Influence of Preparation Method on the Performance of PtSn/C Anode Electrocatalyst for Direct Ethanol Fuel Cells

Carbon-supported platinum-tin (PtSn/C) electrocatalysts were prepared by reducing platinum and tin salts with various reducing agents (such as ethylene glycol (EG), HCHO, and NaBH4) in H2O or EG. The morphology, crystalline structure, and composition of the PtSn/C catalysts were characterized by X-ray diffraction, transmission electron microscopy, and temperature-programmed reduction. The metal particles of PtSn/C(EG) are homogeneously dispersed with a narrow size distribution, centered at 1.8 nm, and tin exists in multi-valence states in this catalyst. Cyclic voltammetry and single cell performance tests show that PtSn/C(EG) has the highest activity for ethanol electro-oxidation, which is attributed to the small metal particles, a suitable dilation of the Pt crystal lattice, and the oxygen-containing species supplied by the tin oxide at a lower potential.