Ti-MCM-41分子筛催化剂的表面硅烷化改性研究  

Silylation Modification on Surface of Ti-MCM-41 Molecular Sieves

作　　者：郭建维[1] 王乐夫[2] 刘卅[3] 

机构地区：[1]广东工业大学轻工化工学院,广东广州510090 [2]华南理工大学化工系,广东广州510640 [3]华南理工大学材料科学与工程学院,广东广州510640

出　　处：《高校化学工程学报》2005年第6期772-775,共4页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金资助项目(20026005);广东省基金团队项目(4205301);广东省科技计划项目(2005B103601008)。

摘　　要：以硅酸四乙酯(TEOS)为硅源,钛酸四丁酯(TBOT)为钛源,阳离子表面活性剂CnTMABr为模板剂,通过水热晶化法合成了含钛中孔分子筛Ti-MCM-41。采用XRD,FT-IR,SEM、N2吸附-脱附等方法对分子筛进行了结构表征,研究了不同硅烷化处理方法对Ti-MCM-41分子筛疏水性及催化氧化性能的影响。结果表明:模板剂CnTMABr碳链长度(n)影响Ti-MCM-41分子筛结构有序度。只有在n=16时所合成的Ti-MCM-41分子筛才具有长程有序结构。经不同硅烷化试剂处理后,Ti-MCM-41分子筛的Si/Ti增大,而比表面积、平均孔径、孔容积均有不同程度降低,但疏水性、催化氧化活性及环氧化物选择性增大。采用TMSCl(氯化三甲基硅烷)的硅烷化效率最高。Titanium-containing mesoporous molecular sieve Ti-MCM-41 was synthesized by hydrothermal crystallization using tetraethyl orthosilicate（TEOS） as Si source, tetrabutylorthotitanate（TBOT） as Ti source and cationic surfactant CnTMABr as template. Serveral analytic methods including XRD, FT-IR, SEM and N2-absorption-desorption were used to characterize the structures of the synthesized Ti-MCM-41 molecular sieves. Effects of silylation methods on hydrophobicity and catalytic oxidation performance of Ti-MCM-41 molecular sieves were investigated as well. The results show that the chain length of template CnTMABr influences the ordered structures of Ti-MCM-41 molecular sieves. A long-ranged ordered structure of Ti-MCM-41 could be obtained only when n=16. Through different treatments of silylation, BET surface area, pore diameter and pore volume of Ti-MCM-41 are decreased, while Si/Ti, the hydrophobicity, catalytic oxidation performance of Ti-MCM-41 molecular sieves and the selectivity ofepoxide are increased. Among the selected silylation agents, TMSCl（trimetnylsilyl chloride）shows the highest silylation efficiency.

关 键 词：中孔分子筛 TI-MCM-41 硅烷化处理 催化氧化 

分 类 号：TQ426.61[化学工程] O643.361[理学—物理化学]