CATALYTIC BEHAVIOUR OF VMoOx CATALYSTS SUPPORTED ON HEXAGONAL MESOPOROUS SILICA IN PARTIAL OXIDATION OF BUTANE

The vanadium oxide, molybdenum oxide and mixed vanadium-molybdenum oxide supported catalysts (1-2.5 wt % of vanadium and/or 1-2 wt % molybdenum on HMS (hexagonal meso porous s if ica) were prepared by impregnation method. The prepared catalysts were studied by means of XRF, NrBET, UV- Vis spectroscopy, H2-TPR and studied oxidative dehydrogenation (ODH) activity of butane. The mixed V-Mo oxide units were determined on the catalyst surface by HrTPR. The UV-Vis spectroscopy proved the presence of isolated tetrahedrally coordinated monomeric VOx species and isolated tetrahedrally coordinated dimeric MoOx species. The catalyst containing only VOx species had the highest activity. The catalyst containing only MoOx species was selective but of a very low activity. The highest selectivity (60 %) and productivity (0.35 gprod gkol- ' h-') were obtained with mixed VMoOx catalysts with the molar ratio 1: 1. I To whom correspondence should be addressed. 6