Ethanol electro-oxidation on catalysts with TiO2 coated carbon nanotubes as support

Pt-TiO2/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 TiO2/CNTs is 3.5-4 nm and with narrow particle size distribution. HRTEM revealed that a thin layer of uniform amorphous TiO2 on CNTs was formed and the faces of the Pt crystal on Pt-TiO2/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 voltarnmetry indicate that Pt-TiO2/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/TiO2 molar ratio was also optimized and proved that 1:1 was the best Pt/TiO2 molar ratio. (C) 2007 Elsevier BN. All rights reserved.