Improved performance of direct methanol fuel cells with tungsten carbide promoted Pt/C composite cathode electrocatalyst

Oxygen reduction reaction (ORR) on tungsten carbide promoted Pt/C (Pt-W2C/C) composite catalysts prepared by the intermittent microwave irradiation method has been investigated in acidic media. The exchange current density for the ORR on Pt-W2C/C is more than 2 orders of magnitude higher than that on a conventional Pt/C catalyst with a significantly improved onset potential. A direct methanol fuel cell (DMFC) using a Pt-W2C/C cathode achieved a power output of 190 mW cm(-2), which is 36% higher than that of a conventional Pt/C cathode with a much higher Pt loading. The results show that the incorporation of tungsten carbide greatly enhances the electrocatalytic activities of the Pt/C catalyst and significantly improves the DMFC performance, probably due to the synergetic catalytic effect between nanocrystalline tungsten carbide and Pt catalysts. (c) 2006 The Electrochemical Society.