Role of V in supported V–Sb–O catalysts for the ammoxidation of propane to acrylonitrile: Multilayered VOx/SbOx/Al2O3 catalysts

A synthesis method for multilayered V–Sb–O catalysts on Al2O3 is described and compared to coimpregnated series; these catalysts are tested for propane ammoxidation. With this preparation method, vanadium and antimony are added sequentially. First, alumina support is impregnated with a loading corresponding to a monolayer of antimony dispersed, it is dried and calcined; then; this solid is impregnated with a vanadium oxide precursor solution. The data obtained are compared with previous papers with catalysts prepared adding both antimony and vanadium at the same time. The new method facilitates the reaction between vanadium and antimony to form the rutile VSbO4 active phase. The presence of dispersed vanadium oxide species along with the rutile VSbO4 phase improves propane conversion.