteid=26

&magazineid=1004&instanceid=8578&pageid=1

126&srid=10250. Dec 27. Visited March 3, 2002.

4. Kurylko, Diana T. (2001). “DCX plans Hybrid 

pickup for 2005.” Automotive News, May 7. 

http://www.autonews.com/

article.cms?articleId=1894&a=a&bt= 

contractor+special. Visited April 14, 2002. 

5. North American Fleet Association (NAFA), 1997. 

“NAFA's 1998 Model Year New Vehicle 

Acquisition Survey Results” http://www.nafa.org/

public/searchidx.html. Fleet Executive, Volume 

11, Number 12, December.

6. Recreational Vehicles Industry Association 

(RVIA), (2002). “RV Info.” http://www.rvia.org/

consumers/recreationvehicles/types.htm. Visited 

March 7.

7. U.S. Department of Commerce (2001). “Truck 

Trailers: Summary.” Current Industry Report. 

Website, http://www.census.gov/ftp/pub/industry/

1/m37l0013.pdf. M336L(00)-13. August.8. U.S. 

Department of Commerce’s Vehicle Inventory & 

Use Survey (VIUS), (1997). U.S. Department of 

Commerce, Economics and Statistics 

Administration, U.S. Census Bureau. CD-ROM 

CD-EC97-VIUS. February.

FY 2002 Publications/Presentations

1. Presentation to 21st Century Truck Industrial 

Working Group in conjunction with SAE 

Government & Industry meeting, Washington, 

DC, May 15, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

522

IV.F.3 Guidance for Transportation Technologies: Fuel Choice for Fuel Cell 

Vehicles

Stephen Lasher (Primary Contact), Johannes Thijssen, Stefan Unnasch

TIAX, LLC

Acorn Park

Cambridge MA, 02140

(617) 498-6108, fax: (617) 498-7054, e-mail: lasher.stephen@tiax.biz

DOE Technology Development Manager: Peter Devlin 

(202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

ANL Technical Advisor: Robert Sutton

(630) 252-4321, fax: (630) 972-4430, e-mail: sutton@cmt.anl.gov

Objectives

• Support refined R&D targets for direct-hydrogen fuel cell vehicles (FCV) based on an analysis of wellto-wheel energy use, greenhouse gas (GHG) emissions, cost, and safety of direct-hydrogen FCVs and 

competing vehicle technologies.

• Assess opportunities and risks of various FCV and fuel choices, specifically hydrogen, comparing the 

technical, efficiency, economic, safety and financial risks of each option with onboard reforming of 

gasoline.

Approach

• In Phases 1 and 2, TIAX developed detailed well-to-wheel performance and cost calculations, taking 

into account technology options, system integration and efficiencies, hybridization, vehicle weight, 

and drive cycle. Last year’s annual report included some of the results from these Phases; in this 

report, we present those results which were not previously reported.

• In Phase 3, we are evaluating the financial risks of various FCV options and potential triggers that may 

reduce the risks compared to conventional vehicles.

- Perform detailed analysis of market introduction issues.

- Evaluate the effect that potential triggers may have on the various stakeholders using a net present 

value (NPV) analysis.

Accomplishments

• Completed Phases 1 and 2.

• Developed a NPV analysis framework and a preliminary analysis of hydrogen and gasoline FCV 

options.

Future Directions

• Verify and refine NPV assumptions and analysis and use it to identify low-cost options for introduction 

of hydrogen or other fuel infrastructures.

• Evaluate the technology risk, financial exposure, and safety and regulatory risks associated with the 

various fueling options for each respective stakeholder.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

523

Introduction

The focus of this project is to assess the potential 

impact of on-board storage of hydrogen, rather than 

on-board reforming of gasoline as a means of 

supplying fuel to FCVs. The overall risk involved in 

each of the fuel options for FCVs varies, and the risk 

may shift from one player in the value chain to 

another. This risk trade-off is the focus of Phase 3.

Approach

Phase 2

The approach to Phase 2 was described in detail 

in the full report (Arthur D. Little 2002), as well as in 

last year’s annual report (Lasher, et al 2001). Key 

points are:

• Fuel cell system and vehicle analysis based on 

detailed performance and drive-cycle models, 

but based on a future fuel cell technology 

scenario, assuming success in current R&D 

efforts.

• Hydrogen costs based on detailed on-site 

hydrogen fueling station cost analysis.

• Vehicle cost estimates based on a detailed 

bottom-up analysis consistent with TIAX’s 

automotive fuel cell costing study. 

Phase 3

In Phase 3, we are performing NPV calculations 

to determine overall and individual stakeholder 

investment risks for various fuel and FCV options. 

Minimizing risks will require managing utilization 

factors, FCV introduction strategies, and 

infrastructure options. The NPV analysis is being 

used to evaluate the effect that potential triggers and 

drivers may have on the various stakeholders for 

each fuel chain and FCV option. Potential factors 

include:

• Crude oil and gasoline price increases

• FCV cost reduction

• Value of emissions reduction

• Subsidies and R&D funding and timing

• FCV fuel economy improvements

• Energy and capital cost improvements for 

hydrogen generation

Results

Phase 2

An overview of the well-to-wheels energy, GHG 

emissions, and fuel cost results were presented in last 

year’s annual report (Lasher, et al 2001). Complete 

results can be found in the full report at: http://

www.cartech.doe.gov/pdfs/FC/192.pdf. Last year’s 

presentation of vehicle and ownership cost results 

was preliminary, and the final results are presented 

herein.

Vehicle Factory Cost Results

• Based on our scenario analysis, hydrogen-fueled 

FCV factory costs are around 30% ($4,000 per 

vehicle) higher than hybrid electric vehicles 

(HEVs).

• Fuel processor-based FCVs are projected to cost 

about 10% ($1,000-$2,000 per vehicle) more 

than compressed-hydrogen vehicles - roughly the 

same as metal hydride-based FCVs.

• However, FCV costs, even reformer-based 

FCVs, would be lower than battery EV costs 

while offering longer range.

Vehicle Ownership Cost Results (Figure 1)

• Vehicle ownership costs are dominated by 

vehicle depreciation, representing over 70% of 

annual cost for all vehicles.

• Fuel costs typically amount to less than $500 per 

year.

- High efficiency of direct hydrogen and 

methanol-based FCVs compensates for higher 

hydrogen and methanol costs, bringing annual 

fuel costs on par with ICEVs.

• Sensitivity analysis shows that cost differences 

between FCVs and petroleum ICEVs are 

statistically significant.

- Differences among FCV options are not 

statistically significant.

Safety Analysis Results

• Hydrogen transportation, fueling station, and onboard safety issues can likely be resolved 

without onerous cost increases.

• However, fuel cell vehicles will require 

modifications to garages, maintenance facilities, 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

524

and on-road infrastructure that could be costly 

and difficult to implement.

Phase 3

We are currently refining our preliminary 

analysis based on existing information and using the 

on-site generated hydrogen FCV and gasoline FCV 

cases as the first examples. We started from the 

results of the previous phase and made the necessary 

updates and assumptions needed to perform NPV 

calculations. Progress towards the preliminary 

analysis includes:

• An initial set of NPV variables and outputs has 

been established.

• We have incorporated two FCV introduction 

scenarios and the associated R&D funding 

levels, consistent with scenarios used in DOE’s 

Vision Model.

• We have estimated the fueling station capacity 

requirements based on FCV introduction, 

utilization factors, and infrastructure limitations.

• High and low production volume FCV and 

hydrogen fueling station equipment costs have 

been estimated using progress ratios.

• Large and small fueling station costs have been 

estimated using scaling factors for individual 

equipment based on vendor quotes or internal 

analysis.

• Preliminary costs and revenues of the major 

stakeholders have been estimated.

Conclusions

FCVs are expected to be able to achieve the 

lowest well-to-wheel energy consumption, provided 

efficient fuel chains are used. Direct-hydrogen FCVs 

carrying compressed hydrogen produced from 

natural gas can offer well-to-wheel energy 

consumption of approximately half that of 

conventional gasoline-fueled vehicles. However, 

substantial additional technology breakthroughs will 

be required to achieve FCV cost competitiveness 

with ICEVs.

Alternative fuels, especially hydrogen, will 

require significant up-front investment, representing 

a risk to both vehicle manufacturers and fuel 

providers. Dealing with this risk represents a 

formidable barrier to the use of hydrogen for FCVs.

References

1. Arthur D. Little, “Guidance for Transportation 

Technologies: Fuel Choice for Fuel Cell 

Vehicles, Phase II Final Report”, available at 

http://www.cartech.doe.gov/pdfs/FC/192.pdf, 

February 2002

2. Lasher, S., J. Thijssen, S. Unnasch, “Guidance 

for Transportation Technologies: Fuel Choice for 

Fuel Cell Vehicles”, 2001 Annual Progress 

Report – Fuels for Advanced CIDI Engines and 

Fuel Cells, EERE OTT, November 2001

Publications/Presentations

1. Arthur D. Little, “Guidance for Transportation 

Technologies: Fuel Choice for Fuel Cell 

Vehicles, Phase II Final Report”, available at 

http://www.cartech.doe.gov/pdfs/FC/192.pdf, 

February 2002

2. Thijssen, J., “Fuel Choice for Fuel Cell 

Vehicles”, presented at 2002 Future Car 

Congress, Arlington VA, June 3-5, 2002

Notes: Assumes 14,000 mi/yr driving and 350 mile range (except 

the Battery EV that has 120 mile range); vehicle costs are 

adjusted for resale value with monthly payments over 5 

years at 4% finance rate; insurance, tax, and license costs 

are excluded.

Assumes identical O&M costs for all vehicles.

Hydrogen is assumed to cost $20/GJ.

Figure 1. Estimated Vehicle Ownership Costs for 

Various Types of Vehicles
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

525

3. Weber, B., “Economics/Commercialization 

Issues and Opportunities”, presented at ASME 

Workshop on Fuel Cell Technologies for 

Advanced Vehicles, Rochester Institute of 

Technology, Rochester NY, April 22-24, 2002

4. Weber, B., “Future of Hydrogen Fuels, Fuel 

Cells and Alternative Energy Technology”, 

presented at 7th ASCOPE (ASEAN Council on 

Petroleum), Kuala Lumpur, Malaysia, November 

5-8, 2001
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

526

IV.F.4 Fuel Cell R&D and Demonstration

Robert E. Fields, E. John Rowley, Mahlon S. Wilson (Primary Contact), Christine Zawodzinski

Los Alamos National Laboratory

PO Box 1663, MS D429

Los Alamos, NM 87545

(505) 667-9178, fax: (505) 665-4292, e-mail: mahlon@lanl.gov

DOE Technology Development Manager: Neil Rossmeissl

(202) 586-8668, fax: (202) 586-5860, e-mail: Neil.Rossmeissl@ee.doe.gov

Objectives 

• Develop a fuel cell test bed to enhance understanding of fuel cell operation under real-world 

conditions.

• Develop a hybrid fuel cell-powered demonstration vehicle.

• Develop specialized circuitry that can be used to monitor fuel cell stack performance on the benchtop 

while mimicking real-world loading conditions.

• Develop a fuel cell stack system that operates under both active and passive modes for optimal overall 

efficiency.

Approach

• Determine power requirements of a standard battery-powered three-wheeled personal mobility vehicle 

(scooter).

• Design, build, and test a 4-cell, 35 cm2 active/passive short fuel cell stack to verify performance, 

heating, and water balance issues.

• Design, build, and test a 40-cell, 35 cm2 active area active/passive fuel cell stack to power the threewheeled scooter.

• Design, build, write software/firmware for, and test a custom electronics package to monitor, control, 

and protect the fuel cell stack and associated electronics.

• Refine the design based on results to enhance performance, accomplish automatic fuel cell stack 

startup, and incorporate automatic phase-in of power delivery from the fuel cell stack.

Accomplishments 

• Determined the power requirements of a standard three-wheel scooter.

• Verified performance, heating, and water issues with a 4-cell short fuel cell stack.

• Demonstrated active/passive dual-mode fuel cell operation on a stack level.

• Built, tested, and installed a 40-cell fuel cell stack in a three-wheeled scooter.

• Designed, built, and wrote software for a custom electronics package to monitor, control, and protect 

the fuel cell stack.

• Demonstrated fuel cell-powered scooter at public demonstrations and to visiting scientists and DOE 

officials.

• Incorporated electronics package into other DOE fuel cell project testing equipment.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

527

Future Directions 

• Refine software/firmware to accomplish transparent fuel cell stack startup and drive-off and enhance 

reliability.

• Incorporate additional circuitry to more efficiently control fuel cell stack and power conditioning 

circuitry and efficiently switch between active and passive modes of fuel cell stack operation.

• Build lifetime and power use profile data for the scooter under real-world operating conditions.

• Incorporate lifetime and power use profile data into benchtop stack testing procedures.

• Develop and build higher power output fuel cell stack to provide enhanced power reserves for severe 

loading and faster startup transition to all-fuel cell power.

Introduction

Hydrogen fuel cells have yet to have any 

meaningful commercial success. Obstacles include 

cost, reliability, fuel supply/storage and entrenched 

competition. The first market entry points will 

probably be those areas where the extra cost and fuel 

inconvenience are offset by the advantages of the 

fuel cell over the previous technology. A power 

range where this may apply is on the several-hundred 

watt level, where batteries are unwieldy and internal 

combustion engines are inefficient and noisy. A 

potentially interesting commercial application for 

several-hundred watt fuel cells is in powering 

personal mobility vehicles (PMVs). These include 

powered wheelchairs and three-wheeled electric 

powered "scooters" often used by the elderly or 

infirm. The users of PMVs are often located in 

environments where hydrogen supply could be 

established (e.g., nursing homes or hospitals) or 

routine customers of medical supply houses. The 

usefulness and benefits of PMVs to many users are 

often limited by battery considerations. The 

additional range (and possibly life and reliability) 

offered by fuel cells may more than compensate for 

higher cost and fuel supply issues.

To this end, we have modified a Victory®

personal mobility vehicle (Pride Mobility Products 

Corporation, Exeter, PA), as shown in Figure 1, to 

accept a mid-range fuel cell system with a custom 

monitoring, control, and data logging electronics 

package. The control system consists of two 

components - a main monitor and control board 

which handles low-level monitoring and near realtime protection features, and a Handspring 

(Mountain View, CA) Visor Pro personal digital 

assistant that acts as an operator display and data 

logger and provides manual systems control. The 

electronics protect the fuel cell stack and store 

operational information that can be used to further 

optimize stack installation and operation.

Approach

To adapt a personal mobility scooter to fuel cellpowered operation, it was first necessary to 

determine peak and average power requirements of a 

standard battery-equipped scooter. A batterypowered scooter was equipped with current and 

voltage monitoring circuitry and was driven under 

common operating conditions. A minimum power 

output requirement for the fuel cell stack was found. 

The scooter electrical system and physical 

Figure 1. A Pride Mobility Products Corporation 

Victory® Personal Mobility Vehicle (scooter)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

528

configuration were inspected to find the best way to 

equip it with a hydrogen fuel cell, hydrogen storage 

system, and control and monitoring electronics with 

minimum modification to the scooter and while 

maintaining the original mechanical outline. 

Hydrogen storage methods were investigated, and it 

was determined that a metal hydride would provide 

the optimum solution without adding significantly to 

the overall scooter weight.

An initial monitoring and control strategy was 

determined and suitable electronic circuitry was 

designed, constructed, tested, and installed. 

Preliminary testing of the fuel cell system revealed 

an issue with power distribution between the fuel cell 

stack and the lead-acid batteries used to supply 

power during peak loading during acceleration or hill 

climbing. This issue was addressed and solved to a 

first approximation with rudimentary additional 

circuitry. Stack protection methods were further 

optimized over the initial strategy. A more optimum 

power distribution and stack protection method that 

will also significantly increase overall system 

efficiency was determined.

The original design for passive "air-breather" 

fuel cell stacks developed under a Hydrogen Program 

Cooperative Research and Development Agreement 

was scaled-up and modified to accommodate active 

(fan-supplied air) operation. Single-cell and short 

stack testing of various component permutations 

were used to design the eventual 40-cell stack. 

While it was necessary to restrict air access in the 40-

cell design to prevent dryout, the stack exhibited 

stable performance and operated well in both active 

and passive modes.

Results

A hybrid fuel cell powered personal mobility 

research, development, and demonstration vehicle 

was constructed based on a commercially available 

standard three-wheeled scooter and fuel cell designs 

developed at Los Alamos National Laboratory. The 

fuel cell-powered scooter required minimal 

modification to the standard scooter aside from the 

actual fuel cell, metal hydride cylinder, and 

electronics installation (Figures 2-5). The electronics 

package developed for the project has proven 

valuable in providing insight into operational, gas 

flow, and temperature issues with the fuel cell 

developed for the scooter and in testing other fuel 

cell stacks developed for other DOE projects. The 

scooter has been used in several successful private 

and public demonstrations highlighting the utility 

and advantages of fuel cell power.

Figure 2. Overview of hydrogen fuel cell installation. 

The scooter body shroud has been removed 

for photographs.

Figure 3. The 40-cell hydrogen stack installed on the 

scooter chassis. Ribbon cable allows 

monitoring all cell voltages.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

529

Conclusions

The fuel cell-powered scooter project has 

provided valuable insights into fuel cell operation 

under real-world conditions as well as monitoring 

and control strategies to maximize power and 

efficiency. The electronics developed for the project 

have found dual use with other fuel cell testing 

systems. Additionally, the fuel cell-powered scooter 

has proven valuable as a way to illustrate and 

demystify fuel cell systems, and as a public relations 

tool to promote alternative energy research at Los 

Alamos National Laboratory.

FY 2002 Publications/Presentations

1. R. Fields, E.J. Rowley, M. Wilson, and C. 

Zawodzinski, "A Fuel Cell Monitoring and 

Control System for a Personal Mobility Vehicle". 

To be presented at the Electrochemical Society 

Meeting, Salt Lake City, UT (Fall 2002).

2. Robert E. Fields, E. John Rowley, Mahlon S. 

Wilson and Christine Zawodzinski, "Fuel Cell 

R&D and Demonstration" U.S. DOE Hydrogen 

and Fuel Cells Annual Program/Lab R&D 

Review, Golden, Colorado (May 2002).

Figure 4. Metal Hydride Hydrogen Storage Tank 

Mounted in Stock Scooter Battery Location

Figure 5. Fuel Cell Monitoring and Control Electronics 

Circuit Board Mounted on Scooter Drive Unit
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

530

IV.F.5 Advanced Underground Vehicle Power and Control Fuel Cell Mine 

Locomotive

David L. Barnes (Primary Contact), Arnold R. Miller

Vehicle Projects, LLC

621 Seventeenth Street, Suite 2131

Denver, Colorado 80293-2101

(303) 296-4218, fax: (303) 296-4219, e-mail: david.barnes@vehicleprojects.com

DOE Technology Development Manager: Sigmund Gronich

(202) 586-1623, fax: (202) 586-5860, e-mail: Sigmund.Gronich@ee.doe.gov

Main Subcontractors: Canada Center for Mineral and Energy Technology, Ottawa, ON, Canada; 

Hatch Associates Ltd, Sudbury, ON, Canada; Sandia National Laboratories, Livermore, California; 

University of Nevada, Reno, Nevada; Kappes, Cassiday & Associates, Reno, Nevada

Objectives

• Develop a zero-emissions, fuel cell-powered metal-mining locomotive

• Evaluate its safety and performance, primarily in surface tests

• Evaluate its productivity in an underground mine in Canada

Approach

• Design 14 kilowatts (kW) fuel cell powerplant

• Design metal-hydride storage

• Integrate powerplant and hydride storage onto locomotive base vehicle

• Conduct preliminary tests and evaluate

• Refine final design

• Perform safety and risk analysis and complete documentation to meet regulatory approval

• Evaluate productivity performance in an underground metal mine

Accomplishments

• Designed 14 kW fuel cell powerplant and metal-hydride storage

• Integrated powerplant and metal-hydride storage onto locomotive base vehicle

• Performed preliminary testing and evaluation in Nevada

• Conducted safety and risk assessment

Future Directions

• Integrate recommended safety improvements into final design

• Complete documentation for final regulatory approval

• Evaluate performance on surface and underground in a metal mine
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

531

Introduction

Underground mining is one of the most 

promising applications in which fuel cell vehicles 

can compete strictly on economic merit (1). The 

mining industry, one of the most regulated, faces 

economic losses resulting from the health and safety 

deficiencies of conventional underground traction 

power. Conventional power technologies - tethered 

(including trolley), diesel, and battery - are not 

simultaneously clean, safe, and productive. Fuel cell 

power would solve the challenges by providing large 

cost savings relative to the high capital cost of 

current underground traction power. Lower recurring 

costs, reduced ventilation costs, and higher vehicle 

productivity could make the fuel cell vehicle costcompetitive years before surface applications. The 

fuel cell locomotive is shown in Figure 1. 

Approach

A joint venture between the Fuel Cell Propulsion 

Institute (a nonprofit consortium of industry 

participants) and Vehicle Projects LLC (project 

management) provided the basis for the 2 phase 

project. In phase 1, Sandia National Laboratories 

was tasked with the design of the fuel cell powerplant 

and the metal-hydride storage, as well as system 

integration. Phase 2 includes system evaluation, 

safety and risk assessment, and underground testing 

in a production environment.

To ensure the locomotive was designed with 

industry in mind, various industry participants were 

involved in assessing the design for risk and 

functionality. When the locomotive is tested 

underground, all regulatory requirements will have 

been met.

Results

The locomotive's fuel cell power system uses 

proton exchange membrane fuel cells. No traction 

battery is employed: thus, the vehicle is a pure fuel 

cell vehicle. Two stacks in electrical series provide 

104 volts and 135 amps at the continuous rated 

power of 14 kW gross. Waste heat from the stacks 

provides the heat to desorb hydrogen from the metalhydride bed. A heat exchanger links the two isolated 

thermal systems: (a) the hydride-bed heating/cooling 

loop and (b) the stack cooling loop. Figure 2 depicts 

the schematic layout of the powerplant and metalhydride storage. Specifications of the fuel cell and 

battery versions of the locomotive are compared in 

Figure 3.

The hydride storage system stores 3 kg of 

hydrogen, sufficient for eight hours of locomotive 

operation at the predicted 6 kW average power of its 

Figure 1. Fuel Cell Mine Locomotive

Figure 2. Schematic Layout of Fuel Cell Powerplant 

and Metal-Hydride Storage

Figure 3. Battery and Fuel Cell Specifications
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

532

duty cycle. Hydride subsystem design allows 

forrapid change-out (swapping) of a discharged bed 

with a freshly charged unit. Recharging will utilize 

gaseous hydrogen and has been measured at 

approximately one hour. 

Bench performance data for the powerplant are 

shown in Figure 4. Both voltage versus current and 

gross power versus current are shown. Maximum 

observed power in the test was 12 kW gross due to 

air pressure of 5 psig, rather than 7 psig as specified 

for 14 kW gross power. Parasitic losses are less than 

10%, a very good performance result.

Mine Safety and Health Administration (MSHA) 

focused on possible hazards of hydrogen 

underground, including detailed review of process 

piping and electrical routing. The assessment 

indicated few changes required to meet existing 

standards and will help establish new standards for 

hydrogen-fueled underground mine vehicles.

MSHA measured noise levels (Table 1) of the 

locomotive under a number of operating conditions, 

including acceleration (2). Unlike some fuel cell 

vehicles, our locomotive is very quiet under all 

conditions. It emanates a pleasant, low frequency 

purring, and normal conversation can easily be 

carried out while standing beside the operating 

powerplant. Consequently, the steel-wheel-to-steeltrack generated noise will be the most prevalent.

Table 1. Average Recorded Sound Levels

* Sound Level Using an “A-weighted”network 

** Sound Level using and unweighted network (flat response)

Conclusions

The problems of vehicle emissions and noise 

have negative economic consequences for 

underground vehicle applications. Fuel cells coupled 

with reversible metal-hydride storage, by solving 

these problems, offer cost offsets - higher 

productivity and lower operating costs - that can 

make underground fuel cell vehicles costcompetitive sooner than surface applications. Our 

hydride-fuel cell locomotive, like the battery version, 

is a zero-emissions vehicle. However, the fuel cell 

locomotive has greater net power, greater energy 

storage, higher gravimetric energy and power 

density, higher volumetric power density, and 

substantially faster recharging. Because weight is 

not an issue, safe and compact metal-hydride storage 

is an ideal storage technology for underground 

locomotive applications.

References

1. A. R. Miller, Tunneling and Mining Applications 

of Fuel Cell Vehicles. Fuel Cells Bulletin, July 

2000, pp. 5-9.

2. Special Acoustical Field Investigation, Hydrogen 

Fuel Cell Powered Locomotive. Investigative 

Report PP-025-02O, Mine Safety and Health 

Administration, Pittsburgh, PA, 17 May 2002.

Figure 4. Fuel Cell Power Curve Showing 12 kW 

Gross Power

Average Sound Levels for the Locomotive

Location/Condition dBA* Linear**

Operator Position/Traveling Forward, Run 1 

(Full Throttle)

75.3 80.1

Operator Position/Traveling Forward, Run 2 76.6 85.1

Operator Position/Traveling in Reverse, Run 1 

(Full Throttle)

76.6 85.1

Operator Position/Traveling in Reverse, Run 2 76.2 82.2

Operator Position/Idle 74.4 81.2

6 Inches from Blower on Right Side/Idle 78.9 85.3

6 Inches from Top Vent on Right SIde/Idle 80.0 84.3

6 Inches from Control Panel on Left Side/Idle 79.5 84.0

1 Foot in Front of Locomotive/Idle 75.3 81.9

Background Near Area of Tests 73.4 78.3
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

533

Presentations

1. R. Sage, "Fuel Cell Mine Loader and Prototype 

Locomotive", Canadian Institute of Mining 

Annual Conference & Exhibition, Vancouver, 

British Columbia (2002)

2. A. Miller, "Fuel Cell Locomotives", European 

Fuel Cell Forum, Lucerne, Switzerland (2002)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

535

Section V. Integrated Hydrogen and Fuel Cell 

Demonstration/Analysis
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

537

V.A System Analysis

V.A.1 Analysis of Hydrogen Production Using Ammonia and Ammonia-Borane 

Complex for Fuel Cell Applications

Ali T-Raissi (Primary Contact)

University of Central Florida

Florida Solar Energy Center

Cocoa, FL 32922-5703

(321) 638-1446, fax: (321) 638-1010, e-mail: ali@fsec.ucf.edu

DOE Technology Development Manager: Roxanne Danz 

(202) 586-7260, fax: (202) 586-4753, e-mail: Roxanne.Danz@ee.doe.gov

Objectives

• Analyze the viability (i.e. cost, safety, and performance) of ammonia-based chemical hydrides as 

hydrogen (H2) storage compounds for fuel cell applications.

• Identify the pros and cons of using ammonia (NH3) as a chemical carrier for H2.

• Evaluate the viability of autothermal NH3 reformation on-board fuel cell vehicles.

• Analyze the viability (cost and performance) of using ammonia-borane complex (H3BNH3) as a 

chemical hydrogen storage medium on-board fuel cell vehicles.

• Identify technoeconomic barriers to the implementation and use of amine borane complexes, in 

general, and H3BNH3, in particular, as prospective chemical hydrogen storage media on-board fuel 

cell vehicles.

Approach

• Review all published papers, reports, patents, etc. in the past 50 years related to the development of 

ammonia-based chemical hydrides as H2 storage compounds.

• Develop contacts with and inquire about information from the researchers and/or companies involved 

with the development of ammonia-based chemical hydrides.

• Use FactSage Program to calculate and optimize the performance parameters for the autothermal 

reformation of ammonia to hydrogen gas.

• Compile information on the physiochemical properties and synthesis of ammonia-borane complex.

• Compare the characteristics and costs of H3BNH3 as a hydrogen storage media to that of sodium 

borohydride (NaBH4) and ionic hydrides such as lithium hydride (LiH) and calcium hydride (CaH2).

• Identify possible approaches that have potential to significantly reduce the cost of ammonia-borane 

synthesis.

Accomplishments

• Reviewed and evaluated more than 120 published papers, reports, patents and other archival records 

related to ammonia-based chemical hydrides, including amine borane complexes, as prospective 

chemical hydrogen storage compounds.

• Completed an assessment of the pros and cons of ammonia-based hydrogen storage compounds for 

vehicular fuel cell power applications.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

538

• Used FactSage 5.1 Program for Computational Thermochemistry to determine the performance 

parameters for the autothermal reformation of NH3 gas to hydrogen.

• Evaluated a number of ammonia adducts, including H3BNH3, as non-toxic, non-cryogenic alternatives 

to ammonia for use in vehicular fuel cell applications.

• Completed a tentative evaluation of the production costs of ammonia- and amine borane-based 

hydrogen storage compounds.

• Identified the current high costs of ammonia-borane complex production as the main drawback to the 

successful implementation of H3BNH3 as a H2 storage compound for the vehicular fuel cell 

applications.

Future Directions

• Complete technoeconomic analysis of ammonia-borane complex as a hydrogen storage compound for 

fuel cell applications.

• Conduct a thorough literature search to identify and evaluate new, more advanced and potentially 

lower cost chemical processes for the synthesis of H3BNH3. 

Introduction

The aim of this project is to assess the issues of 

cost, safety, performance, and environmental impact 

associated with the production of hydrogen (H2) by 

several methods, not presently funded by the U.S. 

DOE Hydrogen, Fuel Cell and Infrastructure 

Program. Three technology areas being evaluated 

are: 1) thermochemical reformation of methane 

(CH4) and hydrogen sulfide (H2S) gas with and 

without using solar energy; 2) ammonia (NH3) and 

ammonia adducts as hydrogen storing chemical 

hydrides for fuel cell applications; and 3) 

thermochemical water-splitting cycles suitable for 

solar power interface.

A report on the first topic involving an 

assessment of the thermochemical reformation of 

CH4/H2S has been submitted previously. This second 

report is concerned with the prospects of NH3 and 

ammonia-borane as hydrogen storage media for fuel 

cell applications. 

Advantages and Drawbacks to Ammonia Use

Ammonia is the second largest synthetic 

commodity product of the chemical industry, with 

world production capacity exceeding 140 million 

metric tons. In 2000, the U.S. consumed in excess of 

20 million metric tons of NH3. Anhydrous ammonia 

costs about $150 per short ton (f.o.b. U.S. Gulf 

Coast) or less than $6.25 per million BTU of H2

contained. Besides the large volume of production 

and use, and relatively low cost, NH3 has the 

following advantages as a hydrogen-rich fuel for fuel 

cell applications:

• Energy density - contains 17.8 weight % 

hydrogen (liquid ammonia stores 30% more 

energy per unit volume than liquid 

hydrogen).

• Infrastructure for NH3 transportation, 

distribution, storage and use already exists.

• Simplicity - its use requires no shift 

converter, selective oxidizer or co-reactants.

• No purification is needed for NH3 use with 

alkaline fuel cells (AFCs).

• Only 16% of the energy stored in NH3 is 

needed for its conversion to N2 and H2.

• There are good NH3 decomposition catalysts 

such as: ICI-47-1 (10 weight % nickel on 

alumina); Haldor Topsøe DNK-2R (triply 

promoted iron-cobalt); SÜD-Chemie 27-2 

(nickel oxide on alumina); various supported 

nitrided catalysts (e.g. molybdenum nitride 

and nickel molybdenum nitride on - α

alumina); and ruthenium modified nickel 

oxide on alumina.

• Flammability range for ammonia -air (at 0°C 

and 1 atm) is much narrower than that for 

hydrogen-air mixtures (i.e. 16-27 volume % 

NH3 vs. 18.3-59 volume % H2).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

539

• Using ammonia in fuel cell power plants 

does not generate carbon dioxide (CO2) or 

nitrogen oxides (NO2) emissions.

There are several drawbacks to ammonia as a 

fuel and chemical carrier for H2, especially in 

vehicular applications, including safety concerns 

with the widespread transportation, utilization and 

use of ammonia as a transportation fuel; storage 

requirements for sub-ambient temperatures and/or 

elevated pressures; and requirements for on-board 

reformation to liberate H2. These limitations make 

the widespread ammonia use as a transportation fuel 

problematic. Furthermore, cost and energy efficiency 

considerations dictate that any chemical hydride 

employed as a vehicular hydrogen storage medium, 

including ammonia, not require complicated onboard reformation in order to generate hydrogen.

To mitigate ammonia's shortcomings, our 

approach involved complexing NH3 with other 

hydrides to form compounds that are stable but not 

toxic or cryogenic. In particular, our approach 

considered a class of compounds (with generalized 

formula amine boranes [BxNxHy]) known as amineboranes that contain H2 at gravimetric and 

volumetric densities comparable to that of anhydrous 

ammonia. The simplest known stable compound in 

this class is ammonia-borane, H3BNH3 (or 

borazane). Borazane is a white crystalline solid that 

when heated releases hydrogen in a sequence of 

reactions that occur at distinct temperature ranges. 

