Tuning surface V5+ concentration in M1 phase MoVSbOx catalysts for ethylene production from ethane through oxidative dehydrogenation reaction

Abstract

MoVSbOx complex metal oxides are efficient catalysts for converting ethane to ethylene through oxidative dehydrogenation (ODE) reaction. Active sites containing V5+ are crucial to the catalytic performance of molybdenum-vanadium based catalysts. One of the main challenges of these catalysts lies in controlling active sites containing V5+ on the surface. In this work, a series of pure M1 phase MoVSbOx catalysts with different surface contents of V5+ sites were prepared by hydrothermal and self-assembly methods. Their catalytic ODE performance was found to have a strong correlation with surface V5+, showing firstly an increase and then a substantial drop as a function of surface V5+ concentration on M1 phase MoVSbOx catalysts. This may be attributable to the presence of different catalytic sites on the catalysts. The best catalyst synthesized by hydrothermal method has excellent reaction stability and gives 77.6 % ethane conversion and 64.1 % ethylene selectivity. The results of this study may be useful in developing highly efficient complex metal oxide catalysts for ODE.