Hydrated Alkali Metal Halides as Efficient Catalysts for the Synthesis of Cyclic Carbonates from CO2 and Epoxides

Abstract

The synthesis of propylene carbonate from carbon dioxide and propylene oxide using hydrated alkali metal halides as catalysts in the absence of a co-catalyst and a solvent was investigated. The hydrated alkali metal halides showed much higher catalytic activity than the anhydrous alkali metal halides. Sodium iodide dihydrate was found to be the most efficient among them and it gave a 97% yield of propylene carbonate at 120 °C under 1 MPa within 1.5 h. The corresponding cyclic carbonates from CO2 and other epoxides using sodium iodide dihydrate as catalyst were also successfully synthesized.