H3BNH3 contains about 20 weight % hydrogen and 

is stable in water and ambient air.

Physiochemical Properties and Synthesis of 

Ammonia-Borane Complex

Pyrolysis of ammonia-borane is a complex 

process, and the products of the decomposition 

reaction markedly depend on the conditions 

employed. Furthermore, the initial process is a solidstate reaction for which the onset of decomposition is 

a function of heating rate of the substrate (β). In 

thermogravimetric analyzer-Fourier transform 

infrared (TGA-FTIR) and thermogravimetric 

analyzer-differential scanning (TGA-DSC) analysis, 

heating a borazane sample to 90°C at a rate of 0.5°C/

min and then holding it at that temperature for 200 

min resulted in a loss of about 10.2% of initial 

sample mass. FTIR analysis of the evolved gases has 

shown approximately one mol of H2 forming per mol 

of BH3NH3 reacted. Reaction products, in addition to 

hydrogen, have included monomeric aminoborane 

(BH2NH2) and a small amount of volatile borazine 

(B3N3H6). The monomeric aminoborane is unstable 

at room temperature, oligomerizing to form a nonvolatile white solid residue of poly (aminoboranes) 

(BH2NH2)x. The inorganic analog of polyethylene, 

polymeric (NH2BH2)x, is still not fully characterized. 

Crystalline cyclic oligomers, (NH2BH2)n (where, n = 

2, 3, 4, 5) have been prepared, and an amorphous 

(NH2BH2)x consisting of solvated linear chains with 

x= 3-5 has also been produced by gas-phase 

pyrolysis of ammonia-borane.

Unlike aminoborane oligomers, borazine 

(isoelectronic with benzene) is a volatile colorless 

liquid that boils at 55°C. Based on the TGA and DSC 

analysis, pyrolysis of ammonia-borane begins with a 

sharp endothermic peak that appears just above the 

melting point of BH3NH3 (112-114°C depending on 

the sample heating rate). Near 117°C, a steep 

exothermic peak occurs, reaching a maximum at 

about 130°C with rapid evolution of gas. A final 

broad exotherm appears near 150°C. Although 

processes other than step-wise decomposition and 

hydrogen loss are involved to some extent in 

H3BNH3 and its intermediate compounds, 

nonetheless the following sequence of events occur 

(BN = boron nitride, g = gas phase, [HBNH]x = 

polyborazine, [HBNH]3 = borazine, H2BNHx = 

monomeric aminoborane, [H2BNHx)x = polymeric 

aminoborane, kJ/mol = kilo Joule per mole, s = solid 

phase, ∆Hr = heat of reaction, β = heating rate):

H3BNH3 (l) → H2BNH2 (s) + H2 (g) ~137°C, 

β= 5-10°C/min, ∆Hr = – (21.7 ± 1.2) kJ/mol

x (H2BNH2) (s) → (H2BNH2)x (s) at ~125°C

(H2BNH2)x (s) → (HBNH)x (s) + x H2 (g) at ~155°C

(HBNH)x (s) → borazine + other products

(HBNH)3 → 3 BN + 3 H2 at above 500°C

 (H2BNH2)x (s) → (BN)x (s) + 2x H2 (g) at ~ 450°C, β= 

10°C/min

Due to the large amount of evolved H2 and the 

exothermicity of the process, ammonia-borane 

appears to be a more effective chemical carrier for H2

than anhydrous NH3. Other physicochemical 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

540

properties of ammonia-borane complex are given in 

Table 1 below.

 Table 1. Selected Physiochemical Properties of 

Ammonia-Borane Complex

Another important factor is interaction with 

water and other solvents. Unlike ionic hydrides, 

NH3BH3 does not react violently with water. Table 2 

depicts the solubilities of borazane in water and a 

number of organic solvents. 

Borazane can be prepared through several 

indirect procedures including the reaction with 

lithium borohydride, LiBH4, in diethyl ether by 

either of the following two methods ( LiCl = lithium 

chloride, Li2SO4 = lithium sulfate, NH4Cl = 

ammonium chloride, [NH4]2SO4 = ammonium 

sulfate :

LiBH4 + NH4Cl – in diethyl ether → LiCl + H3BNH3 + H2

2 LiBH4 + (NH4)2SO4 – in diethyl ether → Li2SO4 + 

2 H3BNH3 + 2 H2

Alternatively, H3BNH3 is prepared directly from 

the gases by reacting diborane with ammonia in polar 

organic solvents (e.g. ether and dioxan) and in 

aqueous media: 

(diborane) B2H6 + 2 NH3 – in ether or dioxan → 2 

H3BNH3

Table 2. Solubilities of Ammonia-Borane Complex in 

Various Solvents

For vehicular fuel cell applications, the main 

drawback to the use of amine-boranes, in general, 

and H3BNH3, in particular, is the present high cost of 

these compounds and lack of a suitable reformer 

design for the on demand generation of hydrogen. No 

data could be found for the large-scale production 

costs of ammonia-borane. However, the Callery 

Chemical Co manufactures large quantities of 

dimethylamine borane (DMAB), which has 

significant use in the electroless plating industry. 

Depending on the volume, the price of DMAB is in 

the range of about $75-100/lb. It can be expected 

that the large volume price of ammonia-borane 

would also be in this range. The issue of the cost of 

ammonia-borane can be highlighted by comparing its 

price to the bulk material prices for other chemical 

hydrides under consideration as hydrogen storage 

compounds. The feasibility of using various ionic 

hydrides as potential H2 storage compounds for AFC 

applications has been analyzed. This application 

requires a hydrogen storage system capable of 

supplying H2 to an AFC producing 1 kW of electrical 

power for 8 h. The fuel cell is assumed to operate at 

57% efficiency (at 0.7 volt), requiring 231 mol of H2

Property Description

Formula NH3BH3

Molecular 

weight

30.86

X-ray 

structure

C4V symmetry; unit cell is 

tetragonal

Odor Ammonia-like

Density, kg/L 0.74

Melting point 112-114°C, slow decomposition at 

approx. 70°C

Heat of 

formation

∆Hf

°= -178 ± 6 kJ/mol

Heat of 

combustion

∆Hc°= -1350 ± 3 kJ/mol

Water stability 10% solution stored at ambient 

temperatures:

Dormancy % hydrogen loss

4 days 1.8

11 days 3.6

1 month 4.8

2.5 months 9.3

18 months 45.0

Solvent Weight 

%

Temperature, 

°C

Density of 

saturated 

solution, kg/L

Water 26 23 0.89

Methanol 23 23 0.78

Ethyl Ether 0.80 24 0.71

Hexane 0.003 25 0.56

Benzene 0.03 25 0.87

Methylene 

Chloride

0.08 21 1.32
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

541

(assuming 100% utilization). Table 3 depicts the cost 

of several H2 storage media including H3BNH3.

Table 3. Required Mass, Volume and Cost of Chemical 

Hydrides for 8 hours/1 kW Duty

New chemical synthesis techniques and/or 

processes are needed to reduce the H3BNH3

production costs. In addition to the cost issues, new 

processes must be developed to allow recycling of 

the by-products of ammonia-borane decomposition 

on-board fuel cell powered vehicles. For example, if 

an on-board ammonia-borane based hydrogen 

storage system is to be developed for maximum H2

delivery, then it will be desirable, if not necessary, to 

be able to retrieve and recycle the boron nitride 

residue. Here, the challenge is to develop a chemical 

route for activating the boron-nitrogen bond in a 

manner analogous to dinitrogen bond activation in 

the Haber-Bosch process for ammonia synthesis. In a 

modern ammonia plant, steam reformation of natural 

gas is used as the primary source of hydrogen. A 

simple stoichiometric equation for ammonia 

production by steam methane reformation (SMR) is 

as follows:

CH4 + 0.3035 O2 + 1.131 N2 + 1.393 H2O → CO2 + 2.262 NH3

 1.4345 AIR 

In practical processes, a high degree of 

irreversibility exists, and a considerable amount of 

energy is needed to produce ammonia from methane, 

air and water. The stoichiometric quantity of methane 

required in the equation above is about 583 m3 per 

ton of NH3 produced. Energetically, this corresponds 

to approximately 20.9 giga-joule (GJ) per ton of NH3

(lower heating value). This is the minimum amount 

of energy needed per ton of ammonia produced using 

the SMR process. It is interesting to note that the best 

energy figure reported for commercial ammonia 

production is about 27 giga Joule per metric ton (GJ/

t) NH3. This figure corresponds to a rather high 

efficiency of around 75% with respect to the 

theoretical minimum of 20.9 GJ/t NH3, calculated as 

stoichiometric methane demand discussed above.

In a like manner, an idealized process for 

ammonia-borane synthesis from recycled BN (or 

borazine) may be written as:

CH4 + 1.33 BN + 2 H2O → CO2 + 1.33 H3BNH3

Or,

CH4 + 0.667 (HBNH)3 + 2 H2O → CO2 + 2 H3BNH3

If similar processes could be developed at energy 

conversion efficiency levels that are comparable to 

the present day SMR-based NH3 synthesis plants, 

then it would be possible to realize a major reduction 

in the production costs of ammonia-borane complex. 

We note that a concept similar to that discussed 

above has already been developed for nitric acid 

synthesis process based on boron nitride analogous to 

the Haber-Bosch route for nitric acid production 

from NH3. Finally, recent results have shown that 

unusual parallel behavior exists between 

hydrocarbons and their corresponding B-N 

analogues. Thus, hydrogenation of benzene to 

cyclohexane may also provide a model for the 

reformation of borazine to other amine-boranes.

Conclusions

There are many advantages to the use of NH3 as 

hydrogen source for vehicular fuel cell vehicle 

applications. However, a major drawback is 

ammonia's extreme toxicity and adverse health 

effects. By complexing NH3 with diborane, a stable, 

non-toxic and non-cryogenic material (H3BNH3) can 

be prepared. This ammonia-borane complex is stable 

in water and ambient air and when heated liberates 

H2 in a sequence of reactions between 137°C and 

400°C that reaches about 20% of the initial mass of 

H3BNH3. Successful implementation of ammoniaborane as a potential future transportation fuel, 

however, requires new chemical techniques and/or 

processes for its synthesis that promise substantial 

reduction in its production costs.

Storer Mass, 

kg

Volume, 

Liters

Cost, 

US$

LiH 1.7 3.7 109

CaH2 4.5 4.0 104

NaBH4 (35 Weight 

% aqueous)

6.21 6.21 102

H3BNH3 2.38 3.21 390-525
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

542

FY 2002 Publications/Presentations

1. A. T-Raissi, "Ammonia and Ammonia Adducts as 

Hydrogen Energy Storers for Fuel Cell 

Applications," Proceedings of the 14th WHEC, 

Montreal, Canada, June 9-13 (2002). 

2. C.A. Linkous, C. Huang, J. Fowler, G. Scott, A. TRaissi, and N.Z. Muradov, "Closed Cycle 

Photochemical Methods for Deriving Hydrogen 

from Hydrogen Sulfide," Proceedings of the 14th 

WHEC, Montreal, Canada, June 9-13 (2002).

3. A. T-Raissi, "Technoeconomic Analysis of Area II 

Hydrogen Production, Part II - Hydrogen from 

Ammonia and Ammonia-Borane Complex for 

Fuel Cell Applications," Proceedings of the U.S. 

DOE Hydrogen Program Annual Review, Golden, 

CO, May 7 (2002), URL: http://erendev.nrel.gov/

hydrogen/pdfs/ 32405b15.pdf.

4. A. T-Raissi, "Ammonia and Ammonia-Borane 

Complexes as Hydrogen Energy Storers for Fuel 

Cell Applications," at Session A2.8: Hydrides II, 

14th WHEC, Montreal, Canada, June 10 (2002).

5. A. T-Raissi, "Technical Analysis of Hydrogen 

Production," Hydrogen Program Annual Review, 

Session B: Storage, Utilization, Analysis, Golden, 

CO, May 7 (2002).

Patent Applications

1. A. T-Raissi, N.Z. Muradov and E.D. Martin, 

"Method and Apparatus for Low Flux 

Photocatalytic Pollution Control," Serial No. 09/

782,427, Feb. 12 (2001).

2. A. T-Raissi, N.Z. Muradov and E.D. Martin, 

"Apparatus and Method for Decoupled ThermoPhotocatalytic Pollution Control," U.S. Pat. No. 

6,342,128 B1, Jan. 29 (2002).

3. A. T-Raissi, N.Z. Muradov and E.D. Martin, 

"Apparatus and Method for Decoupled 

Thermocatalytic Pollution Control," U.S. Pat. No. 

6,334,936 B1, Jan. 1 (2002).

4. A. T-Raissi, N.Z. Muradov and E.D. Martin, 

"Method for High Flux Photocatalytic Pollution 

Control," U.S. Pat. No. 6,315,870 B1, Nov. 13 

(2001).

5. A. T-Raissi, N.Z. Muradov and E.D. Martin, 

"Apparatus for Low Flux Photocatalytic Pollution 

Control," U.S. Pat. No. 6,309,611 B1, October 30 

(2001).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

543

V.A.2 Well-to-Wheels Analysis of Energy and Emission Impacts of Fuel Cell 

Vehicle Fuels

Michael Wang

Argonne National Laboratory

ESD362/B215

9700 S. Cass Avenue

Argonne, IL 60439

(630) 252-2819, fax: (630) 252-3443, e-mail: mqwang@anl.gov

DOE Technology Development Manager: Peter Devlin

(202) 586-4905, fax: (202) 586-9811, e-mail: Peter.Devlin@ee.doe.gov

Objectives

• Evaluate well-to-wheels (WTW) energy and emission impacts of various potential fuels for fuel-cell 

vehicles.

• Update and upgrade Argonne’s GREET (Greenhouse gasses, Regulated Emissions, and Energy use in 

Transportation) model to analyze new fuels and new fuel production pathways for fuel-cell vehicle 

applications. 

• Characterize production pathways of various fuel-cell fuels, such as gaseous hydrogen, liquid 

hydrogen, methanol, gasoline, ethanol, and Fischer-Tropsch (FT) naphtha.

• Analyze key issues in production and distribution of fuel-cell fuels and evaluate their impacts on 

WTW energy use and emissions.

Approach

• Revise Argonne’s GREET model to accommodate fuel-cell fuels for WTW analyses.

• Estimate emissions of greenhouse gases (CO2, CH4, and N2O) and criteria pollutants [VOCs, CO, 

NOx, PM10 (particulate matter with diameter less than 10 microns), and SOx] and energy use for all 

energy sources, fossil fuels (petroleum, natural gas, and coal), and petroleum.

• Specify production and distribution pathways for individual fuel-cell fuels.

• Obtain data on new technologies, energy efficiencies, and emissions associated with key WTW 

activities (e.g., fuel production and fuel-cell vehicle operations).

• Evaluate and process the data obtained for application to the GREET model.

• Conduct GREET simulations to generate WTW energy and emission results for various fuel-cell fuels.

Accomplishments

• Evaluated energy use and greenhouse gas (GHG) emissions impacts of central gaseous hydrogen 

(GH2) from natural gas (NG), central liquid hydrogen (LH2) from NG, station GH2 from NG, station 

LH2 from NG, solar photovoltaic (PV) GH2, solar PV LH2, station GH2 via electrolysis, station LH2

from electrolysis, gasoline, methanol, cellulosic ethanol, and naphtha from both crude and NG.

• Specified production and distribution pathways for each of the above fuels and fuel production 

pathways.

• Revised GREET 1.6. The version is posted at the GREET website for download and evaluations (http:/

/greet.anl.gov).

• Reviewed completed studies on energy and emission impacts of fuel-cell vehicle fuels.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

544

Future Directions

• Continue to revise key assumptions in GREET l.6 to reflect technology developments related to 

hydrogen production, distribution, and storage.

• Review completed studies on the topic of fuel-cell fuel energy and emission impacts and summarize 

differences and similarities among the reviewed studies.

• Add additional hydrogen production pathways as needed.

• Seek feedbacks from GREET users to further improve the functionality of the GREET model.

• Continue to evaluate WTW energy and emission impacts of fuel-cell fuels.

Introduction

Fuel-cell vehicles (FCVs) are being promoted for 

their energy efficiency gains and zero or near-zero 

emissions. Although experts agree that hydrogen is 

the ultimate fuel-cell fuel in the long term, it may not 

be available on a large scale for FCV applications in 

the foreseeable future, mainly because of hydrogen 

production and distribution infrastructure constraints. 

Intensive R&D efforts are being focused on 

hydrocarbon fuels, besides hydrogen, for FCV 

applications. Because production and distribution of 

various fuel-cell fuels are subject to different energy 

efficiencies and emissions, WTW analysis is 

necessary to obtain impartial evaluations of fuel-cell 

vehicle/fuel systems.

Approach

For a given vehicle technology/transportation 

fuel combination, the GREET model separately 

calculates the following items on the WTW basis:

1. Energy consumption for three energy categories 

(total energy, fossil fuels, and petroleum)

2. Emissions of three greenhouse gases (CO2, CH4, 

N2O)

3. Emissions of five criteria pollutants (total and 

urban emissions, VOCs, CO, NOx, PM10, and 

SOx)

Figure 1 shows the stages covered in GREET 

simulations. A WTW analysis includes the feedstock, 

fuel, and vehicle operation stages. The feedstock and 

fuel stages together are called well-to-pump stages, 

and the vehicle operation stage is called the pump-towheels stage. In GREET, WTW energy and emission 

results are presented separately for each of the three 

stages.

GREET includes a variety of vehicle propulsion 

technologies and transportation fuels, of which fuelcell vehicle technologies and fuel-cell fuels are a subset. Table 1 lists the fuel-cell fuels included in the 

GREET model. GREET can simulate multiple 

options for a given pathway. For example, GREET 

1.6 includes 48 options for GH2 and LH2 pathways.

Results and Conclusions

Argonne applied GREET 1.6 to estimate WTW 

energy and emission impacts of various fuel-cell 

fuels. We cannot include all the results here, but 

Figures 2-5 provide a snapshot of WTW total energy 

use, fossil energy use, petroleum use, and CO2-

equivalent GHG emission impacts of some key fuelcell fuels. (For each figure, the bars represent 

average values while the lines superimposed on the 

bars represent uncertainty ranges.)

For total energy use (including both 

nonrenewable and renewable energy sources), use of 

electrolysis hydrogen, liquid hydrogen from NG, and 

cellulosic ethanol may increase total energy use, 

relative to baseline gasoline internal combustion 

engine vehicles (GVs) (Figure 2). However, when 

one considers fossil energy use (petroleum, natural 

gas, and coal), cellulosic ethanol, solar PV hydrogen, 

and station electrolysis hydrogen from renewable 

Figure 1. Stages Covered in GREET Well-to-Wheels 

Analysis
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

545

electricity are superior to any other fuel-cell fuels 

(Figure 3). Furthermore, if one is concerned about 

petroleum use of motor vehicles, all non-petroleumbased fuel pathways almost eliminate petroleum use 

(Figure 4). The two petroleum pathways, gasoline 

and crude naphtha, result in significant reductions in 

petroleum use because of the high energy efficiency 

of FCVs.

Except for electrolysis hydrogen generated with 

the U.S. average electricity mix and station-produced 

liquid hydrogen from NG, all fuel-cell fuels provide 

GHG emission reduction benefits (Figure 5). Not 

surprisingly, renewable ethanol, solar PV hydrogen, 

and electrolysis hydrogen from renewable electricity 

achieve the largest GHG emission benefits. 

FuelCell Fuel Production Pathways

GH2 & 

LH2

Central plant production from North American 

(NA) and Non-North American (NNA) NG

Central plant production from NNA FG

Refueling station production from NA and NNA 

NG

Refueling station production from NNA FG

Solar photovoltaic

Electrolysis of water with conventional 

electricity

Methanol Production from NA and NNA NG

Production from NNA FG

Gasoline Federal RFG

California RFG

Diesel Low-sulfur diesel

Ethanol

Production from corn

Production from woody biomass

Production from herbaceous biomass

CNG & 

LNG

Production from NA and NNA NG

Production from NNA FG

LPG Production from crude oil

Production from NG

Naphtha

Production from NA and NNA NG via the FT 

process

Production from NNA FG via the FT process

Production from crude oil

Table 1. Fuel-Cell Fuels and Production Pathways

Figure 2. WTW Total Energy Use Changes by FuelCell Vehicles (Relative to GVs)

Figure 3. WTW Fossil Energy Use Changes by FuelCell Vehicles (Relative to GVs)

Figure 4. WTW Petroleum Use Changes by Fuel-Cell 

Vehicles (Relative to GVs)

Figure 5. WTW Greenhouse Gas Emissions Changes 

by Fuel-Cell Vehicles (Relative to GVs)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

546

Notes for Table 1 and Figures 2-5:

WTW results depend heavily on the assumptions 

regarding fuel production efficiencies and fuel-cell 

vehicle fuel economy. The GREET model can 

readily test alternative assumptions and provide 

WTW energy and emission results.

Reference

1. Wang, M., 2001, Development and Use of 

GREET 1.6 Fuel-Cycle Model for 

Transportation Fuels and Vehicle Technologies,

ANL/ESD/TM-163, Center for Transportation 

Research, Argonne National Laboratory, 

Argonne, Ill., June.

Central GH2, NG gaseous hydrogen produced in centralized plants with NA NG

Central LH2, NG liquid hydrogen produced in centralized plants with NA NG

Station GH2, NG gaseous hydrogen produced in refueling stations with NA NG

Station LH2, NG liquid hydrogen produced in refueling stations with NA NG

Solar PV GH2 gaseous hydrogen produced in central locations from solar photovoltaic via electrolysis

Solar PV LH2 liquid hydrogen produced in central locations from solar photovoltaic via electrolysis

Electro GH2, U.S. Mix gaseous hydrogen produced in refueling stations via electrolysis with U.S. average 

electricity

Electro L.H2, U.S. Mix liquid hydrogen produced in refueling stations via electrolysis with U.S. average electricity

Electro GH2, Renew. gaseous hydrogen produced in refueling stations via electrolysis with renewable electricity

Electro L.H2, Renew. liquid hydrogen produced in refueling stations via electrolysis with renewable electricity

MeOH methanol produced from NA NG

NG naphtha naphtha produced from NNA NG via the FT process

Crude naphtha naphtha produced from crude oil in petroleum refineries

HC hydrocarbon

RFG reformulated gasoline

NA North American

NNA non-North American

FG flared gas

CNG compressed natural gas

LNG liquefied natural gas

LPG liquefied petroleum gas (propane)

EtOH ethanol
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

547

V.A.3 Hydrogen and Fuel Cell Vehicle Evaluation

Richard Parish (Primary Contact), Leslie Eudy, and Ken Proc

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401

(303) 275-4453, fax: (303) 275-4415, e-mail: richard_parish@nrel.gov

DOE Technology Development Manager: John Garbak

(202) 586-1723, fax: (202) 586-9811, e-mail: John.Garbak@ee.doe.gov

Objectives

• Gather performance information on hydrogen fuel cell vehicles to establish their operating 

characteristics and applicability to fleet service and the general transportation marketplace.

• Gather and evaluate information on establishing a hydrogen fueling and maintenance infrastructure.

Approach

• Continue working with SunLine Transit Agency and Alameda-Contra Costa Transit District (AC 

Transit) to define the hydrogen fuel cell bus evaluation process and required fueling infrastructure at 

the AC Transit site.

• Evaluate the performance and operational characteristics of a hydrogen fuel cell bus in revenue service 

at SunLine Transit Agency.

• Establish an effective relationship with the California Fuel Cell Partnership (CaFCP) and define the 

value added tasks that the National Renewable Energy Laboratory (NREL) can provide to their fuel 

cell vehicle testing and evaluation program.

Accomplishments

• Contract with AC Transit and ISE Research-Thunderbolt to provide fuel cell buses for AC Transit in 

Oakland, California was approved, with delivery of the first bus scheduled for June 2004.

• NREL, AC Transit, and University of California-Davis have completed a preliminary vehicle 

evaluation plan for the AC Transit fuel cell bus demonstration.

• Identified products that NREL could provide as a partner in the California Fuel Cell Partnership 

(CaFCP), e.g., status reports on partnership activities and fueling technologies, and a web-based 

“suggestion box”.

Future Directions

• Continue evaluation of ISE/UTC Fuel Cells fuel cell bus operation at SunLine Transit Agency.

• Define AC Transit hydrogen fueling infrastructure.

• Develop hydrogen reference guide documents: (1) Hydrogen Fuel Systems for Vehicles, and (2) 

Hydrogen Fueling Systems.

• In cooperation with CaFCP, characterize existing hydrogen fueling stations and define critical 

elements for designing and implementing new stations.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

548

Introduction

Government- and industry-sponsored research 

regarding hydrogen as a transportation fuel—

particularly in mobile fuel cells—is growing rapidly. 

One of the first fuel cell applications in the 

transportation arena will be powering transit buses. 

This is due to their capacity for handling the extra 

volume currently required for the fuel cell and the 

associated hydrogen fuel storage tanks. The NREL 

Fleet Test & Evaluation (FT&E) team in Golden, 

Colorado, is dedicated to evaluating and 

documenting the performance and operational 

characteristics of advanced vehicle technologies that 

use alternative fuels or other concepts that reduce 

dependency on conventional petroleum fuels. The 

NREL FT&E team is investigating the status of fuel 

cell technology and hydrogen as key elements in a 

future transportation scenario. Specifically, FT&E is 

developing plans for evaluating prototype fuel cell 

buses; near-production light-, medium-, and heavyduty fuel cell vehicles; and the hydrogen fueling and 

maintenance infrastructure required to make the 

vehicles fully operational.

Approach

The California Fuel Cell Partnership (CaFCP) is 

a focal point for fuel cell development and 

demonstration activity, and one of its tasks will be to 

evaluate fuel cells used in transit bus applications. 

The CaFCP is also evaluating fuel cells in light-duty 

vehicles and looking at a variety of feedstock fuels 

for the hydrogen required for the fuel cells. Based on 

past experience of developing and evaluating 

alternative fuel and hybrid electric vehicles, NREL 

has taken the initiative to establish a relationship with 

the CaFCP to determine how it could assist the 

partnership with its fuel cell vehicle and hydrogen 

infrastructure development and evaluation. To gain 

experience and knowledge with fuel cell 

performance and operation characteristics, SunLine 

Transit Agency and the Alameda-Contra Costa 

Transit District (AC Transit), both associate 

members of the CaFCP, will acquire fuel cell buses 

for evaluation in normal operation. NREL will assist 

these agencies in acquiring data to evaluate the bus 

performance and prepare the transit agency for its 

fully commercial fuel cell buses. The XCELLSIS 

fuel cell bus shown in Figure 1 was demonstrated at 

SunLine Transit Agency in 2001.

Results

In April 2002, AC Transit announced the 

purchase of four fuel cell buses using compressed 

hydrogen. The 40-foot buses will be built on a Van 

Hool (from Belgium) bus platform in a hybrid 

electric configuration using fuel cells from UTC Fuel 

Cells, and will be integrated by ISE Research. The 

buses will not be delivered until mid-2004. In the 

interim, a prototype fuel cell bus from ISE Research 

will be operated by SunLine to evaluate the bus 

performance and prepare the transit agency for its 

fully commercial fuel cell buses. Evaluation of the 

ISE prototype fuel cell bus performance is expected 

to occur during FY 2003. The design and 

construction of a hydrogen fueling station and 

necessary maintenance facility modifications is on 

hold until a contract can be placed. The FT&E team 

produced a preliminary vehicle evaluation plan. 

NREL will conduct the evaluation with AC Transit 

and University of California, Davis (UC Davis). 

Finalization of the evaluation plan will occur as the 

delivery date of the fuel cell buses approaches. 

NREL met with the CaFCP Light-Duty Vehicle 

(Vehicle Operation or VeOps) and Fuels Teams to 

define activities in which NREL/DOE could become 

involved to increase the amount of information 

available. NREL has developed a web-based 

“suggestion box” for the VeOps Team to identify 

problems, issues, and development needs they might 

be reluctant to identify in a meeting with other 

manufacturers or fuel providers. NREL is also 

developing a web-based fleet information database to 

gather information on California fleets to identify 

Figure 1. The XCELLSIS Bus being Fueled at SunLine 

Transit Agency in 2001
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

549

good candidates for evaluation and testing of lightduty fuel cell vehicles. For the Fuels Team, NREL 

will develop fact sheets on existing hydrogen fueling 

stations that could be used by partnership auto 

manufacturers, and on the process of hydrogen 

fueling station siting and implementation. The 

existing hydrogen fueling station at the California 

Fuel Cell Partnership’s facility in Sacramento, 

California is shown in Figure 2. 

Conclusions

• NREL’s FT&E Team is working to develop 

a strong role in the CaFCP, providing 

creative options for gathering and 

disseminating information about hydrogen 

fuel cell vehicles and associated hydrogen 

infrastructure, without revealing prototypic 

and proprietary information about the 

vehicle technology. 

• In collaboration with the CaFCP, once the 

fuel cell buses are delivered and the 

hydrogen fueling and vehicle maintenance 

facilities are completed, NREL will begin 

collecting and evaluating data that will help 

to demonstrate that fuel cell buses can be 

fueled and maintained efficiently and 

perform consistently.

FY 2002 Publications/Presentations

1. Levin, J., Miller, M., and Eudy, L. “Fuel Cells for 

the Transportation Industry: Developing a 

Credible Demonstration Program on the Path to 

Commercialization,” Presented to the 14th World 

Hydrogen Energy Conference held June 9-13, 

2002 in Montreal, Quebec, Canada.

Figure 2. A Fueling Demonstration of the Nissan Xterra 

Fuel Cell Vehicle at the California Fuel Cell 

Partnership’s Hydrogen Fueling Station
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

550

V.A.4 Power Parks System Simulation

Andrew Lutz (Primary Contact)

Sandia National Laboratories

MS 9053

Livermore, CA 94551-0969

(925) 294-2761, fax: (925) 294-1004, e-mail: aelutz@sandia.gov

DOE Technology Development Manager: Sigmund Gronich

(202) 586-1623, fax: (202) 586-5860, e-mail: Sigmund.Gronich@ee.doe.gov

Objectives 

• Develop a system model to simulate distributed power generation in power parks.

• Demonstrate the potential of hydrogen technologies for power generation. 

• Analyze the dynamic performance of the system to examine the thermal efficiency, power availability, 

and cost.

Approach

• Develop a library of Simulink modules for the various components being proposed for power parks. 

• Assemble the components into a sample power park to demonstrate the model’s ability to analyze 

thermal efficiency and supply an electric load.

Accomplishments 

• The library of components includes a fuel cell stack, a steam-methane reformer, a multi-stage 

compressor, and hydrogen storage in a high-pressure vessel.

• In the initial power park, a reformer operates at a steady rate to produce hydrogen, which feeds a fuel 

cell to provide an electric load. When excess hydrogen is available, it is compressed and stored.

• The model evaluates the combined efficiency of the power system.

Future Directions 

• Continue to develop additional modules in the Simulink library, including a photovoltaic array, an 

electrolyzer, a battery, a wind turbine, and an autothermal reformer.

• Implement a control strategy to direct the power within the park to meet the internal load while 

optimizing the energy efficiency and cost.

• Develop a layer of analysis to compute the cost of the power and hydrogen generated, including the 

initial capital costs of the components and the continuous operation costs during the life of the 

simulation. 

• Compare the simulations of dynamic performance with data collected from demonstration sites.

Introduction

Power parks are distributed energy sites where 

power generation is co-located with businesses or 

industrial energy consumers. Proposed power parks 

use combinations of technologies. A local power 

source is often combined with a storage technology 

to adapt the dynamic nature of the source to the load. 

In some cases, the system operates completely 

separate from the utility grid. Alternatively, the 

power park may use the utility grid as a storage 

device, selling power to the utility when there is 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

551

excess and drawing power when the local source 

cannot meet the load. 

Often, power parks are sited in order to take 

advantage of a renewable energy source. Generation 

by photovoltaic collectors or wind turbines can be 

combined with energy storage technologies. Power 

parks provide an excellent opportunity for using 

hydrogen technologies. Electricity from the 

renewable source can be used to generate hydrogen 

by electrolysis, which is stored for use in fuel cells or 

to refuel vehicles. Similarly, heat from a renewable 

source can be used to reform hydrocarbon fuels into 

hydrogen. 

The variety of technologies and their 

combinations that are being proposed for power 

parks suggests that each system will be novel, at least 

in some aspect of its design. Consequently, a 

simulation tool will be very useful in evaluating the 

various systems and optimizing their performance 

with respect to efficiency and cost. 

