Reactivity of methanol on TiO2 nanoparticles supported on the Au(111) surface

The reactivity of methanol on TiO(2) nanoparticles supported on Au(111) was examined using temperature-programmed reaction spectroscopy. Since quantitative analytical techniques have shown that the nanoparticles formed by oxidation of sputtered Ti metal on Au(111) have TiO(2) stoichiometry, the reactivity of these particles towards methanol was compared to the reactivity of TiO(2)(110), the most thermodynamically stable single crystal surface. The reactivity of the nanoparticles differed from that of the TiO(2)(110) stoichiometric surface. Specifically, the nanoparticles produced methane from methanol while the TiO(2)(110) stoichiometric surface did not. This difference is attributed to under-coordinated titanium cations present on facets of the nanoparticles, such as those found on {011}-facetted TiO(2)(001) planes, which lead to methane formation. The differences in reactivity towards methanol between the nanoparticles and the extended TiO(2)(110) stoichiometric surfaces suggest that the three-dimensional, local structure plays a very significant role in the reactivity of these nanoparticles towards methanol. (c) 2005 Published by Elsevier B.V.