bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Catalyst Layer Using Gas Diffusion Electrode Half-Cell System for High Temperature Polymer Electrolyte Membrane Fuel Cell
Authors: Jung Hyeon Seung , Kim Dong Hee , Kim Jong Gyeong , Pak Chanho 
Published: February 2024

High-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) is being developed for the heavy-duty vehicle which requires high power density and operation under extreme conditions. Conventional HT-PEMFC using phosphoric acid (PA) immersed PBI membranes and polytetrafluoroethylene (PTFE) binder faced issues such as unstable durability and low performance of membrane electrode assembly (MEA) due to PA leakage and uneven distribution within the catalyst layer.
In recent years, ion-pair membranes and ionomers for high temperatures have been developed, which can reduce PA leakage in MEA and improve ionic conduction within the catalyst layer. Incorporation of a new material into the MEA requires further research to enhance electrode design, catalyst utilization, and performance for the appropriate ionomer, as this material exhibits different characteristics from the conventional PTFE binder.
In this study, various gas diffusion electrode (GDE) was fabricated with the new ionomer, and GDE half-cell setups were introduced for rapid and efficient characterization of performance in the oxygen reduction reaction. This system serves as an intermediate step between rotating disk electrodes and single cells, providing a powerful tool for quickly screening and evaluating GDEs using small amounts of catalyst. Recent publications from Wilkinson [1] and Gasteiger [2] groups reviewed this new system, proposed new measurement protocols, and suggested improvements. Accordingly, GDE half-cell setups are designed to simulate HT-PEMFC operating conditions at 150 ℃ temperature with 85 wt.% PA electrolyte.
Electrochemical characteristics were evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) following the protocols in previous papers with GDE half-cell. Resistance values obtained through EIS were further differentiated by peaks and frequency-based responses through the distribution of relaxation times transformation. Performance comparison between GDEs was carried out by measuring the voltage at 0.2 A/cm² and peak power density at 150 ℃, simulating a single cell-like environment. GDEs were fabricated with variables such as Pt loading, thickness, and porosity. And their physical properties were confirmed through mercury intrusion porosimetry and scanning electron microscopy. Ultimately, the study elucidated the correlation between the electrochemical data and physical properties.

References

[1] B.A. Pinaud, A. Bonakdarpour, L. Daniel, J. Sharman, D.P. Wilkinson, Key considerations for high current fuel cell catalyst testing in an electrochemical half-cell, J. Electrochem. Soc. 164 (2017) F321–F327.
[2] T. Lazaridis, B.M. Stühmeier, H.A. Gasteiger, H.A. El-Sayed, Capabilities and limitations of rotating disk electrodes versus membrane electrode assemblies in the investigation of electrocatalysts, Nat. Catal. 5 (2022) 363–373.
Structure, Ionomer and Water Distribution in Catalyst Layer of Proton Exchange Membrane Fuel Cell
Authors: Morin Arnaud , Chabot Florian , Porcar Lionel , Rosini Sébastien 
Published: February 2024

Catalyst layer’s (CL) ionomer plays a crucial role in the operation of Proton Exchange Membrane Fuel Cell (PEMFC), not simply because it binds the catalyst nanopowder but mostly because it allows proton transport and affects both gas diffusivity and water management [1]. In the CL, the ionomer is a perfluorosulfonic acid polymer similar to that use in the membrane as electrolyte. It is in the form of a few nanometer thick film dispersed around the carbon support or as aggregates larger than 150 nm within the pores of the carbon network [2,3]. In contrast with bulk ionomer membrane or model thin films that have been extensively studied, still little is known on the distributions of ionomer, and especially of water, within the catalyst layer upon hydration [4]. However, this information is crucial to understand the operation and degradation of PEMFC.
In the frame of the project FURTHER-FC [5], we perform extensive analysis of the water sorption properties, and in a more unusual way, of the structure of the catalyst layer as a function of relative humidity for different types of carbon support, using Small Angle Neutron Scattering (SANS). It allows us to estimate qualitatively the distribution of the ionomer, and to quantify the average thickness of the ionomer film coating the catalyst, as well as the location of water within the CL upon hydration.