Approach 

The deliverable of this project will be a tool for 

simulation of the local power generation system, 

constructed in the language of the Simulink software 

[1]. Simulink provides a graphical workspace for 

block diagram construction. The workspace 

provides the flexibility to quickly assemble 

components into a system. Simulink performs 

dynamic simulation by integrating the system in time 

using a collection of ordinary differential equation 

solvers. After the simulation is completed, the 

solution can be examined by plotting variables at 

various states in the system. Simulink also contains 

modules for dynamic control and solution of iterative 

loops within the system. 

The system design begins with development of a 

library of Simulink modules that represent 

components in the power system. The component 

models are based on fundamental physics to the 

extent practical. These models are generic in that 

they are not customized to represent a specific brand 

or manufacturer’s features for the component. 

However, the generic components from the library 

can be tied to a specific unit by relying on 

performance data. The library components can be 

quickly modified to represent new or specialized 

components, thereby expanding the library’s 

collection.

Many of the basic modules that represent 

hydrogen and other gas mixtures use the Chemkin [2] 

software package to provide thermodynamic 

properties of the species and mixtures. For example, 

the mixer component accepts two gas streams and 

adiabatically mixes them to yield an output stream. 

The temperature of the new stream depends on the 

temperatures, compositions, and relative flow rates 

of the two inlet streams. Solution for the outlet 

temperature uses Newton iteration over Chemkin 

calls, which returns the updated enthalpy of the 

mixture. Another example is the Equil module, 

which computes the equilibrium composition at a 

given temperature and pressure. This module is 

coupled to a Chemkin-implementation of the Stanjan 

[3] equilibrium solver. The Equil module is used to 

represent chemical reactions in either a reformer or a 

combustor component. These modules are combined 

in a sub-system to form a module for the steammethane reformer.

Results 

We have developed a library of Simulink 

modules for some of the various components being 

proposed for power parks. Existing components 

include a fuel cell stack, a steam-methane reformer, a 

multi-stage compressor, a high-pressure storage 

vessel, and an internal electric load. The load versus 

time is read from a file, so it can be changed quickly.

The reformer takes an input flow rate of methane 

and computes the hydrogen output. The reformer 

module balances energy by combusting the reformate 

stream with air and exchanging the heat released to 

the catalyst reactor. Parameters on the reformer are 

the steam-to-carbon ratio and the outlet temperature 

of the exhaust products from the internal burner. The 

temperature at which the equilibrium reforming 

occurs depends on these parameters. Figure 1 shows 

the variation in thermal efficiency of the reformer 

with temperature and steam-to-carbon ratio. The 

minimum steam-to-carbon ratio is 2; however, 

reformers are often operated with excess steam to 

improve the efficiency and prevent coking problems. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

552

More detailed analysis of the reformer sub-system is 

presented in reference [4].

The fuel cell module takes a hydrogen inlet flow 

rate and a requested power, then determines if 

sufficient power can be supplied. The stack model 

uses a simple map of efficiency versus power. This 

data is read from an input file to allow the fuel cell to 

be calibrated to real performance data. If sufficient 

power can be provided, the excess hydrogen flow is 

returned for compression and storage. A compressor 

module represents an ideal two-stage compressor that 

assumes isentropic compression in each stage. The 

power required by the compressor is included in the 

analysis of the overall thermal efficiency of the 

system. 

The simulation in this example runs over a daily 

load cycle. The power output by the fuel cell, which 

in this case matches the demand, is shown by the 

solid line in Figure 2. The power consumed by the 

hydrogen compressor is shown by the dotted line in 

Figure 2. During the night, when the load is low, the 

compressor load is large because most of the 

hydrogen produced by the reformer is being 

compressed for storage. During the peak daytime 

loads, the compressor is not operating because there 

is no excess hydrogen.

The model evaluates the overall thermal 

efficiency of the power system, as shown in Figure 3. 

The system efficiency is the hydrogen stored and 

electric power supplied to the load, divided by the 

methane input to the reformer and the power 

consumed by the compressor. The system efficiency 

is highest when the reformer is producing hydrogen 

to be stored during the low-load periods. In contrast, 

the system efficiency drops when the combined 

reformer and fuel cell are working at capacity to 

supply the peak load. 

Figure 1. Thermal Efficiency of the Steam-Methane 

Reformer Module Versus the Temperature 

and Steam-to-Carbon Ratio, Computed at 

Chemical Equilibrium

Figure 2. Power Output of the Fuel Cell (solid line) and 

Power Consumed by the Compressor (dashed 

line) for a Sample Simulation over a Daily 

Cycle

Figure 3. Thermal Efficiency of the Power System for 

a Sample Simulation over a Daily Cycle
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

553

Conclusions and Future Directions

The demonstration of the sample power park 

shows the usefulness of system simulations in 

evaluating the overall performance. The flexibility 

provided by the block diagram structure will allow 

for rapid construction of various system 

configurations.

Future efforts will continue to develop modules 

for the Simulink library, adding modules for 

electricity generation by a photovoltaic array, 

temporary electricity storage in batteries, and 

hydrogen generation by an electrolyzer and an 

autothermal reformer. The final stages of the work 

will implement a control strategy to direct the power 

within the park to balance meeting internal load with 

supplying external power to the grid. We will also 

include a layer of analysis to compute the cost of the 

power and hydrogen generated. The cost analysis 

will accept input of the initial capital costs of the 

components, as well as the continuous operation 

costs during the life of the simulation, and add the 

costs using time-value adjustments. We expect the 

simulation tool will provide valuable assistance in 

the planning and design of hydrogen technologies in 

distributed power systems. In addition, the 

simulations of dynamic performance can be 

compared with data collected from demonstration 

sites.

References 

1. Simulink. The MathWorks, Inc, MA 

(www.mathworks.com) 2002.

2. The CHEMKIN program and subroutine library 

are part of the Chemkin Collection. R. J. Kee, F. 

M. Rupley, J. A. Miller, M. E. Coltrin, J. F. Grcar, 

E Meeks, H. K. Moffat, A. E. Lutz, G. DixonLewis, M. D. Smooke, J. Warnatz, G. H. Evans, 

R. S. Larson, R. E. Mitchell, L. R. Petzold, W. C. 

Reynolds, Caracotsios, M., Stewart, W. E. and 

Glarborg, P., Chemkin Collection, Release 3.5, 

Reaction Design, Inc., San Diego, CA (1999). 

3. “Stanjan: Interactive Computer Programs for 

Chemkin Equilibrium Analysis", W C Reynolds, 

Stanford University report, January (1981). 

4. Lutz, A. E., Bradshaw, R. W., Keller, J. O., and 

Witmer, D. E., “Thermodynamic Analysis of 

Hydrogen Production by Steam Reforming,” 

accepted for publication in the International 

Journal of Hydrogen Energy, 2002.

FY 2002 Publications/Presentations 

1. Lutz, A. E., Bradshaw, R. W., Keller, J. O., and 

Witmer, D. E., “Thermodynamic Analysis of 

Hydrogen Production by Steam Reforming,” Int. 

J. of Hydrogen Engy, accepted for publication, 

2002.

2. Lutz, A. E., Larson, R. S., and Keller, J. O., 

“Thermodynamic Comparison of Fuel Cells to the 

Carnot Cycle,” Int. J. of Hydrogen Engy, 27 (10), 

(2002) pp. 1103-1111.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

554

V.A.5 Process Analysis Work for the DOE Hydrogen Program - 2001

Pamela L. Spath, Wade A. Amos, and Margaret K. Mann (Primary Contact)

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401

(303) 275-2921, fax: (303) 275-2905, e-mail: margaret_mann@nrel.gov

DOE Technology Development Manager: Matthew Kauffman

(202) 586-5824, fax: (202) 586-5860, e-mail: Matthew.Kauffman@ee.doe.gov

Objectives

• Add to the suite of technoeconomic analyses (TEAs) performed on hydrogen research projects.

• Update previous analyses using recent experimental results.

• Determine delivered hydrogen costs by incorporating storage and transportation costs into previous 

analyses.

• Provide information to DOE and task researchers, to guide ongoing and proposed research projects.

Approach

• Identify the hydrogen production, storage, and utilization projects and processes to be analyzed.

• Using available data (technical literature, laboratory data, pilot-scale data, etc.), generate process flow 

sheets, material and energy balances, and equipment capital costs using ASPEN Plus process 

simulation computer software.

• Determine hydrogen selling price and conduct sensitivity analyses to determine the largest cost drivers 

and areas for continued cost reduction.

• Use the results of these analyses to guide ongoing and proposed research projects.

Accomplishments

• Completed analyses and produced reports in the following areas:

- Technoeconomic Analysis of the Thermocatalytic Decomposition of Natural Gas, May 2001.

- Assessment of the Mass Production of Nanotubes, August 2001.

- Economic Analysis of the Biological Water Gas Shift Process for the Production of Hydrogen from 

Synthesis Gas, October 2001.

- Assessment of Hydrogen from Small-Scale Reformers-Available Technologies and Costs, October 

2001. 

- Assessment of Natural Gas Splitting with a Concentrating Solar Reactor for Hydrogen Production, 

April 2002.

• Drafted analysis plan at DOE workshop held in March 2002.

Future Directions

• Evaluate water requirements for large-scale hydrogen use.

• Complete a Monte Carlo sensitivity analysis of hydrogen storage and transportation costs.

• Evaluate the market potential of coproducts from biomass pyrolysis oil reforming.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

555

• Integrate various renewable forms of hydrogen production to supply future transportation needs into 

TEA models.

• Continue to coordinate analysis work for the DOE Hydrogen, Fuel Cells, and Infrastructure 

Technologies Program.

Introduction

The goal of the process analysis work conducted 

at the National Renewable Energy Laboratory 

(NREL) for the DOE's Hydrogen, Fuel Cells, and 

Infrastructure Technologies Program is to provide 

direction, focus, and support to the development of 

renewable hydrogen through evaluation of technical, 

economic, and environmental aspects of hydrogen 

production and storage technologies. The primary 

purpose of this work is to identify those areas of 

research in which improvements will result in the 

largest reductions in system costs. This helps to 

define research goals and moves novel technologies 

more quickly to commercialization. Additionally, 

this project provides information to DOE on the 

long-term technical and economic feasibility of 

ongoing and proposed research projects. 

This year, areas of analysis included (1) 

hydrogen production via natural gas splitting with a 

solar reactor, (2) biological water gas shift for 

hydrogen production from synthesis gas, and (3) 

assessment of the mass production of carbon 

nanotubes for hydrogen storage. 

Approach

Technoeconomic analyses are performed to 

determine the potential economic viability of a 

research process. The selection of projects to be 

analyzed is made in conjuction with DOE program 

management. Detailed TEAs begin with discussions 

between researchers and analysts, to obtain 

experimental data and a common understanding of 

project goals. Experimental results are used to 

develop material and energy balances in ASPEN 

Plus, a chemical engineering process simulator that 

contains extensive thermodynamic data. The material 

and energy balance results are used to determine the 

size, and subsequently, the capital cost, of major 

pieces of process equipment. Along with operating 

costs, these are used in a cash flow spreadsheet to 

determine the necessary hydrogen selling price to 

obtain a 15% after-tax internal rate of return. Storage 

and transportation costs are integrated with process 

costs to obtain a delivered hydrogen selling price. 

Monte Carlo sensitivity analyses are used to 

determine the largest cost drivers and areas for 

continued cost reduction. These results are used to 

make focused recommendations to the researchers 

and to DOE.

Results

Hydrogen Production via Natural Gas Splitting with 

a Solar Reactor

This study analyzed hydrogen production via 

thermal decomposition of methane using a solar 

reactor for two different applications: (1) a fueling 

station and (2) power production. The analysis 

shows that for either application, the production of 

carbon black plays a key role in the economics of the 

process. In addition, the net greenhouse gas 

emissions and overall fossil energy consumption are 

lower for the solar processes than for the 

conventional fossil system.

In the stand-alone fueling station application, 

there are many times when the storage capacity is 

reached and the hydrogen production system must be 

shut down. For this reason, only 54%-66% of the 

total possible hydrogen production can actually be 

realized. Increasing the size of the hydrogen storage 

results in a small increase in useable hydrogen, 

which does not outweigh the large cost associated 

with storing the hydrogen. Supplying hydrogen 

directly to a pipeline network was examined as one 

option to overcome these physical and economic 

limitations. The reduction in the hydrogen selling 

price is 68% from the stand-alone base case ($18/

giga-Joule [GJ] compared to $57/GJ). Another 

option that was examined to improve the productivity 

of the solar process was adding a small electric heater 

that can be turned on when the hydrogen supply gets 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

556

low to provide heat to the solar reactor. The hydrogen 

selling price with the supplemental heater is 

considerably less than the stand-alone base case at 

$42-$46/GJ, compared to $57/GJ.

For the power production scenario, the hydrogen 

is co-fired in a turbine at a natural gas combinedcycle (NGCC) plant. Two options were examined: 

(1) selling the carbon black and (2) burning the 

carbon to produce more power. Because of its value, 

it is more profitable to sell the carbon instead of 

burning it. In order for the electricity produced from 

the hydrogen to be less than the base electricity 

production cost of the NGCC plant, the price of the 

carbon must be greater than $0.80/kilogram (kg). 

However, even if the power produced from hydrogen 

is more that the base power production price, overall 

it would not significantly increase the price of power 

from the NGCC power plant. This is because the 

fraction of electricity generated from the solar 

process is small compared to the total (0.2%-1.1% of 

the total output of a 500-MW NGCC plant).

Biological Water-Gas Shift for Hydrogen Production

The biological water-gas shift (WGS) reaction 

uses photosynthetic bacteria to convert CO into CO2

and H2. After successful proof-of-concept tests 

showed that high CO to H2 rates were possible, 

researchers focused on collecting reliable kinetic data 

for the biological WGS process. Based on this 

laboratory kinetic data, a preliminary process design 

was proposed for shifting the CO from a biomass 

gasification process into hydrogen. The capital and 

operating costs were estimated for such a system and 

showed that the WGS reactor was a significant cost, 

nearly $3 million for a small facility (2.5 million 

standard cubic feet per day [scf/d]) and over $10 

million for a larger facility (10.0 million scf/d). The 

projected costs were cut nearly in half by redesigning 

the system. Two important conclusions came out of 

the economic analysis:

• Pressurizing the system reduces the size of 

the WGS reactor, thereby reducing the 

capital cost of the system.

• An increase in shift rate by a factor of 2 

decreases the reactor size enough that the 

reactor then becomes a relatively small cost 

compared to the balance of plant costs. 

Increasing the shift rate beyond this point has 

diminishing returns.

These two results have shifted the course of the 

laboratory research. Rather than concentrating on 

getting large improvements in the shift rate, the 

researchers have designed a high-pressure reactor for 

testing the biological WGS reaction at pressures up 

to 400 pounds per square inch gauge (2,900 

kilopascal). 

Assessment of the Mass Production of Carbon 

Nanotubes

Neoterics International was contracted by NREL 

to assess the mass production of carbon nanotubes 

for hydrogen storage applications. The technology 

base for this analysis is the single-wall nanotubes 

extrusion concept being developed at NREL, in 

which carbon nanotubes are produced using methane 

decomposition chemistry. The design basis is a 

grassroots facility producing 75,000 metric tons per 

year of active material. Hydrogen is also produced 

as a coproduct from this manufacturing facility.

Four scenarios were evaluated. The high and low 

conversion cases assumed a per-pass conversion of 

44.48% (corresponds to thermodynamic equilibrium 

at the reactor outlet) and 30% (accounts for the 

possibility that mass transfer or other mechanisms 

could limit the reaction), respectively. Lab 

experiments to date have only been able to 

demonstrate 7% per pass conversion, but these 

experiments were designed to demonstrate catalyst 

activity rather than high per pass conversion. The 

high and low levels assumed for selectivity were 

100% and 80%, respectively, reflecting the fact that 

very high selectivity has already been demonstrated 

in the lab.

Fixed capital ranged from $164.1 million to 

$208.2 million for the four cases considered. This 

translates into $2.2 to $2.8 per annual kg of capacity. 

Natural gas is the dominant component of the cash 

operating costs. The hydrogen coproduct is a 

significant source of revenue, contributing 

approximately one-third of the revenue for all cases 

considered. The selling price for the carbon 

nanotubes varied from $0.8 to $1.1 per kg. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

557

Conclusions

Hydrogen Production via Natural Gas Splitting with 

a Solar Reactor

• Hydrogen storage is costly. If the hydrogen 

can be consumed directly or used in another 

application where storage is eliminated and 

compression is moderate, then the hydrogen 

selling price decreases significantly. 

• The price of carbon black has the greatest 

effect on the economics of hydrogen 

production from a solar reactor, regardless of 

application. Thus, higher value carbon 

markets should be pursued as a way to 

improve the process economics.

• There is a significant environmental benefit 

from carbon black production via the solar 

route compared to the conventional route. 

Biological Water-Gas Shift for Hydrogen Production

• The WGS system must be operated under 

pressure to be economical. If the process 

cannot be operated at high pressures, an 

incremental improvement in shift rate alone 

will not significantly reduce hydrogen 

production costs.

Assessment of the Mass Production of Carbon 

Nanotubes

• The concept of using carbon nanotubes for 

hydrogen storage is still at relatively early 

stage of development. Further fundamental 

studies on the mechanism of hydrogen 

adsorption are needed to assess whether 

carbon nanotubes are capable of meeting 

DOE's technical storage goals (greater than 

5.5 weight % and 50 kg/m3).

• The current analysis shows that the hydrogen 

coproduct is a significant source of revenue 

in the large-scale nanotube production 

process. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

558

V.B Integrated Hydrogen and Fuel Cell Demonstration

V.B.1 Real-World Demonstration of Fuel Cell Vehicles and Refueling 

Technology

Joseph J. Irvin

California Fuel Cell Partnership

3300 Industrial Boulevard, Suite 1000

West Sacramento, CA 95691

(916) 371-2870, fax: (916) 375-2008, e-mail: jirvin@cafcp.org

DOE Technology Development Manager: Christopher Bordeaux

(202) 586-3070, fax: (202) 586-5860, e-mail: Christopher.Bordeaux@ee.doe.gov

Objectives

• Demonstrate fuel cell technology by operating and testing vehicles on California’s roads.

• Demonstrate alternative fuel infrastructure technology.

• Explore the path to commercialization for fuel cell-powered vehicles.

• Increase public awareness through a coordinated outreach plan.

Approach

• Adopt a California Fuel Cell Partnership (CaFCP) organizational structure consisting of an Executive 

Committee, Working Group and Communications Team to provide and implement a decision-making 

structure for developing a workplan, budget, headquarters facility, and outreach strategy under the 

following timetable:

- Phase I — through 1999, project development and planning, adding new partners, and preparing 

vehicle and refueling facilities;

- Phase II — 2000-2001, demonstrate cars and buses using hydrogen fuel;

- Phase III — 2002-2003, demonstrate more cars and buses using hydrogen, methanol, gasoline or 

other fuels as determined by the Partnership.

Accomplishments

• Established and opened the West Sacramento headquarters facility as an operations base for on-road 

vehicle usage and fueling.

• Established a “safety first” policy and culture at the facility.

• Dedicated 16 vehicles to the project by the end of the year – together these vehicles accumulated over 

34,000 miles, conducted 754 refueling events, and totaled 1,880 persons who rode or drove in the 

vehicles.

• Conducted 25 public outreach events to increase awareness among media, stakeholder groups, 

educators, and the general public – together, these events directly reached more than 176,000 people.

• Accommodated more than 80 headquarters tours, tallying more than 1,500 headquarters visitors.

• Staged a Technology Forum at the headquarters facility, bringing fuel cell industry suppliers and 

consultants together with CaFCP members for business-to-business discussions – the 2001 event 

featured more than 30 exhibitors and 300 attendees.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

559

• Released a “Fuel Scenarios Study” examining four potential fuel sources for fuel cells and the 

challenges to their commercialization.

• Established strong ties with the environmental and legislative communities through the Environmental 

Team and stakeholder outreach activities. 

• Tested one fuel cell bus, the Ballard/XCELLSiS ZEbus, in the Palm Springs area.

• Participated as a team entry in the third annual Michelin Bibendum Challenge, and drove from Los 

Angeles to Las Vegas in relay fashion.

• Hosted the Electric Vehicle Association of the Americas’ “Electric Transportation Industry 

Conference” for a daylong tour and Ride ‘n’ Drive event at CaFCP’s demonstration center.

Future Directions

• Operate twenty (20) CaFCP vehicles, together accumulating 60,000 miles in calendar year 2002.

• Install a methanol fueling station at the West Sacramento headquarters.

• Install a satellite hydrogen fuel station in Richmond, California, as well as two additional hydrogen 

stations at appropriate locations.

• Commence a second joint study that examines hydrogen vehicle facility construction and use issues.

• Educate two regional emergency response agencies about how to address potential health and safety 

issues in the event of vehicle/fuel station accidents.

• Determine and announce the membership’s plans for beyond 2003 [current CaFCP plans have been 

announced through 2003].

• Through multiple public outreach events, familiarize 250,000 people with fuel cell technology.

• Distribute 1,000 Teacher Learning Kits to middle and high school science teachers. 

Introduction

California is the home to the California Fuel Cell 

Partnership (CaFCP), a unique collaboration between 

auto manufacturers, energy companies, fuel cell 

technology companies, and government agencies. 

This partnership is advancing a new vehicle 

technology that could move the world toward 

practical and affordable environmental solutions. For 

the first time ever, automobile companies and fuel 

suppliers have joined together to demonstrate fuel 

cell vehicles under real day-to-day driving 

conditions. 

The California Fuel Cell Partnership expects to 

place up to 60 fuel cell passenger cars and fuel cell 

buses on the road by 2003. In addition to testing the 

fuel cell vehicles, the partnership is examining fuel 

infrastructure issues and beginning to prepare the 

California market for this new technology.

The members include companies and 

organizations from around the world: 

DaimlerChrysler, Ford, General Motors, Honda, 

Hyundai, Nissan, Toyota, and Volkswagen; Ballard 

Power Systems, UTC Fuel Cells; BP, ExxonMobil, 

Shell Hydrogen, and ChevronTexaco; and the 

California Air Resources Board, the California 

Energy Commission, the United States Department 

of Energy, the United States Department of 

Transportation and the South Coast Air Quality 

Management District. 

Additionally, there are nine Associate Partners 

who assist with specific areas of expertise to help 

meet the CaFCP’s goals: hydrogen gas suppliers (Air 

Products and Chemicals, Inc. and Praxair); hydrogen 

fueling stations (Pacific Gas & Electric, Proton 

Energy Systems, Inc., and Stuart Energy Systems); a 

methanol fuel supplier (Methanex); and bus transit 

agencies (AC Transit and Santa Clara Valley 

Transportation Authority which operate in the 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

560

Greater San Francisco Bay area, and SunLine Transit 

Agency in the Palm Springs area).

Approach

The CaFCP is testing and demonstrating fuel cell 

electric vehicles in California through 2003 under 

day-to-day driving conditions; demonstrating 

alternative fuel infrastructure technology; exploring 

the path to commercializing fuel cell electric vehicles 

by examining such issues as fuel infrastructure 

requirements, vehicle and fuel safety, market 

incentives, and consumer acceptance; and working to 

increase public awareness of fuel cell vehicle 

technology and the benefits it can offer.

Results

For the California Fuel Cell Partnership, the past 

year could be summarized as a year of “taking it to 

the streets” -- that is, driving fuel cell-powered 

electric vehicles on California’s roadways in realworld conditions. Together, members worked hard in 

many ways to raise public awareness; gain 

experience with fuel cell technology, vehicles and 

fuels; and evaluate the commercialization of fuel cell 

vehicle technology for the 21st Century. 

A functional headquarters facility in West 

Sacramento, California serves as an operations base 

for demonstrating and housing vehicles and their fuel 

supplies. Automotive partners are test-driving full 

scale fuel cell-powered vehicles on California 

roadways in real-world conditions -- in traffic, up 

and down hills, and in wide-ranging weather 

conditions. A few years ago, there wasn’t a single 

running fuel cell vehicle on the road; today, there are 

eighteen operating in the Partnership.

Energy providers are working through the 

challenges of developing fuel infrastructure for fuel 

cell vehicles. They are providing the fuel needed for 

the partnership’s demonstration program. During this 

early stage, all of the vehicles have been powered by 

hydrogen stored and dispensed onsite at the facility. 

CaFCP will also test liquid fuels rich in hydrogen – 

methanol and a cleaner form of gasoline – in order to 

learn more and determine what will best serve a 

successful commercial launch. (A methanol fueling 

station was installed in April 2002.)

Fuel cell makers have achieved remarkable 

success developing smaller, better and more 

powerful fuel cell systems. Their progress has 

stimulated an entirely new fuel cell supply industry – 

and prompted the Partnership’s formation of a 

Technology Forum to provide an opportunity for 

non-member companies to meet the partners in a 

business-to-business environment. 

Because success will require the active 

cooperation and assistance of the public sector, 

CaFCP’s state and federal government partners are 

helping to build awareness and support among key 

stakeholders and the public, as well as identify 

Photo 1. FCVs and Staff Next to the Hydrogen Fueling 

Station at the CaFCP Headquarters Facility in 

West Sacramento, California

Photo 2. The Methanol Fueling Station – West 

Sacramento, California
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

561

possible roles for government participation in the 

promotion of fuel cell technology. 

One of the remaining challenges to 

commercialization is fuel choice. On one hand, fuel 

cells are ideal because they can be operated on a 

number of fuels; on the other, there are serious 

factors to be considered with each fuel – 

infrastructure cost, environmental tradeoffs, 

technological readiness, and, perhaps most 

importantly, consumer comfort and acceptance. 

To help address these issues, the CaFCP 

commissioned a consultant-prepared study to 

examine how to bring fuel cell vehicles to actual 

showrooms as quickly as possible, taking into 

account the challenges and potential solutions in 

using several fuel options, including hydrogen, 

methanol, gasoline, and ethanol. The “Fuel 

Scenarios Study” can be found on the partnership’s 

website at 

http://fuelcellpartnership.org/event_roundtable.html.

The members have also formalized safety 

standards for headquarters vehicle and fueling 

operations, including the safe management of 

thousands of visitors. 

Photo 3. CaFCP Participated in the Michelin 

Bibendum Challenge

Photo 4. CaFCP Takes Vehicles and Displays into 

Local Communities to Increase Awareness

Photo 5. A Hands-on Fueling Demonstration Exhibit 

Was Created to Familiarize People with 

Hydrogen Fueling and Fuel Choice Issues
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

562

Dozens of public outreach events featuring 

vehicle, fuel, and fuel cell displays were conducted to 

increase awareness. Highlights included participation 

in the Michelin Bibendum Challenge by six of the 

CaFCP’s automotive companies and the Ballard 

ZEbus. This alternative fuel vehicle event included a 

road rally drive from Los Angeles to Las Vegas. The 

Partnership also developed a unique, portable exhibit 

that simulates refueling with hydrogen and presents 

fuel choice issues in DVD format.

The ZEbus was the first Partnership fuel cellpowered bus to be demonstrated in real-world 

conditions. The successful year-long test was 

conducted through the work of SunLine Transit 

Agency, located in the Palm Springs area. 

Conclusion

The third year of the project featured new, 

measurable achievements in vehicle and fuel 

demonstrations. The construction of a headquarters 

facility has boosted the effort to provide hands-on, 

visible evidence of the fuel cell in operation – a 

necessary step on the road to commercialization.

CaFCP members continue to gain real-world 

experience driving vehicle miles, refueling with 

hydrogen and now methanol, and participating in 

public outreach events. There is a very unique 

strength within the California Fuel Cell Partnership, 

as members work cooperatively and competitively at 

the same time in a stimulating environment, 

exchanging experiences, learning from each other 

and exploring the pathways to commercialization.

The world is watching what happens with fuel 

cell transportation technology in the Sacramento 

area. The work of the California Fuel Cell 

Partnership has the potential to bring about 

revolutionary change to transportation systems 

worldwide – change that is beneficial for the 

environment, for the economy, and for future 

generations. 

FY 2002 Publications/Presentations

1. Bringing Fuel Cell Vehicles to Market: 

Scenarios and Challenges with Fuel Alternatives 

(Oct. 2001)

2. EVS-18: Driving for the Future: An Update on 

the California Fuel Cell Partnership Experience
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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V.B.2 Filling Up With Hydrogen 2000

Matthew Fairlie (Primary Contact), Paul Scott, Alex Lambert

Stuart Energy USA

7949 Woodley Ave.

Van Nuys, CA 91406

(818) 375-5052, fax: (818) 780-0515, e-mail: mfairlie@stuartenergy.com

DOE Technology Development Manager: Sigmund Gronich 

(202) 586-1623, fax: (202) 586-5860, e-mail: Sigmond.Gronich@ee.doe.gov

Objectives 

• Design and build fuel appliances based on new low-cost electrolyser technology.

• Demonstrate hydrogen vehicle re-fueling using fuel appliance systems.

• Obtain ‘third party operating experience feedback’ in refueling applications. 

• Establish precedents for development of codes and standards.

• Determine cost effectiveness of fuel supply pathway. 

Approach

• Conduct prototype development project involving building eight different appliances; each appliance 

project has five phases:

- Design 

- Build

- Test 

- Customer Evaluation

- Tear-down and post mortem 

Accomplishments 

• Seven fleet fuel appliance prototypes have been constructed, featuring different technical advances. 

Three units have been placed in the field at the following sites: SunLine Transit, Powertech, and 

Southwest Research Institute; two units are built and being tested prior to delivery to the Fuel Cell 

Propulsion Institute and Alemeda County Transit; one additional unit is in testing un-deployed at this 

time. In addition, two smaller fueling systems called personal fuel appliances were built under this 

project, one of which is under evaluation with Ford Motor Company, supporting their fuel cell car 

program.

Future Directions 

• Complete prototype deployment. P4-1B unit will be moved from Southwest Research Institute, where 

it is supplying fuel to a hydrogen motor generator set (joint development with Ford Power Products), 

to Wind Site at South Coast Air Quality District. 

• Analyze performance of systems in the field; determine operating and manufacturing costs. 

• Commercialize systems within market potential; establish market and product support systems. 

• Project scheduled to be complete by March 31, 2003. Report results and recommend improvements for 

next cycle of fuel appliance development. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

564

Introduction

“Filling Up with Hydrogen 2000” is a 

prototyping development project intended to validate 

the Stuart Fuel Appliance Model for hydrogen 

vehicle fuel supply infrastructure. Stuart fuel 

appliances are on-site electrolytic hydrogen 

generators for refueling gaseous hydrogen vehicles. 

Using only electricity and water and having no 

emissions beyond oxygen, electrolytic fuel 

appliances can be readily deployed to create a highly 

distributed fuel supply network. 

The objective of the Stuart/DOE project is to 

design, build and deploy a variety of fuel appliances. 

Two types of appliance are being built under this 

project: Fleet Fuel Appliances and Personal Fuel 

Appliances, both of which target the needs of nascent 

hydrogen vehicle commercialization. The Fleet Fuel 

Appliance targets buses, trucks and other centrally 

fuelled fleet vehicles, where fuel production rates in 

excess of 400 standard cubic feet per hour (scfh) are 

required. The Personal Fuel Appliance is geared 

towards consumers’ vehicles at the home or office, 

and can be powered by the utilities found in the 

typical North American home. The production rate of 

these units is in the range of 50 scfh. Both types of 

appliances are capable of delivering gaseous 

hydrogen at high pressure (up to 5000 pounds per 

square inch gauge [psig]) to the vehicle. 

Approach

The successful development and demonstration 

of fuel appliance technology will enable a cost 

effective pathway for building a hydrogen fuel 

supply infrastructure to support hydrogen vehicles in 

their early commercialization. The fuel appliance 

addresses the issue of fuel delivery by providing 

point of use fuel generation using existing energy 

utilities. Using the existing electricity grid, a full 

service infrastructure can be built up as a distributed 

network of small electricity-to-hydrogen fuel 

converters. 

Key to meeting the market requirements is 

reducing the cost of electrolysis. Stuart’s patented 

alkaline water electrolysis cell technology is 

designed to achieve the cost targets demanded by 

transportation fuels. The Double Electrode Plate 

(DEP)

 technology uses low-cost polymer and metal 

sheets, which are easily assembled in a stack. The 

DEP electrolyser can be configured either as a 

single stack or multi-stack electrolyser. The multistack electrolyser, having multiple cells in parallel, 

can run cell currents up to 30,000 amps and is 

suitable for large fueler applications. All the 

prototypes built under “Filling Up With Hydrogen 

2000” use DEP technology. The electrolyser 

packaged with the power system, compressor, 

purification and controls needed in a refueling 

application make up the fuel appliance.

