Copper–Manganese Mixed Metal Oxide Catalysts for the Direct Epoxidation of Propylene by Molecular Oxygen

Abstract

Cu–Mn mixed metal oxide (MMO) catalysts doped with NaCl were synthesized using combustion synthesis technique with a variety of fuels for the direct gas-phase epoxidation of propylene with molecular oxygen. The catalyst structure consisted of Mn2O3 and Cu1+xMn2–xO4 crystals. The catalyst crystallinity, primarily influenced by the combustion synthesis fuel choice and calcination temperature, has been found to be of particular importance in affecting the selectivity of the epoxidation reaction. The optimum catalyst composition was 10–20 mol % Cu in Mn doped with 0.1–0.2 mol % NaCl. It exhibited 30–37% propylene oxide selectivity and 1.3–1.5% propylene conversion.