Abstract: An basic ionic liquid 1-methyl-3-(triethoxysilyl)propylimidazolium hydroxide (［Smim］OH) were grafted on mesoporous silica gel (SiO₂) with different amount by post-grafting method. The prepared materials, which were verified by means of FTIR, element analysis, ²⁹Si MAS NMR and TG could be used as heterogeneous catalysts toward propylene carbonate (PC) synthesis through cycloaddition of CO₂ with propylene oxide (PO) under solventless and mild conditions. The results showed that such grafted ionic liquids (GILs) were successfully grafted on the support of silica gel via covalent bonds, but the degree of ionic liquids grafted on the silica gel was different. Under the optimal reaction conditions, the PO conversion could reach 99.5% and 100% selectivity towards PC. The catalyst could be recovered and recycled easily with filtration. In addition, the catalytic activity basically remained after being used for several times.

Key words: ionic liquid, degree of graft, carbon dioxide, propylene carbonate

摘要： 采用后嫁接法将不同量的1-甲基-3-丙基(三乙氧基硅基)咪唑的氢氧化物(［Smim］OH)嫁接到介孔硅胶(SiO₂)上，采用傅里叶变换红外光谱、元素分析、硅核磁共振及热重分析等技术对所制备的材料进行表征。在无溶剂、温和的条件下，将碱性嫁接型离子液体用于CO₂与环氧丙烷(PO)合成碳酸丙烯酯(PC)的环加成反应来考察其催化活性。结果表明，离子液体［Smim］OH成功地以共价键嫁接到介孔硅胶上得到碱性嫁接型离子液体(GILs)，但不同量的［Smim］OH嫁接程度有所不同；在优化条件下，PO的转化率为99.5%，选择性为100%。反应后催化剂经过滤即可分离回收利用，且多次使用仍保持较高的反应活性。

关键词: 碱性, 离子液体, 嫁接程度, 二氧化碳, 碳酸丙烯酯