Hybrid Catalysts for Degradation Mitigation in PEFCs

Abstract

Carbon-tungsten oxide (C/WO3), Carbon-phosphotungstic acid (C/PTA) and Platinum/Carbon-PTA (Pt/C-PTA) hybrid catalysts were prepared by wet chemical methods. Rotating ring-disk electrode (RRDE) experiments were performed using these materials to estimate the amount of hydrogen peroxide (H2O2) formed during the oxygen reduction reaction (ORR). C-WO3 15 wt% and C-PTA hybrid catalysts produced 30-40% less hydrogen peroxide than C and Pt/C-PTA had 20-30% less peroxide production than the baseline Pt/C electrocatalyst. The hybrid catalysts were used to prepare membrane electrode assemblies that were tested at 90{degree sign}C and 30% RH at open circuit with pure hydrogen as fuel and oxygen as the oxidant. The concentration of F- in the anode condensate over 24 hours was found to be reduced by a factor of 50-60% when C-WO3 15wt% and C-PTA replaced C as the catalyst.