Core–Shell Dispersed Polymeric Ionic Liquids as Efficient Heterogeneous Catalyst for CO2 Conversion into Cyclic Carbonates.

Core–shell polyionic liquids were successfully constructed to reduce the amount of bulk ionic liquids and realize heterogeneous catalysis in the reaction of CO₂ conversion into carbonate. The core–shell polyionic liquid structure is formed by one-step surface polymerization with cheap and readily available SiO₂ as the carrier. By optimizing the ratio of ionic liquid monomer to SiO₂, PIL@SiO₂(1:1.5) of high activity and low ionic liquid dosage was successfully obtained, and only 40% of bulk ionic liquid dosage was used to achieve high activity of quasi-homogeneous phase (PO conversion 95.5%). Combined with the characterization and mechanism study, it was found that at an appropriate ratio (1:1.5), good mesoporous structure and a certain extent dispersion of polyionic liquid can make the active site better dispersed to facilitate the simultaneous activation of multiple molecules, which is the reason for the high activity. In addition, the core–shell structure also has good substrate suitability and recyclability stability. This study provides good ideas for the development of low-cost heterogeneous ionic liquid catalysts. [ABSTRACT FROM AUTHOR]