Partial reduction of Si(IV) in SiO2 thin film by deposited metal particles:: an XPS study

Metal-support interactions in systems of dispersed metals supported on thin-film silica surfaces were examined by x-ray photoelectron spectroscopy. Four metal-silica systems-Pt-, Pd-, Ag- and Au-SiO2-all indicated the formation of partially reduced Si(IV) species by the metal deposition. The extent of the reduction varied little with the kind or amount of deposited metal species. On the other hand, the amount of this newly formed Si(IV-delta) indicated a strong metal species dependence. Copyright (C) 2001 John Wiley & Sons, Ltd.