The structure and catalytic properties of Bi-V-Mo-O composite oxide catalysts with different composition for selective oxidation of propane have been studied by using X-ray diffraction (XRD), laser Raman spectroscopy (LRS), temperature-programmed reduction (TPR) and microreactor tests. It has been shown that Bi-V-Mo-O composite oxides formed scheelite-type structure, and the composition and structure of catalysts exert great influences on the catalytic properties for selective oxidation of propane. Increasing Mo content in the composite oxide catalysts, complete oxidation of propane can be suppressed, while the selectivity to acrolein increased to a maximum at Mo/(V+Mo) atomic ratio = 0.45. Further increasing the Mo content results in the remarkable decrease of acrolein selectivity. It has been suggested that the catalytic selectivity is correlated to the reactivity of oxygen ions species in the composite oxides.

Key words: BISMUTH OXIDE, VANADIUM OXIDE, MOLYBDENUM OXIDE, PROPANE, PROPENAL, OXIDATION, XRD, TPD