氯丙烯环氧化合成环氧氯丙烷

Synthesis of Epichlorohydrin by Epoxidation of Allyl Chloride

用合成的复合季铵磷钨酸盐为催化剂,35%双氧水溶液为氧源,催化氯丙烯合成环氧氯丙烷,并考察了反应条件对反应的影响。结果表明,加入适量的磷酸二氢铵能抑制环氧氯丙烷的水解,从而提高反应的选择性。反应的适宜条件为：氯丙烯为原料和反应溶剂,磷酸氢二铵用量（相对于总反应物的质量分数）0.04%,反应温度45~50℃,反应时间4h,n（氯丙烯）：n（H2O2）=5∶1,n（催化剂）：n（H2O2）=1∶100。H2O2的转化率为98.8%,环氧氯丙烷的选择性和收率分别为91.1%和85.7%。该催化剂的稳定性好,回收的催化剂性能接近新鲜催化剂。

With 35% hydrogen peroxide as oxidant and synthesized compound quaternary ammonium phosphotungstates as catalyst,epichlorohydrin（ECH） is synthesized from allyl chloride.During this experiment,effects of additives,catalyst dosage,mole ratio of hydrogen peroxide of allyl chloride,reaction time and temperature of reaction are studied.The result indicates that addition of（NH4）2HPO4 can improve selectivity of ECH due to inhibition of ECH hydrolysis.Optimal conditions of the epoxidation of allyl chloride are as follows：n（allyl chloride）∶n（H2O2）=5∶1,n（catalyst）∶n（H2O2）=1∶100,reaction temperature is 45~50℃ and time is 4h,0.04%（w/w）（NH4）2HPO4 as additives and allyl chloride as solvent,H2O2 conversion is 98.8%,selectivity to ECH is 91.1% and yield to ECH is 85.7%.When the catalyst,which possesses high stability,is recycled,it can still keep similar catalytic activity to fresh catalyst.