“Filling Up With Hydrogen 2000” will provide 

an experience base with the cell stack technology for 

later commercialization and is a cost effective 

approach for equipment testing in that the user/

customer picks up operating costs for the benefit of 

the hydrogen produced. In addition to testing the cell 

technology, the prototype development plan provides 

public exposure to the fuel appliance concept, 

Figure 1. P3-5 Bus Fueler Appliance Cell Stack
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

565

introducing customers to the idea of distributed onsite hydrogen production as well as providing 

valuable precedents for the development of codes 

and standards and hydrogen project risk assessment. 

The operation of the bus fuel appliance (P3-1A) at 

SunLine Transit provides public access to the 

technology through SunLine. The low-pressure 

fueler (P3-1B LP) provides a demonstration of a 

system which can refuel metal hydride gas storage. 

The high-pressure fueler (P3-1B HP) demonstrates 

the concept of a distributed “community fueler”. The 

design of the bus fueler, P3-5, demonstrates the large 

format cell technology which could be used in large 

bus fleet fueling applications (Figure 1). The P4 

prototypes are being used to test different 

configurations of the cell stack integration with the 

compressor, including a pressurized stack 

configuration and integration with a wind turbine in a 

semi-stand-alone energy system. Prototyping of the 

personal fuel appliance (PFA P1 Model 25) at major 

automakers will provide the auto industry the 

opportunity to evaluate the concept of a small onsite 

hydrogen generator and potential home-based fueling 

appliance. 

Results

Highlights of progress made in the past year in 

the prototyping project include the following:

• P3-1A: Bus Fuel Appliance, which produces 

up to 1,400 scfh at 4,000 psig, has operated 

for over 2,000 hours and produced over 2.5 

million SCF of hydrogen fuel. The appliance 

has been used to fuel a variety of hydrogen 

and Hythane vehicles operated at SunLine 

(Figure 2).

• P3-1B (HP): Community Fuel Appliance, 

which produces up to 400 scfh at 5,000 psig, 

has operated for over 1500 hours, producing 

650,000 SCF. The appliance has been used 

to test/certify hydrogen vehicle fuel tanks 

and fuel a fleet of Hythane vehicles (Figure 

3). An identical version of this appliance will 

be provided to the California Fuel Cell 

Partnership.

• P3-1B(LP): Community Fuel Appliance, 

which produces up to 400 scfh at 200 psig. 

This unit has operated in-house for 3,000 

hours has been refitted for refueling the 

metal hydride – hydrogen fuel cell mining 

locomotive in a joint project with the Fuel 

Cell Propulsion Institute. The siting of the 

appliance is approved and installation is 

expected to occur in September 2002.

• P4-1A: This fuel appliance, capable of 400 

scfh at 6,000 psig, incorporating a higherpressure stack, is being tested in house. 

Problems have arisen because of 

contamination of sensors used to control 

pressure in the cell. The approach to 

pressurize the cell is under review. 

• P4-1B: Community Fuel Appliance, which 

produces up to 900 scfh, is currently being 

used to test a hydrogen internal combustion 

Figure 2. P3-1A Fuel Appliance at SunLine Transit, 

1000 Palms, California

Figure 3. P3-1B Fuel Appliance at Powertech, 

Vancouver, BC 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

566

engine generator set at Southwest Research 

Institute. After tests are

• complete, the unit will be moved to Palm 

Springs for the South Coast Air Quality 

Management District wind-hydrogen 

project.

• PFA Model 25: The Personal Fuel Appliance 

is on tour with the Ford Think fuel cell 

vehicle to demonstrate the household fuel 

supply system (Figure 4).

Conclusions

Fuel appliances can reliably meet needs of 

hydrogen vehicle refueling, delivering gas up to 5000 

psig. Prototyping has indicated further work is 

required to reduce equipment and installation costs 

and refine process automation. 

References

1. Stuart Energy USA, Filling Up With Hydrogen, 

1998, under DOE Cooperative Agreement No. 

DE-97GO10221

Figure 4. Personal Fuel Appliance in Public 

Demonstration
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

567

V.B.3 Hydrogen Reformer, Fuel Cell Power Plant, and Vehicle Refueling System

Venki Raman (Primary Contact)

Air Products and Chemicals Inc.

7201 Hamilton Boulevard

Allentown, PA 18195

(610) 481-8336, fax: (610) 706-7463, e-mail: ramansv@apci.com

DOE Technology Development Manager: Chris Bordeaux

(202) 586-3070, fax: (202) 586-5860, e-mail: Chris.Bordeaux.ee.doe.gov

Main Subcontractors: Plug Power Inc., Latham, New York, City of Las Vegas, Las Vegas, Nevada

Objectives

• Resolve design issues and demonstrate small, on-site hydrogen (H2) production for fuel cells and H2

fuel stations

• Design, construct, and operate a multipurpose refueling station

• Dispense compressed natural gas (CNG), H2/CNG blends, and pure H2 to up to 27 vehicles

• Design, construct, and operate a stationary 50 kW fuel cell on pure H2

• Evaluate operability, reliability, and economic feasibility of integrated power generation and vehicle 

refueling designs

• Maintain safety as a top priority in the refueling station and fuel cell design and operation

• Obtain adequate operational data on the fuel station to provide a basis for future commercial fueling 

station designs; develop appropriate “standard” designs for commercial applications

• Expand the current facility to serve as the first commercial facility when sufficient hydrogen demand 

develops. Ultimately serve as a link in a national H2 corridor

Approach

• Further develop an existing small-scale (1,000 standard cubic feet per hour [scfh] H2) natural gasbased autothermal reformer (ATR) prototype and test in conjunction with pressure swing adsorption 

(PSA) for on-site production of hydrogen

• Design and develop a scaled-up H2 generator (3,000 scfh H2)

• Develop a 50 kW proton exchange membrane (PEM) fuel cell capable of operating on pure hydrogen, 

based on 7 kW modules developed for a residential fuel cell product

• Design and develop a multi-purpose fuel station capable of dispensing various blends of H2 and CNG 

and pure H2 at pressures of 3,600 pounds per square inch (psi) and 5,000 psi for vehicle fueling

• Achieve integrated operation of the complete system and conduct a nominal two-year test program to 

determine reliability and maintainability

• Operating modes for the integrated system will be developed for testing various operational scenarios 

of the overall system

Accomplishments

• The ATR prototype unit was fully characterized at the Air Products and Chemicals, Inc. (APCI) labs 

after extensive changes necessitated by various operational issues
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

568

• Conclusions of economic analysis, which indicated that steam-methane reforming was the more 

appropriate choice for the scaled-up H2 generator, and recurring maintenance issues lead to decision 

not to install the prototype unit in Las Vegas in FY 02

• Constructed scaled-up H2 generator, and completed performance testing in the lab; shipped unit to Las 

Vegas (June 2002)

• Completed detailed design, fabrication, and testing on Plug Power’s first large scale stationary fuel cell 

system (50 kW); shipped 50 kW fuel cell systems to Las Vegas (October 2001)

• All subsystems (vehicle refueling system, hydrogen generator and fuel cell power generator) currently 

being installed (August 2002)

Introduction

A part of the strategy for implementing hydrogen 

infrastructure for fuel cells, particularly in the early 

years of fuel cell vehicle introduction, involves the 

development of very small reformers that can use 

natural gas to produce hydrogen on-site at the fuel 

station. These reformers will need to have about a 

ten-fold lower production capacity than current 

economically sized hydrogen plants. Furthermore, 

their utilization factors will be very poor due to the 

limited number of vehicles and their sporadic filling 

demands, in turn leading to poor economics. An 

approach to improving the economics of hydrogen 

fuel production at these scales may be to integrate a 

fuel cell power plant with the fuel station to produce 

power and sell it back to the electricity grid when 

there is low fuel demand by vehicles. This coproduction of electric power and hydrogen fuel is 

referred to as the “Energy Station” concept.

This project involves the development and 

validation of small-scale hydrogen reformer 

technology, a 50 kW PEM fuel cell power plant, and 

a multipurpose vehicle fuel station capable of 

dispensing hydrogen; hydrogen enriched natural gas; 

and CNG.

Approach

The project is a combined effort of three 

organizations: Air Products (prime contractor) with 

responsibility for the overall project and specifically 

for the hydrogen reformer and the multipurpose fuel 

station; Plug Power Inc. with responsibility for the 50 

kW PEM fuel cell development; and the City of Las 

Vegas with responsibility for providing the project 

site, for installing a CNG fuel station (outside the 

scope of this project), for providing several vehicles 

operating on hydrogen/CNG blend fuels, and for 

facility operations support during the test period. 

Figure 1 shows a schematic of the overall integrated 

system configuration.

The project got started by testing an existing 

prototype small-scale (1,000 scfh) natural gas ATR 

previously under development by Air Products in 

conjunction with PSA for on-site production of 

hydrogen. Simultaneously, technical and economic 

studies of new small-scale reformer technologies 

were undertaken, outside the scope of this project, to 

select appropriate technology for a scaled-up 

hydrogen reformer (3,000 scfh) capable of meeting 

the hydrogen demands of up to 27 vehicles, and the 

50 kW fuel cell.

The fuel station draws natural gas from a 

separate CNG fuel station installed by the City of Las 

Vegas. The multi-purpose fuel station was designed 

and developed by Air Products and utilized dynamic 

Figure 1. Overall System Integration Configuration
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

569

blending of hydrogen and CNG to achieve various 

ratios and with the capability of dispensing the fuels 

at pressures of 3,600 psi and 5,000 psi.

Plug Power Inc. undertook the design and 

development of a 50 kW PEM fuel cell capable of 

operating on pure hydrogen, based on multiple 7 kW 

modules developed for a residential fuel cell product.

Results

Significant progress was made in the 

development of this project in the current year as 

described below.

H2 Generator

The fully integrated ATR prototype H2 generator 

that was completed last year and successfully tested 

at the Air Products laboratories in Allentown, PA, 

experienced ongoing operational issues requiring 

several changes. Major changes included 

replacement of the air blower to obtain additional 

capacity, steam generation coil and waste gas 

combustion chamber modifications due to failures, 

change of recycle water system to once-through due 

to solids build up, and PSA adsorbent change-out. 

Following these changes, a full characterization of 

the ATR was completed at the Air Products 

laboratories. However, based on an economic 

analysis that concluded that SMR technology was 

more economical than ATR technology to generate 

pure hydrogen at this size range (1000-3000 scfh H2), 

and the recurring maintenance issues, it was decided 

not to install it in Las Vegas in FY 02. 

A SMR (3,000 scfh H2) based on technology 

from Harvest Energy Technologies was developed 

and tested at the Harvest facilities in California. 

Lessons learned in the previous ATR development 

were incorporated in the SMR development, 

including one button start capability, improved PSA 

recovery, and recycle of off-gas. The unit was 

moved to Las Vegas site.

Fuel Station

Air Products completed the fuel station design, 

and fabrication of all the equipment components such 

as the compressor, storage tubes, blender, and 

dispenser in November 2000. The integration of a 

metal hydride “thermal” compressor to compress 

hydrogen for the fuel station was evaluated but 

dropped from the project since it was determined that 

there was insufficient waste heat from the reformer to 

provide the thermal energy required by the metal 

hydride compressor.

 Installation of the fueling equipment at the 

project site was delayed by one year awaiting 

completion of the CLV CNG station, which was 

completed in March 2002. The required permits for 

installation of the hydrogen station were issued and 

site work initiated in late March 2002.

Fuel Cell

The 50 kW fuel cell stack system comprised of 

eight 7.5 kW stack modules was fully assembled and 

tested at Plug Power’s Latham, New York facility. 

This is Plug Power’s first large scale stationary 

system. Initial startup and qualification testing 

yielded a number of design changes related to 

component selection, control and electronic 

equipment, software algorithms, and gas delivery 

systems. Plug Power first qualified individual 

subsystems, followed by final system configuration 

testing. Test data provided an operational baseline 

and validation of the interface conditions to support 

integration into the refueling station.

The 50 kW fuel cell system was shipped to the 

Las Vegas site in October 2001. Figure 2 is a 

photograph of the complete 50 kW fuel cell power 

plant.

Figure 2. 50 kW Fuel Cell Power Plant
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

570

Conclusions

• Studies indicated that SMR technology was 

the more economical option than ATR 

technology for production of pure hydrogen 

in the size range of interest and was selected 

for the scale-up hydrogen generator.

• As of this writing (August 2002), all 

equipment items have been installed at the 

site and individual equipment checkout is 

underway.

• Current progress indicates that target start-up 

of fully integrated operations by September 

1, 2002 will be met.

FY2002 Presentations

Presentations on the “Energy Station” concept 

and the Las Vegas project have been given to various 

audiences separately or in conjunction with a 

discussion of developing hydrogen infrastructure, 

including: 

1. Merrill-Lynch Global Energy Technology 

Conference – New York City, May 2001

2. California Fuel Cell Partnership Steering Team – 

Diamond Bar, CA, October 2001

3. The EVAA Electric Transportation Industry 

Conference & Exposition – Sacramento, CA, 

December 2001 

4. NRC Hydrogen Study Team Meeting - 

Washington D.C. CHALLENGES FOR THE 

CHEMICAL SCIENCES IN THE 21ST 

CENTURY – January 2002

5. Globe 2002 – Vancouver, Canada, March 2002

6. H2 Investor Forum – Washington, D.C., April 

2002

Outreach efforts have been made to auto participants 

of the California Fuel Cell Partnership with a view to 

promote the Las Vegas site as a link in a CaliforniaNevada hydrogen corridor.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

571

Section VI. Safety and Codes & Standards
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

572
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

573

VI.A Safety

VI.A.1 Gallium Nitride Integrated Gas/Temperature Sensors for Fuel Cell 

System Monitoring for Hydrogen and Carbon Monoxide

Steve Pyke (Primary Contact)

Peterson Ridge LLC

PO Box 1257

Sisters, OR 97759

(541) 318-8265, fax: (541) 330-0073, e-mail: spyke@empnet.com

DOE Technology Development Manager: Neil Rossmeissl

(202) 586-8668, fax: (202) 586-5860, e-mail: Neil Rossmeissl@ee.doe.gov

Objectives 

• Adapt catalytic gate field effect transistor (FET) sensors to resolve and detect carbon monoxide (CO) 

contamination levels from 1-100 ppm in reformer produced hydrogen (H2) fuel for (proton exchange 

membrane (PEM) fuel cells

• Use FET sensors on gallium nitride (GaN) for increased sensitivity and faster response in high 

temperature 

• Compare performance against industry requirements to assess outcome and opportunity

• Improve measurement precision and accuracy

• Field test for reliability and lifetime

Approach

• Design catalytic gate FET sensor for high temperature applications

• Build 1st generation FETs with platinium (Pt), rhodium (Rh) and palladium silver (PdAg) gates for 

evaluation

• Determine the performance requirements against which to measure performance

• Test and determine the population statistics for sensitivity, interferent resolution and temperature 

coefficients (electrical and chemical) for 1st generation devices

• Redesign for improved performance and build and evaluate 2nd generation test articles

Accomplishments 

• Built GaN MODFET sensors with Pt, Rh and PdAg gate metallization

• Demonstrated CO sensitivity enhancement at T>150o

C for Pt and Rh GaN FET sensorss

• Demonstrated Pt sensitivity to CO from 0-100 ppm at 150, 250, 350 and 450oC in 10%, 35 and 50% 

H2 in diatomic nitrogen (N2)

• Demonstrated Pt sensitivity to H2 from 0-100% at 450o

C in N2 background

Future Directions 

• Fabricate 2nd generation sensors with high surface area gate metal films and architectures for greater 

sensitivity, adhesion layers under the gate metal for a higher yield of working devices, insulating 

nitride layers between the catalytic metal and the GaN substrate for reduced gate-drain leakage current 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

574

and device protection, chromium/gold (Cr/Au) cap layers for protecting source and drain ohmic 

contacts and Ir and other new gate metals for greater resolution and interference rejection

• Design and build five low-cost prototypes including digital sensor control electronics for improved 

precision (ca. 1 millivolt)

• Adapt high temperature ceramic "spark plug" packaging for field testing

• Field test prototypes at Idatech, H2Gen, Teledyne Energy Systems and National Renewable Energy 

Laboratory 

Introduction 

The need addressed by this project is for a sensor 

to detect the presence of CO in the H2 produced from 

hydrocarbon feedstocks in reformers and used to 

power PEM fuel cells. Low-cost sensors are not 

available for measuring CO at 1-100 ppm levels in a 

fuel cell environment. The primary goal of this 

project is to develop a low-cost microelectronic gas 

sensor for detecting CO (1-100 ppm) in the fuel 

stream. The sensors must operate in hydrogen (30-

75%), with carbon dioxide (CO2) (15%), CO (0-

10,000 ppm), H2O (30%), percent levels 

hydrocarbons, and N2 (balance), from 1-3 atm total 

pressure and temperatures as high as 800o

C (Glass et. 

al. 2000). There is also a need for hydrogen sensors 

that can also be addressed by this technology and 

must be part of the CO measurement in order to 

remove the confounding effect of H2. 

Approach

The technical approach is a catalytic-gate (Pt, Rh 

and PdAg) GaN FET sensor for operating in high H2

and at high temperature. The detection of hydrogen 

was reported first by Lundstrom (Lundstrom 1975) 

on a palladium gate FET sensor on silicon, but high 

temperature operation of silicon-based FETs is 

limited to <150o

C. A higher bandgap semiconductor 

FET specifically, GaN, was proposed to extend this 

range for potential improvements in sensitivity and 

response times. Recent reports on GaN Schottky 

diode sensors (Schalwig et al 2001) and silicon 

carbide (SiC) FET based sensors show enhanced 

sensitivity at high temperature to combustion gases 

and suggest the potential of the technology in 

automotive exhaust gas monitoring applications. 

These and other sensor developments for automotive 

and aerospace applications have been recently 

reviewed (Mueller et. al. 2001).

Results

The results reported previously were for CO 

dependence at constant hydrogen concentration 

(35%). The data demonstrated CO sensitivity that 

increased with increasing temperature, but 

potentially interfering effects of changing H2

concentration were not explored. The Rh gate FET 

sensor was sensitive to CO above 200o

C with 

apparent sensitivity only above 200 ppm. The Pt 

sensor was sensitive to CO between 50 and 500 ppm 

at 150o

C. The interfering effects of O2 on the Pt 

sensor are substantial. The scanning and 

transmission electron microscopy and X-ray analysis 

shows no interdiffusion of contact metallization with 

GaN at the resolution limit of the analysis (<125D) 

for process temperatures to 600oC for all of the gate 

metals and the Ti/Al source/drain metallization. The 

yield of working devices was <25% due to the poor 

adhesion of the gate metal to the gallium nitride.

Recent testing of Pt sensors extended sensitivity 

studies for CO and H2 to 450oC and suggested 

substantial confounding effects for changes in H2

concentration from 30-75%. Device failure occurred 

in the range 550oC-750oC probably due to oxidation 

of the ohmic contact metallization. Preliminary 

indications are sensitivity to CO is high at low levels 

(0-20 ppm) (see Figure 1), but more experimental 

precision is necessary to confirm the results. The 

response is nonlinear and dependent on both 

temperature and H2 and measurement precision is 

crude (Signal to noise ~3) with the first generation 

electronics. In addition, gas chromatography 

analysis using the helium ionization detector does not 

have sufficient precision below about 20 ppm CO for 

an accurate measurement of concentration. A more 

sensitive detector will be needed to accurately 

measure CO at levels below 20 ppm. Results show 

H2 sensitivity of the Pt sensor is high below 5% H2

and no saturation to 100% (see Figure 2).
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

575

Sensor failure was promoted by increasing the 

temperature from 450o

C to higher temperatures in 

100o

C increments in an oxidizing background gas 

consisting of 2% O2, 10% CO2, 100 ppm CO, and 

100 ppm nitric oxide (NO), chosen for a more 

aggressive environment characteristic of combustion 

gas. The damage to the sensor and package is shown 

in a comparison of the sensor before and after heating 

in Figure 3.

Conclusion 

• The Pt and Rh gate GaN FET sensors can be 

used to detect CO in the 0-100 ppm level in 

H2 above 150oC

• The Pt sensor is sensitive to H2 below 1% in 

N2 and can be used for H2 safety (0-4% in 

air)

• The lack of H2 saturation suggest the Pt 

sensor could be useful H2 monitoring and 

control

• Low CO sensitivity on Rh below 200 ppm at 

200oC can be used to provide a measure of 

H2 and correct the measurement of CO by Pt 

for changes in H2

• Sensor failure results from oxidation of the 

source and drain contact metallization

References

1. Glass, R.S., J. Milliken, K. Howden and R. 

Sullivan (eds), 2000. "Sensor Needs and 

Requirements for Proton-Exchange Membrane 

Fuel Cell Systems and Direct-Injection Engines", 

LLNL, (http://www.ott.doe.gov/pdfs/

sensors_report.pdf).

2. Lundstrom, I., M.S. Shivaraman, C. Svensson, 

and L. Lundqvist, 1975. J. Appl. Phys., 26:55.

3. Mueller, G., G. Krotz and J. Schalk, 2001. "New 

Sensors for Automotive and Aerospace 

Applications", Phys. Stat. Sol. (a) 185, No. 1, 

pages 1-14.

4. Schalwig, J., G. Mueller, O. Ambacher and M. 

Stutzman, 2001. "Group III-Nitride Based Gas 

Sensing Devices", Phys. Stat. Sol., (a) 185, No. 1, 

pages 39-45.

5. Lloyd Spetz, A., L. Uneas, H. Svenningstorp, P. 

Tobias, L.-G. Ekedahl, O. Larsson, A. Goras, S. 

Savage, C. Harris, P. Martensson, R. Wigren, P. 

Salomonsson, B. Haggendahl, P. Liung, M. 

Figure 1. Pt Sensor Response with Low and Changing 

Concentrations CO in 35% H2 at 450o

C

Figure 2. Pt Sensor Response with Changing H2 at 

450o

C

Figure 3. Comparison of Pt Sensor before and after 

Heating to 750oC shows the Black 

Rectangular Source and Drain Metallization 

Has Become Transparent Consistent
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

576

Mattsson and I. Lundstrom, 2001. "SiC Based 

Field Effect Gas Sensors for Industrial 

Applications", Phys. Stat. Sol., (a) 185, No. 1, 

pages 15-25.

FY 2002 Publications/Presentations

1. Pyke, S.C. and L. Sadwick, 2002. "Gallium 

Nitride Integrated Gas/Temperature Sensors for 

Fuel Cell System Monitoring for Hydrogen and 

Carbon Monoxide", Annual Review of the DOE 

Hydrogen/Fuel Cell Program, Golden, CO.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

577

VI.A.2 Interfacial Stability of Thin Film Hydrogen Sensors

J. Roland Pitts (Primary Contact), Se-Hee Lee, Ping Liu, R. Davis Smith and Ed Tracy 

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401

(303) 384-6485, fax: (303) 384-6655, e-mail: roland_pitts@nrel.gov

DOE Technology Development Manager: Neil Rossmeissl

(202) 586-8668, fax: (202) 586-5860, e-mail: Neil.Rossmeissl@ee.doe.gov

Objectives 

• Make available the technology to produce safe, reliable, sensitive, fast, lightweight, and inexpensive 

hydrogen sensors.

• Determine the factors affecting the stability and performance of thin film sensors in practical 

environments.

• Find solutions for extending the lifetime and functionality of thin film hydrogen sensors.

 Approach

• Study service lifetime of sensors in ambient environments and in the presence of suspect contaminant 

gases. 

• Investigate the effects of variations in temperature and relative humidity on sensor performance.

• Continue research on fundamental properties of sensor materials.

Accomplishments 

• Constructed gas manifold with mass flow controllers (MFCs) for accurate gas proportioning.

• Investigated new protective layers to enhance protection from liquid water.

• Fundamental studies have yielded new chemochromic materials produced from electrochemical 

deposition techniques with controlled morphologies. 

• Lifetime studies with protected sensor films indicate functional sensor lifetime has been extended to 

12 months.

Future Directions 

• Continue documentation of lifetimes of current sensors for realistic exposure conditions.

• Continue to optimize the thin film constructions for the protection of the palladium (Pd) catalyst.

• Improve large area sensors for visible detection and bio-hydrogen applications.

Introduction

The goal of this project is to develop safe, low 

cost, lightweight, reliable hydrogen sensors that can 

be used as safety sensors where hydrogen is used, 

stored, or transported. These sensors must be 

inexpensive enough to use several of them on a 

hydrogen powered vehicle, and they must be 

sensitive and fast enough to provide early leak 

detection so that action can be taken before the 

flammability limit in air is reached. We have chosen 

to work on a fiber-optic sensor configuration that 

stands the best chance of meeting all of these goals.

The National Renewable Energy laboratory 

(NREL) fiber-optic sensor consists of chemochromic 

(a color change produced as a result of a chemical 

reaction) coatings at the end of an optical fiber that 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

578

sense the presence of hydrogen in air. When the 

coating reacts with the hydrogen, its optical 

properties are changed. Light from a central electrooptic control unit is projected down the optical fiber, 

where it is either reflected from the sensor coating 

back to a central optical detector, or is transmitted to 

another fiber leading to the central optical detector. 

A change in the reflected or transmitted intensity 

indicates the presence of hydrogen. The fiber-optic 

detector offers inherent safety by removing all 

electrical power from the test site, and it reduces 

signal-processing problems by minimizing 

electromagnetic interference. Critical detector 

performance requirements include high selectivity, 

response speed, and durability as well as potential for 

low-cost fabrication, meeting or exceeding most of 

the proposed criteria for safety sensors.

The NREL sensor shares a common link with 

many other hydrogen sensor concepts in that they all 

use Pd or one of its alloys as a catalyst. Molecular 

hydrogen dissociates on the catalyst surface sites 

forming atomic hydrogen that diffuses rapidly 

through the film, reacting with the underlying 

chemochromic layer. All the sensor configurations 

utilizing Pd have the potential for degradation in their 

performance over time as a result of their cyclic 

interaction with hydrogen or contamination from 

impurities in the environments in which they will be 

used. Therefore, we have chosen to focus on stability 

issues related to ambient exposure of Pd and cyclic 

exposure of Pd to hydrogen.

Approach

A number of strategies for protecting the Pd 

catalyst were investigated in fiscal year (FY) 2001. 

The most effective of these was the application of 

novel inorganic coatings, which could offer effective 

protection to the hydrogen dissociation sites. Work 

continued in FY 2002 on the most effective of these 

strategies. Tests were conducted to determine the 

response of the sensor films with varying 

temperature and relative humidity (RH). For the 

latter work, a new gas manifold and proportioner was 

constructed, as well as an environmental chamber to 

allow control of gas and sensor temperature.

Work was also undertaken in the application of 

polymeric films that provide protection against water 

condensation on the Pd surface, in particular for the 

sensors used by the NREL bio-hydrogen group. 

Interaction with representatives of GVD Corporation 

resulted in a short-term collaboration to test the 

efficacy of their proprietary polymer coatings. These 

coatings are deposited using a chemical vapor 

deposition technique, which results in a substantial 

amount of control of the film composition, density, 

and morphology.

In addition to innovative coatings for the 

protection of the hydrogen dissociation catalyst, 

mesoporous metal oxide layers for enhanced 

performance of the sensor elements were 

investigated. The results demonstrated the suitability 

of an electrodeposited tungsten oxide (WO3) as a 

chemochromic layer for hydrogen detection, 

providing a valuable alternative to vacuum 

deposition.

Results

Inorganic Coatings

 The study of inorganic coatings was focused 

mainly on the coating strategy that was found to be 

most effective during FY 2001. Samples made 

during this period were continually tested and have 

survived more than one year with some degradation 

in performance noted. An example of this 

performance is illustrated in Figure 1.

Figure 1. Response of Pd/WO3 Sensor with Protectiv

Coating, after One Year of Aging in Polluted

Atmospheres and Cycling in Hydrogen
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

579

Organic Coatings

Sensor films were fabricated at NREL and sent 

to GVD Corporation for application of a variety of 

polymeric films. After coating, the films were 

returned to NREL for testing, and these films showed 

good resistance to pollutants in ambient air. Figure 2 

illustrates the resistance to contamination of a sensor 

film over 2 months of testing. This represents a 

remarkable degree of protection for a polymer film 

and gives us an attractive avenue for exploration in 

the future, especially to control the ingress of water 

into the optically active elements of the sensor.

Sensor Response as a Function of Temperature/

Relative Humidity

The construction of a gas manifold incorporating 

four mass flow controllers allowed the mixing of 

water saturated air with dry air to produce test 

streams of gas with accurate RH. Measured amounts 

of hydrogen were then added to the test stream. An 

environmental test chamber was also constructed 

from an insulated cooler. A heating element on the 

test chamber and a proportional temperature 

controller allowed control of the gas temperature and 

thus the thin film temperature to within 0.1°C.

Experiments were conducted on the sensor films 

at various temperatures and RH values. The 

response of a Pd/vanadium oxide (VOx) sensor to 

changes in temperature and RH is illustrated in 

Figures 3 and 4. The sensor exhibits degradation in 

performance at temperatures below 0°C and above 

40°C. Response of the sensor is also slowed 

significantly by the presence of water vapor when the 

relative humidity exceeds 50%.

Mesoporous Metal Oxides

Figure 5 shows the optical response of a Pd/

electrodeposited-WO3 sensor to 0.1% hydrogen/

nitrogen. The sensor exhibits a fast response that is 

comparable to that of an evaporated tungsten oxidebased sensor.

Figure 2. Response of Pd/WO3 Sensor Coated with 

GVD Film after Ambient Exposure

Figure 3. Pd/VOx Sensor Tested with 4% H2 in Air as a 

Function of Temperature

Figure 4. Pd/VOx Sensor Response to 4% H2 in Air as 

a Function of Relative Humidity
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

580

Conclusions and Future Direrctions

• Primary goals of speed, sensitivity, weight, 

and inherent safety have been met. 

• Some sensor films have been demonstrated 

to be functional over one year.

• Collaboration with GVD Corporation 

produced promising results on organic 

protective coatings.

• Electrodeposited mesoporous metal oxides 

were investigated as chemochromic 

hydrogen sensor films. 

• An environmental chamber was constructed 

to test sensor films at various temperatures. 

• A gas manifold for proportioning gases and 

controlling relative humidity was 

constructed. 

• Preliminary experiments indicate that both 

the speed and sensitivity of the sensor films 

vary with both temperature and relative 

humidity. 

• Work continues on functional lifetime and 

response to variations in environmental 

conditions. 

FY 2002 Publications/Presentations

1. S.-H. Lee, H. M. Cheong, P. Liu, D. Smith, C. E. 

Tracy, A. Mascarenhas, J. R. Pitts, and S. K. Deb, 

“Raman Spectroscopic Studies of Gasochromic aWO3 Thin Films,” Electrochimica Acta, 46, 1995 

(2001).

2. R. D. Smith II, D. K. Benson, J. R. Pitts, D. L. 

Olson, and T. R. Wildeman, Diffusible Weld 

Hydrogen (Measurement by Fiber Optic 

Sensors),” MP (Materialprüfung), Jahrg. 43, 26 

(2001).

3. Ping Liu, Se-Hee Lee, C. E. Tracy, J. R. Pitts and 

R. D. Smith, “Stable Pd/V2O5 Optical H2 Sensor,” 

J. Electrochem. Soc., 149, H76 (2002).

4. E. Ozkan, S.-H. Lee, P. Liu, C. E. Tracy, F. Z. 

Tepehan, J. R. Pitts, and S. K. Deb, 

“Electrochromic and Optical Properties of 

Mesoporous Tungsten Oxide Films,” Solid State 

Ionics, in press.

5. R. D. Smith II, Ping Liu, Se-Hee Lee, C. Edwin 

Tracy and J. Roland Pitts, "Low-cost Fiber Optic 

Hydrogen Sensors", to be presented at the 224th 

ACS National Meeting, Boston, MA, August 18-

22, 2002.

Patents Issued

 1. P. Liu, C. E. Tracy, J. R. Pitts, and S.-H. Lee, 

“H2O Doped WO3, Ultra-Fast, High-Sensitivity 

Hydrogen Sensors,” PCT/US01/14375, published 

Nov. 15, 2001.

2. S.-H. Lee, C. E. Tracy, J. R. Pitts, and P. Liu, “Pd/

Ni-WO3 Anodic Double Layer Gasochromic 

Device,” PCT/US01/14381, published Nov. 15, 

2001.

3. P. Liu, C. E. Tracy, J. R. Pitts, S.-H. Lee, and D. 

Smith, “Pd/V2O5 Device for H2 Detection,” PCT/

US0114411, published Nov. 15, 2001.

4. P. Liu, C. E. Tracy, J. R. Pitts, and S.-H. Lee, 

“Protective Coating for Gasochromic-Based 

Sensors Used in Sensing the Presence of 

Hydrogen,” ROI, NREL #01-41, application 

submitted.

