| Summary: | The present work focuses on developing heterogeneous catalysts for conversion of CO2 and mono-/di-epoxides to mono-/bis-cyclic carbonates. To achieve this purpose, two types of recyclable solid catalysts, namely polyurethane (PU-BTP) and polyurethane modified on silica gel-solid support (SG-AU-BPT), are synthesized. On these catalysts, the key promoter CaI2 is pre-absorbed. Both catalysts show high catalytic activity under mild conditions. For example, phenyl glycidyl ether (PGE) can be converted to 4-(phenoxymethyl)− 1,3-dioxolan-2-one at 60 °C within 6 h under 1 atm pressure of CO2. PU-BTP and SG-AU-BPT can be recollected by suction filtration and reused for eight times with conversion larger than 81% and 95% respectively. These results indicate that the degree of CaI2 leaching out from the catalysts in each cycle and loss is low.
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