Ethanol Electro-Oxidation on PtSn/C-ATO Electrocatalysts

摘要

PtSn/C-ATO electrocatalysts with different Pt:Sn atomic ratios (90:10, 70:30 and 50:50) were preparedin a single step by an alcohol-reduction process using H2PtCl6.6H2O and SnCl2.2H2O as metal sourcesand ethylene glycol as solvent and reducing agent and a physical mixture of carbon Vulcan XC72 (85wt%) and Sb2O5.SnO2 (15 wt%) as support (C-ATO). The obtained materials were characterized by X- ray diffraction (XRD) and transmission electron microscopy (TEM). The catalytic activity for ethanolelectro-oxidation in acid medium was investigated by cyclic voltammetry and chroamperometry and insingle direct ethanol fuel cell (DEFC). XRD analyses showed that Pt(fcc), SnO2, carbon and ATOphases coexist in the obtained materials. The electrochemical studies showed that PtSn/C-ATOelectrocatalysts were more active for ethanol electro-oxidation than PtSn/C electrocatalyst. Theo experiments at 100 C on a single DEFC showed that the power density of the cell using PtSn/C-ATO(90:10) was nearly 100% higher than the one obtained using PtSn/C (50:50). FTIR measurementsshowed that the addition of ATO to PtSn/C favors the formation of acetic acid as a product while forPtSn/C acetaldehyde was the principal product formed.