聚苯乙烯负载Salen-Mn(Ⅲ)配合物的制备及其催化空气环氧化烯烃反应  

Preparation of Polystyrene-Supported Salen-Mn(Ⅲ) Complex and its Catalytic Property for Aerobic Epoxidation of Alkenes

作　　者：郭锋[1] 张洪起[1] 冯磊[1] 赵继全[1] 

机构地区：[1]河北工业大学化工学院应用化学系,天津300130

出　　处：《高校化学工程学报》2008年第6期972-977,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金资助项目(20376017)

摘　　要：Salen Mn(Ⅲ)配合物是空气环氧化烯烃的优良均相催化剂。然而,与反应混合物难于分离的缺点限制了其大规模地使用,利用高聚物为载体负载此类配合物有望解决这一问题。因此,通过多步接枝法将一Salen-Mn(Ⅲ)配合物负载在聚苯乙烯(交联度2%)树脂上制备了高分子负载的催化剂。利用傅立叶变换-红外光谱、原子吸收以及元素分析等方法对该催化剂及其前体进行了表征。分别以环己烯,苯乙烯,1-辛烯为底物考察了该负载配合物催化空气环氧化烯烃反应的性能;考察了环氧化反应条件对催化剂性能的影响,并得出优化的环氧化反应条件。在此条件下环己烯的转化率可达91.4%,环氧环己烷的选择性达86.3%。同时在优化条件下考察了催化剂的循环使用性能。上述结果表明该负载催化剂对环己烯和苯乙烯的空气环氧化具有很高活性和环氧化物选择性。该催化剂能够循环使用几次,但未达到预期效果。Salen-Mn（Ⅲ） complexes are excellent homogenous catalysts for the aerobic epoxidation ofolefins. However, they cannot be used in large scale due to the difficulty of separation of them from reaction mixture. It is expected that immobilization of the complexes on organic polymer may solve this problem. Therefore, a Salen-Mn（Ⅲ） complex was successfully immobilized on the polystyrene resin （a 2% divinylbenzene-styrene copolymer） by a multi-step grafting method to form a polymer-supported catalyst. The prepared catalyst and its precursor were characterized by FT-IR, atomic absorption analysis and elemental analysis, respectively, and its performances on aerobic epoxidation of cyclohexene, styrene and 1-octene were studied. Factors affecting catalytic performance of the prepared polymer-supported catalyst were also investigated, and optimal conditions were obtained. Under the optimized conditions the conversion of cyclohexene and the selectivity of epoxycyclohexane could reach up to 91.4% and 86.3%, respectively. The recycle test of the catalyst was also carried out under the optimized conditions. The results reveal that the supported catalyst has high catalytic activity and good selectivity of epoxide for the epoxidation of cyclohexene and styrene, respectively. It can be recycled for several times, though it is not so good as expected.

关 键 词：聚苯乙烯 负载 salen-Mn(Ⅲ)配合物 空气环氧化 环己烯 

分 类 号：TQ426.61[化学工程] TQ203.2