MSE 结构钛硅分子筛的快速合成及其催化正己烯环氧化反应性能

Using dimethyldipropylammonium hydroxide (DMDPAOH) as the organic structure-directing agent and ultra-stable dealuminated FAU zeolite (USY) as the silica and alumina sources, the pure phase UZM-35 zeolite was synthesized without adding MSE zeolite seeds, while the Si/Al ratio in the synthetic gel was adjusted with additional silica source. Ti-UZM-35 was then obtained through subsequent dealumination and TiCl₄ vapor treatment. The results of X-ray diffraction (XRD), scanning electron microscopy (SEM) and N₂ adsorption and desorption measurements showed that the subsequent dealumination and isomorphous substitution did not change the pore structure and morphology of the UZM-35 zeolite. Ti-UZM-35 was used to catalyze the liquid-phase epoxidation of n-hexene. The effects of operation parameters, such as solvent type, molar ratio of H₂O₂ to n-hexene, reaction temperature and time, on the epoxidation activity of n-hexene were investigated. The cycle testing and the deactivation analysis of the reaction were further carried out, demonstrating that Ti-UZM-35 was an active and robust epoxidation catalyst. Thus, Ti-UZM-35 zeolite prepared by this method is an effective catalyst for the selective oxidation reaction.