Oxygen Evolution Co-Catalysts at Fuel Cell Cathodes for Degradation Mitigation during Simulated Start-up Shut-down Cycles

Abstract

We herein report a methodology which uses an oxygen evolution reaction (OER) co-catalyst, such as Ru and RuO2 together with a highly active ORR catalyst. The co-catalyst is applied in the cathode layer with loadings of 0.035 - 0.04 mgRu/cm2 and is uniformly mixed with the ORR catalyst prior to electrode preparation. Oxygen evolution catalysts (OER) like Ru/C and RuO2/C mixed with ORR catalysts enhance the oxidation of water/OH- to oxygen and therefore provide significant protection of other redox active species at high cathode potentials Our measurements indicate that loss in ECSA, carbon support and activity for ORR catalyst combined with OER was significantly reduced as compared to an unprotected catalyst layer.