相转移条件下杂多酸催化合成氧化苯乙烯

Synthesis of Styrene Oxide with Hydrogen Peroxide Catalyzed by Heteropoly Acids Under PTC

为研究开发污染少、能耗低且对环境友好的催化剂和氧化剂,在相转移条件下,用新合成的杂多酸催化剂催化环氧化苯乙烯合成氧化苯乙烯,用15%的双氧水氧化苯乙烯,1,2 二氧乙烷作溶剂时,得出最佳的工艺条件为:反应时间3h,反应温度60℃,溶液的pH值2.00左右,催化剂由1mol钨酸与9mol钼酸组成,其催化选择性和催化活性高,用高压液相色谱分析氧化苯乙烯的产率为81.2%.在该条件下考察了催化剂的重复使用情况,效果较好.

Styrene was epoxidized with commercially available hydrogen peroxide (15% H_2O_2) by using a combination of Mo- and W-based heteropoly acids with an appropriate ammonium salt such as tert-butylammonium chloride,under two-phase conditions using 1,2-dichloroethane as the solvent.By this method,styrene was epoxidized in high yields under mild conditions and after relatively short reaction times.It was found that the optimum reaction time was 3 h,the reaction temperature was 60 ℃, pH was (2.00),and the best catalyst for the epoxidation of styrene was composed of 9 mol molybdic acid and 1 mol tungstic acid.Under these conditions, the yield of styrene oxide is 81.2%.Meanwhile,the fresh catalyst has been characterized by IR and UV.