Preparation and characterization of Pt-WO₃/C catalysts for direct ethanol fuel cells

Three co-impregnation/chemical reduction methods in acidic solutions of pH < 1, including ethylene glycol(EG), NaBH₄, and HCOOH, were compared for Pt-WO₃/C catalysts. Pt-WO₃/C catalysts containing 10 wt.% and 20 wt.% platinum per carbon were prepared by the three methods; their morphology and electrocatalytic activities were characterized. The 20 wt.% Pt-WO₃/C catalyst prepared by the co-impregnation/EG method presented the optimal dispersion with an average particle size of 4.6 nm and subsequently the best electrocata-lytic activity, and so, it was further characterized. Its anodic peak current density for ethanol oxidation from linear sweep voltammetry(LSV) is 7.9 mA-cm-2, which is 1.4 and 5.2 times as high as those of the catalysts prepared by co-impregnation/NaBH₄ and co-impregnation/ HCOOH reduction methods, 2.1 times as high as that of the 10 wt.% Pt-WO₃/C catalyst prepared by co-impregnation/EG method, respectively.