Figure 5. Optical Response of a Pd/WO3 Sensor in 

which the Tungsten Oxide is an 

Electrodeposited Mesoporous Film
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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VI.A.3 Micro-Machined Thin Film H2 Gas Sensors

Frank DiMeo, Jr. (Primary Contact), Ing-Shin Chen, Philip Chen, Jeffrey Neuner, Michele Stawasz, 

James Welch, and Andreas Rohrl

ATMI, Inc.

7 Commerce Drive

Danbury, Connecticut 06810

(203) 794-1100, fax: (203) 830-2123, e-mail: fdimeo@atmi.com 

DOE Technology Development Manager: Neil Rossmeisel

(202) 586-8668, fax: (202) 586-5860, e-mail: Neil.Rossmeisel@ee.doe.gov

Objectives

• Optimize micro-hotplate based H2 sensor design and fabrication processes

• Investigate potential sensor cross sensitivities and degradation mechanisms

• Demonstrate an extrapolated sensor lifetime greater than 3 years

Approach

• Investigate the use of alternative micro-hotplate geometries to increase power density and reduce heat 

loss

• Develop surface treatment processing to minimize the contact resistance between the sensing layer and 

the underlying metal contact

• Construct test manifolds and signal-conditioning circuitry for advanced sensor testing

• Study sensor response to H2 in the presence of contaminant gases

• Evaluate sensor response performance for an extended time period

Accomplishments

• Designed new micro-hotplates for low voltage (5 V), low power (5 mW) operation

• Evaluated the effectiveness of protective coatings against high-level H2 exposure

• Demonstrated working sensors in atmospheres containing low-level contaminant gas - 100 ppm CO, 

20 ppm H2S, or 600 ppm isopropyl alcohol (IPA)

• Collected long-term sensor performance data over a three-month period

Future Directions

• Implement advanced micro-fabrication processing methods and statistical process control

• Evaluate environment-tolerant protective coatings

• Investigate catalytic chemistry at sensor surface

• Examine the phase transformation mechanism of the sensing materials

• Develop integrated system solution
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

582

 Introduction

The reputation of hydrogen as the next 

generation energy delivery agent, supplementing 

today's electricity, is firmly established. Multifaceted 

use of hydrogen will play a crucial role in future 

communities. However, hydrogen is a gas at 

atmospheric conditions and can escape from its 

containment to cause an explosion hazard. Safe 

storage and delivery of hydrogen is a necessity for 

public acceptance of hydrogen as an energy medium.

The ability to detect and quantify the amount of 

gaseous hydrogen present is fundamental to all 

aspects of hydrogen processes. In addition to safety 

needs, hydrogen sensing is also required as a means 

of monitoring and controlling hydrogen-based 

processes used in fuel cells. The demand for 

hydrogen sensors is very great in terms of quantity 

and variety because each application may have 

specific requirements for sensor characteristics. The 

quantity demand also translates into a requirement 

for low production cost so that needs, rather than 

costs, are the determining factor for sensor use.

Approach

Essential features required for H2 sensor 

applications include fast response, high sensitivity, 

and amenability to large-volume manufacturing, to 

name a few. Micro-machined thin film hydrogen gas 

sensors were developed at ATMI to meet these needs. 

These sensors combine novel H2 responsive 

materials and micro-hotplate structures based on 

proven silicon technology. Our implementation of 

the micro-hotplate is a surface micro-machined 

thermal isolation structure with an embedded 

polycrystalline silicon resistive heater where elevated 

temperature can be achieved with ease (Semancik, et 

al., 2001). A typical ATMI micro-hotplate structure 

is shown in Figure 1.

A rare earth metal thin film over-coated with a 

palladium-based capping film serves as the active 

sensing layer. Detection of H2 is based on the phase 

transformation induced by hydrogenation of rare 

earth metals. The rare earth metal reacts with 

hydrogen upon exposure, leading to a change in 

electrical resistance that scales with hydrogen 

concentration in the gas phase. When this sensing 

layer is coated on the surface of a micro-hotplate, as 

shown in Figure 2, the reaction kinetics can be 

engineered by the micro-hotplate temperature.

Results

Designed for safety applications, our micromachined thin film H2 sensors have been tailored for 

H2 concentrations at half of the lower explosive limit 

(4% in air for H2) or lower. In this concentration 

range, we have demonstrated an extremely fast 

response and large signal-to-noise ratio.

Sensor operation in real applications is usually 

affected by the interference from common 

contaminant gases. These contaminant gases are 

known to cause false alarms or outright failure of 

sensors based on existing technology. To examine 

sensor performance in the presence of contaminant 

gases, sensors were exposed to low-level 

contaminant gases in a background of air. The first 

experiment was performed without H2 in the gas 

stream. Dry air was used as the purge gas, and lowFigure 1. SEM Photo of a Released Micro-Hotplate 

Thermal Isolation Structure

Figure 2. Schematic of Functional Layer Stack on a 

Micro-Hotplate Platform
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

583

level contaminant gas was blended in air as test gas. 

A set of representative data is shown in Figure 3. 

The sensors did not respond to the presence of the 

contaminant test gas in the absence of hydrogen and 

thus caused no false alarms.

The next experiment was performed with H2 in 

the gas stream during the test cycle. Low-level 

contaminant gas - 100 ppm CO, 20 ppm H2S, or 600 

ppm IPA - was blended with 0.5% H2 as the test gas. 

A set of representative data is shown in Figure 4. 

The first, third, fifth, and the last subsets of data were 

collected with 0.5% H2 in dry air with no 

contaminant gas, providing a reference background. 

The sensor exhibited enhanced response in the 

presence of CO and H2S. The sensor remains 

functional during and after repeated exposure to any 

of these contaminant gases.

An experiment was carried out where a sensor 

was exposed to H2 over a three-month period. The 

temporal sequence of the gas stream included a 24-

hour dry air purge followed by a 10-minute exposure 

to 1% H2. Figure 5 shows the long-term test results. 

The sensor remains fully functional after 

approximately three months of repeated exposure to 

H2. This observation, while it does not directly 

provide a measure of sensor lifetime, is encouraging.

Conclusions

• The sensors tested do not respond to 

contaminant gases 

• The sensors exhibited enhanced response to 

H2 in the presence of CO and H2S

• The sensors continued to operate after 

exposure to contaminant gases

• Long-term performance at low-level H2

exposure shows no intrinsic failure mode 

during normal operation

References

1. S. Semancik, R.E. Cavicchi, M.C. Wheeler, J.E. 

Tiffany, G.E. Poirier, R.M. Walton, J.S. Suehle, 

B. Panchapakesan, D.L. DeVoe, "Microhotplate 

platforms for chemical sensor research," Sensors 

and Actuators B 77, 579-591 (2001).

Presentations

1. "Advanced Gas Sensor R&D at ATMI" 

presented at ATMI's Emerging Technologies 

Figure 3. Response of a Sensor to Low-Level 

Contaminant Gases in Air

Figure 4. Response of a Sensor to 0.5% H2 in the 

Presence of Contaminant Gases in Air

Figure 5. Response of a Sensor Under Repeated 

Exposure to 1% H2 Over a 3-Month Period
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

584

Lunch at SESHA (Semiconductor 

Environmental, Safety, and Health Association) 

24th Annual Symposium, April 4-6, 2002, Palm 

Springs, California.

2. "MEMS Based H2 Gas Sensors" presented at 

symposium AL1 (Sensing In Industrial And 

Extreme Applications) of The Electrochemical 

Society 201st Meeting in Philadelphia, 

Pennsylvania, May 12-17, 2002.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

585

VI.B Codes & Standards

VI.B.1 Hydrogen Infrastructure Activities Codes and Standards: Hydrogen 

Codes and Standards Outreach

Karen Miller

The National Hydrogen Association

1800 M Street NW, Suite 300

Washington, DC 20036-5802

(202) 223-5547, fax: (202) 223-5537, e-mail: kmiller@ttcorp.com

DOE Technology Development Manager: Neil Rossmeissl

(202) 586-8668, fax: (202) 586-5860, e-mail: Neil.Rossmeissl@ee.doe.gov

Technical Advisor: Robert L. Mauro

(202) 223-5547, fax: (202) 223-5537, e-mail: rmauro@ttcorp.com

Objectives 

• Bring industry experts together to establish technical criteria for hydrogen energy components and 

systems nearing commercialization. 

• Continue to advance U.S. industry positions in the international arena, including the International 

Standards Organization Technical Committee 197 (ISO TC 197) and the International Electrochemical 

Committee Technical Committee for Fuel Cells (IEC TC 105). 

• Work closely with the International Code Council (ICC) Ad Hoc Hydrogen Committee (AHC) to 

include hydrogen and hydrogen energy systems in the model codes in the United States.

• Identify code and standard organizations that can begin to or are in the process of developing hydrogen 

codes and standards. 

• Pull industry experts together to assure technical accuracy and consistency of these codes and 

standards. 

• Report on the activities to a wide audience, assuring information transfer regarding the status of efforts 

and technical (and sometimes political) issues remaining.

• Working with the National Renewable Energy Laboratory (NREL), the National Hydrogen 

Association (NHA) also seeks to facilitate the coordination of hydrogen codes and standards activities 

through the Hydrogen Codes and Standards Coordination Committee (HCSCC), and disseminate 

timely information about these efforts through a monthly electronic publication, the “Hydrogen Safety 

Report”. 

Approach

• Hold technical conferences with industry, academia, national laboratories, government laboratories, 

code officials and code organizations to develop and write new standards for hydrogen technologies, 

including storage tanks, fueling nozzles, connectors, safety equipment, and other key components and 

integrated systems needed to move hydrogen into the energy sector. 

• Participate in the International Standards Organization and its Technical Committee 197, which is 

responsible for the presentation and approval of the developed standards.

• Publish Codes and Standards (C&S) Workshop Proceedings online - available to the public. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

586

• Support the International Code Council in their efforts to review, develop and promulgate new codes 

for the use of hydrogen. This includes providing experts, technical reports, data and other information 

needed by the code officials to complete the development of these new codes.

• Present the U.S. hydrogen positions at international forums and participate in international meetings 

that are of benefit to the whole hydrogen community in the areas of hydrogen safety, codes and 

standards. 

• Publish and present pertinent hydrogen safety, codes and standards information at a variety of forums, 

including Global Parks conference to be held in September in Michigan; American Society of 

Nondestructive Testing (ASNT) conference held in March in Portland, Oregon; and SAE (Society of 

Automotive Engineers) Fuel Cell Transportation Technology Summit II in Michigan in April.

• Keep its members informed of progress in the development of hydrogen safety, codes and standards 

through publication in its Quarterly Newsletter, the NHA News and by posting sensitive draft 

information, including draft standards, on the NHA Members Only website. 

• Conduct safety codes and standards outreach in an open, non-competitive manner by conducting 

workshops; participate in the development efforts of other organizations; work with the HCSCC to 

coordinate the efforts; present hydrogen safety, codes and standards activities at conferences and 

workshops; and make information available in a timely manner to all interested parties.

Accomplishments 

• The NHA hosts two Hydrogen Safety Codes and Standards Workshops per year. The most recent one 

was held February 26, 2002. Proceedings were available on-line through the electronic newsletter and 

on the NHA website within 2 weeks of the workshop. The “Hydrogen Safety Report” has been 

published by the 15th of each month since December 2001, and it is free to all interested parties 

through the NHA website (www.HydrogenUS.com) and on its own site at 

(www.HydrogenSafety.info). 

• The ICC AHC has proposed changes for including hydrogen energy systems and the NHA participated 

in all the hydrogen-related hearings. The two proposed code changes to the International Fire Code 

were approved, with modifications. 

• ISO TC 197 and IEC TC 105 working group meetings and plenaries were held in June, 2002 in 

Montreal in conjunction with the World Hydrogen Energy Conference (WHEC). NHA has organized 

three technical sessions at WHEC on hydrogen safety, codes and standards.

• The U.S. TAG meeting for ISO TC 197 was held in Washington, DC during the third week of May, 

2002. NHA discussed and proposed a new work item on charged metal hydrides. 

• The NHA presented hydrogen codes and standards activities at the DOE Fuel Cell Summit at the end 

of May.

• The ICC process has recently brought a number of associations that serve the petroleum and natural 

gas industries to the fold, all in support of developing codes and standards for hydrogen energy 

systems.

• In October 2001, the NHA had a large article published in the U.S. General Services Administration 

(GSA) publication “Vehicle News”. 

Future Directions 

• The next NHA C&S Workshop is to be held in Fort Worth, Texas on September 30, 2002 -in 

conjunction with the BOCA - ICBO - SBCCI Joint Annual Conference.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

587

• Information dissemination remains crucial to building consensus and developing a national and 

international dialog. The NHA would like to expand on these efforts to develop informational 

materials, presentations, and forums for targeted audiences, such as code officials; regulators; early 

adopters for transportation, stationary, and portable power applications; and the public. It is important 

to educate the public on several levels. For example, the tax payers must understand hydrogen in order 

to support efforts to purchase and operate hydrogen buses, then the general public must feel safe and 

good about riding in them. The benefits of hydrogen technologies need to be clearly articulated. For 

example, with hydrogen fuel cells running auxiliary power in a vehicle, it is possible to have air 

conditioning running without the engine operating. There are many value-added benefits that can help 

prepare the market for these emerging technologies.

Introduction 

The mission of the National Hydrogen 

Association (NHA) is to foster the development of 

hydrogen technologies and their use in commercial 

and industrial applications and to promote the role of 

hydrogen as a major energy carrier of the future. 

The NHA holds technical conferences with 

industry, academia, national laboratories, 

government laboratories, code officials and code 

organizations to bring experts together in a focused 

activity to develop and write new standards for 

hydrogen technologies. This includes such items as 

storage tanks, fueling nozzles, connectors, safety 

equipment, and other key components and integrated 

systems needed to move hydrogen into the energy 

sector. The NHA has members and staff who are 

active participants in the International Standards 

Organization and its Technical Committee 197, 

which is responsible for the presentation and 

approval of the developed standards.

Approach 

The NHA works with DOE, NREL, and others to 

coordinate codes and standards activities to avoid 

duplication of effort and enable hydrogen systems to 

be sited. This requires coordination with industry 

groups and standards organizations such as the 

International Organization for Standardization, 

American Society of Mechanical Engineers, IEC TC 

105, the U.S. Fuel Cell Council, the Society of 

Automotive Engineers, Fuel Cell Propulsion 

Institute, National Fire Protection Association, and 

the DOE Fuel Cell Codes and Standards Summit.

NHA staff publishes and presents pertinent 

hydrogen safety, codes and standards information at 

a variety of forums, including Global Parks 

conference to be held in September in Michigan; 

ASNT conference held in March in Portland, 

Oregon; and SAE Fuel Cell Transportation 

Technology Summit II in Michigan in April.

The NHA keeps its members informed of 

progress in the development of hydrogen safety, 

codes and standards through publication in its 

Quarterly Newsletter, the NHA News and by posting 

sensitive draft information, including draft standards, 

on the NHA Members Only website. This allows 

NHA members an opportunity to review the work of 

other organizations who have requested collaboration 

with the hydrogen community but can not make these 

items publicly available. The general articles 

published in the newsletter are made available to the 

public on the NHA website and mailed to NHA 

members. In addition, we produce a monthly 

electronic newsletter dedicated to hydrogen safety 

issues. It is available on the NHA website, and also 

has its own dedicated site. Anyone can sign up to 

receive email notification each month when it is 

posted online. In this way, the information is 

distributed broadly, and interested parties are given 

an opportunity to get involved in the standards 

development process.

Results 

The NHA presented hydrogen codes and 

standards activities at the DOE Fuel Cell Summit at 

the end of May, 2002. The NHA has successfully 

encouraged industry experts to join the NHA C&S 

Committee and the US TAG for ISO TC 197. The 

ICC process has recently brought a number of 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

588

associations that serve the petroleum and natural gas 

industries to the fold, all in support of developing 

codes and standards for hydrogen energy systems. In 

October 2001, the NHA had a large article published 

in the GSA publication “Vehicle News”. Photos 

from that article showed sample demonstration 

vehicles and refueling station projects for which 

safety codes and standards are needed.

Figure 1 shows the XCELLSiS Zebus (Zero 

Emission Bus) and Honda's FCX fuel cell vehicle at 

the SunLine Transit Agency hydrogen refueling 

station in the Coachella Valley. SunLine plans to 

have a number of fuel cell buses by 2003.

Ford Motor Company delivered the world’s first 

production prototype, direct-hydrogen powered fuel 

cell vehicle (Ford Focus, Figure 2) to the California 

Fuel Cell Partnership in November 2000.

Figure 3 depicts the hydrogen fueling station at 

the California Fuel Cell Partnership’s West 

Sacramento Headquarters Facility, which was jointly 

designed and installed by five of the world leaders in 

energy and industrial gas supply: Air Products and 

Chemicals, BP, Praxair, Shell, and Texaco. The 

station is used to fill vehicles with gaseous hydrogen.

The NHA hosts two Hydrogen Safety Codes and 

Standards Workshops per year. The most recent one 

was held February 26, 2002, in conjunction with a 

WSRC Hydrogen Storage Workshop. Over thirty 

experts gathered to exchange information on the 

status of these efforts and how to participate in them. 

Proceedings were available on-line through the 

electronic newsletter and on the NHA website within 

2 weeks of the workshop. The “Hydrogen Safety 

Report” has been published by the 15th of each 

month since December 2001 and is free to all 

interested parties through the NHA website 

(www.HydrogenUS.com), and on its own site at 

(www.HydrogenSafety.info). Over 300 interested 

parties receive email notification when a new issue is 

posted, with a hotlink to the information.

In December 2001, the National Hydrogen 

Association launched a monthly electronic newsletter 

on hydrogen safety, called the Hydrogen Safety 

Report (Figure 4). It is available to all interested 

parties on the Internet at www.HydrogenSafety.info.

Figure 1. Next Generation Fuel Cell ZEBus 

Figure 2. Ford Focus Fuel Cell Vehicle

Figure 3. CaFCP Hydrogen Refueling Station
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

589

Another major effort has been garnering industry 

support for the ICC hearings in Pittsburgh in April, 

2002. The ICC AHC has proposed changes for 

including hydrogen energy systems. The NHA 

participated in all the hydrogen-related hearings. 

The two proposed code changes to the International 

Fire Code were approved, with modifications. There 

was huge support for the need to put something in the 

code now, knowing we have the next 18 months to 

work out the details, and include exceptions as 

appropriate. Only one person stood up in opposition 

claiming "hydrogen is a very dangerous gas and 

scares the living daylights out of me". It was a very 

touch-and-go situation, and we all learned quite a bit 

about process, and how important it is to have built 

support across communities, and have assistance, 

real-time, from those familiar with procedure. F176-

02 was approved as modified. The modifications are 

consistent with SE/SW Fire Chiefs' 

recommendations to AHC. In addition, all four (4) 

exceptions to Section 2209.3 were deleted. F-177-02 

also passed as amended, with issues of venting to be 

worked out. F177-02 was approved as modified. IFC 

Committee Chair ruled AHC modification 'editorial'. 

All International Fuel Gas Code proposals were 

disapproved by the IFGC committee; however floor 

action was taken on each. Support for the changes 

was overwhelming, and the committee 

recommendation along with the floor action will go 

on to the Final Action Consideration at the end of 

September. The NHA is working with the HCSCC 

to coordinate information dissemination to voting 

members and industry as well as technical support to 

the ICC AHC.

Some interesting developments in Europe have 

necessitated an open dialog on the U.S. position in 

the development of international standards. This has 

implications both technically and politically, and 

relates to proposed European-wide regulations which 

are likely to be proposed as global regulations, 

despite lack of U.S. involvement in setting the 

framework.

ISO TC 197 and IEC TC 105 working group 

meetings and plenaries were held in June, 2002, in 

Montreal in conjunction with the World Hydrogen 

Energy Conference (WHEC). NHA organized three 

technical sessions at WHEC on hydrogen safety, 

codes and standards and actively participated by 

serving on the Technical Committee for these 

sessions, co-chairing a session, presenting a paper, 

and coordinating with speakers.

The U.S. TAG meeting for ISO TC 197 was held 

in Washington, DC during the third week of May. 

NHA proposed a new work item on charged metal 

hydrides. 

Conclusions 

The need to develop a U.S. position on the 

international level must go well beyond the current 

efforts. The NHA supports efforts to assure that 

decisions are made by consensus using international 

standards bodies and that U.S. interests are not 

disadvantaged. 

In addition, with such excellent cooperation 

developing on a national level, the current efforts 

must continue, with additional support for 

coordinated activities, such as those of the HCSCC. 

The NHA is poised to lead efforts best led by the 

hydrogen industry, and play an active role in broader 

efforts.

There is a very meaningful international role for 

the U.S. Department of Energy (DOE):

Figure 4. Hydrogen Safety Report 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

590

• Make sure that U.S. interests are involved 

and adequately represented in the standards 

making process; and

• Make sure that the U.S. government speaks 

with the same voice in presenting U.S. 

interests internationally (WP29), as the 

consensus position of U.S. industry speaks 

with in international standards organizations.

The National Hydrogen Association will hold its 

next Hydrogen Safety, Codes and Standards 

Workshop on September 30, 2002 in Fort Worth, 

Texas (Figure 5). (For more information, visit 

www.HydrogenUS.org.) The NHA would like to 

expand on these efforts to develop informational 

materials, presentations, and forums for targeted 

audiences, such as code officials, regulators, early 

adopters for transportation, stationary, and portable 

power applications, and the public. The benefits of 

hydrogen technologies need to be clearly articulated. 

References 

1. Hydrogen Codes and Standards – NHA’s 

presentation for the 2002 DOE Hydrogen 

Program Peer Review.

FY 2002 Publications/Presentations 

1. Peer Review Presentation and Paper: NHA-DOE 

Cost Shared Activities: Hydrogen Codes and 

Standards Outreach

2. DOE Fuel Cell Summit Presentation: International 

Standards Activities in Hydrogen Technologies

3. Paper for Global Powertrain Conference: 

Hydrogen Power - Driving Our Future

4. AIAA Joint Propulsion Conference presentation: 

Safety Siting of Commercial Hydrogen Facilities

5. NHA Hydrogen Codes and Standards Workshop 

Proceedings – February 26, 2002

6. SAE Fuel Cell Transportation Summit II: NHA 

Fueling and Infrastructure

7. ASNT 2002 Spring Conference: NDE Issues for 

Hydrogen Energy Systems

8. HTAP Safety Summit: NHA Codes and Standards 

Activities

Special Recognitions 

1. Outstanding Contribution to The Hydrogen Planet, 

14th World Hydrogen Energy Conference

Figure 5. Workshop Announcement 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

591

VI.B.2 Codes and Standards Analysis

Dr. Michael R. Swain (Primary Contact), Patrick Filoso, Dr. Matthew N. Swain

University of Miami

Coral Gables, FL 33124

(305) 284-3321, fax: (305) 284-2580,e-mail: mswain@miami.edu

DOE Technical Development Manager: Neil P. Rossmeissl

(202) 586-8668, fax: (202) 586-5860, e-mail: Neil.Rossmeissl@ee.doe.gov

Objectives 

Task A - California Fuel Cell Partnership (CaFCP) Building Safety Analysis

• Determine whether garage door should be opened when hydrogen is detected. 

• Quantify the risk of hydrogen ignition in the air conditioning (A/C) system during pressure relief 

device failure.

• Determine whether risk due to pressure relief device failure could be reduced by restricting vehicle 

location.

• Determine whether risk during pressure relief device failure could be reduced by relocating air 

conditioning return duct.

• Determine the severity of ignition of hydrogen leaking in bay.

• Determine the severity of ignition of hydrogen leaking under a large vehicle.

Task B - Development of Method to Determine Hydrogen Sensor Placement

• Develop a method to visualize the motion of gases from a hydrogen leak to aid in determining 

optimized hydrogen sensor locations for safety applications.

Task C - Safety and Analysis for Writing of Codes and Standards

• Determine the effect of hydrogen flame impingement on gypsum board.

• Determine the effect of hydrogen gas leakage from a residential refueler.

Approach

• Identify questions concerning safety of hydrogen installations or safety concerns of authors of codes 

and standards.

• Design tests or computer models to answer questions identified.

• Conduct tests to directly answer questions or verify computer model.

Accomplishments 

• Implemented conclusion that CaFCP garage door should not be opened upon detecting hydrogen in 

bay.

• Determined that pressure relief device failure could cause hydrogen ignition in the CaFCP air 

conditioning system.

• Determined that restricting vehicle location to prevent the above scenario would reduce usable CaFCP 

bay space by 50%.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

592

• Implemented conclusion that lowering air conditioning duct by eight feet would reduce the likelihood 

that pressure relief device failure would lead to hydrogen ignition in the CaFCP air conditioning 

system.

• Determined the maximum-recorded overpressure created by a 38.5 SCFM hydrogen leak in the bay 

was 0.17 psi at a distance of 1.5 ft from the centerline of the leak.

• Determined the maximum-recorded overpressure created by a 13 SCFM hydrogen leak under the fullscale model of the front half of a hydrogen-fueled bus was less than 0.03 psi.

• Developed a machine to produce a stream of helium-filled bubbles to track conservative path of rising 

gas.

• Determined maximum temperature rise on the backside of gypsum board during hydrogen flame 

impingement was 144°F.

• Determined residential garage could undergo 12 SCFM leak of hydrogen with proper venting and 

electrical restrictions.

Future Directions 

• Determine proper separation distances for hydrogen facilities.

• Determine additional costs incurred when constructing hydrogen facilities.

Introduction 

The goals and objectives of this work effort were 

developed anticipating the needs of various projects 

and authors of codes and standards. This work 

addresses potential safety concerns due to hydrogen 

leakage in three areas of hydrogen utilization. These 

safety concerns affect the widespread use of 

hydrogen in the private sector. The three areas of 

hydrogen utilization are as follows:

• Task A -- Safety Analysis of California Fuel 

Cell Partnership Building

• Task B -- Development of Method to 

Determine Hydrogen Sensor Placement

• Task C -- Safety Analysis for Writing of 

Codes

Approach 

As noted in the above list of objectives, nine 

different questions were addressed in this year's 

work. The six questions of Task A dealt with 

potential modifications to the existing CaFCP 

building. Computer models of various accident 

scenarios involving hydrogen leaks inside the 

building resulted in two modifications. The models 

were used to define the problem and also to 

investigate potential solutions. Task B was the design 

and construction of a device to aid in hydrogen 

sensor placement. This was done by creating a 

helium soap bubble machine that created a stream of 

single helium soap bubbles. Running the machine, 

positioned at the location of a potential hydrogen 

leak, allows the operator to visualize a conservative 

estimate of how the gas cloud is affected by air 

circulation inside the enclosure. Task C employed 

experimental measurements of temperature rises 

produced by hydrogen flames impinging on gypsum 

board and the same computer modeling approach as 

used in Task A to aid in determining the effects of 

hydrogen gas leakage from a residential refueler. 

Results 

Examples of some of the results are shown in 

Figures 1 - 5. Figure 1 shows that a burnable cloud 

of hydrogen surrounds the electric motor, which 

opens the garage door, at the time the motor would 

be opening the door. The motor would likely ignite 

the cloud. The original hydrogen detection protocol 

was changed to prevent the problem. Figure 2 shows 

a burnable cloud of hydrogen filling the CaFCP A/C 

system (top of figure). Note the burnable mixture 

exiting the A/C vents on the floor. Since the A/C 

system would probably ignite the cloud, the A/C 

return duct was lowered to prevent the problem. 

Figure 3 shows the ignition of a 38.5 CFM leak of 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

593

hydrogen inside the bay. Resulting pressure rises 

were less than would result from bursting a child's 

balloon by overfilling it. Figure 4 shows the helium 

soap bubble machine designed to aid in visualizing 

hydrogen leakage and to assist in hydrogen sensor 

placement. Figure 5 shows hydrogen flames 

impinging on a gypsum board enclosure. Maximum 

temperature rise was 144°F.

Conclusions 

• CaFCP Building - keep garage door in it's 

current position when hydrogen is detected 

to prevent motor from becoming ignition 

source.

• CaFCP Building - lower air-conditioning 

return duct to greatly reduce likelihood of 

hydrogen entering air-conditioning system.

• Hydrogen leaks up to 38.5 SCFM in 

buildings will not produce dangerous 

Figure 1. 4.1% Hydrogen Constant Concentration 

Surface for an 80 SCFM Leak after 16 

Seconds with the A/C Off and 2100 SCFM 

Figure 2. 4.1% Hydrogen Constant Concentration 

Surface for a PRD Failure after 10 Seconds 

with 4400 SCFM A/C Flow and 2100 SCFM 

Exhaust Fan Flow

Figure 3. Ignition of 38.5 SCFM Hydrogen Leak in Bay

Figure 4. Helium Bubble Machine
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

594

overpressures if ignited as long as the 

building is ventilated well enough to prevent 

accumulation of hydrogen at the ceiling.

• Hydrogen leaks up to 13.0 SCFM under a 

vehicle will not produce dangerous 

overpressures if ignited as long as the 

hydrogen is not allowed to enter the vehicle 

and the undercarriage is properly shaped to 

vent hydrogen.

• A stream of helium filled soap bubbles can 

be utilized to visualize hydrogen leakage in 

an enclosure.

• Gypsum board resisted hydrogen flame 

impingement.

• Leakage of hydrogen from residential 

refueling system can be removed from 

garage with proper ventilation.

FY 2002 Publications/Presentations 

1. "Hydrogen Leakage into Simple Enclosures", 

Swain, M.R., Filoso, P., Grilliot, E.S. and Swain, 

M.S., in publication in the International Journal of 

Hydrogen Energy

2. Invited Speaker, "The Safe Use of Hydrogen", 

National Fire Protection Association (NFPA), 

Anaheim California, May 12-16, 2001

3. Invited Panelist, "Hydrogen Venting" International 

Code Council (ICC) Ad hoc Committee, Denver 

Colorado, June 4-5, 2001

4. Invited Panelist, "CaFCP Building Safety 

Analysis", California Fuel Cell Partnership 

(CaFCP), Sacramento California, June 6-7, 2001

5. Invited Panelist, "Hydrogen Usage in Residential 

Garages", International Code Council (ICC) Ad 

Hoc Committee, Houston Texas, October 2-3, 

2001

6. Invited Lecturer, for ICC Educational Session, 

Greensboro North Carolina, October 30-31, 2001

7. Invited Speaker, International Code Council draft 

code presentation, Pittsburgh Pennsylvania, April 

18-19, 2002 Figure 5. Gypsum Board Flame Impingement Test
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

595

VI.B.3 Hydrogen Codes and Standards

Jim Ohi (Primary Contact) and Russ Hewett

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401

(303) 275-3706, fax: (303) 275-3886, e-mail: jim_ohi@nrel.gov

DOE Technology Development Manager: Neil Rossmeissl 

(202) 586-8668, fax: (202) 586-5860, e-mail: Neil.Rossmeissl@ee.doe.gov

Objectives

• Expedite hydrogen infrastructure development. 

• Coordinate infrastructure development activities, especially codes and standards, for the DOE 

Hydrogen, Fuel Cells, and Infrastructure Technologies Program.

• Incorporate hydrogen safety considerations into existing and proposed national and international codes 

and standards in order to facilitate market acceptance and penetration of the hydrogen technologies.

Approach

• Coordinate a collaborative national effort by government and industry to prepare, review, and 

promulgate hydrogen codes and standards.

• Bring together experts to address key issues and needs in national codes and standards workshops.

• Serve as a database repository, clearinghouse, and gatekeeper for the codes and standards activities 

being conducted within the DOE through the Hydrogen Codes and Standards Coordination Committee 

(HCSCC).

Accomplishments

• Established the DOE Hydrogen Codes and Standards Coordinating Committee (HCSCC) and 

conducted monthly conference calls and quarterly meetings.

• Aided the Hydrogen Ad Hoc Committee (HAHC) of the International Code Council (ICC) in 

developing and establishing support for the proposed changes to the ICC model codes regarding 

hydrogen.

• Completed first draft of a Hydrogen Codes and Standards Matrix and Database.

• Initiated work on a collaborative project with National Fire Protection Association (NFPA) to develop 

publications to assist local code officials.

• Assisted in the creation of the Hydrogen Technical Advisory Panel (HTAP) Hydrogen Safety 

Committee, contributing to the adoption of a charter, mission statement, and action plan.

Future Directions

• Continue the work of the HCSCC as the DOE focus for (a) coordinating codes and standards 

development efforts; (b) identifying and addressing codes and standards gaps and deficiencies; (c) 

identifying barriers with respect to getting codes and standards implemented; and (d) working with 

codes and standards development organizations to overcome such barriers.

• Facilitate incorporation of changes in the family of ICC model codes proposed by the HAHC.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

596

• Continue working with the Society of Automotive Engineers (SAE) and NFPA to facilitate 

development and dissemination of standards for transportation and stationary applications, 

respectively.

