Enhancing methanol electrooxidation activity using double oxide catalyst support of tin oxide clusters on doped titanium dioxides

Electrooxidation of methanol was investigated on platinum catalyst supported on a double oxide nanocomposite of tin oxide clusters and carbon-doped titanium dioxide nanocoatings on carbon nanotubes. Formation kinetics of the oxygenated species (OH) groups was dramatically enhanced in the catalyst with double oxide support. This leads to a much lower onset potential for adsorbed CO oxidation with a much enhanced bifunctional effect in tin oxide. The electrocatalyst demonstrated a higher forward peak current density in methanol electrooxidation than the electrocatalyst with single tin oxide or bare carbon as support. Binding energy shift in oxidation states was observed for the double oxide support catalyst and is attributed to strong metal support interactions. Doping with carbon in the titanium oxide enables backward electron donation, making the supported platinum more electron negative and stable. This study demonstrated a synergistic effect of combining bifunctional and electronic mechanisms with double oxide support in the enhancement of methanol electrooxidation.