Catalytic oxidation of olefins over oxide catalysts containing molybdenum IV. Catalysts for the oxidation of propylene to acetone

Various metal oxides combined with molybdenum trioxide have been examined for their catalytic activities in the oxidation of propylene to acetone. In the molybdenum-poor series (10 at. % molybdenum), TiO2-, Fe2O3-, and Cr2O3MoO3 as well as Co3O4MoO3 and SnO2MoO3 reported previously, are active for the selective formation of acetone. V2O5-, NiO-, CuO-, and ZnOMoO3 are able to form acetone but with poorer selectivity. SnO2MoO3 shows the highest activity among the effective catalysts. An increase in molybdenum concentration decreases the catalytic activity for acetone formation in several of the binary systems. However, molybdenum-rich SnO2MoO3 and TiO2MoO3 catalysts (70 at. % molybdenum) show high activity and selectivity for acetone formation in common with the corresponding poor catalysts. Tungsten trioxide or triuranium octoxide fails to be an effective component instead of molybdenum trioxide. Molybdenum trioxide seems to be an essential component for an active catalyst. Over any effective catalyst the reaction temperature to form acetone is far lower than that of the allylic oxidiation. No allylic oxidation product is formed under the reaction conditions at which acetone is mainly produced.