Performance of direct methanol fuel cell using carbon nanotube-supported Pt-Ru anode catalyst with controlled composition

The performance of a single-cell direct methanol fuel cell (DMFC) using carbon nanotube-supported Pt-Ru (Pt-Ru/CNT) as an anode catalyst has been investigated. In this study, the Pt-Ru/CNT electrocatalyst was successfully synthesized using a modified polyol approach with a controlled composition very close to 20 wt.%Pt-10 wt.%Ru, and the anode was prepared by coating Pt-Ru/CNT electrocatalyst on a wet-proof carbon cloth substrate with a metal loading of about 4 mg cm(-2). A commercial gas diffusion electrode (GDE) with a platinum black loading of 4 mg cm-2 obtained from E-TEK was employed as the cathode. The membrane electrode assembly (MEA) was fabricated using Nafion 117 membrane and the single-cell DMFC was assembled with graphite endplates as current collectors. Experiments were carried out at moderate low temperatures using 1 M CH3OH aqueous solution and pure oxygen as reactants. Excellent cell performance was observed. The tested cell significantly outperformed a comparison cell using a commercial anode coated with carbon-supported Pt-Ru (Pt-Ru/C) electrocatalyst of similar composition and loading. High conductivity of carbon nanotube, good catalyst morphology and suitable catalyst composition of the prepared Pt-Ru/CNT electrocatalyst are considered to be some of the key factors leading to enhanced cell performance. (c) 2006 Elsevier B.V. All rights reserved.