Pt/Ru–Sn Oxide/Carbon Catalysts for Ethanol Oxidation

Abstract

Mixed Ru–Sn oxides have been deposited onto a high surface area carbon support by thermal decomposition of Ru and Sn acetylacetonate (acac) complexes. Adsorption of preformed Pt nanoparticles produced catalysts with enhanced low potential activity for the oxidation of ethanol in aqueous sulfuric acid at ambient temperature and in a proton exchange membrane (PEM) cell at 80 °C. Varying the oxide composition between Ru 0.38 Sn 0.62 O 2 and Ru 0.67 Sn 0.33 O 2 did not influence the catalyst’s activity greatly but did increase stability in the sulfuric acid solution. Higher stability was observed in the PEM cell, where a Pt/Ru 0.55 Sn 0.45 O 2 /C anode provided much higher currents than a commercial Pt/C catalyst for ethanol oxidation at low potentials. Anodes for direct ethanol fuel cells can be fabricated by coating a carbon fibre paper backing layer consecutively with carbon black, Ru(acac) 3 + Sn(acac) 2 , and Pt nanoparticles, with appropriate thermal processing.