咪唑类离子液体催化合成碳酸丙烯酯

Synthesis of Propylene Carbonate in the Presence of Catalysts of N,N'-Dialkylimidazolium-Based Ionic Liquids

在釜式反应器内考察以3种咪唑类离子液体为催化剂合成碳酸丙烯酯(PC)的催化活性及影响因素进行研究。实验结果表明,[BMIM]Br、[BMIM]BF4对上述反应具有较高的催化活性,助剂ZnBr2的加入能显著提高PO转化率。得出最适宜的反应条件为:主催化剂用量0.25%(物质的量比例,下同),n(ZnBr2)/n([BMIM]Br)=1/5,反应温度110℃,反应压力1.5 MPa条件下反应1 h,PC的收率98.29%,选择性为100%;催化剂经4次重复使用反应的转化率均在92%以上,PC的选择性均为100%。

The synthesis of propylene carbonate from carbon dioxide and propylene oxide was studied using three kinds of ionic liquids（ [ BMIM ] Br, [ BMIM ] BF4, [ BMIM ] PF6 ） as catalysts. The experimen- tal results showed that [ BMIM ] Br, [ BMIM ] BF4 perform well and the presence of zinc bromide could improve significantly the conversion of propylene oxide in reaction process. The yield and selectivity of PC could be over 98% and 100% after 1 h, respectively, with 2 mol propylene oxide, 0.25% catalyst of [BMIM]Br and 0.05% zinc bromide under 1.5 MPa at 120 ~C. The catalyst showed a good catalyzing performance on the above conditions after it was used four times, as the yield of PC was always over 92% and selectivity 100%.