Low Pt loading high performance cathodes for PEM fuel cells

A simple direct mixing of carbon-supported catalysts with Nafion without adding any additional organic solvents was used to make electrodes for oxygen reduction in PEM fuel cells. For E-TEK 20% Pt/C, a Nafion content of 30% in the catalyst layer exhibited the best performance. Electrode dried from 90 to 150 °C showed little difference in performance. Highest power densities increased almost linearly with cell temperature, and values of 0.52, 0.60, 0.63, and 0.72 W/cm2 were achieved at 35, 50, 60, and 75 °C, respectively, for a cathode with a Pt loading of 0.12 mg/cm2 and operated using air at ambient pressure. A maximum performance was achieved with Pt loadings of 0.20±0.05 and 0.35±0.05 mg/cm2 for 20 and 40% Pt/C, respectively, while the maximum performance using 40% Pt/C was only slightly better than that using 20% Pt/C. A Nafion/carbon sublayer with up to 30% Nafion content added between ELAT and the catalyst layer did not show any effect on performance.