Ethanol Oxidation at Pt Nanoparticles Supported on Titanium Modified by Thermal Decomposition of Tin and Ruthenium Acetylacetonate Complexes

Abstract

Sn and Ru oxides prepared by thermal decomposition of metal acetylacetonate (acac) complexes on Ti have a substantial support effect on platinum catalyzed oxidation of ethanol. Sn and Ru oxides and mixed Sn–Ru oxides (Ru-doped SnO2) deposited onto Ti foils were drop coated with preformed Pt nanoparticles. Cyclic voltammetry in H2SO4(aq) showed a strong synergistic effect between Ru and Sn oxide for ethanol oxidation, with a 2:1 ratio of Ru(acac)3 to Sn(acac)2 in the oxide precursor solution producing the most active catalyst. X-ray photoelectron spectroscopy revealed a significant transfer of electron density from the Ru-doped SnO2 to the Pt nanoparticles (electronic/ligand effect), and increased Pt oxide formation. Both of these effects can promote the oxidation of adsorbed CO, while the electronic effect also influences the adsorption strength of ethanol. The variation of the balance of these effects with the level of Ru doping is a plausible explanation for the dependence the ethanol oxidation activity on the composition of the oxide layer.