Low platinum-ruthenium alloy and oxide-based electrocatalysts for direct methanol oxidation in phosphoric acid

Five per cent Pt/Ru (1 :1)-oxide based electrocatalysts were investigated for direct methanol fuel cells (DMFC). The properties of differents electrocatalysts fabricated from the dispersion of various oxides (Al2O3, ZnO, Cu2O, TiO2, Fe2O3, SiO2, etc,...) with 5% Pt-Ru onto carbon was studied for methanol oxidation in phosphoric acid at 150 degrees C. The resulting electrode has a Pt-Ru loading of 0.15 mg/cm(2). From the potential-current curves and the overvoltage at different current densities, the best anode for this reaction was deduced. It was shown that several Pt/Ru/oxides based anodes have better electrocatalytic properties for methanol oxidation than Pt-Ru anodes. In particular, the best anode for the methanol oxidation in phosphoric acid at 150 degrees C was the Pt-Ru Fe2O3-based electrode. The Pt-Ru-30% Fe2O3-based anode, for example, exhibited an overvoltage of 500 mV at 200 mA.cm(-2) for this reaction at one atmosphere.