New Multicomponent MoVSbNbCeOx/SiO2Catalyst with Enhanced Catalytic Activity for Oxidative Dehydrogenation of Ethane to Ethylene

In our study, we have obtained a multicomponent MoVSbNbCeOx/SiO(2)catalyst with high catalytic activity for oxidative dehydrogenation of ethane (ODE) to ethylene. To date, multicomponent MoVTe(Sb)NbO(x)catalysts, which have been intensively studied during the last years, were found as very promising for the ODE to produce ethylene. It was generally agreed that the MoVTeNbO(x)catalyst was more efficient than MoVSbNbOx. The major drawback of using Te-containing catalysts is the presence of environmentally harmful, toxic tellurium, and its volatility during the catalyst preparation and catalytic reaction conditions. In our work, the Mo1V0.24Sb0.23Nb0.08Ce0.01Ox/50 wt. % SiO(2)catalyst was prepared via the spray-dry method of aqueous solutions of the starting components, followed by heat-treatment in He at 350 and 600 degrees C. For comparative purpose, one of the best Te-containing catalysts Mo(1)V(0.3)Te(0.23)Nb(0.12)O(x)was also tested in this reaction under the similar reaction conditions. A comparison of the catalytic properties of Sb- and Te- containing catalysts at the reaction temperature of 400-450 degrees C illustrates for both catalysts relatively high catalytic properties for ODE. The yield of ethylene of ca. 74 % was obtained for these catalysts, which exceeds the best yield reported in literature for Sb-containing catalysts. The two main phases - M1 and M2 were revealed by XRD in the Sb-containing catalyst. Intergrowth between the crystals of M1 and M2 phases with the formation of the interphase boundary in the highly active and selective Sb-containing catalyst can be proposed from HRTEM results. The nature of the active state in this catalyst is discussed.