Properties of a Multicomponent MoVSbNbCeO_x/SiO₂ Catalyst in the Oxidative Dehydrogenation of Ethane to Ethylene¹

Abstract—A multicomponent MoVSbNbCeO_x/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 MoVTeNbO_x, 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.