Pt∕C–WO[sub 3] Electrocatalysts for Degradation Mitigation in Polymer Electrolyte Fuel Cells

Carbon-tungsten oxide and platinum/carbon-tungsten oxide catalysts were prepared by chemical methods. The loading in the catalyst was . catalysts produced less hydrogen peroxide than baseline and electrocatalysts produced less hydrogen peroxide formation than baseline . Membrane electrode assemblies (MEAs) were prepared using and electrocatalysts and subjected to accelerated durability tests at and 30% relative humidity (RH) at open circuit with hydrogen as fuel and oxygen as oxidant. The fluoride emission rate (in ) over was found to be reduced by at the anode and at the cathode condensate when replaced in the electrode. Fuel cell polarization data was obtained using and in the cathode at and 75, 50, and 25% RH, with air and oxygen as oxidants and hydrogen as fuel. For all the test conditions, the performance of MEAs with was found to be lower than that of MEAs with . Through electrochemical impedance spectroscopy experiments and polarization data analysis, the lower performance was attributed to lower catalytic activity, and higher ionic and transport resistances in the electrodes.