Homogeneous and Heterogeneous Ionic Liquid System: Promising Ideal Catalysts for the Fixation of CO2 into Cyclic Carbonates

Massive emissions of CO2 have caused environmental problems all over the world. The fixation of CO2 into cyclic carbonates is regarded as an effective way of capturing and utilizing CO2. Ionic liquid catalysts (ILCs) have received great attention and been employed for catalyzing the above reaction in recent years due to their unique properties. However, there are still a few problems requiring solutions in order to finally find the ideal catalyst. Herein, we reviewed a number of recent related literature. The progresses of both homogeneous and heterogeneous ILCs were discussed to find out where we are and which directions to work on. The effects of cations and anions of ionic liquids (ILs), functional groups, reaction phase states, structures of supports, preparation methods of supported ionic liquids (SILs), and interactions between the ILs and supports were investigated systematically. Accordingly, basic principles of designing ILCs for the title reaction are summarized and directions of future investigations are highlighted.

Automated summary

This article reviews recent literature on the use of ionic liquid catalysts to fix carbon dioxide into cyclic carbonates, discusses the progress of current research and the problems that need to be addressed, and summarizes the basic principles for designing ionic liquid catalysts for the reaction in question as well as highlighting directions for future research.