Abstract
The catalytic activity of oxide-supported vanadium oxide is improved by the presence of tungsten oxide for the selective catalytic reduction of nitric oxides. We propose a mechanism for V-W synergy through studies of the reduction-oxidation behavior of near-monolayer VOX and WOX species grown by atomic layer deposition on the α-Al2O3 (0001) single crystal surface. In situ X-ray standing wave measurements reveal an overlayer of W6+ species that is correlated with the substrate lattice as well as a redox-reversible shift from uncorrelated V5+ to correlated V4+. X-ray photoelectron spectroscopy and electronic structure calculations show a partial reduction of W6+ in the presence of V4+, improving the Brønsted acidity in mixed V-W catalyst systems. This mechanism of V-W synergy suggests that control of W d-states might be used as a design parameter for Brønsted acid sites in multicomponent oxide catalysts.
Original language | English (US) |
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Pages (from-to) | 16179-16187 |
Number of pages | 9 |
Journal | Journal of Physical Chemistry C |
Volume | 119 |
Issue number | 28 |
DOIs | |
State | Published - Jul 16 2015 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films