Propane oxidative dehydrogenation over VOx/SBA-15 catalysts

VOx/SBA-15 catalysts with five different vanadium loadings were prepared by a modified wet impregnation method, characterized using N-2 adsorption, XRD, EDX, SEM, Raman and UV-vis spectroscopies and H-2-TPR techniques, and tested in the oxidative dehydrogenation of propane in the temperature range 450-600 degrees C. For all the catalysts the propane conversion increases with both reaction temperature and vanadium loading, while the selectivity for propene decreases mainly to the benefit of carbon oxides. Several types of VOx species coexist on the catalyst surface, with monomeric and low-polymerized ones leading mainly to propene, while V2O5 crystallites at high vanadium loadings producing more carbon oxides. Propene was determined to be the only primary product irrespective of the vanadium content. (C) 2016 Elsevier B.V. All rights reserved.