Oxidative carbonylation of propylene glycol to propylene carbonate by copper-based catalysts

Background: Development of copper -based catalyst and associated reaction engineering for heterogeneous oxidative carbonylation of propylene glycol (PG) to optimize conversion and selectivity. Coupling reactions with reverse water -gas shift reaction is a good way of realizing CO 2 utilization . Method: The synthesis of propylene carbonate (PC) through the oxidative carbonylation of propylene glycol is carried out in a pressurized autoclave reactor using solid copper catalysts. Various types of copper and composite copper/ceria catalysts are prepared by coprecipitation or impregnation method. Significant findings: Reaction temperature and the roles of sodium acetate (SA) and potassium iodide (KI) additives are systematically studied with pure copper to map out the optimum reaction condition, i.e., a 100 degrees C- reaction using 2.0 g of PG mixed with 8.0 g of solvent with 0.02 g of SA and 0.02 g of KI additives. Using this optimized condition, the copper and composite copper/ceria catalysts are investigated with the composite catalysts composed of metallic copper on ceria, showing the highest selectivity of 94.7% towards PC. These findings in this study should pave way for the development of practical industrial scale CO 2 utilization processes.