The local structure of OH species on the V2O3(0001) surface : a scanned-energy mode photoelectron diffraction study

Scanned-energy mode photoelectron diffraction (PhD), using O Is photoemission, together with multiple-scattering simulations, have been used to investigate the structure of the hydroxyl species, OH, adsorbed on a V2O3(0001) surface. Surface OH species were obtained by two alternative methods;, reaction with molecular water and exposure to atomic H resulted in closely similar PhD spectra. Both qualitative assessment and the results of multiple-scattering calculations are consistent with a model in which only the O atoms of outermost layer of the oxide surface are hydroxylated. These results specifically exclude significant coverage of OH species atop the outermost V atoms, i.e. in vanadyl O atom sites. Ab initio density-functional theory cluster calculations provide partial rationalisation of this result, which is discussed the context of the general understanding of this system. (c) 2008 Elsevier B.V. All rights reserved