bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Analysis of Ni Infiltrated Nanoporous GDC Scaffold for Metal Supported SOFCs Anode
Authors: Lee Kunho , Lee Jaeseok , Kang Juhyun , Bae Joongmyeon 
Published: February 2020

Metal-supported SOFCs have been investigated to overcome the disadvantages of ceramic-supported SOFCs, such as mechanical strength and sealing. In the case of ceramic-supported cells, the mechanical support is a brittle ceramic or cermet, and it contains expensive materials. However, metal-supported cells utilize ceramic layers that are only as thick as necessary for electrochemical functioning, thereby compensating for the disadvantages of ceramic-supported cells. The mechanical support is fabricated from inexpensive and robust metals, and the electrochemically active layers are applied directly to the metal support. In other words, metal-supported SOFCs can provide a reduced system cost, easy manufacturing, and operational advantages. These features make metal-supported SOFCs a very promising candidate for commercialization.
To improve productivity and accelerate the commercialization, the metal supported SOFCs have to be fabricated at low temperature under oxidized environment. In these days, some metal substrates which can withstand corrosion from ≤1000 °C already have been developed. However, the low fabrication temperature is insufficient for conventional sub-micron scaled NiO/YSZ or GDC to generate smooth electrical and ionic paths. Furthermore, the unsuitable anode can affect to interfaces; and as a result, it can cause decrease of electrical conduction.
Therefore, we have tried to apply a wet infiltration technique for anode fabrication. It can fabricate nanosize particles into a porous scaffold at relatively low temperatures and achieve higher performance electrode structures. Then, to substitute the conventional anode, a nanoporous GDC scaffold layer, and the Ni solution were selected as a scaffold and catalyst material, respectively. It is known that the GDC has high ionic conductivity and can be sintered at relatively low temperature. Therefore, it was considered that the GDC could be well matched with the requirements for anode of metal supported SOFC.
For investigating the electrochemical performance according to Ni amounts, the half-cell tests were carried out via solatron 1287/1260 device under 97%H2+3%H2O condition. Then, the appropriate Ni infiltrated GDC was applied to the metal-supported SOFC, and the electrochemical performance of infiltrated metal-supported SOFC single cell was measured via the solatron 1287/1260 device.
Assessment of Sulfur Poisoning of Ni/CGO-Based SOFC Anodes
Authors: Riegraf Matthias , Zekri Atef , Yurkiv Vitaliy , Costa Rémi , Schiller Guenter , Friedrich K. Andreas 
Published: February 2020

The presence of fuel impurities, such as sulfur, siloxane and phosphorus, in biogas, diesel and natural gas can cause Solid Oxide Fuel Cell (SOFC) degradation due to surface poisoning of Ni-containing anodes. In this regard, Ni/CGO anodes were shown to display higher sulfur tolerance than Ni/YSZ anodes and a comparable high performance. In order to allow for a more profound understanding of the processes underlying sulfur poisoning, this study presents an extensive experimental investigation of commercial Ni/CGO-based SOFC operating on H2/H2O gas and reformate fuel mixtures with trace amounts of hydrogen sulfide (H2S).
The short-term poisoning behavior of high-performance electrolyte-supported Ni/CGO10-based cells was systematically investigated by means of transient voltage stability experiments and electrochemical impedance measurements for a wide range of operating conditions. The effects of temperature (800 – 950 °C) and current density (OCV – 0.75 A·cm‒2) on the extent of sulfur poisoning (1 – 20 ppm H2S) was evaluated. The poisoning behavior was shown to be completely reversible for short exposure times in all cases. By means of equivalent circuit modeling, the chemical capacitance of Ni/CGO10 anodes was demonstrated to be strongly dependent on temperature and gas phase composition reflecting a changing Ce3+/Ce4+ ratio in the CGO phase. Using a model reformate as fuel gas, it was shown that CO can still be electrochemically converted under sulfur exposure.
Furthermore, long-term experiments of 1000 h were conducted at 900 °C and 0.5 A·cm‒2 with and without sulfur exposure and the degradation progress was monitored by impedance spectroscopy. Moreover, comprehensive post-mortem analysis including FIB/SEM, TEM and XRF was carried out in order to identify the nature and location of the occurring microstructural changes.
(Invited) Research By Students That Were Inspired By Russ Kunz in High Temperature Pemfcs, DMFCs, Analysis for Polarization Loses and FC Durability
Authors: Fenton James M , Kunz H. Russell 
Published: February 2020

