XANES Study of Hydrothermal Mo−V-Based Mixed Oxide M1-Phase Catalysts for the (Amm)oxidation of Propane

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• 作者：N. Raveendran Shiju ; Adam J. Rondinone ; David R. Mullins ; Viviane Schwartz ; Steven H. Overbury ; Vadim V. Guliants
• 刊名：Chemistry of Materials
• 出版年：2008
• 出版时间：November 11, 2008
• 年：2008
• 卷：20
• 期：21
• 页码：6611-6616
• 全文大小：176K
• 年卷期：v.20,no.21(November 11, 2008)
• ISSN：1520-5002

文摘

The hydrothermal Mo−V-based mixed oxide catalysts possessing the M1-phase structure were investigated by XANES and in situ X-ray diffraction under ambient and dynamic redox conditions in the presence of O₂ and H₂ at 693 K. Under ambient conditions, XANES, with the use of model compounds, suggested oxidation states of Nb, Te, Mo, and V close to 5+, 4+, 6+, and 4+, respectively, in the bulk M1 phase. The oxidation state changes of Nb, Te, and Mo were not detected under the dynamic redox conditions employed, while the pre-edge peak of vanadium in the M1 phase exhibited small, reproducible shifts, suggesting that VO_x is the active catalytic species in the bulk M1-phase catalysts for selective (amm)oxidation of propane.