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Advances in Physical Chemistry
Volume 2011 (2011), Article ID 679246, 10 pages
http://dx.doi.org/10.1155/2011/679246
Research Article

Sequential Electrodeposition of Platinum-Ruthenium at Boron-Doped Diamond Electrodes for Methanol Oxidation

1Department of Chemistry, University of Puerto Rico, Río Piedras Campus, P.O. Box 70377, San Juan, PR 00936-8377, USA
2Center for Advanced Nanoscale Materials, University of Puerto Rico, Río Piedras Campus, P.O. Box 70377, San Juan, PR 00936-8377, USA

Received 5 April 2011; Revised 11 July 2011; Accepted 18 July 2011

Academic Editor: Milan M. Jaksic

Copyright © 2011 Ileana González-González et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Sequential electrodeposition of Pt and Ru on boron-doped diamond (BDD) films, in 0.5 M H2SO4 by cyclic voltammetry, has been prepared. The potential cycling, in the aqueous solutions of the respective metals, was between 0.00 and 1.00 V versus Ag/AgCl. The catalyst composites, Pt and PtRu, deposited on BDD film substrates, were tested for methanol oxidation. The modified diamond surfaces were also characterized by scanning electron microscopy-X-ray fluorescence-energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and Auger electron spectroscopy. The scanning Auger electron spectroscopy mapping showed the ruthenium signal only in areas where platinum was electrodeposited. Ruthenium does not deposit on the oxidized diamond surface of the boron-doped diamond. Particles with 5–10% of ruthenium with respect to platinum exhibited better performance for methanol oxidation in terms of methanol oxidation peak current and chronoamperometric current stability. The electrogenerated OH radicals on BDD may interact with Pt surface, participating in the methanol oxidation as shown in oxidation current and the shift in the peak position. The conductive diamond surface is a good candidate as the support for the platinum electrocatalyst, because it ensures catalytic activity, which compares with the used carbon, and higher stability under severe anodic and cathodic conditions.