Selective oxidative dehydrogenation of ethane over MoVSbO mixed oxide catalysts

Mo-V-Sb-O mixed metal oxides were prepared, characterized and tested for the oxidative dehydrogenation of ethane (ODH). These catalysts are active and selective in the oxidative dehydrogenation of ethane to ethylene, although their catalytic performance depends strongly on the calcination temperature. The best catalytic results were obtained on samples heat-treated at 600 degrees C in N-2 (with selectivities to ethylene higher than 80% at ethane conversions about 65%). Moreover, a loss in the catalyst activity is initially observed on these catalysts as a consequence of modifications in the nature of the crystalline phases. Changes on the oxidation state of antimony ions on the surface of the used catalyst have also been observed, with the appearance of Sb5+ on the surface of used catalysts. The good catalytic performance of these catalysts is related to the presence of (SbO)(2)M20O56 crystalline phase in a similar way to that proposed for selective Mo-V-Te-Nb-O mixed metal oxide catalysts. (c) 2005 Elsevier B.V. All rights reserved.