The efficiency and versatility of catalysts in the multi-step reaction of carbonates with carbon dioxide (CO₂) as raw material are barely satisfactory. Herein, ternary copolymerized bifunctional poly(ionic liquid)s (TBPILs) rich in hydroxyls, halogen anions and tertiary N were fabricated via free radical copolymerization. Due to the ingenious modification of tertiary N in the polymeric framework to form multi-site activation with hydroxyls and halogen anions, the specific activity of TBPILs reached to 17.87 mmol_SC m⁻²_catal h⁻¹ in CO₂ cycloaddition reaction. Meanwhile, for the transesterification reaction of cyclic carbonates with methanol, by the introduction of tertiary N, the yield of dimethyl carbonate increased from trace to 80.31 % in the absence of any solvent or co-catalyst. Density functional theory calculations, combined with electrostatic potential and average local ionization energy analyses confirmed the dual roles of tertiary N in the formation of carbonates by CO₂. This work provides an originality idea to design high-efficiency catalysts for CO₂ insertion into carbonates, and study the effects of basic sites on CO₂ conversion.

在碳酸盐与二氧化碳（CO ₂）为原料的多步反应中，催化剂的效率和通用性几乎不能令人满意。在此，通过自由基共聚制备了富含羟基，卤素阴离子和叔N的三元共聚双官能聚（离子液体）（TBPIL）。由于聚合物框架中叔氮的巧妙修饰，形成了羟基和卤素阴离子的多位活化，因此TBPIL的比活性在CO _2中达到17.87 mmol _SC m ^-2 _cath h ^-1环加成反应。同时，对于环状碳酸酯与甲醇的酯交换反应，通过引入叔N，在没有任何溶剂或助催化剂的情况下，碳酸二甲酯的产率从痕量增加至80.31％。密度泛函理论计算，结合静电势和平均局部电离能分析，证实了叔氮在CO ₂形成碳酸盐中的双重作用。这项工作为设计将CO ₂插入碳酸盐中的高效催化剂，并研究碱性位点对CO ₂转化的影响提供了独创的想法。