Mapping of Heterogeneous Catalyst Degradation in Polymer Electrolyte Fuel Cells
| Autor: | Nobumichi Tamura, Saravanan Kuppan, Christina Johnston, Kaustubh Khedekar, Iryna V. Zenyuk, Metzger Michael, Andrea Perego, Craig Nathan P, Sarah Stewart, Plamen Atanassov, Morteza Rezaei Talarposhti, Lei Cheng |
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| Rok vydání: | 2020 |
| Předmět: |
Length scale
energy conversion Materials science Life on Land 02 engineering and technology 010402 general chemistry Heterogeneous catalysis heterogeneous degradation 01 natural sciences electrocatalysts Catalysis law.invention Macromolecular and Materials Chemistry Micrometre law General Materials Science polymer electrolyte fuel cells Renewable Energy Sustainability and the Environment Materials Engineering 021001 nanoscience & nanotechnology Synchrotron 0104 chemical sciences Chemical engineering Electrode Degradation (geology) Particle size Interdisciplinary Engineering 0210 nano-technology |
| Zdroj: | Advanced Energy Materials, vol 10, iss 28 |
| Popis: | Durability of cathode catalyst in polymer electrolyte fuel cells (PEFCs) is a key factor, limiting large-scale commercialization of PEFC for transportation applications. The catalyst degradation occurs during operational load profiles switches from ideal to peak, where multiple operational factors affect the degradation rate. The catalyst degrades heterogeneously as the catalyst particles are exposed to local variations throughout the entire catalyst layer during operation. State-of-the-art analytical techniques for studying degradation of Pt catalyst do not possess fine spatial resolution to elucidate such non-uniform degradation behavior at a large electrode level. We report a new methodology to spatially resolve and quantify the heterogeneous Pt catalyst degradation over a large area (several cm2) of aged MEAs based on synchrotron X-ray micro-diffraction. PEFC samples were aged using voltage cycling as an accelerated stress test. The heterogeneity of catalyst degradation at a micrometer length scale was visualized by mapping Pt catalyst particle size after voltage cycling between 0.6V and open circuit potential. We demonstrated in details that the Pt catalyst particle size growth was non-uniform and followed the flow field geometry. The Pt particle size growth was greater in the area under the flow field land, while it was minimal in the area under the flow field channel. Additional non-uniformity was observed with the Pt particle size increasing more rapidly at the gas outlet area of than the Pt particle size at the inlet area. Figure 1 |
| Databáze: | OpenAIRE |
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