After retiring from United Technologies Corporation Dr. H. Russell Kunz, started a new career inspiring graduate, post-doctoral students and young researchers to innovate in fuel cell research at the University of Connecticut. These young researchers with the help of Russ published 47 peer reviewed publications, a book “Experimental Methods and Data Analyses for Polymer Electrolyte Fuel Cells (PEMFCs)” and produced three patents. This historical presentation will be presented with slides taken from Russ Kunz’s presentations from 1997 until 2014. From 1997 to 2004, research at UConn was focused on catalysts for methanol oxidation in phosphoric acid and direct methanol proton exchange membrane fuel cells (DMFCs), and development of selective CO oxidation catalysts for PEMFCs. From 2003 to 2014 membranes with barrier layers for DMFCs and high temperature membranes for PEMFCs were developed and studied. From 2004 to 2014, gas diffusion layers and catalyst structures were being developed along with high temperature membranes into innovative proton exchange membrane-electrode assemblies (MEAs) that provided excellent ionic conductivity and good performance in an under-saturated environment (120 oC, 1 atm., 35%RH and 70 oC, 1 atm., dry). To optimize the performance of these MEAs techniques for analysis of polarization curves to evaluate polarization loses were developed using air, oxygen, oxygen/helium experiments and AC impedance. Ionomen (a company founded by Russ Kunz, Len Bonville and Jim Fenton) together students from UConn demonstrated MEA performance that greatly exceeded that of commercial MEAs in a four-cell full-scale stack that provided 288 watts at a current of 120 A while providing 116 oC hot water. From 2006 on finding the degradation mechanisms for membrane and catalysts layers were explored along with the performance of MEAs with lower equivalent weight PFSA in the catalyst layers. From 2006 to 2013 Russ Kunz played a pivitol role in the leadership of the U.S. Department of Energy (DOE) High Temperature Membrane Working Group (HTMWG). The HTMWG investigated membrane performance at elevated temperature/low relative humidity conditions. For the final three years of the project, Russ and the team at the Florida Solar Energy Center worked with six teams to develop membrane electrode assembly (MEA) fabrication methods for their respective membranes.
(Energy Technology Division Research Award Address) MEA & DM Characterization/Optimization for Low Pt Loadings and High Current Densities
Authors: Orfanidi Alin , Simon Christoph , Harzer Gregor S. , Madkikar Pankaj , El-Sayed Hany A , Gasteiger Hubert A. 
Published: February 2020

The large-scale commercial viability of fuel cell electric vehicles (FCEVs) requires a reduction of the platinum-specific power density (gPt/kW) from currently ca. 0.3 gPt/kW to levels of ≤0.1 gPt/kW [1]. This can only be accomplished by improving fuel cell performance at high current density (≥2 A/cm2) with membrane electrode assemblies (MEAs) containing ultra-low anode and cathode platinum loadings (<0.1 mgPt/cm2).
Owing to the fast hydrogen oxidation kinetics on platinum [2], anode loadings of 0.05 mgPt/cm2 and below can be realized without significant MEA performance losses. On the other hand, large mass transport related voltage losses at high current density are observed when the cathode loadings are reduced to 0.05-0.10 mgPt/cm2, which can be influenced by catalyst and electrode design [3]. In addition to optimization of catalysts and MEAs, the high current density performance is also affected by the diffusion medium, namely by the choice of substrate and the composition/design of the micro-porous layer (MPL) [4].
In this presentation, we will discuss various options for electrode and MPL design, illustrating their impact in 5 cm2 single-cell differential-flow experiments. The measured voltage losses will be deconvoluted into kinetic losses based on data from H2/O2 measurements, into oxygen transport induced losses obtained from limiting current density measurements [5], and into contributions from the proton conduction resistance in the cathode electrode determined by AC impedance [6].

