Development of ultra-low loading Pt alloy cathode catalyst for PEM fuel cells

Low loading Pt and Pt-alloy hybrid cathode catalysts are developed for PEM fuel cell application. A novel low temperature pyrolysis procedure was developed for the synthesis of graphitic carbon composite supports and a polyol synthesis was employed for uniform Pt deposition on the carbon composite supports. Rotating ring disk electrode and fuel cell studies indicated the synergistic effect of hybrid cathode catalyst (HCC) which combines the catalytically active carbon composite support and Pt catalyst. The support durability test results indicated that both the HCC₂₅₀-2^nd generation catalyst and Pt/USC-AGC catalysts satisfy the 2017 DOE target of 30 mV loss after 400 h potential holding at 1.2 V under high current density operation in H ₂/air. The Pt/CCC₁₄₀-3^rd and Pt/USC-AGC catalysts show much lower mass activity loss (<40% loss) after 400 h potential holding experiment.