The project FURTHER-FC [2] has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking (now Clean Hydrogen Partnership) under Grant Agreement No 875025. This Joint Undertaking receives support from the European Union’s Horizon 2020 Research and Innovation program, Hydrogen Europe and Hydrogen Europe Research.

Jinnouchi, R. et al. Nat. Commun. 12, (2021)

Ueda, S. et al., Phys B Condens Matter 551, 309–314 (2018)

Morawietz, T. et al., Fuel Cells 18, 239–250 (2018)

Kusoglu et al., Chem. Rev. 117, 987−1104 (2017)

https://further-fc.eu/
Investigation of the Effect of Airborne Contaminants on PEM Fuel Cell Stack Performance and Degradation Using Electrochemical Impedance Spectroscopy, AVL Thda™ and FTIR Gas Analyzer
Authors: Özel Tansu , Bürger Stefan , Cremers Carsten 
Published: February 2024

Air pollution is still a bitter truth in many locations in the world. In highly populated regions like metropolitan areas as well as in agricultural areas there are various airborne contaminants which can be harmful to organisms. Also fuel cells, especially PEMFC are sensitive to airborne contaminants.
In most mobile and stationary PEM fuel cell systems, ambient air is used as oxidant gas at the cathode of the fuel cell. It is cost and weight saving because there is no need to install additional tank for pure oxygen and to refill it, but the performance of fuel cell can suffer beyond the oxygen gain from airborne contaminants, which also have the potential to accelerate degradation. To prevent that airborne contaminants reach the fuel cell cathode, air filter systems consisting of particle filter and additional activated carbon filter are installed at the cathode inlet.
The focus here is on the investigation of the use of AVL THDAtm method to detect effects of airborne contaminants. THDA (total harmonic distortion analysis) is a patented online fuel cell monitoring method based on analyzing harmonic distortion effects of voltage drifts instead of single cell voltage measurement. So far it was successfully demonstrated for the detection of water issues like flooding and drying, and for low media supply issues on both cathode and anode side [1, 2].
For the development and validation of the method, experiments with a PEMFC stack are going to be done on a fuel cell testbed equipped with an AVL X-Ion impedance analyzer. Specific air pollutant gases ammonia (NH3), sulfur dioxide (SO2) and nitrogen oxides (NOx) are going to be mixed into the cathode air in the ppb range. Their effects on PEMFC stack performance are going to be investigated with electrochemical impedance spectroscopy (EIS) and total harmonic distortion analysis. The cathode exhaust gas is also going to be analyzed by an FTIR gas analyzer.
It is planned to test the PEMFC stack under different operating conditions, with various parameters and different cathode gas mix ratios while monitoring possible conversion of impurities via FTIR and the stack state of health using THDA and conventional technologies to understand the link between the effect of airborne contaminants on fuel cell stack performance, on its lifetime and to determine possible early indicators in the THDA signals.
References
[1] Mitzel, J., Sanchez‐Monreal, J., Garcia‐Sanchez, D., Gazdzicki, P., Schulze, M., Häußler, F., Hunger, J., Schlumberger, G., Janicka, E., Mielniczek, M., and Gawel, L. 2020. Fault Diagnostics in PEMFC Stacks by Evaluation of Local Performance and Cell Impedance Analysis. Fuel Cells 20, 4, 403–412.
[2] Ramschak, E., Peinecke, V., Prenninger, P., Schaffer, T., and Hacker, V. 2006. Detection of fuel cell critical status by stack voltage analysis. Journal of Power Sources 157, 2, 837–840.
Development of New Electrochemical Method for Measuring Gas Permeability of PEM Fuel Cell Components
Authors: Darabut Alina Madalina , Lobko Yevheniia , Yakovlev Yurii , Matolin Vladimír , Matolínová Iva 
Published: February 2024

