Catalytic performance of zeolitic imidazolate framework ZIF-95 for the solventless synthesis of cyclic carbonates from CO2 and epoxides

Abstract

The catalytic potential of a chloro-functionalized zeolitic imidazolate framework ZIF-95 was investigated for the solventless cycloaddition of carbon dioxide with epoxides. The reaction parameters were optimized and moderate set of reaction conditions (80°C and 1.2MPa CO2 pressure) were chosen for the detailed catalytic study. Eventhough ZIF-95 alone was catalytically active at higher temperatures, the addition of a co-catalyst was found beneficial to bring down the temperature required to achieve high conversions of the substrate. The synergistic effect of the catalyst and the co-catalyst was explored through the investigation of reaction mechanism. The scope of extending the catalysis for other epoxides was verified. The catalyst was successfully recovered and reused for cycloaddition up to 4 cycles.