催化学报

催化学报 ›› 2007, Vol. 28 ›› Issue (6): 551-556.

• 研究论文 • 上一篇    下一篇

硅烷化对Ti/HMS分子筛催化性能的影响

李学峰1,高焕新2,金国杰2,丁琳2,陈璐2,杨洪云2,何欣2,陈庆龄1,2   

  1. 1 华东理工大学化学与分子工程学院, 上海 200237; 2 中国石化上海石油化工研究院, 上海 201208
  • 收稿日期:2007-06-25 出版日期:2007-06-25 发布日期:2011-05-28

Influence of Silylation on Catalytic Performance of Ti/HMS Molecular Sieve

LI Xuefeng1, GAO Huanxin2, JIN Guojie2, DING Lin2, CHEN Lu2, YANG Hongyun2, HE Xin2, CHEN Qingling1,2*   

  1. 1 School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China; 2 Shanghai Research Institute of Petrochemical Technology, SINOPEC, Shanghai 201208, China
  • Received:2007-06-25 Online:2007-06-25 Published:2011-05-28

PDF

937

被引次数

38

摘要： 分别用水热法和气相沉积法制备了Ti/HMS分子筛,采用三甲基氯硅烷(TMCS)和六甲基二硅氮烷(HMDSZ)对Ti/HMS样品进行了气相硅烷化,并用X射线衍射、N2吸附、红外光谱、29Si核磁共振和紫外-可见光谱对样品进行了表征. 丙烯环氧化反应的测定结果表明,硅烷化可显著提高环氧化催化活性. 水热法制备的Ti/HMS经HMDSZ硅烷化后的催化活性比经TMCS硅烷化后的稍高; 气相沉积法制备的Ti/HMS经HMDSZ硅烷化后的催化活性远高于经TMCS硅烷化后的催化活性. 这是由于TMCS不但能与分子筛表面的硅羟基反应,而且能破坏分子筛骨架中的Si-O-Ti甚至Si-O-Si键,形成新的羟基,导致样品的亲水性较强,同时还能对气相沉积法制备的Ti/HMS中的四配位骨架钛产生破坏作用.

关键词: 钛, HMS分子筛, 水热合成, 气相沉积, 硅烷化, 丙烯, 环氧化

Abstract: Ti/HMS samples were prepared by hydrothermal synthesis (HTS) and chemical vapor deposition (CVD) methods and then silylated by trimethylchlorosilane (TMCS) and hexamethyldisilazane (HMDSZ) in a vapor phase. The samples were characterized by XRD, N2 adsorption, FT-IR,29SiNMR, and DRUV-Vis, and their catalytic performance for the epoxidation of propylene using cumene hydroperoxide as oxidant was measured. The silylation could promote remarkably the catalytic performance. The Ti/HMS silylated by HMDSZ had much higher catalytic activity than that silylated by TMCS. This is because TMCS could not only react with silanol but also breakSi-O-TiandSi-O-Sibonds to form new silanol, which led to higher hydrophilicity for the silylated samples than those silylated by HMDSZ. The silylation with TMCS partially destroyed the tetracoordinated framework titanium species in Ti/HMS, but this did not occur in the silylation with HMDSZ.

Key words: titanium, HMS molecular sieve, hydrothermal synthesis, chemical vapor deposition, silylation, propylene, epoxidation