Construction of DBU–based Poly (ionic liquid)s for the Conversion of CO2, Glycerol, and Propylene Oxide into Glycerol Carbonate

Graphical A high glycerol carbonate yield of 90 % is achieved by the one–pot reaction of CO 2 , propylene oxide, and glycerol catalysed by DBU–based PIL, which can be facilely recovered and steadily reused without deactivation. The development of efficient heterogeneous catalysts for upgrading CO 2 , a greenhouse gas, and glycerol (Gly), an untapped biomass resource, into glycerol carbonate (GC) remains a challenge. Herein, 1,8-diazabicyclo[5.4.0] undec–7–ene (DBU)–based poly (ionic liquid)s (PILs) were constructed for the one–pot synthesis of GC from CO 2 , Gly, and propylene oxide. Among them, P−DVB−DBUVBI–1 exhibited the best catalytic performance, achieving a GC yield of 90 % under optimal reaction conditions (100 °C, 6 h). The PIL catalyst was easily recovered and reused, as demonstrated by stable activity over five cycles. Density functional theory calculations showed that owing the strong positive charge delocalization ability of DBU onium, DBU–based PILs exhibit high nucleophilicity, which is the key to their efficient catalytic performance in the one–pot reaction.