title: Controlling the duality of the mechanism in liquid-phase oxidation of benzyl alcohol catalysed by supported Au-Pd nanoparticles.
abstract: In the solvent-free oxidation of benzyl alcohol to benzaldehyde using supported gold-palladium nanoparticles as catalysts, two pathways have been identified as the sources of the principal product, benzaldehyde. One is the direct catalytic oxidation of benzyl alcohol to benzaldehyde by O(2), whereas the second is the disproportionation of two molecules of benzyl alcohol to give equal amounts of benzaldehyde and toluene. Herein we report that by changing the metal oxide used to support the metal-nanoparticles catalyst from titania or niobium oxide to magnesium oxide or zinc oxide, it is possible to switch off the disproportionation reaction and thereby completely stop the toluene formation. It has been observed that the presence of O(2) increases the turnover number of this disproportionation reaction as compared to reactions in a helium atmosphere, implying that there are two catalytic pathways leading to toluene.
authors.affiliation: Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Cardiff CF10 3AT, UK.
authors.forename: Meenakshisundaram
authors.initials: M
authors.lastname: Sankar
authors.forename: Ewa
authors.initials: E
authors.lastname: Nowicka
authors.forename: Ramchandra
authors.initials: R
authors.lastname: Tiruvalam
authors.forename: Qian
authors.initials: Q
authors.lastname: He
authors.forename: Stuart H
authors.initials: SH
authors.lastname: Taylor
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Kiely
authors.forename: Donald
authors.initials: D
authors.lastname: Bethell
authors.forename: David W
authors.initials: DW
authors.lastname: Knight
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Hutchings