References

[1] O. Gröger, H. A. Gasteiger, J.-P. Suchsland, J. Electrochem.
Soc., 162, A2605 (2015).
[2] J. Durst, C. Simon, F. Hasché, H. A. Gasteiger, J. Electrochem.
Soc., 162, F190 (2015).
[3] A. Kongkanand, M. F. Mathias, J. Phys. Chem.
Lett., 7, 1127 (2016).
[4] J. M. Morgan, R. Datta, J. Power Sources, 251, 269 (2014).
[5] D. R. Baker, D. A. Caulk, K. C. Neyerlin, M. W. Murphy J. Electrochem. Soc., 156, B991 (2009).
[6] Y. Liu, C. Ji, W. Gu, D. R. Baker, J. Jorne, H. A. Gasteiger, J. Electrochem. Soc., 157, B1154 (2010).

Acknowledgements: We gratefully acknowledge funding from the German Federal Ministry for Economic Affairs and Energy (BMWi) for the project “Optigaa2” (funding number 03ET6015E) in collaboration with Freudenberg as well as for the BMWi funded subcontracts with Greenerity GmbH and Umicore (project “HyMotion5-Brennstoffzellenstapel”).
(Invited) Polymer Electrolyte Membranes for Fuel Cells: An Overview of Where We Have Been
Authors: Zawodzinski Thomas A. 
Published: February 2020

In this contribution, a review of the efforts to improve membranes for fuel cells will be presented. Several themes will be interwoven:

What we have measured over the years, the insight provided and what is missing in most studies of membranes.

A historical perspective on the time-sequential major membrane issues, including some resolution and some circumvention of these issues.

Types of membranes used and their relative merits as applicable to specific requirements.

Our state of understanding of membrane processes.

The roles of experimental and computational studies of membranes.

This talk is dedicated to Russ Kunz who always engaged in discussions as a gentleman with appropriate skepticism and obvious enthusiasm.

Acknowledgements

We gratefully acknowledge the long support of this work by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy FCTO, DARPA and by the Office of Naval Research. We also thank 3M, DuPont and Dow for providing membranes.
(Invited) Advances in PEM and Phosphoric Acid Fuel Cells
Authors: Mustain William E , Bonville Leonard J. , Pasaogullari Ugur , Maric Radenka , Singh Prabhakar 
Published: February 2020

After a long and very successful industrial career spanning over 4 decades, Russ Kunz joined the University of Connecticut in 1992 and was one of the most passionate and influential voices in energy and energy systems at the university. Russ not only was the principle investigator of numerous research projects and awards, he was also instrumental in the formation of the Connecticut Global Fuel Cell Center – since renamed the Center for Clean Energy Engineering – which remains today one of the premier academic facilities in the United States focusing on fuel cell technology. During his over 20 years at UConn, Russ contributed to a wide range of projects and touched the lives of young faculty and countless students. During this talk, we will share stories about Russ’ life and career at UConn, as well as discuss specific projects and concepts in recent years where he was an integral partner in our team. We will also discuss his influence on what we continue to do today.
More specifically, we will highly Russ’ contributions to electrolyte management in phosphoric acid fuel cells, and manipulation of physical and chemical properties in low temperature and high temperature PEM fuel cells.

Figure 1
(Invited) The Growing Importance of Hydrogen in Our Energy System and Extended Surface Electrocatalyst Development and Implementation
Authors: Alia Shaun M , Hurst Katherine , Mauger Scott A , Neyerlin K.C. , Kocha Shyam S. , Ngo Chilan , Shulda Sarah M , Pylypenko Svitlana , Pivovar Bryan S 
Published: February 2020

Today represents a particularly exciting time, as our planet’s energy system is undergoing major changes due to dramatically decreasing renewable energy prices and increasing societal concerns over greenhouse gas emissions, criteria pollutants (arsenic, mercury, NOx, particulate matter), and climate change. These factors are pushing society towards deep decarbonization of our energy system, perhaps the most challenging issue facing the planet today. Unfortunately, wind and solar energy, while both promising generation sources, come with intermittency challenges and have limitations in their abilities to impact industrial and transportation sector demands where fossil fuel energy carriers based on chemical bonds have provided the basis for historic energy demands. Hydrogen offers the potential to meet the multi-GW demand for both grid-balancing and input into the industrial and transportation sectors, as shown schematically in Figure 1. In such an energy system, hydrogen acts as an energy carrying intermediate that parallels electrons (electricity) within the energy system. Such an energy system allows all of society’s demands to be met with greatly reduced environmental impact.
Fuel cells for transportation and power generation are key enabling technologies for this future. However, the commercial viability of such systems is limited by cost, performance and durability with catalysts and electrodes being of central concern.
Our team has investigated extended surface catalysts as a novel platform for increased performance and durability at lower cost. This presentation will highlight the advances of our team in the synthesis of extended surface electrocatalysts with a focus on PtNi nanowires (NWs). While these materials have shown great promise in ex-situ (rotating disc electrode) studies, performance in-situ (fuel cell tests) has not yet reflected the performance potential seen in these ex-situ tests. In large part we attribute this to challenges in electrode fabrication and integration. This presentation will present results that focus on the differences between in-situ and ex-situ properties, quantification of performance losses in fuel cell tests, and our efforts to further improve performance and durability of such systems. These efforts parallel a number of different areas that Dr. Russ Kunz investigated throughout his career, and have benefitted from the knowledge basis Dr. Kunz contributed to throughout his career.
Figure 1: Illustrative future clean energy system in which hydrogen (water electrolysis) plays a key enabling role.

