A combined theoretical and experimental study of VOx/γ-Al2O3 catalyst

In order to investigate the nature of VOx supported on gamma-Al2O3 a combination of a theoretical study and experimental characterisation is carried out. A Molecular Orbital approach of the Extended Huckel type is performed to calculate the formation and the stabilisation energies of postulated VOx species. The evaluation of these energies indicates that pyrovanadates and divanadates are plausible species. Experimental characterisation of VOx/gamma-Al2O3 catalysts was performed by TPR and Oxygen Uptake Measurements to corroborate theoretical models. Experimental results also indicate that VOx/gamma-Al2O3 catalyst with low vanadium loading should be envisaged as supported vanadium dimers. (C) 1999 Elsevier Science B.V. All rights reserved.