Nanostructured tungsten carbide catalysts for polymer electrolyte fuel cells

Abstract

In this study, high current densities (i.e., $0.9\mathrm{A}∕{\mathrm{cm}}^2$ ) have been obtained in a hydrogen∕air polymer electrolyte fuel cell using nanoscale tungsten carbide as the anode catalyst and carbon supported platinum as the cathode catalyst under normal operating conditions of 80 °C and 3 atm. These results show a possibility of replacing precious metal anode catalysts with transition metal compounds for hydrogen oxidation, thereby creating a fundamental technology to reduce the cost of future fuel cell engines. The tungsten carbide-based catalysts were synthesized by means of chemically reduced mechanical alloying. The high electrocatalytic activity toward hydrogen oxidation reaction is attributed to the inherent W–C valence and the unique nanostructure of synthesized carbides. These properties were confirmed by x-ray diffraction and transmission electron microscopy.