Figure 1
(Invited) How Oxygen-Containing Intermediates and Surface Charge Regulate Oxygen Reduction Reaction of Platinum Electrocatalysts
Authors: Huang Jun , Zhang Jianbo 
Published: February 2020

Oxygen-containing intermediates formed in oxygen reduction reaction (ORR) are widely believed to act as site-blockers. Recent experiments showing positive effects of O-containing intermediates throw doubt upon this prevailing understanding[1]. This situation calls for an overhaul of current understanding of mechanisms of the ORR. The theoretical challenge is how to consistently treat the formation of O-containing intermediates, surface charge on metal surface, ion and potential distribution in the solution, field-dependent behaviors of surficial water molecules, and thermodynamic relations and kinetics of the ORR. In the present article, a self-consistent framework bridging first-principles approaches and mean-field approaches, nanoscale and microscale, interface and bulk, is developed to address the above challenge. Model, parametrized with density functional theory results and rotating disk electrode data, sheds light on the potential-dependent Tafel slope and volcano shape of the activity versus binding energy of intermediate curve, focusing on the effects of surface charge and O-containing intermediates. Chemisorption of O-containing intermediates decreases surface charge density on metal surface, increases proton affinity at the interface, and brings positive effects to the ORR activity other than the negative effects of site-blocking.[2]
Reference:
[1] Gómez-Marín, A.M.; Rizo, R.; Feliu, J.M. Oxygen Reduction Reaction at Pt Single Crystals: A Critical Overview. Catal. Sci. Technol. 2014, 4, 1685-1698.
[2] Huang, J.; Malek, A.; Zhang, J.; Eikerling, M.H. Non-Monotonic Surface Charging Behavior Of Platinum: A Paradigm Change. J. Phys. Chem. C 2016, 120, 13587–13595.

Figure 1
(Invited) Porous Electrode Engineering for Platinum Group Metal-Free Oxygen Reduction Reaction Catalysts
Authors: Komini Babu Siddharth , Ogawa Shohei , Chung Hoon T , Zelenay Piotr , Litster Shawn 
Published: February 2020

As platinum group metal-free (PGM-free) catalysts make significant advances in their acidic oxygen reduction reaction activity when evaluated at low current, it is important to establish electrode designs capable of meeting automotive polymer electrolyte fuel cell (PEFC) demands for power density. Unfortunately, cathode-level transport losses can impose a tremendous penalty on PGM-free catalyst performance in PEFCs. The lower volumetric activity (A/m3) of PGM-free cathodes versus Pt/C cathodes requires cathodes thicknesses on the order of 0.1 mm, or roughly 10 times the thickness of Pt/C cathodes. That extreme thickness combined with hydrophilic, functionalized carbon surfaces, yields a cathode that is highly sensitive to liquid water flooding and large proton conduction Ohmic losses.
This talk will overview methods in the field developed for characterizing electrode-level losses in PGM-free electrodes and identifying the underlying mechanisms that hinder transport and limit high power density. The overview will include methods we have recently applied to Fe-N-C PGM-free catalysts synthesized from polyaniline and cyanimide (Fe-CM-PANI). As the figure illustrates, these methods include electrochemical measurements, nano-scale X-ray computed tomography (nano-CT) of 3D pore and ionomer morphology1, particle-scale simulation2, and PEFC simulation and optimization3. These studies are then subsequently applied to advancing electrode performance as well as guiding targets for future catalyst synthesis.

