Characterisation of vanadium-oxide-based catalysts for the oxidative dehydrogenation of propane to propene

The study is based on the previous development of alpha -Al2O3-supported mu lti-metal-oxide materials for oxidative dehydrogenation of propane by apply ing a combinatorial approach (773 K, ambient pressure, a feed composition o f C3H8; O-2: N-2 =30:10:60 and 40:20:40). For further improvement of cataly tic materials, fundamental insights were derived from oxygen transient expe riments and XRD as well as XPS studies. Fitting transient experiments showe d that irreversible and dissociative adsorption on two active centers provi des a good description of the transient oxygen responses over all the catal ytic materials studied. The composition of these materials influenced stron gly the apparent first-order rate constant of oxygen activation. Based on t he characterisation data it was found that an optimal bulk concentration (2 .6-8.3 wt%) of VOx species on the support and their distribution on the sur face are an essential requirement for the selective oxidative dehydrogenati on of propane to propene.