多相化Salen-Mn(Ⅲ)催化剂的制备及其催化空气环氧化环己烯反应的研究

采用化学键连与溶胶-凝胶包容法制备锚链固定的多相化Salen-Mn(Ⅲ)催化剂。利用傅里叶变换红外光谱和核磁共振氢谱方法对催化剂及其前体进行表征。考察催化剂制备条件及环氧化反应条件对催化剂性能的影响,得到催化剂制备的优化条件及最佳环氧化反应条件。采用最佳条件下制备的催化剂催化环己烯的环氧化反应,当催化剂的摩尔分数为0.250%、n(异丁醛)∶n(环己烯)=2.5、环氧化反应温度35℃、环氧化反应9h时,环己烯的转化率达99.7%,环氧环己烷的选择性达88.8%。

Preparation of Anchored Heterogeneous Salen -Mn( Ⅲ ) Catalyst and Catalytic Aerobic Epoxidation of Cyclohexene on the Catalyst

Heterogeneous Salen-Mn(Ⅲ)catalyst for aerobic epoxidation of cyclohexene was prepared by chemical linkage and sel-gel entrapping method.The catalyst and its precursor were characterized by means of FTIR and 1H NMR.Factors affecting catalytic performances of heterogenized catalyst in its preparation and in aerobic epoxidation of cyclohexene were investigated,and optimal conditions were obtained.Cyclohexene conversion and epoxycyclohexane selectivity with best prepared catalyst could attain 99.7% and 88.8% respectively,when optimal conditions for aerobic epoxidation of cyclohexene were:epoxidation reaction temperature 35℃,reaction time 9h,n(isobutyraldehyde) ∶n(cyclohexene)=2.5 and mole fraction of catalyst to reaction substrate 0.250%.