# Impact of catalyst layer morphology on the operation of high temperature PEM fuel cells

Bevilacqua, N.; Asset, T.; Schmid, M. A.; Markötter, H.; Manke, I.; Atanassov, P.; Zeis, R.

## Abstract:

Electrochemical impedance spectroscopy (EIS) is a well-established method to analyze a polymer electrolyte membrane fuel cell (PEMFC). However, without further data processing, the impedance spectrum yields only qualitative insight into the mechanism and individual contribution of transport, kinetics, and ohmic losses to the overall fuel cell limitations. The distribution of relaxation times (DRT) method allows quantifying each of these polarization losses and evaluates their contribution to a given electrocatalyst's depreciated performances. We coupled this method with a detailed morphology study to investigate the impact of the 3D-structure on the processes occurring inside a high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC). We tested a platinum catalyst (Pt/C), a platinum-cobalt alloy catalyst (Pt$_{3}$Co/C), and a platinum group metal-free iron-nitrogen-carbon (Fe–N–C) catalyst. We found that the hampered mass transport in the latter is mainly responsible for its low performance in the MEA (along with its decreased intrinsic performances for the ORR reaction). The better performance of the alloy catalyst can be explained by both improved mass transport and a lower ORR resistance. ... mehr

 Zugehörige Institution(en) am KIT Helmholtz-Institut Ulm (HIU) Publikationstyp Zeitschriftenaufsatz Publikationsjahr 2021 Sprache Englisch Identifikator ISSN: 2666-2485 KITopen-ID: 1000133855 HGF-Programm 38.02.02 (POF IV, LK 01) Components and Cells Erschienen in Journal of Power Sources Advances Verlag Elsevier ScienceDirect Band 7 Seiten Art.-Nr.: 100042 Nachgewiesen in DimensionsScopus
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