n-Butane oxidation using catalysts prepared by treatment of VOPO4· 2H2O with octanol
| Autor: | Sujata Sajip, Jean Claude Volta, Ian J. Ellison, A. Burrows, Christopher J. Kiely, Graham J. Hutchings, Maria T. Sananes |
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| Rok vydání: | 1996 |
| Předmět: | |
| Zdroj: | J. Chem. Soc., Faraday Trans.. 92:137-142 |
| ISSN: | 1364-5455 0956-5000 |
| DOI: | 10.1039/ft9969200137 |
| Popis: | The preparation of vanadium phosphorus oxide butane oxidation catalysts from the reaction of VOPO4· 2H2O with octan-1-ol, octan-2-ol and octan-3-ol is described and discussed. In these preparations the alcohol acts as a reducing agent forming octanal, octan-2-one or octan-3-one and a VIV catalyst precursor compound. Use of octan-1-ol and octan-2-ol leads to the formation of VOHPO4· 0.5H2O but with distinctly different morphologies for the two alcohols. VOHPO4· 0.5H2O from octan-1-ol comprises thin platelets which are transformed, under the reaction conditions (367 °C, 1.5 %n-butane in air), topotactically to (VO)2P2O7 with a high surface area (31 m2 g–1) and a high catalytic activity. The material derived from octan-2-ol exhibits thicker platelets that result in a final catalyst with a lower surface area (7 m2 g–1) and poorer catalytic performance. Use of octan-3-ol leads to the formation of VO(H2PO4)2, exclusively. Under reaction conditions this is transformed to VO(PO3)2 with a low surface area (2 m2 g–1) which exhibits a high selectivity for the oxidation of n-butane to maleic anhydride without the formation of any carbon oxides as by-products. The origin of this high selectivity is discussed in terms of the isolation of the active sites on the catalyst surface owing to the presence of an excess surface phosphorus concentration. |
| Databáze: | OpenAIRE |
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