Ammoxidation of propane over Mo-V-Nb-Te mixed oxide catalysts

Abstract

Mo-V-Nb-Te mixed metal oxides are highly active and selective for the ammoxidation of propane to acrylonitrile. Acrylonitrile yield reaches nearly 50% by the optimizing reactor temperature and NH3/propane feed ratio. The efficiency of the catalyst is higher than that of V-Sb and Bi-Mo mixed metal oxide catalysts. In addition to a higher acrylonitrile yield, the required reaction temperature is also lower. X-ray diffraction pattern and Raman spectrum of Mo-V-Nb-Te catalysts are unique. There are at least two crystal phases (Phase-M1 and Phase-M2), participating the elementary steps of the ammoxidation of propane, in Mo-V-Nb-Tc mixed metal oxide catalysts. Propane, seems to be activated on Phase-M1 to form dehydrogenated species, which transfer to Phase-M2. And the dehydrogenated species seem to react with activated NH species to form acryronitrilc via ρ-arryl species on Phase-M2.