Introduction

The development and promulgation of codes and 

standards are essential if hydrogen is to become a 

significant energy carrier and fuel; codes and 

standards are critical to establishing a marketreceptive environment for commercializing 

hydrogen-based products and systems. DOE's 

Hydrogen, Fuel Cells, and Infrastructure 

Technologies Program and the National Renewable 

Energy Laboratory, with the help of some key 

stakeholders, are coordinating a collaborative 

national effort by government and industry to 

prepare, review, and promulgate hydrogen codes and 

standards needed to expedite hydrogen infrastructure 

development. 

Approach

This project involves coordinating codes and 

standards development efforts on a number of fronts, 

including: (1) working collaboratively with codes 

and standards developing organizations; (2) keeping 

track of the development of hydrogen technology for 

various applications; (3) working collaboratively 

with technology developers to identify critical codes 

and standards needs; (4) articulating codes and 

standards needs, and working to get needed efforts 

underway; and (5) conducting technology transfer 

activities targeted at building-code and fire-safety 

officials, local/state/Federal policymakers and other 

strategic stakeholders.

Results

International Code Council's Hydrogen Ad-Hoc 

Committee

The International Code Council (ICC) is a joint 

venture of the three major code councils in the U.S., 

established to develop uniform national model 

building codes. The existing ICC model codes do not 

include hydrogen as an energy source or fuel cells as 

either power-generating devices or as appliances. To 

address this limitation, the ICC has established an 

Ad-Hoc Committee (HAHC) on hydrogen 

technologies. The HAHC is working with a diverse 

group of technical and advisory parties to review 

current codes and standards applicable to hydrogen, 

to determine the adequacy of its coverage in the ICC 

International Codes, and to propose changes as 

necessary. The HAHC has prepared proposed 

amendments to the ICC model Building, Fire, 

Electrical, Mechanical, and Fuel Gas codes for 

hydrogen that will be up for final consideration at the 

ICC Code Hearing in October 2002.

DOE Hydrogen Codes and Standards Coordination 

Committee

The DOE Hydrogen Codes and Standards 

Coordination Committee (HCSCC) was established 

with the mission of coordinating the development 

and implementation of a consistent set of hydrogenrelated codes and standards that will ensure the safe 

production, delivery and use of hydrogen, and 

facilitate the accelerated commercialization of 

hydrogen technologies. Since its creation, the 

HCSCC has held monthly conference calls to update 

participants on current activities and to discuss key 

issues. The HCSCC has also convened two quarterly 

meetings in Washington, D.C. The HCSSC is 

planning to conduct workshops, which will provide a 

forum for organizations involved in hydrogen codes 

and standards development to identify the activities, 

gaps, and opportunities in this effort.

DOE Hydrogen Technical Advisory Panel

The Hydrogen Technical Advisory Panel 

(HTAP) Safety Committee was established in 2001 

to provide a national forum to discuss critical issues 

in hydrogen safety, including codes and standards. 

Over the last year, the committee held both an annual 

and regional Hydrogen Safety Summit to define the 

current baseline on hydrogen safety capability and to 

identify critical codes and standards needs and 

priorities. At the national Hydrogen Safety Summit, 

scheduled for October 2002, the committee plans to 

present and discuss a National Hydrogen Safety 

Agenda.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

597

Partnership for Advancing the Transition to 

Hydrogen

The DOE is sponsoring the Partnership for 

Advancing the Transition to Hydrogen (PATH) to 

coordinate codes and standards activities among key 

countries outside of the European Union. To date, 

Canada, Japan, and the U.S. have made commitments 

to join PATH. An organizational meeting was held at 

the World Hydrogen Energy Conference (WHEC) in 

June 2002. The DOE is funding the administrative 

costs for at least the first year of PATH and 

providing technical support.

Outreach

Public education and information dissemination 

on hydrogen safety are key components of the DOE 

hydrogen effort. As a continuing part of its 

coordination effort, the DOE is providing support to 

the National Hydrogen Association (NHA) to publish 

a monthly electronic letter covering codes and 

standards activities and issues for the U.S. hydrogen 

community. The DOE co-sponsored a new 

educational video, Hydrogen Energy: The Safe and 

Clean Alternative, which is targeted at the general 

public and was premiered at the WHEC. The DOE is 

also sponsoring outreach efforts to building and fire 

code officials by developing seminars, training, and 

handbooks on permitting hydrogen facilities. 

Conclusions

• The DOE has supported a growing and 

increasingly important effort to coordinate 

the development and promulgation of 

hydrogen codes and standards.

• In addition to supporting specific projects to 

develop codes, such as that of the ICC/

HAHC, and standards, such as that of ISO 

TC197, the Program is supporting the 

coordination of many other efforts so that 

codes and standards can be developed and 

adopted as efficiently as possible and so that 

the lack of codes and standards will not be a 

barrier to the commercialization of hydrogen 

technologies.

• There are many government and nongovernment organizations independently 

involved in generating codes and standards, 

thus support of codes and standards efforts 

will remain an important part of the 

Hydrogen, Fuel Cells, and Infrastructure 

Technologies Program for many years to 

come.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

598

VI.B.4 SAE Fuel Cell Codes and Standards Initiative

Anthony Androsky 

SAE International

1300 Eye St. NW

Suite 1090 East Tower

Washington, DC 20005-3314

(202) 962-8684, fax: (202) 962-8692, e-mail: tandrosky@sae.org 

DOE Technology Development Manager: Neil Rossmeissl

(202) 586-8668, fax: (202) 586-5860, e-mail: Niel.Rossmeissl@ee.doe.gov 

ANL Technical Advisor: Walter Podolski

(630) 252-7558, fax: (630) 972-4430, e-mail: podolski@cmt.anl.gov

Objectives

• Facilitate and accelerate the development of codes, standards, and recommended practices for fuel cell 

powered vehicles in order to smoothly and uniformly transition fuel cell vehicles into the marketplace.

Approach

• Directly support the SAE Fuel Cell Committee and its seven working groups and establishment of new 

groups where required.

• Develop liaisons, collaborations, and cooperative working agreements with technical topic area 

organizations (e.g. U.S. Fuel Cell Council, National Fire Protection Association, The Methanol 

Institute).

• Directly support Cooperative Research Projects for development and verification of pre-competitive 

data for use in codes, standards and recommended practices.

• Support workshops and meetings to facilitate expert advisor input

• Support technical expert advisors as needed by the SAE Standards Committee, working groups and 

SAE Cooperative Research Projects.

Accomplishments

• J2572, Recommended Practice for Measuring the Exhaust Emissions, Energy Consumption and Range 

of Fuel Cell Powered Electric Vehicles Using Compressed Gaseous Hydrogen (draft)

• J2574, SAE Information Report - Fuel Cell Electric Vehicle Terminology (published)

• J2578, Recommended Practices for General Fuel Cell Vehicle Safety (published)

• J2579, Recommended Practices for Hazardous Fluid Systems in Fuel Cell Vehicles (draft)

• J2594, Fuel Cell Recyclability Guidelines (in ballot)

• J2600, Compressed Hydrogen Vehicle Fueling Connection Devices (published)

• J2601, Compressed Hydrogen Vehicle Fueling Communication Devices (draft)

• J2615, Performance Test Procedures of Fuel Cell Systems for Automotive Applications (final draft)

• J2616, Performance Test Procedures for the Fuel Processor Subsystem of Automotive Fuel Cell 

System (draft)

• J2617, Performance Test Procedures of PEM Fuel Cell Stack Subsystem for Automotive Applications 

(final draft)
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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• Agreement with the IEC TC105 WG-#6 

• Memorandum of Understanding (MOU) with the JEVA (Japanese Electric Vehicle Association)

• Working Relationship with the EIHP-II (European Integrated Hydrogen Project)

• Inclusion of the SAE within the dialogue of the GCG (Global Cooperation Group)

• MOU with the National Fire Protection Association

Future Directions

• The intent of this activity is to assist in providing a safe, reliable product to the public by way of a 

responsible, industry friendly climate that is environmentally sound, i.e., development of Standards, 

Codes and Recommended Practices that enable commercialization of automotive fuel cell 

applications. 

Introduction

As with any new technology that is attempting to 

move towards commercialization, the establishment 

of standards, codes and recommended practices is a 

major concern. If done through a widely accepted 

consensus process that leads credence to industry 

endorsed, globally accepted rule making-- then 

standards development becomes the leveraging 

shoehorn that allows for the perfect fit, and enables 

marketplace acceptance and ease of 

commercialization. 

In early 1999, the fuel cell literate world had no 

clear, defined direction or globally accepted 

leadership in standards development for 

transportation applications of fuel cells. In fact, the 

major standards development organizations, both 

domestic and international, were anticipating a “not 

recommended landscape” of work duplication, 

mismatched data, non-consensus documents and 

chaos that would certainly inhibit commercialization 

and negatively impact rulemaking.

The introduction in mid-1999 of the SAE Fuel 

Cell Standards Initiative and establishment of the 

SAE Fuel Cell Standards Forum changed the climate 

of standards development for vehicles. Not only did 

the U.S. outlook take on a positive source of urgency, 

but also the SAE Fuel Cells Forum was quickly 

recognized as the global leader by the European and 

Pacific concerns.

Approach

The SAE will initiate, facilitate, develop and 

publish required standards and standards processes 

for fuel cell powered vehicles.

The SAE has formed and will form relationships 

with sectors, organizations and committees that 

effect or are affected by fuel cell technology for 

vehicles. These include, but are not limited to, 

vehicle manufacturers and their suppliers, fuel cell 

manufacturers and their suppliers, energy providers 

and their suppliers, national and international 

government agencies and other organizations 

involved with the development of the necessary and 

ancillary infrastructure and support facilities/

structures.

Deliverables will include draft recommended 

practices and codes and standards as applicable that 

are necessary for the operation of fuel cell powered 

vehicles (Figures 1 and 2).

SAE will utilize a fuel cell standards group and 

others to accomplish deliverables. The Fuel Cell 

Standards Group will be chartered on the following 

premise:

To establish standards and test procedures for 

fuel cell powered vehicles. The standards will 

cover safety, performance, reliability and recyclability of fuel cell systems in vehicles with 

emphasis on efficiency and environmental 

impact. The standards will also establish test 

procedures for uniformity in test results for the 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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vehicles/systems/components performance, and 

define interface requirements of the systems to 

the vehicles.

The Fuel Cell Standards Group includes the 

following working groups: safety, performance, 

emissions, interface, terminology, and recyclability. 

These working groups include representatives from 

automotive original equipment manufacturers 

(OEMs), automotive OEM suppliers, fuel cell 

developers/manufacturers, fuel cell manufacturer 

suppliers, energy suppliers, energy supplier 

providers, government agencies and national and 

international organizations that are related to fuel cell 

industry and infrastructure.

The SAE Fuel Cell Standards Group will 

collaborate or liaison directly with ISO/TC22 and 

ISO/TC 22 SC21, IEC/TC105, IEC/TC105 WG6, 

IEC/TC 69, ISO/TC 197, and ISO/TC 58. The SAE 

Fuel Cell Standards Group will work cooperatively 

with U.S. Fuel Cell Council, National Hydrogen 

Association, Canadian Hydrogen Association, 

Japanese Electric Vehicle Association (JEVA), 

American Petroleum Institute, Underwriters 

Laboratory, CSA International, US Air Force, US 

Army, National Laboratories, US Air Force Research 

Labs, and the US Air Force Alternate Fuel Initiative 

among others directly or indirectly involved in fuel 

cells for transportation applications and its support 

infrastructures.

Results

The Emissions & Fuel Consumption working 

group’s mission is to establish standards and test 

procedures for measuring emissions and fuel 

consumption for fuel cell powered vehicles. The 

standards and test procedures to be created will 

provide methods for measuring exhaust and 

evaporative emissions, plus the fuel consumption 

measurement for the fuel cell vehicle. The goal is to 

establish methodology for uniformity in test results 

for all designs of fuel cell vehicles, and allow a 

comparison with conventional vehicles. J2572 is the 

first document that this working group is completing. 

This document is for fuel cell vehicles using 

compressed hydrogen gas supplied by an off-board 

source and stored as a compressed gas onboard. The 

procedure includes hybrid (use of a storage battery 

for traction power) versions of fuel cell vehicles. 

The working group will address fuel cell vehicles 

that have a reformer on-board to produce hydrogen 

once J2572 is completed.

The Interface working group was created to 

develop standards to coordinate between fuel 

suppliers and vehicle manufacturers to ensure safe, 

efficient and customer friendly delivery of fuel to 

fuel cell powered vehicles. Topics to be covered 

include fuel supply, infrastructure, fuel storage, fuel 

processor and vehicle interface. The Interface 

working group has two draft standards in progress, 

J2600 and J2601. J2600, Compressed Hydrogen 

Figure 1. Not Recommended Landscape for Vehicle 

Standards Development

Figure 2. Recommended Landscape for Vehicle 

Standards Development
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Vehicle Fueling Connection Devices, defines the 

geometries of the receptacles for different pressure 

levels. It has been successfully balloted, with a 98% 

APPROVAL rating and NO DISAPPROVAL ballots. 

J2601, Compressed Hydrogen Vehicle Fueling 

Communication Devices, will define the different 

fueling strategies and document their advantages and 

disadvantages with respect to type III and IV tanks. It 

will also develop the strategies and protocols for 

what refueling with and without communications 

should look like. In addition, it will identify what 

technology wireless communication should utilize to 

be most effective in an automotive environment. 

Data is being collected for this draft standard. It is 

targeted is to be completed in the second quarter of 

2003.

Developing a guidance document that 

incorporates and summarizes existing recyclability 

measurement techniques and identifies recyclability 

issues associated with fuel cells in End of Life 

Vehicles (ELVs) is the goal of the Recyclability 

working group. J2594, Fuel Cell Recyclability 

Guidelines is currently under final pre-ballot review 

by the Fuel Cell Standards committee.

To recommend design and construction, 

operation, emergency response and maintenance 

practices for the safe use of fuel cell vehicles by the 

general public is the goal of the Safety working 

group. J2578 is the first safety document that covers 

the general safety of the vehicle. J2578 has already 

been successfully balloted. However, in the attempt 

to address all participating comments, the committee 

has agreed to incorporate, where applicable, this new 

information. The document is currently under its 

second ballot and is expected to be APPROVED by a 

unanimous ballot (100% approval rating). J2579, 

Fuel Systems for Fuel Cell Vehicles, is the second 

document the safety working group currently has 

under work.

The first document of the SAE Fuel Cell 

Standards Committee to be completed was developed 

by the Terminology working group. J2574, Fuel Cell 

Terminology Report, was balloted in September 

2001. It is used world wide as a reference source and 

foundation document for all of the Vehicle Fuel Cell 

Standards efforts. This report defines terminology 

for fuel cell powered vehicles.

The mission of the Performance working group 

is to develop procedures for testing the Proton 

Exchange Membrane (PEM) fuel cell system and its 

major subsystems for automotive applications. The 

working group currently has three draft standards 

under development, J2615, J2616 and J2617. The 

Performance task group is defining performance and 

measured parameters for three test subjects: PEM 

fuel cell system, fuel processor and PEM fuel cell 

stack. Major subsystems of the PEM fuel cell system 

are the following: fuel processor, fuel cell stack, air 

processor, thermal management, water management 

and electronic controller. Test procedures are being 

developed for both steady state and transient (start-up 

and load following) performance measurements. 

Instrumentation to be used, pre-test procedures to 

ensure safety in testing, limitations of test procedures 

and methods of calculating and reporting results will 

all be addressed in the documents. The target 

completion date for these three documents is 2002.

Conclusions

The continued work of the SAE Fuel Cell 

Standards committee and its working groups, has 

provided the single point of reference to all agencies, 

U.S. or global, in regards to standards pertaining to 

transportation/mobility applications. As the 

proliferation of fuel cell vehicles gains momentum, 

the need for standardization becomes critical. 

Regulation and rule-making, coupled with growing 

interest in global technical regulations (GTRs) in 

many countries, cause an urgent demand for 

foundation data and documents. The SAE committee 

remains the best near term solution to address and 

provide this needed data and source documentation.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Section VII. Conversion Devices
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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VII.A Conversion Devices - Turbines

VII.A.1 Reduced Turbine Emissions using Hydrogen-Enriched Fuels

Robert Schefer (Primary Contact), Joe Oefelein

Sandia National Laboratories

7011 East Ave

Livermore CA 94550

(925) 294-2681, fax: (925) 294-2595, e-mail: rwsche@sandia.gov

DOE Technology Development Manager: Neil Rossmeissl 

(202) 586-8668, fax: (202) 586-5860, e-mail: Neil.Rossmeissl@ee.doe.gov

Objectives 

• Quantify effect of hydrogen addition on flame stability, combustor acoustics, emissions and efficiency 

in a gas turbine.

• Establish a scientific and technological database for lean combustion of hydrogen-enriched fuels.

• Establish numerical simulation capabilities that will facilitate design optimization of hydrogen and 

hydrogen-enriched lean gas turbine combustors.

• Develop criteria for use of hydrogen addition as a control knob to eliminate instabilities related to 

varying product gas composition.

Approach

• Design and fabricate a lean premixed swirl burner that simulates the basic features of gas turbine 

combustors.

• Apply advanced experimental diagnostics to understand fluid dynamics, combustion chemistry, and 

pollutant formation.

• Develop a computational model for combustor performance in parallel with an experimental project 

based on next generation Large Eddy Simulation (LES) technique. Use experimental database for 

model validation.

• Identify problem areas in practical gas turbine combustors where hydrogen enrichment of hydrocarbon 

fuels could be beneficial.

Accomplishments 

• Completed design and fabrication of lean premixed swirl burner that will be used to study combustion 

of H2-blended hydrocarbon fuels in stationary gas turbine environment. (Collaboration with the 

National Energy Technology Laboratory).

• Completed design and fabrication of prototype H2/air burner for aircraft gas turbine applications. 

Characterized relationship between flame and fluid dynamics and evaluated fuel/air mixing. 

(Collaboration with NASA Glenn.)

• Formed collaboration with General Electric Aircraft Engines (GEAE) to evaluate production fuel 

injector for use with hydrogen-blended fuels.

• Developed international effort through the International Energy Agency (IEA) to address aspects of 

H2-enriched hydrocarbon fuels for low emission, high efficiency gas turbine combustion. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Future Directions 

• Assess and verify the flow, flame characteristics and dynamic stability limits of the lean premixed 

hydrogen swirl burner.

• Establish a representation of the turbulent recirculating flow characteristics in the swirl burner using 

the LES model approach.

• Establish a framework for modeling hydrogen-enriched lean premixed combustion in the presence of 

acoustically active flame processes.

• Complete development of test matrix for GEAE swirlcup fuel injector and perform testing. Identify 

areas where hydrogen enrichment could be beneficial.

• Continue the formation of a broad consortium of industrial partners.

• Continue development of international collaborations, both directly and through the IEA.

Introduction 

The development of advanced combustion 

capabilities for gaseous hydrogen and hydrogenblended hydrocarbon fuels in gas turbine applications 

is currently an area of much interest. Driving this 

interest are several needs. One need is the costeffective utilization of alternative fuels with a wide 

range of heating values. For example, fuels 

containing significant hydrogen are often produced 

as a by-product in Coal-Gasification Combined 

Cycle installations. These product gases could 

provide a significant source of cost-effective fuels for 

gas turbines. A second need is related to the 

recognition that ultra-lean premixed combustion is an 

effective approach to NOx emissions reduction from 

gas turbine engines. Hydrogen blended with 

traditional hydrocarbon fuels significantly improves 

flame stability during lean combustion and allows 

stable combustion at the low temperatures needed to 

minimize NOx production. 

A longer-term need is to eliminate unburned 

hydrocarbon (UHC) and CO2 emissions. Gas 

turbines account for 20% of U.S. CO2 emissions, 

which is a significant fraction of the total current 

CO2 emissions. This number will increase as natural 

gas turbines replace older coal-fired steam generation 

plants. The use of hydrogen-blended hydrocarbon 

fuels thus provides both a solution to the immediate 

need for NOx reduction, and also provides a 

transition strategy to a carbon free energy system in 

the future.

Approach 

The addition of hydrogen to hydrocarbon fuels 

affects both the chemical and physical processes 

occurring in flames. These changes affect flame 

stability, combustor acoustics, pollutant emissions, 

and combustor efficiency. Few of these issues are 

clearly understood. This project will investigate 

issues surrounding hydrogen and hydrogen-enriched 

hydrocarbon fuel use and will include studies of 

chemical kinetics, fluid dynamics and flame structure 

to better define and understand these issues. Both 

experimental and modeling approaches are being 

utilized. The experimental data will be obtained 

using an array of advanced laser diagnostic 

techniques that provide information on flame 

structure, fluid dynamics, combustion gas species 

concentrations and temperature. These 

measurements, in addition to providing direct 

insights into the effects of hydrogen enrichment on 

combustion and pollutant emissions, will provide the 

technological database needed for the parallel 

development of a numerical code, based on the LES 

technique, to simulate lean premixed combustion of 

hydrogen and hydrogen-enriched fuels. Close 

collaborations have been developed with industrial 

partners to provide a mechanism for the transfer of 

this technology to practical applications in stationary 

and aircraft gas turbines. These collaborations will 

facilitate the identification of problematic areas 

related to practical gas turbine design and hardware. 

Areas where hydrogen addition could prove 

beneficial will be identified, and the potential merits 

of hydrogen-enriched hydrocarbon fuels will be 

demonstrated.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Results 

The design and fabrication of a lean premixed 

swirl burner representative of land-based industrial 

applications was completed. This burner will be used 

to study combustion of hydrogen and hydrogenblended hydrocarbon fuels. The design emphasizes 

well-characterized flow and boundary conditions to 

facilitate the development of a database for LES 

model validation. Emphasis with regard to LES has 

been placed on providing support calculations for 

design purposes and establishing an initial baselinemodeling framework for treatment of hydrogenenriched, premixed methane flames. This burner is 

shown in Figure 1. The burner design is operationally 

relevant to industrial devices and is optimally tuned 

for flow and diagnostic capabilities at the Sandia 

Combustion Research Facility.

The design and fabrication of a prototype 

hydrogen/air burner for aircraft gas turbine 

applications was completed in collaboration with 

NASA Glenn. The stability and burning 

characteristics of fuel-lean hydrogen/methane/air 

flames were characterized over a range of operating 

conditions. Figure 2 shows the effect of hydrogen 

addition on flame stability, where the variable nH2 is 

the fraction of hydrogen in the fuel (nH2=0 

corresponds to pure methane and nH2=1 is pure 

hydrogen). The equivalence ratio is a measure of the 

fuel/air ratio. These measurements were obtained by 

igniting the flame and then decreasing the fuel/air 

ratio until the flame is completely extinguished, or is 

blown out. The flame typically becomes unstable as 

the blowout condition is approached. Increasing the 

hydrogen content from 70% to 100% results in a 

significant shift in flame blowout conditions to leaner 

fuel/air ratios. Since operation at leaner fuel/air ratios 

results in a lower flame temperature and reduced 

NOx emissions, it is clear that hydrogen addition 

allows stable operation at the lean operating 

conditions needed to limit NOx emissions. Mixing of 

the fuel and air is also important, since incomplete 

mixing leads to higher flame temperatures, increased 

NOx and lower efficiency. Planar Laser Induced 

Fluorescence (PLIF) measurements of acetone, 

which was added as a fuel tracer, were obtained to 

evaluate the mixing of the fuel and air. Based on 

these measurements, design improvements will be 

identified and implemented. PLIF measurements of 

the hydroxyl (OH) radical, which is important to 

flame chemistry, were obtained to characterize the 

relationship between the flame and fluid dynamics.

The use of hydrogen addition to natural gas 

feedstocks of midsize (30-150 megawatt) gas 

turbines was analyzed as a method of reducing NOx. 

Cost comparisons were made with current control 

technologies for both existing and new systems to 

determine its benefits and market feasibility. Less 

than 3 ppm NOx should be achievable with 15% H2

addition. The comparisons in Figure 3 show that 15% 

H2 addition is cost competitive with both 

conventional Selective Catalytic Reduction (SCR) 

and high temperature SCR over a wide range of plant 

Figure 1. Lean premixed swirl burner designed to study 

combustion of hydrogen and hydrogenblended hydrocarbon fuels.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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power outputs. Higher levels of hydrogen addition, 

while somewhat more expensive, should offer even 

lower NOx emissions. 

Conclusions 

• Hydrogen addition significantly improves 

flame stability and allows stable burner 

operation at the lean fuel/air ratios needed 

for reduced NOx emissions.

• Hydrogen addition for NOx reduction to the 

3 ppm level is cost competitive with current 

control technologies and has the potential to 

reduce NOx emissions lower than any other 

control strategy.

Publications

1. R. W. Schefer, D. M. Wicksall and A. K. 

Agrawal: "Combustion of Hydrogen-Enriched 

Methane in a Lean Premixed Swirl-Stabilized 

Burner", Proceedings of the 29th Symposium 

(International) on Combustion, (2002).

2. R. W. Schefer: "Hydrogen Enrichment for 

Improved Lean Flame Stability", International 

Journal of Hydrogen Energy (accepted) 2002.

3. R. W. Schefer: "Reduced Turbine Emissions 

using Hydrogen-Enriched Fuels", Proceedings of 

the U.S. DOE Hydrogen Program Review, May 6-

8, Boulder CO (2002). 

Presentations

1. R.W. Schefer: "Reduced Turbine Emissions using 

Hydrogen-Enriched Fuel", 14th World Energy 

Conference, Montreal, Quebec, Canada, June 9-

13, 2002.

2. C. Termaath, E. Skolnick, J. O. Keller and R. W. 

Schefer: "Emissions Reduction Benefits from H2

addition to Midsize Gas Turbine Feedstocks", 

14th World Energy Conference, Montreal, 

Quebec, Canada, June 9-13, 2002.

Figure 2. Effect of Hydrogen Addition on Flame 

Stability in Prototype Hydrogen/Air Burner

Figure 3. Cost Comparison of 15% Hydrogen Addition 

with Current NOx Control Technologies
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VII.B Internal Combustion Engines

VII.B.1 Internal Combustion Engines Research And Development

Peter Van Blarigan

Sandia National Laboratories

7011 East Ave

Livermore, CA 94550

(925) 294-3547, fax: (925) 294-1322, e-mail: pvanbla@sandia.gov

DOE Technology Development Manager: Neil Rossmeissl

(202) 586-8668, fax: (202) 586-5860, e-mail: Neil.Rossmeissl@ee.doe.gov

Objectives

• Design and demonstrate high efficiency, low emissions hydrogen fueled 30 kW electrical generator

- 50% fuel to electricity conversion efficiency and near-zero emissions

Approach

• Utilize highly developed piston engine technology

• Combine free-piston, linear alternator and homogeneous charge compression ignition to achieve the 

following:

- Ideal Otto cycle performance

- Electronic compression ratio control

- NOx control by low equivalence ratio

Accomplishments

• Developed full-scale linear alternator test capability

• Designed two-stroke cycle scavenging system

• Completed analysis of power density and performance for aircraft applications (NASA funded)

• Evaluated 2 kW size combustion experiment (Sandia LDRD funded)

Future Directions

• Complete scavenging system experiment fabrication and testing

• Develop comprehensive system model

• Quantify linear alternator performance

• Form industrial consortium for commercial application

Introduction

Electrical generators capable of high conversion 

efficiencies and extremely low exhaust emissions 

will no doubt power advanced hybrid vehicles and 

stationary power systems. Fuel cells are generally 

considered to be ideal devices for these applications 

where hydrogen or methane is used as fuel. 

However, the extensive development of the internal 

combustion engine and the existence of repair and 

maintenance industries associated with piston 

engines provide strong incentives to remain with this 

technology until fuel cells are proven reliable and 

cost competitive. In addition, the fuel cell may not 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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offer significant efficiency advantages relative to an 

optimized combustion system. 

In Figure 1, the amount of work attained from a 

modern 4-stroke heavy-duty diesel engine is shown. 

The results indicate that under ideal Otto cycle 

conditions (constant volume combustion), 56% more 

work is available than from an ideal constant 

pressure combustion (ideal diesel) cycle. This 

extreme case of non-ideal Otto cycle behavior serves 

to emphasize how much can be gained by 

approaching constant volume combustion systems.

Approach

The free-piston linear alternator illustrated in 

Figure 2 has been designed in hopes of approaching 

ideal Otto cycle performance through homogeneous 

charge compression ignition (HCCI) operation. In 

this configuration, high compression ratios can be 

used and rapid combustion can be achieved.

The linear alternator is designed such that 

electricity is generated directly from the piston’s 

oscillating motion. Combustion occurs alternately at 

each end of the piston, and a modern two-stroke 

cycle scavenging process is used. The alternator 

component controls the piston’s motion and, thus, the 

extent of cylinder gas compression. Compression of 

the fuel/air mixture is achieved inertially, and as a 

result, a mechanically simple, variable compression 

ratio design is possible with sophisticated electronic 

control.

The combination of the HCCI combustion 

process and the free-piston geometry is expected to 

result in significant improvements in the engine’s 

thermal efficiency and its exhaust emissions. 

Combustion System - Tests

Figure 3 shows the result of one of the HCCI 

combustion analyses. In this investigation, a singlestroke rapid compression-expansion machine 

(RCEM) was used to compression ignite 

homogeneous fuel/air mixtures. The piston, for all 

practical purposes, does not move during the 

combustion event. In the free-piston configuration, 

high pressure-rise rates can be handled without 

difficulty since there are no load-bearing linkages, as 

in crankshaft-driven engines. 

Figure 1. Modern 4-Stroke Heavy Duty Diesel Engine 

Figure 2. Free-Piston Linear Alternator

Figure 3. Hydrogen HCCI Combustion using the RCEM
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Results - Linear Alternator

Two parallel paths are being pursued to develop 

the linear alternator. First, an alternator is being 

designed, built and tested in-house. In parallel, 

Magnequench, Inc. has designed and fabricated an 

alternator for this application. Both alternators will 

be tested under full design output conditions. A 

picture of the alternator tester is presented in Figure 

4.

Two Stroke-Cycle Scavenging System

Our approach is to utilize multi-dimensional 

modeling (KIVA–3V) to design the scavenging 

system and then to validate the computational 

predictions for selected operating conditions with the 

use of a single-cycle scavenging experiment. 

Important goals to be achieved with the 

scavenging design are high scavenging efficiency 

(ηsc>90%) and high trapping efficiency (ηtr>97%). 

For the computational study, inverted-loop and 

uniflow scavenging methods were investigated. A 

loop-scavenged option was investigated first due to 

its potential for a mechanically simple system. 

However, the mixing dynamics encourages fuel 

short-circuiting through the exhaust port. 

Additionally, for the configurations considered either 

high pumping losses or low power output must be 

accepted in order to achieve adequate cylinder 

charging.

An inverted-loop option was investigated next, 

with the intent of improving the trapping 

characteristics by placing the inlet ports above the 

exhaust ports. However, KIVA results showed the 

cylinder cannot be adequately charged, and a low 

scavenging efficiency (ηsc~0.45) and highly 

stratified charge result at the time of combustion.

The final scavenging option studied was a 

uniflow arrangement. In this configuration, four 

exhaust valves are located in the cylinder head, with 

intake ports located circumferentially around the 

bottom of the cylinder. Variation of the inlet port 

geometry and exhaust valve timing resulted in a more 

acceptable 83% scavenging efficiency with less than 

1% short-circuiting of the inlet flow. Further, a low 

driving pressure can be used to adequately recharge 

the cylinder. An example of the in-cylinder flows for 

this arrangement is shown in Figure 5. 

NASA Study

NASA-Langley requested assistance from 

Sandia to determine the feasibility of free-piston 

electrical generators in providing propulsive power 

for aircraft. The concept is to distribute generators 

throughout the aircraft and utilize electric motor 

powered fans to propel the aircraft.

Figure 4. Alternator Tester

Figure 5. KIVA-3V Calculated Uniflow Scavenging
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One discovery made during this study was that 

while turbocharging the engine does not allow 

significantly increased power output per stroke due 

to peak pressure limitations, it does appear to be 

capable of providing all of the pumping work 

necessary to scavenge the combustion chamber. The 

result of this is that we will incorporate a 

turbocharger into the baseline 30 kW prototype 

design.

Another interesting discovery was that increased 

boost pressures with hotter fuel/air mixtures can 

maintain peak pressures similar to unboosted 

operation, but this results in significantly increased 

oscillation rates, which in turn increase the power 

output of the device. 

Reduced-Size HCCI Combustion System

Another area for which the Advanced Generator 

Program has additional support is the investigation of 

a greatly reduced power output device. Funding is 

through internal laboratory sources with the objective 

of determining if the free-piston approach would 

work well for a single-occupancy vehicle that 

requires only 2 kW of output power. A small, rapid 

compression-expansion machine was fabricated with 

a bore of 1.2 cm, compared to the larger RCEM 

dimension of 7.6 cm. Figure 6 shows the near Otto 

cycle performance achieved, which is similar to that 

shown in Figure 3. Efficiencies were comparable to 

the 30 kW experiment. 

