Oxidative dehydrogenation of cyclohexane with Mg3(VO4)2 synthesized by the citrate process

Citric acid complexation under mild condition was proposed to prepare monophasic and well crystallized Mg3(VO4)2 particle to be used as an active catalyst for the oxidative dehydrogenation of cyclohexane to cyclohexene. The catalyst prepared above was characterized by N2-physisorption, X-ray diffraction, scanning electron microscopy, and thermal gravimetric analysis. The characterization results displayed that the Mg3(VO4)2 particle was typically 100–160 nm and the specific surface area was 12.0–26.7 m2/g. Moreover, it showed that the purity and the structure of the catalyst were principally subjected to the calcination temperature and the amount of citric acid used in the sol–gel procedure. The Mg3(VO4)2 catalyst calcined at 823 K for 6 h with a molar ratio of (Mg + V):citric acid = 1:1.2 exhibited the best catalytic performance with an excellent thermal stability.