离子液体接枝的有机介孔催化剂的制备及催化碳酸丙烯酯水解反应

Preparation of Ionic Liquid Grafted Organic Mesoporous Catalyst and Its Catalytic Performance on Hydrolysis of Propylene Carbonate

以甲基咪唑和3-氯-1-丙醇为原料合成离子液体(1-羟丙基-3-甲基咪唑四氟硼酸盐,NpmimBF4),并将其接枝固载到有机介孔材料(FDU-15)上,合成制备了有机介孔催化剂(NpmimBF4-FDU)。采用热重、X射线衍射、红外光谱及透射电子显微镜等技术手段对催化剂结构进行了表征,并考察了催化剂在碳酸丙烯酯(PC)水解反应中的催化性能,结果表明,该催化体系在常压下能有效催化碳酸丙烯酯水解生成1,2-丙二醇。在催化剂的质量分数为4%、温度80℃、反应时间2 h的条件下,1,2-丙二醇的产率大于99%。经简单分离后催化剂可重复使用5次,但活性变化较大。同时对催化碳酸丙烯酯水解生成1,2-丙二醇(PG)的机理进行了初步探讨。

Methylimidazole and 3-chloro-1 propanol were used as materials to synthesize ionic liquids（1-hydroxypropyl-3-methylimidazolium tetrafluoroborate, NpmimBF4）, and its graft was immobilized to mesoporous materials（FDU-15）, thus for synthesizing and preparing mesoporous catalyst（NpmimBF4-FDU）. Techniques such as thermogravimetry, X-ray diffraction, infra-red spectrum and transmission electron microscope were employed to characterize the structure of catalyst. The catalytic activity of the catalyst was investigated in the hydrolysis reaction of propylene carbonate（PC）. The result shows that the catalyst can effectively catalyze the hydrolysis of propylene carbonate to 1,2-propanediol glycol at normal pressure. When mass fraction of the catalyst is 4%, temperature is 80 ℃ and the reaction time is 2 h, the yield of 1,2-propanediol glycol is more than 99%. The catalyst can be repeatedly used for 5 times after simple separation but its activity changes greatly. A reaction mechanism is proposed.