Conclusions

A novel combustion-driven reciprocating 

electrical generator has been designed to produce 

50% fuel to electricity conversion efficiency and 

essentially zero emissions. The prototype design is 

moving forward, with quantification of the 

performance of each piece of the prototype 

proceeding. To date no unsolvable technical barriers 

have materialized. 

Figure 6. HCCI Combustion using the Small RCEM
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VII.B.2 HCNG Heavy Duty Vehicle Prime Mover

Kirk Collier (Primary Contact), Neal Mulligan, Ranson Roser

NRG Tech

681 Edison Way

Reno, NV 89502

(775) 857-1937, fax: (775) 857-1938, e-mail: kcollier@nrgtech.com

DOE Technology Development Manager: Sigmund Gronich

(202) 586-1623, fax: (202) 586-5860, e-mail: Sigmund.Gronich@ee.doe.gov

Objectives

• Develop a low-emissions heavy-duty vehicle engine package to seamlessly repower today’s buses and 

trucks with existing natural gas and diesel engines. 

• Exceed DOE’s goal of reducing 1998 emission standards by 75% by achieving 99.5% reduction. 

Carbon monoxide (CO) emissions will be <1 ppm, non-methane hydrocarbon (NMHC) emissions will 

be <0.05 g/hp-hr, and oxides of nitrogen (NOx) will be <0.15 g/hp-hr. 

• Maintain or enhance current vehicle driveability by effective selection, matching, and configuring of 

off-the-shelf components.

• Maintain thermal efficiency of greater than 35%.

• Prove and enhance the engine design through in-service testing.

• Develop a public/private partnership to implement a commercialization plan that will bring new 

business and economic opportunities to Nevada. 

Approach

• Use hydrogen added to the natural gas fuel mixture to achieve high charge dilution ratios to create 

near-zero NOx emissions. 

• Incorporate an alternative engine design from that of current heavy-duty engines which includes: 

- Nickel silicon carbide cylinder bores

- Quiescent combustion

- Higher rpm operation 

- Larger displacement

- Mass air flow engine control

Accomplishments

• Demonstrated 0.22 g/hp-hr NOx simulated driving cycle emissions

• Produced equivalent power and torque to natural gas engine

• Demonstrated 36% engine efficiency

Future Directions

• Expand the work to convert five additional City of Las Vegas Buses to HCNG
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Introduction

The use of hydrogen as a fuel additive to extend 

the lean burn limit of conventional fuels has been 

repeatedly demonstrated to be a viable approach to 

achieving near-zero exhaust emissions from internal 

combustion engines. This technology is intended to 

be a near-term application for hydrogen and 

hydrogen infrastructure development given the 

current economic climate. Hydrogen fuel-related 

problems such as high fuel cost, high prime mover 

costs (fuel cells) and low energy density are largely 

overcome by supplementing natural gas, with 

hydrogen and using it in low-cost internal 

combustion engines. 

Although lean-burn has been widely accepted as 

a viable approach to lowering exhaust emissions, 

achieving it with conventional fuels has not been as 

successful as exhaust catalyst systems. Finding the 

best application for hydrogen-supplemented leanburn technology depends greatly on the nature of the 

engine loads and the standards used to test for 

exhaust emissions.

A significant philosophical difference between 

lean-burn and catalysts for controlling exhaust 

emissions is that lean-burn does not create the 

pollutants while catalysts chemically convert them. 

Understanding this basic difference is the key to 

recognizing the relative merits of each approach. 

Because pollutants are not created using the leanburn technology, the types and frequency of engine 

loads are inconsequential to emission levels. With 

catalyst systems, the temperature of the catalyst is 

extremely important in determining the efficiency of 

emissions control. When catalyst temperatures are 

too low, as exists when a vehicle is first started, 

catalyst efficiency is poor. When catalyst 

temperatures are too high, the catalyst is degraded. 

Both scenarios result in high exhaust emissions. 

Therefore, engine loading and the frequency of those 

loads are very important in determining how catalyst 

systems work because they affect catalyst 

temperature. Given this technology base, heavy-duty 

transportation is the area where hydrogensupplemented natural gas utilizing high charge 

dilution strategies can have the most significant 

impact on urban air quality.

Producing ultra-low exhaust emissions from 

heavy-duty vehicles differs markedly from that of 

light-duty vehicles. The most significant reason for 

this difference has to do with the relative power-toweight ratios between the two. Light-duty engines 

typically produce much more ultimate power than is 

required by the emissions certification driving test. 

On the other hand, the engines used in heavy-duty 

applications typically are operated at their maximum 

power level most of the time, and the heavy-duty 

emissions test mirrors that use. Where this impacts 

emissions reduction technology is the effect that 

charge dilution (adding excess gases to the air-fuel 

mixture over what is required for stoichiometric 

combustion) has on engine power.

Charge dilution, whether it be excess air (leanburn) or recirculated exhaust gases (EGR) or a 

combination of the two, is an extremely effective 

method of producing very low NOx emissions. The 

support of complete combustion under these extreme 

charge diluted conditions is the rationale for using 

hydrogen in the fuel mix. The disadvantage to 

charge dilution is the reduction in the engine’s 

maximum power output. This reduction in 

maximum power is the key to understanding why 

emissions control between light-duty and heavy-duty 

applications are significantly different.

The most effective way to recuperate lost engine 

power is to move more air through the engine. This 

is typically achieved by super/turbocharging or 

increasing engine rotational speed. Both of these 

techniques are readily implemented into light-duty 

engines. However, for heavy-duty engines, these 

techniques are not necessarily viable solutions. In 

the first place, heavy-duty engines are already 

turbocharged with significant levels of boost pressure 

to achieve high brake mean effective pressure 

(BMEP) at low rpm. Secondly, they are not readily 

adaptable to increased engine speed due to their 

extremely high reciprocating mass and low bore-tostroke ratios. Therefore, using extremely high boost 

pressures (~ 2-3 bar) with existing heavy-duty 

engines would create large parasitic loads and reduce 

fuel efficiency. Increasing engine speed on these 

heavy pieces would seriously compromise reliability. 

These observations along with the fact that heavyduty engines operate a great deal at maximum output, 

creates a serious problem for using charge dilution as 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

615

a technique for lowering heavy-duty vehicle 

emissions with existing engine platforms.

The solution to this problem is to create an 

alternative engine platform that is designed for high 

charge dilution with the ability to produce power 

characteristics equivalent to those of current engines. 

Equivalent power characteristics are an important 

consideration. Not only is maximum engine power 

output important, but the maximum engine torque 

and the rpm for maximum torque are also important. 

Approach

NRG Technologies, Inc. is using charge dilution 

as the mechanism for controlling harmful exhaust 

emissions. The basic technique employed is to 

combine EGR and lean-burn. Cooled and dried EGR 

will be used to control NOx emissions, and lean-burn 

will be employed to control CO and NMHC 

emissions. It is anticipated that lean-burn will be 

employed to achieve approximately 2 to 4% oxygen 

in the exhaust. This will allow an off-the-shelf 

oxidizing catalyst to achieve very high conversion 

rates for both CO and NMHC emissions. Because 

the exhaust gas temperatures will be comparatively 

very low (<1000oF), catalyst lifetime will be 

extremely high (>100,000 miles).

To achieve near-zero NOx emissions, (10 to 20 

ppm) using charge dilution, the engine must operate 

with an overall lambda (including EGR) of between 

1.8 and 2.0. To achieve this value, at least 30%, by 

volume, of the fuel must be hydrogen. Any less than 

that will not support sufficiently consistent 

combustion from cylinder-to-cylinder or from cycleto-cycle. Any attempts to achieve this through 

mechanical means (high turbulence combustion 

chambers, etc.) will result in (1) loss of engine 

efficiency through increased combustion chamber 

heat transfer rates and (2) increased NOx emissions 

compared to “quiescent” or open combustion 

chambers and hydrogen addition to the fuel. The 

result is that mechanical enhancement (swirl, tumble, 

etc.) for lean-burn will require higher values of 

lambda to achieve equivalent NOx emissions to that 

achieved by hydrogen-enhanced fuel.

Given the constraints for modifying existing 

heavy-duty engines, NRG proposes to develop an 

engine platform specifically-designed for high 

charge dilution that will create the same power 

characteristics to the rear wheels as the original 

natural gas or diesel engine. This is accomplished as 

follows:

• Large displacement engine:

- An 8.8L V8 engine

• Turbocharging to increase BMEP

• Increased engine speed with gear reduction:

- Using 8 cylinders rather than 6 allows 

greater engine rpm for the same engine 

displacement.

- A gearset mounted on the rear of the 

engine to match the torque and speed 

characteristics of the original natural gas or 

diesel engine. The existing transmission 

can be retained.

The main drawback to NRG’s approach will be 

the tendency to increase the frictional horsepower of 

the engine. All other things being equal, this will 

result in increased fuel consumption. There are 

many ways to combat this problem. They include the 

following:

• Higher values of lambda result in higher 

thermodynamic performance.

• Ratio of specific heats is higher which results 

in higher theoretical Otto Cycle efficiency.

• Very light valve train utilizing low spring 

pressure valve springs and low friction 

components (roller rockers and lifters).

• Cylinder coatings with low friction 

coefficients.

• Nickel-Silicon Carbide (currently used by 

BMW, Mercedes, and Porsche).

The overall engine package is controlled by an 

engine control module. The same basic package that 

NRG has used for electronic fuel, ignition, and 

actuator controls on all of their light-duty vehicles 

will also be used for this heavy-duty engine.

The test project will include the evaluation of 

exhaust emissions, engine performance, engine 

reliability, and vehicle performance. During Phase I, 

exhaust emissions were verified using a steady-state 

simulation of the Federal Driving Test. For Phase II 

of the project, emissions will be verified by a vehicle 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

616

driving test conducted at CAVTEC, an independent 

testing laboratory in Oakland, CA. For the on-theroad testing to be conducted in Las Vegas, an onboard data acquisition system (Campbell Scientific) 

with cell phone access will be installed on the bus. 

The measurements anticipated to be monitored 

include:

• Engine oil, water, and intake air 

temperatures

• Turbocharger boost pressure

• Engine rpm

• Throttle position

• Vehicle speed

Fuel economy will be measured using records of 

gas usage vs. bus mileage.

The maintenance program for Phase II will 

include:

• Periodic oil analysis

• Training of city personnel for:

- Engine oil usage

- Gearbox oil usage

- Filter replacements

- Gearbox troubleshooting

Results

A 30-ft. transit bus was purchased by DOE and 

shipped to NRG Tech for conversion to HCNG 

operation. This bus came equipped with a Cummins 

8.3L natural gas engine. The project called for 

characterizing the exhaust emissions from the current 

configuration so that the benefits of HCNG can be 

quantitatively assessed. Baseline exhaust emissions 

were taken from the engine using a steady-state 

emissions test protocol that is designed to simulate 

the heavy-duty driving test procedure. This protocol 

is as follows:

Engine rpm at Maximum Torque Value

Engine rpm at Maximum Power Value

The results of testing the Cummins engine that 

was installed in this bus using the protocol listed 

above are shown in Table 1.

Emissions results for the 8.8L NRG engine using 

the same testing protocol and using a 30/70 mixture 

of hydrogen and natural gas are shown in Table 2.

The final configuration for the 8.8L NRG engine 

consists of the following:

• 8.8L aluminum V8 engine

• Nickel-silicon carbide coated cylinder 

sleeves

• DIS ignition system

• Fuel injection system with feedback control

• Fully computer-controlled engine 

management system

Conclusions

Emissions, power, torque, and efficiency goals 

have been met. NOx emissions have been reduced by 

a factor of 20 when compared to the existing engine 

without a loss of power, torque characteristics, or 

fuel efficiency. Major milestones for the remainder 

of the project will be to demonstrate drivability in an 

operating bus and verify exhaust emissions in a 

driving test.

Test Point 1 100% load Emissions are 15% of 

weighted value

Test Point 2 75% load Emissions are 15% of 

weighted value

Test Point 3 50% load Emissions are 15% of 

weighted value

Test Point 4 10% load Emissions are 10% of 

weighted value

Test Point 5 100% power Emissions are 10% of 

weighted value

Test Point 6 75% power Emissions are 10% of 

weighted value

Test Point 7 50% power Emissions are 10% of 

weighted value

Test Point 8 Idle Emissions are 15% of 

weighted value
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

617

Table 1. 8 Mode Steady State Emissions Summary

Cummins 8.3L Natural Gas Engine (as received)

Individual Modes NOx

g/hp-hr

THC

g/hp-hr

NMHC

(g/hp-hr)

CO

g/hp-hr

Weighting

Factor

1400 rpm - 100% Load

 - 75% Load

 - 50% Load

 - 10% Load

2400 rpm - 100% Load

 - 75% Load

 - 50% Load

 800 rpm - Idle

7.42

4.70

5.67

5.77

1.18

0.80

0.44

6.96

5.21

2.57

3.37

7.70

2.82

4.26

5.56

107.74

0.16

0.08

0.10

0.23

0.08

0.13

0.17

3.23

0.19

0.22

0.25

0.59

0.28

0.32

0.37

12.98

0.15

0.15

0.15

0.10

0.10

0.10

0.10

0.15

Weighted 8 Mode (g/hp-hr) 4.60 19.87 0.58 2.20

Weighted 8 Mode (g/kw-hr) 6.16 26.63 0.78 2.95

Table 2. 8 Mode Steady State Emissions Summary

NRG Hydrogen-Enriched Natural Gas Bus Engine

Individual Modes NOx

g/hp-hr

THC

g/hp-hr

NMHC

(g/hp-hr)

CO

g/hp-hr

Weighting

Factor

1800 rpm - 100% Load

 - 75% Load

 - 50% Load

 - 10% Load

2800 rpm - 100% Load

 - 75% Load

 - 50% Load

 800 rpm - Idle

0.37

0.20

0.10

0.25

0.10

0.09

0.11

0.40

3.70

5.80

5.48

5.10

5.63

4.71

6.01

17.44

0.07

0.10

0.10

0.10

0.26

0.19

0.26

0.36

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.15

0.15

0.15

0.10

0.10

0.10

0.10

0.15

Weighted 8 Mode (g/hp-hr) 0.22 7.00 0.18 0.00

Weighted 8 Mode (g/kw-hr) 0.29 9.38 0.24 0.00
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Acronyms

A Amp

AAS Atomic Adsorption Spectroscopy

ACR Autothermal Cyclic Reforming 

ADVISOR Advanced Vehicle Simulator

AES Auger Electron Spectroscopy

AFC Alkaline Fuel Cell

AFV Alternative Fuel Vehicle

Ag Silver

AHC Ad Hoc Hydrogen Committee

AIAA American Institute for Aeronautics 

and Astronautics

Al Aluminum

Al/Si Aluminosilicate 

Al2O3 Aluminum Oxides

AMS Accelerator Mass Spectrometry

ANL Argonne National Laboratory

APCI Air Products and Chemicals, Inc

APU Auxiliary Power Unit

a-Si Amorphous Silicon

a-Si:Ge Amorphous Silicon/Germanium

a-SiC Amorphous Silicon Carbide

ASNT The American Society for 

Nondestructive Testing

ATDC After Top Dead Center

atm atmospheres

ATR Autothermal Reformer

ATR Auto-Thermal Reformer

Au Gold

BDI Boothroyd-Dewhurst, Inc.

BKI Bevilacqua-Knight, Inc. 

bmep Brake Mean Effective Pressure

BN Boron Nitride

BPSH Bi-Phenol Sulfone

BTI Breakthrough Technology Institute

C Carbon

oC Degrees Celsius

C2 plus Hydrocarbon gases containing 2 or 

more carbon atoms

C2H4 Ethylene

CAD Computer-Aided Drafting

CaFCP California Fuel Cell Partnership 

CaH2 Calcium Hydride

CAM Computer Aided Machining

CAM Computer Aided Manufacture

CAO Chlorophyll a Oxygenase

CARB California Air Resources Board

CCD Charge-Coupled Device

CCM Catalyst Coated Membrane

CEM Compressor Expander Module

CEM Continuous Emissions Monitor

CESI Catalystic Energy Systems, Inc.

CFD Computational Fluid Dynamics

CGO Gadolinium-Doped Ceria

CH2 Compressed Hydrogen Gas

CH2-ISS Compressed Hydrogen Gas 

Integrated Storage System 

CH4 Methane

CIDI Compressed Ignition Direct 

Injection

CIGS Copper-Indium-Gallium-Diselenide

Chl Chlorophyll

Cl Chlorine

CLP Corner Linked Polyhedral

cm Centimeters

cm2 Centimeters Squared

CMC Carbonxymethylcellulose

CNG Compressed Natural Gas

CO Carbon Monoxide

Co Cobalt

CO2 Carbon Dioxide

COD Chemical Oxygen Demand

CODH Carbon Monoxide Dehydrogenase

Cr Chromium

CSA Canadian Standards Association 

Cu Copper

Cu/ZnO Copper/zinc oxide

CVI Chemical Vapor Infiltration

CWRU Case Western Reserve University

DBM Dibutyl Maleate

dc Direct Current

DCM Dichloromethane

DCSF Diesel Combustion Simulation 

Facility

DECSE Diesel Emission Control-Sulfur 

Effects

DEP Double Electrode Plate technology

DFMA Design for Manufacturing and 

Assembly

DMAB Dimethylamine Borane

DMFC Direct Methanol Fuel Cell

DMI Diversified Manufacturing Inc. 

DOC Diesel Oxidation Catalyst

DOE Department of Energy

DPF Diesel Particulate Filter
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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DPG Distributed Power Generation

DSC Differential Scanning Calorimeter

EC TC 105 International Electrotechnical 

Committee Technical Committee for 

Fuel 

ECA Electrochemical Surface Area

ECD Energy Conversion Devices, Inc.

ECD-1 Emission Control Diesel-1

EDS Energy Dispersive Spectroscopy 

EDX Electron Dispersive X-Ray

EGR Exhaust Gas Recirculation

EIHP European Integrated Hydrogen 

Project

ELV End of Life Vehicle

EMC Electro Magnetic Compatibility

EPAct Energy Policy Act

ESR Electron Spin Resonance

EtOH Ethanol

eV Electron Volts

EXAFS Extended X-ray Absorption Fine 

Structure oF Degrees Fahrenheit

FCC Face-Centered Cubic

FCPS Fuel Cell Power System

FCV Fuel Cell Vehicle

Fe Iron

FeO2 Iron Oxide 

FET Field Effect Transistor

FG Flared Gas

FHDS Federal Highway Driving Schedule

Fl MH Fluorinated Metal Hydride

FMEA Failure Mode and Effects Analysis

FMEA Failure Mode Evaluation and 

Analysis

FOS Factor of Safety

FPS Fuel Processing System

FreedomCAR U.S. Department of Energy 

Automotive Research Partnership 

FT Fischer-Tropsch

FT100 Neat Fischer-Tropsch fuel

FTIR Fourier Transform Infrared

FTP Federal Test Procedure

FUDS Federal Urban Driving Schedule

FY Fiscal Year

g Gas Phase

g/s Gallons per Second

GA General Atomics

Ga2S3 Gallium Sulfide

GeS2 Germanium Sulfide

GeO2 Germanium Oxide

GaN Gallium Nitride

GC Gas Chromatography

GC/MS Gas Chromatography/Mass 

Spectrometry

GCG Global Corporation Group

GDATP General Dynamic Armaments and 

Technical Products 

GDL Gas Diffusion Layer

GE EER GE Energy and Environmental 

Research Corporation 

GHG Greenhouse Gas

GHSV Gas Hourly Space Velocity

GJ Giga-Joule 

GJ/t Giga Joule per Metric Ton

gm Gram

GRC Global Research Center

GREET Greenhouse gases, Regulated 

Emissions and Energy Use in 

Transportation

GTI Gas Technology Institute

GTR Global Technical Regulation

GV Gasoline internal combustion engine 

Vehicle

h Hours

H Hydrogen

h-1 per hour

(H2BNH2)x Polymeric Aminoborane

(HBNH)3 Borazine

(HBNH)x Polyborazine

H2Ge4S9 Dihydrogen Tetragermanium 

Sulfide

H4Ge4S10 Tetrahydrogen Tetragermanium 

Sulfide

H4Ge4S10·nH2STetrahydrogen Tetragermanium 

Sulfide with n Molecules of H2S

H4Ge4S10·xH2S Tetrahydrogen Tetragermanium 

Sulfide with x Molecules of H2S

H2-O2 Hydrogen and Oxygen Gas Mixture

H2 Hydrogen 

H2BNH2 Monomeric Aminoborane

H2O Water

H2S Hydrogen Sulfide

H2SO4 Sulfuric Acid

H3BNH3 Ammonia-Borane Complex 

HAD Hydrogen Adsorption/Desorption

HALT Highly Accelerated Life Testing 

HAZOP Hazardous Operations

HC Hydrocarbon

∆Hc° Heat of Combustion

HCI Hydrochloric Acid
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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HCN Hydrochloric Cyanide

HCNG Hydrogen Enriched Natural Gas

hcp Hexagonal Close Pack

HCSCC Hydrogen Codes and Standards 

Coordinating Committee

HDPE High Density Polyethylene

HEV Hybrid Electric Vehicle

∆Hf° Heat of Formation

HFA Hydrogen Fueling Appliance

HFSF High-Flux-Solar Furnace

HGS Hydrogen Generating System

HHV Higher Heating Value

H-ICE Hydrogen- Internal Combustion 

Engine

HOGEN Hydrogen Oxygen Generator

HOR Hydrogen Oxidation Reaction

∆Hr Heat of Reaction

HRT Hydraulic Retention Time 

HRTEM High-Resolution Transmission 

Electron Microscopy

HTAP Hydrogen Technical Advisory Panel

HTM High Temperature Membrane

HTM Hydrogen Transport Membrane 

HTPMWG High-Temperature Polymer 

Membrane Working Group

HTS High Temperature Shift

I

2R Ohmic Resistances

ICC International Code Council 

ICE Internal Combustion Engine

ICEV Internal Combustion Engine Vehicle

INEEL Idaho National Engineering & 

Environmental Laboratory

IPA Isopropyl Alcohol

ISO TC 197 International Organization of 

Standardization Technical 

Committee for Hydrogen 

Technologies

ISS Integrated Storage System

ITM Ion Transport Membrane

JEVA Japanese Electric Vehicle 

Association

JHU/APL Johns Hopkins University Applied 

Physics Laboratory 

JPL Jet Propulsion Laboratory

K Kelvin

K2O Potassium Oxide

kg Kilogram

kj/mole Kilo Joule

kJ/Mol-kilo Joule per Mole

km kilometers

KOH Potassium Hydroxide

kPa Kilopascal

Krpm Thousands of Rotations per Minute

kW Kilowatt

kWe Kilowatt Electrical

L Liter

LANL Los Alamos National Laboratory

LCHPP Low Cost Hydrogen Production 

Platform

LH2 Cryogenic Liquid Hydrogen

LHV Lower Heating Value

Li Lithium

Li2SO4 Lithium Sulfate

LiBH4 Lithium Borohydride

LiCl Lithium Chloride

LiF Lithium Flouride

LiH Lithium Hydride

LII Laser-Induced Incandescence

LME London Metals Exchange

LNG Liquefied Natural Gas

LPG Liquefied Petroleum Gas (Propane)

LPM I Liters Per Minute

LTS Low Temperature Shift 

M Molar

M HCIO4 Molar Perchloric Acid

m2Pa sec Mole per Meter Squared Pascal 

Second (flux unit) 

m3/hr Moles per hour cubed

mA Milliamps

MBMS Molecular-Beam Mass Spectrometer

MCH Methylcyclohexane

MDSC Modulated Differential Scanning 

Calorimetry

MEA Membrane Electrode Assembly

MECA Manufacturers of Emission Controls 

Association

MEMS Micro Electro Mechanical Systems 

MFC Mass Flow Controller

Mg Magnesium

mg Milligram

MHSS Metal Hydride Storage System

ML Monolayer

mm Millimeter

μm Microns

MMSCFD Million Standard Cubic Feet per Day 

Gas Flowrate

Mn Manganese

Mo Molybdenum

MOU Memorandum of Understanding

MPR Modular Pressurized Reformer
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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MSCFD Thousand Standard Cubic Feet per 

Day Gas Flowrate 

MSHA Mine Safety and Health 

Administration

MSW Municipal Solid Waste

MTS Medium Temperature Shift

mV Millivolt

mW Megawatt

mW/mg Milliwatts Per Milligram

N Normal

N2 Diatomic Nitrogen

NA North American

NaCl Sodium Chloride

NaF Sodium Flouride

NADP Nicotinamide Adenine Dinucleotide 

Phosphate

NaH Sodium Hydride

NaAlH4 Sodium Tetrahydroaluminate

Na3AlH6 TriSodium Hexahydroaluminate

Nb Niobium

NCNR NIST Center for Neutron 

Technology

NDIR Non-Dispersive Infrared

NEDC New European Drive Cycle

NETL National Energy Technology 

Laboratory

NFC Near Frictionless Carbon

NG Natural Gas

NGASE Natural-Gas-Assisted Steam 

Electrolyzer

NGCC Natural Gas Combined-Cycle

NH3 Ammonia

NH4Cl Ammonium Chloride

(NH4)2SO4 Ammonium Sulfate

NHA National Hydrogen Association

Ni Nickel

NIST National Institute of Standards and 

Technology

NL Natural Luminosity

Nm Nanometer

NMHC Non-Methane Hydrocarbon

NMOG Non-Methane Organic Gases

NMR Nuclear Magnetic Resonance 

NNA Non-North American

NOx Nitrogen Oxides

NOxEI Nitrogen Oxide Index

NPD Neutron Powder Diffractometer

NPV Net Present Value

NREL National Renewable Energy 

Laboratory

NRL Naval Research Laboratory

O&M Operating and Maintenance

O2 Oxygen Gas or Diatomic Oxygen

OECD Organization for Economic 

Cooperation and Development

OEM Original Equipment Manufacturer

OEP Octaethyl Porphyrin

ORNL Oak Ridge National Laboratory

ORR Oxygen Reduction Reaction

OTM Oxygen Transport Membrane

P&ID Piping and Instrumentation Diagram

PADT Phoenix Analysis and Design 

Technologies

PAH Polycyclic Aromatic Hydrocarbon

PCR Polymerase Chain Reaction

Pd Palladium

PDF Pair Distribution Function

PDF Pair-Density Function

PDU Process Development Unit

PEC Photoelectrochemical

PECVD Plasma-Enhanced Chemical Vapor 

Disposition

PEM Polymer Electrolyte Membrane

PEM Proton Exchange Membrane

PEMFC Proton Exchange Membrane Fuel 

Cell

PFA Personal Fuel Appliance

PFCT Porvair Fuel Cell Technology, Inc. 

PFD Process Flow Diagram

p-GaInP2 Gallium Indium Phosphide 

PGM Platinum Group Metal

PHA Personal Hazard Analysis

PM Particulate Matter

PM Precious Metal

PMV Personal Mobility Vehicle

PNNL Pacific Northwest National 

Laboratory

POEM Porous Oxide Electrolyte Membrane

POx Partial Oxidation

POx/SR Partial Oxidation/Steam Reformer

ppm Parts per Million

ppmv Parts per Million Volume

ppmw Parts per Million Weight

PQ Plastoquinone

PROX Preferential Oxidation

PrOx Preferential Oxidizer

PSA Pressure Swing Adsorption

PSI Photosystem I

Psi Pounds per Square Inch

PSIA Pounds Per Square Inch Absolute
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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PSIG Pounds Per Square Inch Gauge

PSII Photosystem II

Pt Platinum

Pt-FeOx Platinum-iron oxide 

PV Photovoltaic

R&D Research and Development

RDE Rotating-Disk Electrode

Re Rhenium

RFG Reformulated Gasoline

RH Relative Humidity

Rh Rhodium

ROI Record of Invention

RPECS Rapid Prototyping Electronic 

Control System

Ru Ruthenium

RuCl3 Ruthenium Chloride

Rx Rubrivivax 

s Solid Phase

S/C Steam/Carbon 

S/cm Siemens per centimeter

S2 Sulfur

SAE Society of Automotive Engineers

scc/hr/l Standard Cubic Centimeters per 

Hour per Liter

sccm Standard Cubic Centimeters per 

Minute

scfd Standard Cubic Feet per Day

scfh Standard Cubic Feet per Hour

scfm Standard Cubic Feet per Minute

SCORE Sandia/Caterpillar Optical Research 

Engine

SCP Single Cell Protein

SD Sputter Deposition

SECA Solid State Energy Conversion 

Alliance 

SEM Scanning Electron Microscope

SEP Subscale Engineering Prototype

SESHA Semiconductor Environmental, 

Safety, and Health Association

SET Sustainable Energy Technologies

SF6 Sulfur Hexafluoride

SFTP Supplemental Federal Test 

Procedure

SHE Standard Hydrogen Electrode

S-HTS Scrubber-High Temperature Shift 

SiC Silicon Carbide

SINL Spatially Integrated Natural 

Luminosity

SiO2 Silica Dioxide

slpm Standard Liters per Minute 

SMR Steam Methane Reformer

SO2 Sulfur Dioxide

SOFC Solid Oxide Fuel Cell

SR Steam Reformer

STAR Substrate based Transportation 

application Autothermal Reformer

SUV Sport Utility Vehicle

SWNT Single Walled Nanotube

SWOP Supercritical Water Partial 

Oxidation

SwRI Southwest Research Institute

t/yr tonnes/year 

Ta Tantalum

TBD To Be Determined

TCD Thermal Conductivity Detector

TCD Thermocatalytic Decomposition

TCR Thermocatalytic Reactor

TCR Total Capital Requirement

TCUF Thermochemical User’s Facility

TEA Technoeconomic Analysis

TEM Transmission Electron Microscopy

TEM Transmission Electron 

Photomicrograh

TGA-DSC Thermogravimetric AnalyzerDifferential Scanning

TGA-FTIR Thermogravimetric AnalyzerFourier Transform Infrared

TGC Tail Gas Combustor

THC Total Hydrocarbons

Ti Titanium

(TiAl0.1V0.04) Metal Hydride Alloy 

TiCl2 Titanium Dichloride

TiCl3 Titanium Trichloride

TiF3 Titanium Triflouride

TiO2 Titanium Dioxide

tla truncated light-harvesting Chl 

antenna

TMI Technology Management, Inc.

TPC Total Plant Cost

TPGME Tripropylene Glycol Monomethyl 

Ether

TPR Temperature-Programmed 

Reduction

T-RFLP Terminal Restriction Fragment 

Length Polymorphism

TVA Thermovolumetric analyzer

UH University of Hawaii

UIC University of Illinois at Chicago

UTRC United Technologies Research 

Center
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

624

V Vanadium

V Volt

VC Vulcan carbon, XC-72

VFA Volatile Fatty Acids

VNT7 Variable Nozzle Turbine

VOx Vanadium Oxide 

VRA Vehicle Refueling Appliance

W Tungsten

W Watt

WGS Water-Gas Shift

WHEC World Hydrogen Energy Conference

WHSV Weekly Hourly Space Velocity

WO3 Tungsten Oxide

Wt Weight

Wt% Weight Percent

WTW Well-to-Wheels

XAS X-ray Absorption Spectroscopy

XPS X-ray Photoelectron Spectroscopy

XRD X-ray Diffraction

XRF X-ray Fluorescense

ZEV Zero-Emission Vehicle

Zn Zinc

ZnO Zinc Oxide

Zr Zirconium

ZrOx Zirconia Dioxide

Ωcm2 Ohm-centimeter-squared
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Appendix A. Draft DOE Technical Targets

Tables 1 through 3 list the DOE technical targets for PEM fuel cell stack systems, fuel-flexible fuel 

processors, and integrated fuel cell power systems operating on gasoline. Target values listed in these tables 

represent a self-consistent set and must be achieved simultaneously. Targets for 2010 are R&D milestones for 

the purpose of measuring progress, not necessarily the targets required for successful commercialization of the 

technology. Table 4 lists the DOE technical targets for integrated fuel cell power systems running on direct 

hydrogen. Table 5 shows the technical targets for on-board hydrogen storage, and Table 6 lists the technical 

targets for off-board hydrogen production and dispensing infrastructure. Tables 7 through 10 list technical 

targets for fuel cell stack and fuel processor components. All targets were developed with industry through 

preliminary vehicle system analyses and will be refined further as the technology matures and power system 

trade-offs are identified. Targets for hydrocarbon-based systems are based on operation with reformulated 

gasoline containing an average of 30 ppm sulfur (80 ppm maximum); except for the hydrogen storage targets 

in Table 5, all power target values indicate electric power (We).