A Proton Exchange Membrane Fuel Cell (PEMFC) is an electrochemical device that converts directly chemical energy into electrical energy. PEM fuel cells have high efficiency (up to 65%), low working temperatures (between 60‒80 ºC), and produce only water as byproduct [1]. Moreover, these devices are suitable for the replacement of the internal combustion engines with insignificant modifications to the automobile.
The PEMFC consists of a membrane with a catalytic layer, also known as membrane electrode assembling (MEA), gas diffusion layer (GDL), bipolar plates (BPs), and auxiliar components likewise sub-gaskets, and sealings used for preventing the gas leakage [1,2]. An essential material property directly influencing the performance and long-life capacity of the PEM fuel cells is the permeability of their components toward gases (H2 and O2).
Two classical methods can be used for measuring the H2 permeation of the bipolar plates. First one is based on the differential pressure method where the pressurized H2 is passed through the sample and the time rate of decrease/increase of the pressure on the same/opposite side of the sample is measured. The second method is drawn on introducing H2 maintaining the same pressure on both sides, then the transmitted H2 is measured by a chromatography detector [3].
In the present work is proposed a new electrochemical technique for measuring the gas permeability of the BPs. The own-prepared reactor is shown in Fig. 1a. The method is based on covering the sample with a catalytic layer (Fig. 1b) and submerging it in electrolyte. The pressurized H2 is introduced from the bottom of the sample, and the transmitted H2 through it reacts with O2 giving the measured current. Worth noticing that this method is universal and can be used for the analysis of the gas permeation of other semi-conductive and conductive materials not just for FC (e.g., MEAs and GDLs), but other applications.
References:
[1] G. Hoogers, Fuel Cell Technology Handbook, 2003.
[2] Y. Wang, Y. Pang, H. Xu, A. Martinez, K.S. Chen, PEM Fuel cell and electrolysis cell technologies and hydrogen infrastructure development – a review, Energy Environ. Sci. 15 (2022) 2288–2328. https://doi.org/10.1039/d2ee00790h.
[3] R. Blunk, F. Zhong, J. Owens, Automotive composite fuel cell bipolar plates: Hydrogen permeation concerns, J. Power Sources. 159 (2006) 533–542. https://doi.org/10.1016/j.jpowsour.2005.09.068.

Figure 1
(Digital Presentation) Modeling the Effect of Membrane Electrode Assembly Microstructure on Thermal and Water Transport in Polymer Electrolyte Fuel Cells
Authors: Sánchez-Ramos Arturo , Garcia-Salaberri Pablo A. 
Published: February 2024

