Properties of a Multicomponent MoVSbNbCeOx/SiO2 Catalyst in the Oxidative Dehydrogenation of Ethane to Ethylene

Abstract A multicomponent MoVSbNbCeOx/SiO2 oxide catalyst exhibiting high catalytic activity in the oxidative dehydrogenation of ethane to ethylene is synthesized by spray drying of a suspension of aqueous solutions of the precursors and the subsequent heat treatment in He at 350 and 600°C. At a temperature of 400–450°С in a wide ethane conversion range, the catalyst exhibits a fairly high activity and ethylene selectivity. In the presence of this catalyst, the maximum ethylene yield achieves 74% (ethane conversion of 91%, ethylene selectivity of 81.5%); this value significantly exceeds the yield in the presence of Sb-containing catalysts known from the literature. The catalyst exhibits a long-term stable on-stream behavior under reaction medium conditions without any change in the phase composition and a deterioration of the catalytic characteristics. It is shown that the catalytic properties of the synthesized catalyst are comparable to the properties of MoVTeNbOx, which is one of the best catalysts for this process. However, the use of a Te-containing catalyst is limited, because tellurium exhibits a high toxicity and volatility during the synthesis and use of the catalysts. According to X-ray diffraction analysis, the main components of the catalyst are M1 and M2 phases stabilized on a SiO2 surface. The HRTEM data show that a structural feature of the catalyst is the presence of an interface formed by the coherently intergrown crystals of the M1 and M2 phases.