References

1. S. Komini Babu, H.T Chung, P. Zelenay, ACS Appl. Mater. Interfaces, 2016 8 (48), pp 32764–32777.
2. S. Ogawa, S. Komini Babu, H.T. Chung, P Zelenay, S Litster, ECS Trans 75 (14), pp 139-146.
3. S. Komini Babu, HT Chung, G Wu, P Zelenay, S Litster, ECS Trans. 64 (3), pp 281-292.

Figure 1
(Invited) Commercialization Road Map of Fuel Cell Commercial Vehicle (FCCV) at Telos Auto Power Systems Inc (TAPS)
Authors: Zhang Ruiming 
Published: February 2020

In cope with increasing serious emission problems, Chinese government has officially launched a series policies and legislations to stimulate the development and deployment of zero emission vehicles (ZEV). Currently in China, ZEV is heading to a crossroad – the competition and choice among battery powered vehicle, hybrid system, and fuel cell powered vehicle. Leveraging strong commercialization capability on fuel cell system and well-defined supplier chain, Telos Auto Power Systems (TAPS) focuses on bringing FCCV, including metro bus and industrial truck, to China market. Aiming at being the leader of manufacturing power systems of FCCV in China, TAPS has formed a holistic strategy as below:
· Establish a multifunction platform of advanced fuel cell power systems in combination with battery (fuel cell and battery hybrid systems, FCBHS) for automotive applications;
· Team up with prestigious vehicle and battery makers on FCBHS and FCCV forward engineering;
· Lead the efforts of supply chain integration and localization;
· Collect and utilize Big Data of FCCV end-to-end from manufacturing, daily usage, demonstration, to commercial operation, including operations of hydrogen infrastructure for further technology and business development.
(Invited) Integrating Theory and Experiment to Understand and Control Reaction Pathways
Authors: Toney Michael F 
Published: February 2020

DuraMat - or the Durable Module Materials - Consortium is a Department of Energy (DOE) Energy Materials Network (EMN) that brings together national lab and university research infrastructure with the photovoltaic (PV) industries to discover, develop, de-risk, and enable the commercialization of new materials and designs for PV modules (1). One enabling aspect of DuraMat is to develop methodologies to understand reaction pathways and mechanisms in order to control the synthesis of novel functional materials. By coupling theory and experiments, we aim to accelerate materials discovery, characterization, scale-up, and commercial deployment. In this talk, I will describe several PV relevant examples where our coupled theory-experiment efforts have accelerated materials discovery, including transparent conducting spinel oxides (2), MnOx synthesis from solution, and the development of multifunctional coatings. Using novel materials discovered with this approach, DuraMat has the potential to develop modules with a levelized cost of electricity of less than 3 cents per kilowatt-hour.
(1) https://www.duramat.org/
(2) Y Shi et al., Chemistry of Materials 26, 1867–1873 (2014).
Metal- and Oxidant-Free Benzylic C-H/Aromatic C-H Cross Coupling Based on the Stabilized Cation Pool Method
Authors: Yoshida Jun-ichi , Hayashi Ryutaro , Shimizu Akihiro 
Published: February 2020

The cation pool method serves as a nice tool in electroorganic synthesis. Organic cations are electrochemically generated and accumulated in solution at low temperatures. Reactions with subsequently added nucleophiles give the desired products. However, the cation pool method cannot be applied to highly unstable cations that decompose during the course of the electrolysis. To expand the scope of the cation pool method, we have developed the stabilized cation pool method, in which organic cations stabilized by suitable stabilizing agents are electrochemically generated and accumulated in solution. The reactions of the stabilized organic cations with subsequently added nucleophiles give the desired products.
In this paper we show that C−H/aromatic C−H cross-coupling can be achieved by the electrochemical generation and accumulation of stabilized benzyl cations followed by their reactions with subsequently added aromatic nucleophiles. Beznylaminosulfonium ions as stabilized benzyl cations are generated and accumulated in the electrochemical oxidation of toluene derivatives. In the next step, the reactions with subsequently added electron-rich aromatic compounds as nucleophiles give the corresponding cross-coupled product. The method has been successfully applied to the synthesis of TP27, an inhibitor of PTPase. The reactions of benzylaminosulfonium ions with other carbon nucleophiles such as acetylacetone, ketene silyl acetals, allyltrimethylsilane, and trimethylsilylacetylene will also be discussed in the presentation.