The effect of water management on oxygen transport plays a critical role in the design of high-performance polymer electrolyte fuel cells (PEFCs) for the automotive industry, especially at low cathode platinum loading [1,2]. In this regard, optimizing the hierarchical pore structure of the membrane electrode assembly (MEA) is crucial to alleviate cathode flooding while ensuring good membrane hydration [3]. However, this task is complicated due to the small dimensions involved in the problem. Mathematical modeling has turned out to be a key tool to understand transport in the thin layered assembly used in PEFCs, including the catalyst layer (CL), microporous layer (MPL) and gas diffusion layer (GDL).
In this work, oxygen, heat and two-phase water transport in the MEA are examined by means of a 1-dimension continuum bundle of capillary tubes model. Experimental pore size distributions (PSDs) are considered for the GDL/MPL/CL assembly. The model takes especial care in analyzing thermal and water behavior in catalyst layer by considering micro (< 20 nm of pore radius), meso (between 20 and 300 nm) and macroscale (> 300 nm) structures as different interconnected domains, each with their own effective thermal conductivity and water saturation. In this aspect, taking into account pore hydrophilicity or hydrophobicity is determinant as water behavior is extremely different.
The model predictions are validated against previous experimental data for various operating conditions and pore structures (Figure 1a). The results offer precise information on the coupling between heat and water transport in both liquid and gas phases, and the impact of operating conditions and transport properties on the saturation distribution through the MEA layers (Figure 1b). Then the continuum bundle of capillary tubes model is also used to run a parametric analysis centered on the obtention of optimal PSD-dependent effective transport properties to produce improved MEA microstructures.
[1] A. Sánchez-Ramos, J.T. Gostick, P.A. García-Salaberri, Modeling the Effect of Low Pt loading Cathode Catalyst Layer in Polymer Electrolyte Fuel Cells: Part I. Model Formulation and Validation, Journal of the Electrochemical Society 168 (2021) 124514.
[2] A. Sánchez-Ramos, J.T. Gostick, P.A. García-Salaberri, Modeling the Effect of Low Pt loading Cathode Catalyst Layer in Polymer Electrolyte Fuel Cells: Part II. Parametric Analysis, Journal of the Electrochemical Society 169 (2022) 074503.
[3] M. Gomaa, A. Sánchez-Ramos, N. Ureña, M.T. Pérez-Prior, B. Levenfeld, P.A. García-Salaberri, M. Rabeh, Characterization and modelling of free volume and ionic conduction in copolymer proton exchange membranes, Polymers 14(9) (2022) 1688.

Figure 1
Recycling of Platinum Group Metals
Authors: Ashfield Laura 
Published: February 2024

The platinum group metals (Pt, Pd, Rh, Ir, and Ru) are cited as critical minerals by the US Geological Survey and appear on the EU Critical Raw Materials list due to their low natural abundance and economic importance. Platinum has many uses including jewellery, medical devices and pharmaceuticals, coatings, automotive catalysts, nitric acid manufacture and other industrial catalysts, electronics, and plays a crucial role in the growing area of fuel cell and water electrolyzers.
Early recognition of the need to recycle these valuable elements has led to the development of a circular economy using highly advanced processes for extracting and separating them from complex materials, returning the metals to use in a highly pure form. This presentation will give an overview of the industry up to the present day, including examples of the application of separation techniques, and will explore the potential for reduced environmental impact from recycling platinum group metals and the benefits of consideration of design for recycle in product development.
Influence of Contact Pressure and Flow Rate on the Performance of Anion Exchange Membrane Electrolysis
Authors: Lemcke Michelle Sophie , Münchgesang Wolfram , Menzel Nadine , Bron Michael 
Published: February 2024

Hydrogen production by electrolysis is a key aspect of a climate-neutral economy. However, there are still weak points in the established low-temperature technologies such as high material costs in case of PEM electrolysis and poor dynamic operations in case of alkaline electrolysis. The emerging electrolysis technology, the anion exchange membrane (AEM) electrolysis, addresses these weaknesses and combines their advantages. Due to the solid polymer electrolyte and the alkaline environment, AEM water electrolysis is featured by a compact zero-gap cell design and inexpensive materials like non-noble metal catalysts. Hence, it offers the potential to a cost-effective and efficient electrolysis technology.
To enable the breakthrough of this technology, we contribute by conducting performance evaluations of membrane electrode assemblies (MEAs) under application-oriented conditions. One focus is on non-noble metal MEAs with an active area of 25 cm2 operated with pure water and low concentrated potassium hydroxide solution.
To ensure comparability of different MEAs, it is crucial to compare them at their performance optimum. This is achieved by determining the optimal set-up parameters like contact pressure and operation parameters like flow rate for each MEA type. Otherwise, deviation from the optimal operating point by up to 50 % may occur.
The influence of the parameters contact pressure and flow rate on the MEA performance is discussed in this presentation. To investigate their impact, we analysed the MEAs in an electrolyser test station using polarisation curves, electrochemical impedance spectroscopy and load tests at constant current and constant voltage.
Some of the results presented are obtained within the project “REVAL – reversible anion exchange membrane electrolysis” (funding code 03ZZ0732D) funded by the German Federal Ministry of Education and Research (BMBF).
Microwave Drying of Catalyst Layers for Fuel Cells and Electrolysers
Authors: Heider Emanuel Albert , Bader Julian , Kiesel Simone , Kühn Steffen , Tran Hai-Anh , Oesterlein Moritz , Joerissen Ludwig 
Published: February 2024

