Pt-Ru/multi-walled carbon nanotubes as electrocatalysts for direct methanol fuel cell

Multi-walled carbon nanotubes (MWNTs) have been synthesized by hemical vapour deposition technique using AB(3) alloy hydride catalyst and platinum supported MWNT (Pt/MWNT) and platinum-ruthenium supported MWNT (Pt-Ru/MWNT) electrocatalysts have been prepared by chemical reduction method. MWNT and electrocatalysts have been characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and energy dispersive X-ray analysis (EDX). The anode and cathode electrodes of direct methanol fuel cells (DMFC) have been fabricated using Pt-Ru/MWNT and 1: 1 Pt/MWNT + Pt/C electrocatalyst, respectively. Performances of DMFC with these electrodes have been studied at different temperatures and the results have been discussed. A maximum power density of 39.3 mW/cm(2) at a current density of 130 mA/cm(2) has been obtained, which could be attributed to dispersion and accessibility of MWNT support and Pt-Ru in the electrocatalyst mixture for methanol oxidation reaction. (C) 2007 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.