Highly Active and Stable Pt₃Cr/C Alloy Catalyst for Oxygen Reduction Reaction

In the present work, Pt₃Cr/C alloy catalyst showed enhanced activity under half-cell and full-cell conditions as well as excellent corrosion stability compared to those of the 40 wt% Pt/C_JM benchmark catalyst. At 2 mA cm^-², Pt₃Cr/C catalyst exhibited 10 mV less over-potential and twofold higher specific and mass activity for ORR than Pt/C_JM. The average particle size grew from 4.5 nm up to "only" 6-8 nm during accelerated degradation tests under half-cell conditions. For comparison, average particle size of Pt/C_JM increased from 4.5 up to 15-20 nm. In full-cell experiments, MEA with Pt₃Cr/C as cathode catalyst exhibits an excellent maximal power density retention of about 76% after 1000 degradation cycles compared to 55% for the MEA with the commercial catalyst.