对苯乙烯的催化环氧化反应

以磷钨酸为催化剂,过氧化尿素为氧化剂,甲醇作为溶剂,对苯乙烯进行环氧化反应。结果表明,磷钨酸的催化活性较高,苯乙烯的转化率可达93.2％,环氧苯乙烷的产率达到81.2％(基于底物),环氧苯乙烷的选择性达到87.2％以上。重点考察了不同的反应时间和不同催化剂的用量等因素对苯乙烯催化环氧化反应的影响,结果发现,当过氧化尿素(CO(NH_2)_2·H_2O_2)、苯乙烯和磷钨酸的摩尔比为511.8:255.9:1时,环氧苯乙烷产率最高。同时,考察了结晶四氯化锡对反应的影响,结果发现向反应中加入四氯化锡能提高环氧苯乙烷的选择性。

Oxidize and Analyze on Styrene

By using phospho - tungstic acid as catalyzer, urea peroxide as oxidant and methanol as solvent, styrene has been oxidized. The results show that phospho- tungstic acid has higher catalytic activity, the transform ratio of styrene reaches 93.2% , the product ratio of epoxy benzethane arrives at 81.2% (which is based substance), and the selectivity of epoxy benzethane adds up to 87.2% . Different reaction time and different catalyzer amount to effect epoxidation reaction are mainly examined by using styrene. The experimental results find that when the ratio of urea peroxide (CO(NH2)2 f33 H2O2) and styrene and phospho- tungstic acid is 511.8: 255. 9 : 1, the product ratio of epoxy benzethane reaches the highest amount. At the same time, the influence of crystal stannic tetrachloride is examined, and the experimental results find that the selectivity of epoxy benzethane is improved by adding stannic tetrachloride.