MCM-41中孔SiO_2分子筛合成新方法

A Novel Synthesis Method for MCM-41 Mesoporous Silica Molecular Sieves

以溴代十六烷基吡啶（CPBr）为模板剂，正硅酸乙酯（TEOS）为硅源，在优化的操作条件下通过S＋X-I+路径合成了高结晶度的MCM－41中孔SiO2分子筛，并提高了其收率；以TG－DTA结果为基础，对分子筛脱模板剂的过程进行了优化，同时以XRD对合成物系中CPBr；TEOSHCl，H2O相对含量对MCM－41分子筛晶相结构的影响以及该结构的形成过程进行了分析，发现MCM－41结构沿S＋X-I+路径的形成经过了Lamellar→Hexagonal相转移历程.

High quality MCM-41 Inesoporous silica molecular sieves were synthesized in high yield via improved S+X-I+ assembly patllway, by using cetylpyridinium bromide(CPBr) as tem-Plate and tetraethyl orthosilicate(TEOS) as silica sollrce. The calcination process of as-synthesizedsamples was optimized on the basis of TG-DTA results. Thus typical MCM-41 sample obtainedwas cllaracterized by powder X-ray diffraction(XRD) and N2 adsorption-desorption techniques.The effects of CPBr, TEOS, HCl and H2O contents on the MCM-41 mesostucture, as well as themechanistic steps involved in the formation of the mesophase were also investigated by XRD. Itwas found that. the titled crystal phase was developed through lamellar to hexagonal mesophasetransformation.