Ethanol electro-oxidation on catalysts with TiO 2 coated carbon nanotubes as support

Abstract

Pt–TiO 2/CNTs electrocatalysts for direct ethanol fuel cells (DEFCs) were prepared by sol–gel and ethylene glycol reduction method. XRD and TEM showed that the size of the Pt particles on TiO 2/CNTs is 3.5–4 nm and with narrow particle size distribution. HRTEM revealed that a thin layer of uniform amorphous TiO 2 on CNTs was formed and the faces of the Pt crystal on Pt–TiO 2/CNTs catalysts were quite “rough” and “rounded” and some grain bounders and/or twins also appeared. The electrochemical studies using cyclic voltammetry (CV), chronoamperometry and CO stripping voltammetry indicate that Pt–TiO 2/CNTs catalysts have higher electro-catalytic activity and CO-tolerance for ethanol oxidation than Pt/C (20 wt% Pt, E-TEK) and Pt/CNTs catalyst in acid. The Pt/TiO 2 molar ratio was also optimized and proved that 1:1 was the best Pt/TiO 2 molar ratio.