Study of ethanol electro-oxidation in acid environment on Pt3Sn/C anode catalysts prepared by a modified polymeric precursor method under controlled synthesis conditions

Abstract

A carbon-supported binary Pt3Sn catalyst has been prepared using a modified polymeric precursor method under controlled synthesis conditions. This material was characterized using X-ray diffraction (XRD), and the results indicate that 23% (of a possible 25%) of Sn is alloyed with Pt, forming a dominant Pt3Sn phase. Transmission electron microscopy (TEM) shows good dispersion of the electrocatalyst and small particle sizes (3.6nm±1nm). The polarization curves for a direct ethanol fuel cell using Pt3Sn/C as the anode demonstrated improved performance compared to that of a PtSn/C E-TEK, especially in the intrinsic resistance-controlled and mass transfer regions. This behavior is probably associated with the Pt3Sn phase. The maximum power density for the Pt3Sn/C electrocatalyst (58mWcm−2) is nearly twice that of a PtSn/C E-TEK electrocatalyst (33mWcm−2). This behavior is attributed to the presence of a mixed Pt9Sn and Pt3Sn alloy phase in the commercial catalysts.