Electro-oxidation of Methanol, Ethanol and Ethylene Glycol over Pt/TiO2-C and PtSn/TiO2-C Anodic Catalysts

Abstract

This study focused on the use of a modified Pt/C anodic catalyst with doping tin (Sn) and titania (TiO2) to improve the efficiency and effective of direct alcohols (methanol, ethanol and ethylene glycol) fuel cells. Decorated the TiO2 dopant on active carbon support (xTiO2-C, x = 10, 20, 30, 40 weight percent) was completed by the impregnation method. Then, the series Pt/TiO2-C and PtSn/TiO2-C anodic catalysts were prepared by the formic acid reduction method using PtCl4 and SnCl22H2O as platinum (Pt, 10 wt%) and tin (Sn, 10 wt%) precursors. The fabricated series anodic catalysts were painted on carbon paper as working electrodes. Evaluation of the catalytic activity for the electro-oxidation of alcohols on working electrodes was performed by cyclic voltammetry (CV) in 0.5 M H2SO4 and 1 M alcohol electrolytes at room temperature. The results showed that all the doped TiO2 and Sn anodic catalysts present well-dispersed platinum with a diameter around 3 - 5 nm. In addition, the activity for electro-oxidation of alcohols was affected remarkably by the content of TiO2 and Sn in the anodic catalysts. Among the prepared Pt/TiO2-C and PtSn/TiO2-C anodic catalysts, the 30 wt% TiO2 catalyst exhibited the best catalytic performance. In comparison with the various alcohols, the the tendency of activity for the ethanol electro-oxidation was: ethanol methanol ethylene glycol.