玻璃纤维负载金属锰催化剂的合成及其催化氧化苯乙烯反应性能

Preparation of Fiber-Supported Mn(II) Complex and Their Catalytic Performance in Oxidation of Styrene

摘要: 本论文制备了一种新型负载催化剂，GF-SALEN-Mn(II)，它以玻璃纤维为载体，纤维表面羟基化后，经过3-(2,3-环氧丙氧)丙基三甲氧基硅烷(GPTS)处理，在纤维表面形成硅烷分子层，经过几步反应负载上含有SALEN结构的配合物，用甲醇做溶剂配合上金属离子锰，制备成GF-SALEN-Mn(II)催化剂，并用红外光谱(IR)及核磁(HNMR)进行表征。以H2O2为氧化剂，考察了GF-SALEN-Mn(II)配合物对苯乙烯氧化反应的催化性能。探究了反应温度，氧化剂用量等条件对催化活性的影响，并考察了纤维固载金属催化剂的循环使用性能。实验结果表明，催化剂有很高的催化活性且苯乙烯的转化率可达84%。最佳反应条件为：温度为70℃，反应时间为10时，氧化剂H₂O₂的量为底物苯乙烯的五倍摩尔量，催化剂可以循环使用3次仍有较好的催化活性。

Abstract: The goal of this paper is to prepare a new type of supported catalyst, GF-SALEN-Mn(II), which is synthesized by the following. The glass fibers were first hydroxylated, after which they were reacted with 3-glycidoxypropyltrimethoxysilane (GPTS) to form a silane monolayer, which was further reacted with synthetic salen ligand on subsequent treatment with Mn(OAc)2 in methanol and gave a glass fiber-supported N,N-bis-(saliylalehydde)-ethylendiamine manganese(II) complex [GF- SALEN-Mn(II)]. It was characterized by physicochemical techniques (FT-IR, HMNR). The catalyst was used in the oxidation of styrene with H₂O₂ as the oxidant. The important reaction conditions, such as the reaction temperature, the ratio of oxidant/styrene, and the recycle times were examined. The experimental results show that the catalyst reveals relatively high catalytic performance with 84% conversion for styrene. The suitable conditions are as follows: n(styrene): n(H2O2) = 1:5; the reaction temperature: 70˚C and the reaction time: 10 h. In addition, the catalyst used repeatedly for 3 times can still possess high catalytic activity.