Targets are reviewed on an annual basis and updated as necessary based on new information.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Table 1. Technical targets: fuel cell stack systems operating on hydrogen-containing fuel from a 

fuel processor (gasoline reformate) in 50 kWe (net) fuel cell systems

(Excludes fuel processing/delivery system) 

(Includes fuel cell ancillaries: thermal, water, air management systems) 

All targets must be achieved simultaneously and are consistent with those of FreedomCAR 

Calendar year 

Characteristics Units 2001 

status 2005 2010 

Stack system power densitya,b W/L 200 400 550 

Stack system specific power W/kg 200 400 550 

Stack system efficiencyc @ 25% of rated power % 45 50 55 

Stack system efficiencyc @ rated power % 40 42 44 

Precious metal loadingd g/rated kW 2.0 0.6 0.2 

Coste $/kW 200 100 35 

Durabilityf hours 1000g >2000h >5000i

Transient response (time for 10% to 90% of rated power) sec 3 2 1 

Cold start-up time to rated power 

 @ –20bC ambient temperature 

 @ +20bC ambient temperature 

min 

min 

2 

1 

1 

0.5 

0.5 

0.25 

Survivabilityj bC –20 –30 –40 

CO tolerancek 

 steady state (with 2% maximum air bleed) 

 transient 

ppm 

ppm 

50 

100 

500 

500 

500 

1000

 aPow er refers to net power (i.e., stack power minus auxiliary power requirements). 

 bVolume is “box” volume, including dead space, and is defined as the water-displaced volume times 1.5 (packaging factor). 

Pow er density includes ancillaries (sensors, controllers, electronics, radiator, compressor, expander, and air, thermal and water 

management) for stand alone operation. 

 cRatio of output DC energy to lower heating value of hydrogen-rich fuel stream (includes converter for 300 V bus); ratio of 

rated power to 25% of rated power efficiencies unchanged, assuming continued proportional reduction in stack efficiency at 

higher current and proportional increase in compressor efficiency at higher flow rates. 

 dEquivalent total precious metal loading (anode+cathode): 0.1 mg/cm2 by 2010 at rated power. Precious metal target based 

on cost target of <$3/kW precious metals in MEA [@$450/troy ounce ($15/g), <0.2 g/kW] 

 eHigh-volume production: 500,000 units per year. 

 f

Performance targets must be achieved at the conclusion of the durability period; durability includes tolerance to CO, H2S and 

NH3 impurities. 

 gContinuous operation (pertains to full power spectrum). 

 hIncludes thermal cycling. 

 i

Includes thermal and realistic driving cycles. 

 j

Performance targets must be achieved at the end of 8-hour cold-soak at temperature.

 kCO tolerance requirements assume capability of fuel processor to reduce CO. Targets for the stack CO tolerance are subject 

to trade-offs between reducing CO in the fuel processor and enhancing CO tolerance in the stack. It is assumed that H2S is 

removed in the fuel processor.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Table 2. Technical targets: fuel processorsa to generate hydrogen-containing fuel gas from 

reformulated gasoline containing 30 ppm sulfur, average, for 50 kWe (net) fuel cell systems

(Excludes fuel storage; includes controls, shift reactors, CO cleanup, heat exchangers) 

All targets must be achieved simultaneously and are consistent with those of FreedomCAR 

Calendar year 

Characteristics Units 2001 

statusb 2005 2010 

Energy efficiencyc % 78 78 80 

Power density W/L 500 700 800 

Specific power W/kg 450 700 800 

Costd $/kW 85 25 10 

Cold start-up time to maximum power 

 @ –20bC ambient temperature 

 @+20bC ambient temperature 

min 

min 

TBD 

<10 

2.0 

<1 

1.0 

<0.5 

Transient response (time for 10% to 90% power) sec 15 5 1 

Emissionse <Tier 2 

Bin 5 

<Tier 2 

Bin 5 

<Tier 2 

Bin 5 

Durabilityf hours 1000g 4000h 5000i

Survivabilityj bC TBD –30 –40 

CO content in product streamk

 steady state 

 transient 

ppm 

ppm 

10 

100 

10 

100 

10 

100 

H2S content in product stream ppb <200 <50 <10 

NH3 content in product stream ppm <10 <0.5 <0.1 

 aWith catalyst system suitable for use in vehicles. 

 bProjected status for system to be delivered in late 2002: 80% efficiency, 900 W/L, 550 W/kg. 

 cFuel processor efficiency = total fuel cell system efficiency/fuel cell stack system efficiency, where total fuel cell system 

efficiency accounts for thermal integration. For purposes of testing fuel-processor-only systems, the efficiency can be estimated 

by measuring the derated heating value efficiency (lower heating value of H2 e 0.95/ lower heating value of the fuel in) where the 

derating factor represents parasitic system pow er losses attributable to the fuel processor. 

 dHigh-volume production: 500,000 units per year. 

 e0.07 g/mile NOx and 0.01 g/mile PM (particulate matter). 

 f

Time betw een catalyst and major component replacement; performance targets must be achieved at the end of the durability 

period. 

 gContinuous operation. 

 hIncludes thermal cycling. 

 i

Includes thermal and realistic driving cycles. 

 j

Performance targets must be achieved at the end of an 8-hour cold-soak at specified temperature.

 kDependent on stack development (CO tolerance) progress.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Table 3. Technical targets: 50 kWe (net) integrated fuel cell power systems operating on Tier 2 

gasoline containing 30 ppm sulfur, average

(Including fuel processor, stack, auxiliaries) 

(Excluding gasoline tank and vehicle traction electronics) 

All targets must be achieved simultaneously and are consistent with those of FreedomCAR 

Calendar year 

Characteristics Units 2001 

status 2005 2010 

Energy efficiencya @ 25% of rated power % 34 40 45 

Energy efficiency @ rated power % 31 33 35 

Power density W/L 140 250 325 

Specific power W/kg 140 250 325 

Costb $/kW 300 125 45 

Transient response (time from 10 to 90% power) sec 15 5 1 

Cold start-up time to rated power 

 @ –20bC ambient temperature 

 @+20bC ambient temperature 

min 

min 

TBD 

<10 

2 

1 

1 

<0.5 

Survivabilityc bC TBD –30 –40 

Emissionsd <Tier 2 

Bin 5e

<Tier 2 

Bin 5e

<Tier 2 

Bin 5e

Durabilityf hours 1000g 2000h 5000i

Greenhouse Gases One-third reduction compared with conventional SIIC engines in similar type vehicles 

 aRatio of dc output energy to the lower heating value of the input fuel (gasoline). 

 bIncludes projected cost advantage of high-volume production (500,000 units per year) and includes cost for 

assembling/integrating the fuel cell system and fuel processor. 

 c

Achieve performance targets at 8-hour cold-soak at temperature. 

 dEmissions levels will comply w ith emissions regulations projected to be in place when the technology is available for market 

introduction. 

 e0.07 NOx g/mile and 0.01 PM g/mile. 

 f

Performance targets must be achieved at the end of the durability time period. 

 gContinuous operation. 

 hIncludes thermal cycling. 

 iIncludes thermal and realistic drive cycles.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Table 4. Technical targets: 50 kWe (net) integrated fuel cell power systems operating on direct 

hydrogena

All targets must be achieved simultaneously and are consistent with those of FreedomCAR 

Calendar year 

Characteristics Units 2001 

status 2005 2010 

Energy efficiencyb @ 25% of rated power % 59 60 60 

Energy efficiency @ rated power % 50 50 50 

Power density 

 excluding H2 storage 

 including H2 storage 

W/L 

W/L 

400 

TBD 

500 

150 

650 

220 

Specific power 

 excluding H2 storage 

 including H2 storage 

W/kg 

W/kg 

400 

TBD 

500 

250 

650 

325 

Costc (including H2 storage) $/kW 200 125 45 

Transient response (time from 10% to 90% of rated power) sec 3 2 1 

Cold start-up time to maximum power 

 @ –20bC ambient temperature 

 @+20bC ambient temperature 

sec 

sec 

120 

60 

60 

30 

30 

15 

Emissions Zero Zero Zero 

Durabilityd hours 1000 2000e 5000f

Survivabilityg bC -20 –30 –40 

 aTargets are based on hydrogen storage targets in an aerodynamic 2500-lb vehicle. 

 bRatio of DC output energy to the lower heating value of the input fuel (hydrogen). 

 cIncludes projected cost advantage of high-volume production (500,000 units per year). 

 dPerformance targets must be achieved at the end of the durability time period. 

 eIncludes thermal cycling. 

 fIncludes thermal and realistic drive cycles. gAchieve performance targets at 8-hour cold-soak at temperature. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

630

Table 5. Technical targets for on-board hydrogen storagea,b subsystem

Characteristic Units Target 2001 Status 

Physical storagec 2001 Status 

Chemical storaged

Storage capacitye wt% 6 5.2 3.4 

Recoverable usable amountf % 90 99.7 >90 

Energy densityg Wh/Lh 1100h 813 1300 

Specific energyi Wh/kgh 2000 1745 1080 

Costj $/kWh 5 50k 18l

Cycle life cycles 500 >500 20-50 

Operating temperaturem bC –40b to +50bC –40b to +50bC 20bC to 50bC 

Start-up time to full flow 

 @+20bC 

 @-20bC 

sec 

sec 

15 

30 

<1 

TBD 

<15 

TBD 

Refueling time min <5 TBD TBD 

Hydrogen loss scc/hour/L <1.0 <1.0 <1.0 

 aBased on lower heating value of hydrogen; includes both physical and chemical methods of hydrogen storage; enables 

greater than 300-mile range, based on an aerodynamic, 2500-lb vehicle. 

 bR&D carried out in collaboration with DOE Hydrogen Program. 

 cIncludes compressed gas and cryogenic liquid tanks. 

 dProjected from laboratory-scale (100 g) test beds and proposed system designs. 

 eWeight percent H2 is the weight of H2 divided by the weight of (H2 + tank). 

 f

Recoverable stored hydrogen, e.g. in a 100-kg H2 storage system containing 6 kg of stored hydrogen, at least 5.4 kg of useful 

hydrogen must be recoverable. 

 gBased on 5 kg hydrogen for >300 mile range at 10,000 psia (volume of stored hydrogen is 135 L). Allow ing for 10% 

containment volume, system volume is 150 L.. 

 hWatts thermal. 

 i

Specific energy is the lower heating value energy of H2 contained, divided by the weight of (H2 + tank) . 

 j

Based on high-volume production of 500,000 units per year. kBased on individual tanks. lProjected hydride material cost only; based on 100-200 kg alanate production. 

 mHydrogen storage system must provide hydrogen to the fuel cell at these ambient temperatures.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Table 6. Technical targets for off-board hydrogen production and dispensing infrastructure

Component Characteristic 

(LHV Basis) 

Units Current 

Statusa

2005 2010 

Cost $/GJ H2 9.9 8.8 7.7b

Reforming WTW GHGs g/km 75 70 65 

Primary Energy Eff. % (LHV) 80c

 82 85 

Cost $/GJ H2 0.56 0.56 0.56d

WTW GHGse Purification g/km 1.1 1.1 1.1 

Primary Energy Eff. % (LHV) 75f

 82 90 

Cost $/GJ H2 2.6 2.3 2.0g

Compression WTW GHGs g/km 14 11 8 

Primary Energy Eff. % (LHV) 82h

 85 88 

Cost $/GJ H2 2.7i 2.7 2.7j

WTW GHGs g/km 0 0 0 Storage & 

Dispensing 

Primary Energy Eff. % (LHV) 100k

 100 100

Costl $/GJ H2 19.2 17.2 16.2m

Total WTW GHGs g/km 90 82 75 

Primary Energy Eff. % (LHV) 62 68 75 

Notes: Well-to-wheel greenhouse gas (WTW GHG) emissions are weighted by their global warming potential. Assumes 84-mpeg f uel 

economy in a direct hy drogen FCV and on-site power f rom the US av erage grid mix. Primary energy eff iciency is def ined as 

Hy drogen Output LHV / Primary Energy Input LHV of the process step. Primary energy associated with on-site power use assumes a

35% production and transmission eff iciency penalty (typical US grid mix). a

 Assumes state-of -the-art technology that is f easible but not necessarily av ailable in a complete system today. This assumption is consistent with 

the automotiv e f uel cell perf ormance target assumptions. 

B Assumes energy cost reductions by way of higher eff iciency and a 50% equipment cost reduction f rom the current scenario. Small-scale 

ref ormers are assumed to come down signif icantly in price with projected adv ances in materials and designs. 

C Assuming a steam methane ref ormer operating at 10 atm. 

D Assumes no equipment cost reduction f rom the current scenario. Conv entional equipment (PSAs) will not likely come down signif icantly in price, 

especially with higher eff iciency requirements. Adv anced technologies may prov ide higher eff iciencies, but are unlikely to be cheaper. E Assumes 100% of the purif ication purge stream (primarily CO2, H2, CH4, and CO) is recycled to the production step, where the purge stream is 

burned to generate heat f or the ref orming process. There may be some additional purif ication emissions in other sy stem conf igurations, but the 

total sum of emissions f rom the production and purif ication steps will remain the same. 

F Assuming a small-scale PSA sy stem operating at ref ormer outlet pressure. 

G Assumes energy cost reductions by way of higher efficiency but no equipment cost reduction f rom the current scenario. Conv entional equipment 

(gas compressors) will not likely come down signif icantly in price, especially with higher eff iciency requirements. Adv anced technologies may 

prov ide higher efficiencies, but are unlikely to be cheaper. 

H Assuming conv entional compressors are used f rom the PSA outlet pressure to 3600-psi maximum on-site storage pressure and accumulatorty pe compressors are used f rom the storage pressure to 5000 psi on-board storage. 

I

 Based on 3600-psi on-site gas storage. 

J

 Assumes no equipment cost reduction f rom the current scenario. Conv entional equipment (high-pressure gas storage tanks) will not likely come 

down signif icantly in price. Adv anced technologies may prov ide higher ov erall efficiencies, but are unlikely to be cheaper. 

K Assuming high-pressure gas storage with no leaks during storage or dispensing. 

L

 Includes operation, site prep, and central control costs. 

M Costs are based on a hy drogen f ueling station serv ing 300 v ehicles per day (~10,000 std m3 per day ) with on-site production. Capital equipment 

costs assume mature production v olumes of 100 units per y ear. Production v olumes of 100 units/y ear were also studied by DTI with analgous 

economic predictions. Production v olumes of 10,000 units per y ear will reduce capital costs substantially to $13/GJ (See “Integrated Vehicle 

Analy sis” DTI, 1998). Energy costs assume a natural gas price of $5/GJ (HHV) and power price of $0.07/kWh.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Table 7. Technical targets for fuel cell stack components

Component Requirement 

Membranes Cost: $5/kW 

Stability: <2 mV w/RH 20–100% , <10% swelling 

H2 crossover: <1 mA/cm2 

O2 crossover: <3 mA/cm2

Area specific resistance: 0.1 ohm-cm2

 

Electrodes Cost: $5/kW 

CO tolerance: 500 ppm steady state, 1000 ppm transient with 0.2 g Pt/rated 

kW 

Durability: 5000 hours 

Utilization: 85% H2, 60% O2

Membrane-Electrode 

Assembly 

Performance: 

 On h ydrogen 

 400 mA/cm2

 at 0.80 V (at rated power) 

 100 mA/cm2

 at 0.85 V (at quarter power) 

 On gasoline reformate 

 500 mA/cm2

 at 0.75 V (at rated power, 30 psig) 

 125 mA/cm2

 at 0.83 V (at quarter power, 9 psig) 

Cost: $10/kW 

Bipolar Plates Cost: $10/kW; <1kg/kW 

H2 permeation rate: <2 e 10–6 cm3 sec-1 cm-2 @ 80o

C, 3 atm 

 (Equivalent to <0.1 mA/cm2

) 

Corrosion limit: <16 microamps/cm2

Resistivity: 0.02 ohm/cm2
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Table 8. Technical targets for sensors for automotive fuel cell systemsa

Sensor Requirements 

Carbon Monoxide (a) 1–100 ppm reformate pre-stack sensor 

• Operational temperature: <150bC 

• Response time: 0.1–1 sec 

• Gas environment: high-humidity reformer/partial oxidation gas: H2 30–

75%, CO2, CO, N2, H2O at 1–3 atm total pressure 

• Accuracy: 1–10% full scale 

(b) 100–1000 ppm CO sensors 

• Operational temperature: 250 bC 

• Response time: 0.1–1 sec 

• Gas environment: high-humidity reformer/partial oxidation gas: H2 30–

75%, CO2, CO, N2, H2O at 1–3 atm total pressure 

• Accuracy: 1–10% full scale 

(c) 0.1–2% CO sensor 250–800bC 

• Operational temperature: 250–800bC. 

• Response time: 0.1–1 sec 

• Gas environment: high-humidity reformer/partial oxidation gas: H2 30–

75%, CO2, CO, N2, H2O at 1–3 atm total pressure 

• Accuracy: 1–10% full scale 

Hydrogen in fuel 

processor output 

• Measurement range: 1–100% 

• Operating temperature: 70–150bC 

• Response time: 0.1–1 sec for 90% response to step change 

• Gas environment: 1–3 atm total pressure, 10–30 mol % water, 30–75% 

total H2 , CO2, N2 

• Accuracy: 1–10% full scale 

Hydrogen in ambient 

air (safety sensor) 

• Measurement range: 0.1–10% 

• Temperature range: –30 to 80bC 

• Response time: under 1 sec 

• Accuracy: 5% 

• Gas environment: ambient air, 10–98% RH range 

• Lifetime: 5 years 

• Interference resistant (e.g., hydrocarbons) 

Sulfur compounds 

(H2S, SO2, organic 

sulfur) 

• Operating temperature: up to 400bC 

• Measurement range: 0.05–0.5 ppm 

• Response time: <1 min at 0.05 ppm 

• Gas environment: Hydrogen, CO, CO2, hydrocarbons, water vapor 

Flow rate of fuel 

processor output 

• Flow rate range: 30–300 standard L/min 

• Temperature: 80bC 

• Gas environment: high-humidity reformer/partial oxidation gas: H2 30–

75%, CO2, N2, H2O, CO at 1–3 atm total pressure 

Ammonia • Operating temperature: 70–150bC 

• Measurement range: 1–10 ppm 

• Selectivity: <1 ppm from matrix gases 

• Lifetime: 5–10 years 

• Response time: seconds 

• Gas environment: high-humidity reformer/partial oxidation gas: H2 30–

75%, CO2, N2, H2O, CO at 1–3 atm total pressure 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Table 8. Technical targets for sensors for automotive fuel cell systemsa

Sensor Requirements 

Temperature • Operating range: –40 to 150bC 

• Response time: in the –40 to 100bC range <O.5 sec with 1.5% accuracy; 

in the 100–150bC range, a response time <1 sec with 2% accuracy 

• Gas environment: high-humidity reformer/partial oxidation gas: H2 30–

75%, CO2, N2, H2O, CO at 1–3 atm total pressure 

• Insensitive to flow velocity 

Relative humidity for 

cathode and anode gas 

streams 

• Operating temperature: 30–110bC 

• Relative humidity: 20–100% 

• Accuracy: 1% 

• Gas environment: high-humidity reformer/partial oxidation gas: H2 30–

75%, CO2, N2, H2O, CO at 1–3 atm 

Oxygen in fuel 

processor and at 

cathode exit 

(a) Oxygen sensors for fuel processor reactor control 

• Operating temperature: 200–800bC 

• Measurement range: 0–20% O2

• Response time: <0.5 sec 

• Accuracy: 2% of full scale 

• Gas environment: high-humidity reformer/partial oxidation gas: H2 30–

75%, CO2, N2, H2O, CO at 1–3 atm 

(b) Oxygen sensors at the cathode exit 

• Measurement range: 0–50% O2

• Operating temperature: 30–110bC 

• Response time: <0.5 sec 

• Accuracy: 1% of full scale 

• Gas environment: H2, CO2, N2, H2O at 1–3 atm total pressure 

Differential pressure in 

fuel cell stack 

• Range: 0–1 psi or (0–10 or 1–3 psi, depending on the design of the fuel 

cell system) 

• Temperature range: 30–100bC 

• Survivability: –40bC 

• Response time: <1 sec 

• Accuracy: 1% of full scale 

• Size: @1 in2

, usable in any orientation 

• Other: Withstand and measure liquid and gas phases 

 aSensors must conform to size, weight, and cost constraints of automotive applications.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Table 9. Technical targets for compre ssor/expander (C/E) units for automotive fuel cell 

systemsa

Characteristic Units Target 

Input powerb at full flow kW 4.3 

Efficiency at full flow 

 Compressor (at 3.2 pressure ratio)c

 Expander 

% 

% 

75 

90 

Efficiency @ 20% of full flow 

 Compressor (at 1.6 pressure ratio)c

 Expander 

% 

% 

65 

80 

Volumed L 4 

Weightd kg 3 

Costd,e $ 200 

Turndown ratio 10 

Noise db <80 

 aTargets are being reviewed as a result of the Compressor Peer Review. 

 bInput pow er to the controller to power a compressor/expander system producing 76 g/sec (dry) maximum flow . This flow rate 

roughly corresponds to maximum pow er for a 50-kW fuel cell system. A 25% flow is 19 g/sec. Expander inlet conditions are 

assumed to be: 82 g/sec, 150bC, and 2.8 atm (at full flow). 

 cThe pressure ratio is allow ed to float as a function of load on the fuel cell system (i.e., as a function of the flow through the 

compressor/expander unit). 

 dWeight, volume, and cost do not include the motor/controller or heat rejection (if required). eCost target based on a manufacturing volume of 100,000 units per year.
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Table 10. Technical targets for fuel proce ssor catalysts and reactors (for reforming Tier II 

gasoline containing 30 ppm Sulfur)a

Characteristic Units Autothermal 

reformer 

Sulfur 

removal 

Water 

gas shift 

CO preferential 

oxidation 

GHSVb per hour 200,000 50,000 30,000 150,000 

Conversionc % >99.9 >99.95 >90 >99.8 

H2 selectivityd (or 

consumption) 

% >80 <0.1 >99 <0.2 

Volumee L/kWe <0.013 <0.06 <0.1 <0.02 

Weighte kg/kWe <0.015 <0.06 <0.1 <0.03 

Durabilityf hours 5000 5000 5000 5000 

Cost $/kWe <5 <1 <1 <1 

 aGHSV (gas hourly space velocity) = the volumetric flow rate of the product gases reduced to 25bC and 1 atm, divided by the 

bulk volume of the catalyst. 

 bTarget values are guidelines for single reactor R&D; system/subsystem targets take precedence. 

 cConversion: (moles of reactant in – moles of reactant out) e 100/(moles of reactant in). 

 dSelectivity: At the autothermal reformer: (moles of H2 in product) e 100/(moles of H2 “extractable” from the reformer feed); at 

the shift reactor: (moles CO converted to H2) e 100/(total moles of CO converted). 

 eThe volume and w eight targets include only the catalysts, not the hardware needed to house the catalysts or any heat 

exchangers.

 f

Over standard driving cycles. 
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

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Index of Primary Contacts

A

Aaron, Timothy M. . . . . . . . . . . . . . . . . . . . .102

Aceves, Salvador M. . . . . . . . . . . . . . . . . . . .210

Adzic, Radoslav . . . . . . . . . . . . . . . . . . . . . .418

Ahmed, S. . . . . . . . . . . . . . . . . . . . . . . . . . . .309

Ahn, Channing . . . . . . . . . . . . . . . . . . . . . . .235

Amrani, Ahmed . . . . . . . . . . . . . . . . . . . . . .290

Anderson, Marc A. . . . . . . . . . . . . . . . . . . . .408

Androsky, Anthony . . . . . . . . . . . . . . . . . . . .598

Anton, Donald . . . . . . . . . . . . . . . . . . . . . . . .247

Arif, Muhammad . . . . . . . . . . . . . . . . . . . . .438

Armstrong, Timothy . . . . . . . . . . . . . . . . . . .283

Arps, James . . . . . . . . . . . . . . . . . . . . . . . . . .386

Atanassova, Paolina . . . . . . . . . . . . . . . . . . . .423

B

Bailey, Sterling . . . . . . . . . . . . . . . . . . . . . . .494

Barnes, David L. . . . . . . . . . . . . . . . . . . . . . .530

Berry, David A. . . . . . . . . . . . . . . . . . . . . . . .337

Besmann, T. M. . . . . . . . . . . . . . . . . . . . . . . .451

Borup, Rod . . . . . . . . . . . . . . . . . . . . . 342, 485

Brady, M.P. . . . . . . . . . . . . . . . . . . . . . . . . . .454

Brown, Robert C. . . . . . . . . . . . . . . . . . . . . .63

Buckley, Jill . . . . . . . . . . . . . . . . . . . . . . . . .522

Bugaj, Shari . . . . . . . . . . . . . . . . . . . . . . . . .395

C

Carlson, Eric J. . . . . . . . . . . . . . . . . . . 279, 513

Chen, Christopher M. . . . . . . . . . . . . . . . . . .92

Chintawar, Prashant S. . . . . . . . . . . . . . . . . .300

Clark, Thomas . . . . . . . . . . . . . . . . . . . . . . . .503

Collier, Kirk . . . . . . . . . . . . . . . . . . . . . . . . .613

D

DaCosta, David H. . . . . . . . . . . . . . . . . . . . .213

Dalla Betta, Ralph . . . . . . . . . . . . . . . . . . . . .320

De Castro, Emory S. . . . . . . . . . . . . . . . . . . .390

DiMeo, Frank Jr. . . . . . . . . . . . . . . . . . . . . . .581

Drnevich, Raymond F. . . . . . . . . . . . . . . . . .97

E

Evans, Barbara R. . . . . . . . . . . . . . . . . . . . . .33

Evans, R.J. . . . . . . . . . . . . . . . . . . . . . . . . . .49

F

Fairlie, Matthew . . . . . . . . . . . . . . . . . . . . . .563

Flynn, Tom . . . . . . . . . . . . . . . . . . . . . . . . . .305

Fonda-Bonardi, P. . . . . . . . . . . . . . . . . . . . . .499

Friedland, Robert J. . . . . . . . . . . . . . . . . . . . .161

Fuchs, Michel . . . . . . . . . . . . . . . . . . . . . . . .285

G

Garzon, Fernando . . . . . . . . . . . . . . . . 156, 468

Gee, Mark K. . . . . . . . . . . . . . . . . . . . . . . . .490

Ghirardi, Maria . . . . . . . . . . . . . . . . . . . . . . .42

Gross, Karl . . . . . . . . . . . . . . . . . . . . . . . . . .260

Guro, David E. . . . . . . . . . . . . . . . . . . . . . . .166

H

Haack, David . . . . . . . . . . . . . . . . . . . . . . . .458

Hartmann, Judith B. . . . . . . . . . . . . . . . . . . .379

Heben, M.J. . . . . . . . . . . . . . . . . . . . . . . . . . .226

Heung, Kit . . . . . . . . . . . . . . . . . . . . . . . . . . .111

Ho, W.S. Winston . . . . . . . . . . . . . . . . . . . . .364

I

Irvin, Joseph J. . . . . . . . . . . . . . . . . . . . . . . .558

Irving, Patricia . . . . . . . . . . . . . . . . . . . . . . .87

J

James, Brian D. . . . . . . . . . . . . . . . . . . 120, 179

Jensen, Craig M. . . . . . . . . . . . . . . . . . . . . . .239

K

Klett, J. W. . . . . . . . . . . . . . . . . . . . . . . . . . .463

Knight, Brian A. . . . . . . . . . . . . . . . . . . . . . .476

Kopasz, John P. . . . . . . . . . . . . . . . . . . . . . . .106

Krause, Theodore . . . . . . . . . . . . . . . . 332, 348

Kumar, Ravi . . . . . . . . . . . . . . . . . . . . 170, 294

Kumar, Romesh . . . . . . . . . . . . . . . . . . . . . .270

L

Lasher, Stephen . . . . . . . . . . . . . . . . . . 189, 522

Lau, Francis S. . . . . . . . . . . . . . . . . . . . . 68, 71

Lessing, Paul A. . . . . . . . . . . . . . . . . . . . . . .223

Liss, William E. . . . . . . . . . . . . . . . . . . . . . .175

Liu, Hongtan . . . . . . . . . . . . . . . . . . . . . . . . .373

Lutz, Andrew . . . . . . . . . . . . . . . . . . . . . . . .550

M

MacQueen, Brent . . . . . . . . . . . . . . . . . . . . .144

Mann, Margaret K. . . . . . . . . . . . . . . . . . . . .554

Mark G. Roelofs . . . . . . . . . . . . . . . . . . . . . .386

Martin, Steve W. . . . . . . . . . . . . . . . . . . . . . .480

McFarland, Eric W. . . . . . . . . . . . . . . . . . . .136

Melis, Tasios . . . . . . . . . . . . . . . . . . . . . . . . .27

Miller, Eric L. . . . . . . . . . . . . . . . . . . . . . . . .130

Miller, Karen . . . . . . . . . . . . . . . . . . . . . . . . .585
Hydrogen, Fuel Cells, and Infrastructure Technologies FY 2002 Progress Report

638

Milliken, Christopher . . . . . . . . . . . . . . . . . .148

Muradov, Nazim . . . . . . . . . . . . . . . . . . . . . .83

Myers, Deborah J. . . . . . . . . . . . . . . . . . . . . .356

N

Narayanan, S. R. . . . . . . . . . . . . . . . . . . . . . .447

Nenoff, Tina M. . . . . . . . . . . . . . . . . . . . . . .115

O

Ohi, Jim . . . . . . . . . . . . . . . . . . . . . . . . . . . . .595

O’Neill, Hugh . . . . . . . . . . . . . . . . . . . . . . . .404

P

Page, Richard A. . . . . . . . . . . . . . . . . . . . . . .251

Parish, Richard . . . . . . . . . . . . . . . . . . . . . . .547

Pederson, Larry R. . . . . . . . . . . . . . . . . . . . .313

Pham, Ai-Quoc . . . . . . . . . . . . . . . . . . 152, 473

Pitts, J. Roland . . . . . . . . . . . . . . . . . . . . . . .577

Pyke, Steve . . . . . . . . . . . . . . . . . . . . . . . . . .573

R

Raman, Venki . . . . . . . . . . . . . . . . . . . . . . . .567

Read, Carole J. . . . . . . . . . . . . . . . . . . . . . . .517

Rehg, Tim . . . . . . . . . . . . . . . . . . . . . . . . . . .369

Ross, Philip N. Jr. . . . . . . . . . . . . . . . . . . . . .429

S

Sapru, Krishna . . . . . . . . . . . . . . . . . . . . . . .255

Schefer, Robert . . . . . . . . . . . . . . . . . . . . . . .605

Schoenung, Susan M. . . . . . . . . . . . . . . . . . .194

Selecman, George E. . . . . . . . . . . . . . . . . . . .508

Sirosh, Neel . . . . . . . . . . . . . . . . . . . . . . . . . .201

Slattery, Darlene K. . . . . . . . . . . . . . . . . . . .244

Smith, Murdo J. . . . . . . . . . . . . . . . . . . . . . .267

Spritzer, Michael H. . . . . . . . . . . . . . . . . . . .59

Sung, Shihwu . . . . . . . . . . . . . . . . . . . . . . . .38

Swain, Michael R. . . . . . . . . . . . . . . . . . . . . .591

Swartz, Scott L. . . . . . . . . . . . . . . . . . . . . . . .352

Swider Lyons, Karen . . . . . . . . . . . . . . . . . .413

T

Thompson, Levi . . . . . . . . . . . . . . . . . 325, 360

T-Raissi, Ali . . . . . . . . . . . . . . . . . . . . . . . . .537

Turner, J.A. . . . . . . . . . . . . . . . . . . . . . . . . . .125

U

Unnasch, Stefan . . . . . . . . . . . . . . . . . 184, 328

Uribe, Francisco A. . . . . . . . . . . . . . . . . . . . .433

V

Van Blarigan, Peter . . . . . . . . . . . . . . . . . . . .609

W

Wang, Michael . . . . . . . . . . . . . . . . . . . . . . .543

Weimer, Alan W. . . . . . . . . . . . . . . . . . . . . .76

Weisberg, Andrew . . . . . . . . . . . . . . . . . . . .205

Wilson, Mahlon S. . . . . . . . . . . . . . . . . . . . .526

Wipke, Keith . . . . . . . . . . . . . . . . . . . . . . . . .275

Wolfrum, Edward J. . . . . . . . . . . . . . . . . . . .21

Wozniak, John . . . . . . . . . . . . . . . . . . . . . . .218

Y

Yuh, Chao-Yi . . . . . . . . . . . . . . . . . . . . . . . .297

Z

Zawodzinski, Thomas A. . . . . . . . . . . . . . . .400

Zelenay, Piotr . . . . . . . . . . . . . . . . . . . . . . . .441

Zidan, Ragaiy . . . . . . . . . . . . . . . . . . . . . . . .231
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