Abstract: The PtSn/C-Ni catalyst was prepared by adding Ni(NO3)2 in the reduction process of SnCl2 and H2PtCl6 with ethylene glycol. The coexistence of the Sn(Ⅱ)/Sn(Ⅳ) redox couple was detected in the catalyst by temperature-programmed reduction experiments. Linear sweep voltammetry, single cell test, and CO stripping voltammetry experiments showed that the ethanol electro-oxidation activity and CO tolerance can be obviously enhanced by increasing the Sn(Ⅱ)/Sn(Ⅳ) ratio in the catalyst. The reason might be attributed to that the Sn(Ⅱ)/Sn(Ⅳ) redox couple accelerates the transfer rate of (OH)adsand then promotes the consequent oxidation of CO-like intermediates that are produced in the ethanol electro-oxidation process on the surface of Pt.

Key words: platinum, tin, supported catalyst, direct ethanol fuel cell, ethanol electro-oxidation, tin redoxcouple