Structure and Chemistry of the Heteronuclear Oxo-Cluster [VPO4]鈥?: A Model System for the Gas-Phase Oxidation of Small Hydrocarbons

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• 作者：Nicolas Dietl ; Torsten Wende ; Kai Chen ; Ling Jiang ; Maria Schlangen ; Xinhao Zhang ; Knut R. Asmis ; Helmut Schwarz
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：March 6, 2013
• 年：2013
• 卷：135
• 期：9
• 页码：3711-3721
• 全文大小：611K
• 年卷期：v.135,no.9(March 6, 2013)
• ISSN：1520-5126

文摘

The heteronuclear oxo-cluster [VPO₄]^鈥? is generated via electrospray ionization and investigated with respect to both its electronic structure as well as its gas-phase reactivity toward small hydrocarbons, thus permitting a comparison to the well-known vanadium-oxide cation [V₂O₄]^鈥?. As described in previous studies, the latter oxide exhibits no or just minor reactivity toward small hydrocarbons, such as CH₄, C₂H₆, C₃H₈, n-C₄H₁₀, and C₂H₄, while substitution of one vanadium by a phosphorus atom yields the reactive [VPO₄]^鈥? ion; the latter brings about oxidative dehydrogenation (ODH) of saturated hydrocarbons, e.g., propane and butane as well as oxygen-atom transfer (OAT) to unsaturated hydrocarbons, e.g. ethene, at thermal conditions. Further, the gas-phase structure of [VPO₄]^鈥? is determined by IR photodissociation spectroscopy and compared to that of [V₂O₄]^鈥?. DFT calculations help to elucidate the reaction mechanism. The results underline the crucial role of phosphorus in terms of C鈥揌 bond activation of hydrocarbons by mixed VPO clusters.