合成方法对Ti-SiZSM-5分子筛合成影响及合成过程探讨

Influence of synthetic method on synthesis of Ti-SiZSM-5 zeolite and exploration of synthesis procedure

在廉价原料水热合成体系中研究了合成原料组成、陈化、超声波振荡处理、加入导向剂或晶种对合成Ti SiZSM 5分子筛的影响 .结果表明 :在较低碱度下、n (SiO2 ) /n (TiO2 )很宽范围内均易生成Ti SiZSM 48;在较高碱度下、n (SiO2 ) /n (TiO2 )在 5 0 40 0时易生成Ti SiZSM 5 .凝胶必须陈化处理才能合成出高结晶度的Ti SiZSM 5分子筛 .但凝胶经超声波振荡后合成钛硅分子筛时 ,钛不易进入骨架 ,并易生成α SiO2 .合成中加入导向剂或晶种有利于Ti SiZSM 5分子筛的合成 ,特别是导向剂的加入可使晶化时间缩短一半以上 ,合成的分子筛结晶度高、晶粒小且有利于钛进入骨架 .

The influence of synthesis method on the synthesis of Ti SiZSM 5 zeolite and the mechanism of synthesis are studied in detail. The synthesis process of Ti SiZSM 5 zeolite using much cheaper raw materials such as silica sol, [Ti(H 2O 2) 2+ ],TEAOH and HDA depends strongly on n (SiO 2)/ n (TiO 2), n (Na 2O)/ n (SiO 2), n (TEAOH +HDA)/ n (SiO 2). It has been found that Ti SiZSM 5 can only be obtained at high n (SiO 2)/ n (TiO 2), low n (Na 2O)/ n (SiO 2) in the synthesis hydrogel and the chemical composition of the synthesis hydrogel may be changed in a small range. Seed, structure directing agent added and the ripening of hydrogel during the synthesis of Ti SiZSM 5 zeolite are beneficial to the improvement of crystallinity and the incorporation of Ti into the framework of Ti SiZSM 5 .