Halogen and metal free porous organic frameworks as effective catalyst for cyclic carbonate synthesis from CO2 and epoxides

초록

Increases in CO2 concentration in the atmosphere by fossil fuel combustion is causing global warming, which alerts scientific community to find new strategies that can reduce the environmental burden. Both carbon capture & storage and catalytic conversion of CO2 are being considered, and cyclic carbonate synthesis via cycloaddition of CO2 to epoxides has been actively investigated for the latter approach. In this work, we have prepared an aromatic porous polymer incorporated with carbonyl groups and functionalized it with ethylenediamine (CBAP-EDA). CBAP-EDA was tested for CO2 and epoxide cycloaddition reaction had shown effective conversion (>99%) of epoxides at 130 oC/1MPa CO2 after 4h. The CBAP-EDA was confirmed for their heterogeneity during the reaction through EA and hot filtration test, and successfully reused for five consecutive cycles without any significant loss in catalytic activity. Reactions of different epoxides such as propylene oxide (PO), allyl glycidyl ether (AGE), styrene oxide (SO) and cyclohexene oxide (CHO) were also explored. Moreover, a plausible mechanism was put forward to explain the cycloaddition reaction over the catalysts used.