Propane oxydehydrogenation over alumina-supported vanadia doped with manganese and potassium

The oxidation of propane over alumina-supported V-Mn-K oxide catalysts has been investigated. The addition of K to vanadia-alumina decreases activity but increases significantly the selectivity to propene. This was found to b e due to the poisoning of the acid sites of the alumina support, that conve rt propene in a number of organic byproducts. Conversely, the addition of M n decreases both activity and selectivity. In both cases the coordination s tate of vanadyl sites is perturbed with an increase of the crystal field. F T-IR mechanistic studies support the idea that isopropoxides are intermedia tes in the formation of propene by propane oxydehydrogenation. (C) 2000 Els evier Science B.V. All rights reserved.