Morphology and Surface Reactions of Rh/VO(x)/SiO(2) Model Catalysts
The interaction between rhodium, the support oxide SiO(2), and the promoter oxide VO(x) has been studied for a Rh/VO(x)/SiO(2)/Mo model system. This system consists of two monolayers of vanadium oxide on a thin silicon oxide layer, both prepared by chemical vapour deposition on molybdenum with a nominal load of one monolayer rhodium. The changes of binding energies of surface species and the morphology of the surface after heating in ultra high vacuum (uhv) were analysed by low-energy ion-scattering (ISS) and X-ray photoelectron spectroscopy (XPS). No formation of rhodium silicide was found on the VO(x) promoted system after thermal treatments up to 873K in ultra high vacuum, in contrast to results reported for the system without vanadia. A reaction mechanism is proposed in which oxygen from VO(x) adsorbs on the rodium surface.Consequences of these reactions for the surface morphology are discussed.
Bibliographic Reference: Article: Morphology and Surface reactions of Rh/VO(x)/SiO(2) - Model Catalysts, (1999), 85-91
Record Number: 199910851 / Last updated on: 1999-06-18
Original language: en
Available languages: en