Abstract: A series of alloyed PtmAg/C catalysts(m: Pt/Ag atomic ratio, 0.05～1.0) were prepared by the co-reduction of K2PtCl6 and AgNO3 precursors with NaBH4 as the reducing agent. The electrocatalytic performance of the PtmAg/C catalysts for the methanol electro-oxidation was investigated. These PtmAg/C catalysts after electrochemical dealloying treatment in H2SO4 show enhanced catalytic activities for the methanol electro-oxidation and the CO tolerance as compared with the pure Pt/C catalyst, and the catalytic performance is strongly dependent on the catalyst composition(m). The mass-specific activity(MSA), intrinsic activity(IA) and stability of PtmAg/C catalysts increase with increasing m up to 0.5. The MSA and IA of Pt0.5Ag/C catalyst is ca. 5.1 and 4.8 times of that of Pt in Pt/C catalyst, respectively.

Key words: platinum, silver, dealloy, acidic electrolyte, methanol electro-oxidation