CO-tolerance of low-loaded Pt/Ru anodes for PEM fuel cells

Anodes with various Pt/Ru loadings were prepared using three different anode catalysts: E-TEK 40% Pt-Ru/Vulcan XC-72 and Engelhard 40 and 50% Pt-Ru/C. These anodes were tested for their CO-tolerance at a cell temperature of 70 °C in the presence of 10 and 50 ppm CO, respectively. The performance declined with CO concentration for all the anodes. However, Engelhard catalysts showed better performance than E-TEK catalyst under our experimental conditions. A minimum Pt/Ru loading of 0.43, 0.22 and 0.30 mg/cm2 was needed to achieve the maximum performance for E-TEK 40% Pt-Ru/C, Engelhard 40 and 50% Pt-Ru/C, respectively, when 10 ppm CO/70% H2/30% CO2 was used at a cell current density of 0.20 A/cm2. Using 50 ppm CO/70% H2/30% CO2 and at a cell current density of 0.20 A/cm2, a minimum Pt/Ru loading of 0.60, 0.32 and 0.36 mg/cm2 was needed to achieve the highest performance for E-TEK 40% Pt-Ru/C, Engelhard 40 and 50% Pt-Ru/C, respectively.