Jump to main content
Jump to site search

Issue 110, 2014
Previous Article Next Article

Redox-driven atomic-scale changes in mixed catalysts: VOX/WOX/α-TiO2 (110)

Author affiliations

Abstract

X-ray studies of vanadium–tungsten mixed-monolayer-oxide catalysts grown on the rutile α-TiO2 (110) single crystal surface show redox behavior not observed for lone supported vanadium or tungsten oxides. Two cases are presented: sub-monolayer (sub-ML) vanadium oxide (vanadia) grown on ML tungsten oxide and ML vanadia grown on sub-ML tungsten oxide. The X-ray standing wave (XSW) and X-ray photoelectron spectroscopy (XPS) observations for both cases show coverage-dependent reversible redox-induced atomic-scale structural and chemical state changes. Atomic force microscopy shows that the mixed VOX/WOX overlayers have a conformal film-like structure in the as-deposited state. XSW analysis in light of XPS reveals that the V and W cations that are uncorrelated with the substrate lattice play an important role in catalytic redox reactions. Distinct differences in the redox-induced changes for these two mixed catalysts result from tuning the ratio of V to W, and relationships are drawn between the catalyst composition, structure, and chemistry. Comparison of these V–W mixed cases and the corresponding unmixed cases reveals a synergistic effect in which the reduction of W can be significantly enhanced by the addition of V.

Graphical abstract: Redox-driven atomic-scale changes in mixed catalysts: VOX/WOX/α-TiO2 (110)

Back to tab navigation

Supplementary files

Publication details

The article was received on 08 Oct 2014, accepted on 20 Nov 2014 and first published on 20 Nov 2014


Article type: Paper
DOI: 10.1039/C4RA14140G
Author version
available:
Download author version (PDF)
RSC Adv., 2014,4, 64608-64616

  •   Request permissions

    Redox-driven atomic-scale changes in mixed catalysts: VOX/WOX/α-TiO2 (110)

    Z. Feng, M. E. McBriarty, A. U. Mane, J. Lu, P. C. Stair, J. W. Elam and M. J. Bedzyk, RSC Adv., 2014, 4, 64608
    DOI: 10.1039/C4RA14140G

Search articles by author

Spotlight

Advertisements