Molybdenum-vanadium supported on mesoporous alumina catalysts for the oxidative dehydrogenation of ethane

摘要

Vanadium and/or molybdenum oxides supported on mesoporous alumina have been prepared by a "wet" impregnation method,characterized (by using several physico-chemical techniques TPR,DR-UV-vis,Raman spectroscopies) and tested in the oxidative dehydrogenation (ODH) of ethane.For comparison Mo-V-mixed oxides supported on gamma-Al_2O_3 have also been studied.The characterization results indicate that the main vanadium species in both Mo-free and Mo-containing V-based samples present low aggregation and coordination,whereas molybdenum is present as monomeric or polymeric tetrahedral molybdenum species.Interestingly,no apparent interaction between molybdenum and vanadia takes place.The catalytic results show that V-containing catalysts are ca.four times more active than pure Mo-catalyst,whereas Mo-V-containing catalysts resulted to be the most selective ones in the ODH of ethane to ethylene,indicating that a synergetic effect between Mo and V takes place.In all cases,catalysts supported on mesoporous alumina were more active and selective in the ODH of ethane than the corresponding catalysts supported on gamma-Al_2O_3.