Interaction of oxygen with the surface of vanadia catalysts

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• 作者：J. S&#x142 ; oczy&#x144 ; ski ; R. Grabowski ; A. Koz&#x142 ; owska ; R. Tokarz-Sobieraj ; M. Witko
• 关键词：Vanadia– ; titania catalyst ; Reduction ; Re-oxidation ; Oxygen forms ; Quantum-chemical calculations
• 刊名：Journal of Molecular Catalysis A: Chemical
• 出版年：2007
• 出版时间：16 November 2007
• 年：2007
• 卷：277
• 期：1-2
• 页码：27-34
• 全文大小：702 K

文摘

Kinetics of the re-oxidation of the H₂-reduced or vacuum treated VO_x/TiO₂ catalyst was studied. It was found that oxygen does not adsorb in the form of ad-atoms on the fully oxidized surface of the catalyst but re-oxidizes oxygen vacancies. On the basis of the surface potential measurements it was concluded that nucleophillic oxygen O_(s)²⁻ is almost exclusively present above 550 K on the catalyst surface. The quantum-chemical calculations were supported by the experimental results. The implications of these results for the reaction mechanism of the oxidative dehydrogenation of propane are discussed.