Due to an increasing demand for sustainable energy, the polymer electrolyte membrane fuel cell (PEMFC) is considered a key technology in energy conversion with hydrogen as an energy carrier. The performance characteristics of a PEMFC is significantly influenced by the morphology of the catalyst layer[1], which is formed predominantly during the drying step in the manufacturing process.
In order to improve the performance of PEMFC and hence reducing production costs, research effort as well as industrial interest has focused on the drying process. Moreover, energy efficiency of the drying step in the production of thin-film catalyst layers is considered a key driver of cost perspective for the mass-market introduction of PEM fuel cells and electrolyzers due to increasing energy costs and the need for reduction of environmental impact.
In the presented work, an innovative drying approach for thin-film catalyst layers, used in PEMFC and electrolyzer applications, is investigated. The thin-film is either coated on a substrate and transferred onto a polymer electrolyte membrane in a second process step or is directly coated onto the polymer electrolyte membrane by doctor blade coating. Drying is performed by coupling of microwave radiation into the wet film, leading to a homogeneous and energy-efficient heating of the coated film. Energy losses of the microwave drying process are significantly reduced compared to conventional convective drying. Additionally, the microwave induced drying step offers maximum control during the process.
Dried thin-films, produced in the lab scale, are transferred to a polymer electrolyte membrane by a hot-pressing step and are completed with gas diffusion layers to membrane electrode assemblies (MEA). Electrochemical performance of the MEA is characterized on a fuel cell test bench in single cell configuration. The morphology of the structure obtained from microwave drying is analyzed and compared to CCM samples dried in a conventional convective oven.
The effect of a microwave-based drying process is discussed with regard to fuel cell performance and structure-property relations of the electrodes.

References

[1] M. Breitwieser, M. Klingele, S. Vierrath, R. Zengerle, S. Thiele, Adv. Energy Mater. 8, 1701257 (2018).
Production of Novel Tubular Electrochemical Hydrogen Compressor
Authors: Zängler Wibke , Keller Robert , Wessling Matthias 
Published: February 2024

For most applications, especially transport, hydrogen needs to be compressed due to its low volumetric density. Conventionally, mechanical compressors are used for hydrogen compression, but they possess disadvantages such as high maintenance due to moving parts and a limited one-stage compression ratio. A promising technology to overcome those obstacles is electrochemical hydrogen compression, in which hydrogen is compressed in an electrochemical membrane reactor.
To date, only planar electrochemical reactors for hydrogen compression have been investigated although tubular designs offer advantages in membrane area to reactor volume ratio, sealing options, pressure stability and reactor complexity. However, high contact and membrane resistances and scalable manufacturing processes are still challenges to be addressed for the advent of tubular electrochemical compressors in application.
Herein we introduce a manufacturing process for tubular electrochemical hydrogen compression reactors. The developed cell comprises a catalyst coated porous tubular anode covered by a tubular proton exchange membrane, which was subsequently coated with the cathode catalyst layer. The porous anode was prepared via metal 3D printing. 3D printing enables tailored porosity and geometry by which mass transport is enhanced. The catalyst layer was applied by manual spray coating. Constant current experiments and electrochemical impedance spectroscopy were performed to characterize the as prepared tubular electrochemical compressor. The results revealed the importance of tailored contacting concepts and the optimization of components regarding water transport, as the efficiency of the process is dominated by contact and membrane resistances.