两亲性TS-1沸石的制备及其相界面催化反应性能的研究

采用三甲基氯硅烷和正十八烷基三氯硅烷对TS-1沸石样品进行表面修饰，制备出了两亲性含钛沸石样品．这类两亲性含钛沸石能分布于水、油两相界面处．改性后样品的骨架未遭破坏，其中钛仍然保持了四配位骨架钛的状态，但其晶貌发生了某些改变．这类两亲性样品在不加共溶剂及静置的反应条件下，对1-辛烯和双氧水的相界面环氧化催化反应表现出优良的催化活性．尤其是三甲基氯硅烷改性后的TS-1沸石，在相界面催化反应中，具有比改性前高得多的活性．我们还发现，在该相界面催化反应条件中，相界面的面积和催化剂用量是两个最重要的影响因素，当相界面面积(cm^2)与催化剂用量(mg)的比例控制在0．15左右时，两亲性TS-1沸石的催化活性达到最高值．

Preparation of Amphiphilic TS-1 Zeolites and Their Phase-boundary Catalysis

Amphiphilic TS-1 zeolites were prepared from TS-1 zeolite modified with trimethylchlorosilane and n-octadecyltrichlorosilane respectively. These amphiphilic zeolites were oriented at the water-organic boundary. Samples after modification retained their original crystal structure and Ti in these zeolites remained tetrahedral coordination, while the crystal morphology was changed. These amphiphilic Ti-containing zeolites showed good catalytic performance in the 1-octene and aqueous hydrogen peroxide phase-boundary epoxidation reaction without adding co-solvents and stirring. Especially by the TS-1 modified with trimethylchlorosilane, much higher catalytic activity was achieved than by parent TS-1 zeolite in the phase-boundary catalysis. In phase-boundary catalysis, the area of the phase-boundary and the amount of catalyst are the two important affecting factors. The amphiphilic TS-1 zeolite showed the highest catalytic activity when the ratio of the area of the phase-boundary (in cm 2) to the usage of catalyst (in mg) was around 0.15.