Atmospheric-pressure synthesis of glycerol carbonate from CO2 and glycerol catalyzed by protic ionic liquids

An ideal strategy for the management of greenhouse gas carbon dioxide (CO2) and surplus industrial product-glycerol (Gly) is to convert them into the valuable glycerol carbonate (GC). However, conventional conversion processes rely on high CO2 pressure and reaction temperature. In this work, a series of easily prepared protic ionic liquids (ILs) were studied for the one-pot synthesis of GC using CO2, Gly, and styrene oxide (SO). A 94% yield of GC was obtained with the catalysis of 1,8-diazabicyclo[5.4.0]undec-7-enenium iodide (HDBUI) under atmospheric pressure at 45 degrees C. Experimental results and density functional theory (DFT) calculations suggest that the high catalytic activity of HDBUI is attributed to the strong nucleophilicity and substrate activation afforded by the synergistic effect of the protic HDBU+ cation and I- anion. In addition, high GC yields were also obtained when simulated flue gas and crude Gly were used as substrates.

Automated summary

In this study, a one-pot synthesis of valuable glycerol carbonate (GC) from CO2, glycerol (Gly), and styrene oxide (SO) was successfully achieved using easily prepared protic ionic liquids (ILs) under atmospheric pressure. The high catalytic activity of 1,8-diazabicyclo[5.4.0]undec-7-enenium iodide (HDBUI) was attributed to the strong nucleophilicity and substrate activation provided by the synergistic effect of the protic HDBU+ cation and I- anion. High GC yields were also obtained when simulated flue gas and crude Gly were used as substrates.