Towards the Reduction of Pt Loading in High Temperature Proton Exchange Membrane Fuel Cells – Effect of Fe−N−C in Pt‐Alloy Cathodes

Pt poisoning by phosphate in high temperature proton exchange membrane fuel cells (HT‐PEMFC) leads to loadings up to 1 mgPt cm−2 per electrode of costly materials. While cheaper Fe−N−C catalysts are unaffected by phosphate deactivation and contribute to the catalysis of the oxygen reduction reaction, their volumetric activity is substantially lower. In this study, the effect of Pt‐loading reduced hybrid cathodes for HT‐PEMFC is investigated using commercial Celtec®‐P‐based assembling. A promising effect of Fe−N−C incorporation in terms of acid attraction and activity retention is found. A longer activation (230 h, 0.3 A cm−2) for the hybrid membrane electrode assembly (MEA) is necessary, due to the slower acid distribution within Fe−N−Cs. This study shows the potential of Pt‐content reduction by up to 25 % compared to standard MEA using hybrid electrodes. Moreover, important insights for future strategies of cell activation are revealed for these hybrid MEAs. Less Pt needed: Hybrid cathodes using PtNi/C and Fe−N−C catalysts are investigated and compared with standard cathodes, showing Pt loading reduction by 11 and 25 %. Different activation processes of hybrid membrane electrode assemblies (MEAs) compared to standard MEA are found with a prolonged activation for hybrid MEAs consistent with the interactions of Fe−N−C and H3PO4 and the lower loading.