Heterogeneous catalysts for cyclic carbonate synthesis from carbon dioxide and epoxides

This review surveys six classes of heterogeneous catalysts that have been used in the conversion of epoxides and CO2 into cyclic carbonates; metal organic frameworks (MOFs); silica-based catalysts; organic polymer supports; metal oxides; zeolites and carbon-based catalysts. Many of these catalysts are extremely active in the ring-opening of terminal epoxides, require fairly mild conditions and can be made in a sustainable manner. Some catalytic systems however require toxic and hazardous chemicals in their synthesis, and many struggle to ring-open the more sterically demanding and hindered internal epoxides. This review covers the most recent heterogeneous catalysts reported in the literature, not only from a catalytic efficiency perspective but also from a green chemistry and sustainable viewpoint.