title: Chemically induced fast solid-state transitions of omega-VOPO4 in vanadium phosphate catalysts.
abstract: Vanadium phosphates are important catalysts for the oxidation of alkanes, and commercial catalysts comprise a complex range of V4+ and V5+ phosphates. We used three complementary in situ characterization methodologies-powder x-ray diffraction and laser Raman and electron paramagnetic resonance spectroscopies-to show that the metastable phase omega-VOPO4 is very sensitive to many of the reactants and products of butane oxidation. A rapid transformation from omega-VOPO4 to delta-VOPO4 occurs on exposure to butane at the reaction temperature, and hence the metastable omega-VOPO4 may play a role in the formation of commercial catalysts.
authors.affiliation: School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK.
authors.forename: Marco
authors.initials: M
authors.lastname: Conte
authors.forename: Gerolamo
authors.initials: G
authors.lastname: Budroni
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Bartley
authors.forename: Stuart H
authors.initials: SH
authors.lastname: Taylor
authors.forename: Albert F
authors.initials: AF
authors.lastname: Carley
authors.forename: Andi
authors.initials: A
authors.lastname: Schmidt
authors.forename: Damien M
authors.initials: DM
authors.lastname: Murphy
authors.forename: Frank
authors.initials: F
authors.lastname: Girgsdies
authors.forename: Thorsten
authors.initials: T
authors.lastname: Ressler
authors.forename: Robert
authors.initials: R
authors.lastname: Schlögl
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Hutchings