Mixed-oxide catalysts involving V, Nb and Si obtained by a non-hydrolytic sol-gel route: preparation and catalytic behaviour in oxydative dehydrogenation of propane

One-step non-hydrolytic condensation reactions, starting from VO(O'Pr)(3) and NbCl5, have been used for the first time to prepare Nb-V oxide catalysts. Different materials containing the NbVO5 phase at different purity levels have been obtained, after thermal treatments, depending on the experimental conditions. The synthetic procedure has also been applied to prepare ternary Nb-V-Si oxide systems. From preliminary catalytic reaction studies it appears that the catalysts so prepared are promising with respect to their interesting performances in the oxidative dehydrogenation (ODH) of propane. It has also been found that alpha-Sb2O4, physically blended with the Nb-V oxide materials, could act as an appropriate promoter to improve the catalytic performances of these systems. (C) 2000 Elsevier Science B.V. All rights reserved.