以哌啶为模板剂静态合成MCM-22和MCM-36分子筛

Static Synthesis of MCM-22 and MCM-36 Zeolites Using Piperidine as an Organic Template

以来源易得的哌啶(PI)取代六亚甲基亚胺(HMI)为模板剂,采用静态合成的方法制备MCM-22分子筛,并进一步以十六烷基三甲基氯化铵(CTMACL)、四丙基氢氧化铵(TPAOH)作为溶胀剂,以正硅酸乙酯(TEOS)为柱撑剂合成MCM-36分子筛,以探索MCM-22和MCM-36的新合成途径。通过XRD、IR、SEM、N2吸附-脱附、NH3-TPD、正丁胺回滴法对MCM-22和MCM-36结构形貌、比表面积、孔径、表面酸量进行表征。结果表明,采用静态法以哌啶为模板剂是合成MCM-22和MCM-36的有效途径,MCM-22结晶度达到98.5%。合成的MCM-22比表面积为382 m2?g-1,孔容为0.25 cm3?g-1,外表面酸量为0.78 mmol?g-1;合成的MCM-36比表面积为468 m2?g-1,孔容为0.39 cm3?g-1,外表面酸量为0.94 mmol?g-1,介孔孔径达2.7 nm。

Piperidine was used as an organic template for its easy availability to replace commonly-used hexamethyleneimine（HMI） in static synthesis of MCM-22 zeolite. A novel synthesis approach for MCM-22 and MCM-36 zeolites was explored using hexadecyltrimethylammoniurn chloride （CTMACL） and tetrapropylarnmonium hydroxide （TPAOH） as swelling agents and tetraethoxysilane（TEOS） as the pillar-support agent. The morphology, specific surface area, pore size and surface acid amount of the synthesized molecular sieves were characterized by XRD, IR, SEM, N2 adsorption-desorption, NH3-TPD, and n-butylamine titration measurments. The results demonstrate that the proposed synthetic route is an effective way to fabricate well-defined MCM-22 and MCM-36 zeolites. The MCM-22 prepared have a high crystallinity degree of 98.5%, specific surface area of 382 m^2·g^-1, pore volume of 0.25 cm^3·g^-1 and a surface acid amount of 0.78 mmol·g^-1, while MCM-36 possesses a specific surface area of 468 m^2·g^-1, pore volume of 0.39 cm^3·g^-1, surface acid amount of 0.94 mmol·g^-1 and a mesoporous pore size of 2.7 nm.