固载化羟肟酸过渡金属配合物催化氧化乙苯的性能

Catalytic property of immobilizedsalicyl hydroxamic acid-transition metal complex in oxidation of ethylbenzene by molecular oxygen

采用付-克烷基化反应,使水杨羟肟酸(SHA)键合到氯甲基化聚苯乙烯微球(CMCPS)表面,制得SHA功能化聚苯乙烯微球(SHA/CPS);再以SHA/CPS为配体,与过渡金属离子M(Co(Ⅱ)、Cu(Ⅱ)、Fe(Ⅲ)、Mn(Ⅱ))配位,制备了M-SHA/CPS配合物固体催化剂。研究了M-SHA/CPS在氧气非均相氧化乙苯中的催化行为。结果表明,M-SHA/CPS可有效地催化分子氧氧化乙苯。中心金属离子的电子结构对配合物催化性能有较大影响,其中Fe-SHA/CPS对乙苯氧化为EBHP的催化活性和选择性最高,在100℃下EBHP的含量高达14%。催化剂浓度、助剂四甘醇浓度和温度对Fe-SHA/CPS催化剂的活性和选择性有较大影响。此外,Fe-SHA/CPS具有较好的重复使用性。

Salicylhydroxamic acid(SHA)was covalently bounded onto the chloromethylated cross-linked polystyrene microspheres(CMCPS)through the Friedel-Crafts alkylation reaction,obtained SHA-functionalized CPS(SHA/CPS).Then the supported catalyst M-SHA/CPS was prepared by the coordination between SHA/CPS ligand and metal ions(Co(Ⅱ),Cu(Ⅱ),Fe(Ⅱ),or Mn(Ⅱ)).Catalytic performances of M-SHA/CPS for the heterogenous oxygen oxidation of ethylbenzene in the absence of solvent were investigated and compared in detail.The results showed that M-SHA/CPS could effectively activate dioxygen and obviously catalyze the oxidation of ethylbenzene.The electronic structure of central metal ion had a strong effect on the catalytic properties of M-SHA/CPS,and the yield of EBHP obtained using Fe-SHA/CPS as catalyst was up to 14% at 100 ℃.The catalytic activity was affected by the Fe-SHA/CPS concentration,additive concentration,and temperature.In addition,Fe-SHA/CPS had a good reusability.