氨水介质中Al-MCM-41的合成与表征

Synthesis of mesoporous molecular sieve Al-MCM-41 in ammonia water and its characterization

以十六烷基三甲基溴化铵(CTABr)为模板剂,正硅酸乙酯(TOES)为硅源,水合氯化铝为铝源,采用水热晶化法在氨水介质中合成了Al-MCM-41介孔分子筛.采用XRD表征手段研究了物料配比及合成条件对合成Al-MCM-41结构的影响,同时对合成样品进行了N2吸附和IR等表征.结果表明:在体系的氨浓度为5～10mol.L-1、模板剂与SiO2之物质的量比为0.3、晶化温度为120℃、晶化时间为72h的条件下,可合成出结晶度和有序性高、BET比表面积大等特点的Al-MCM-41介孔分子筛.

The mesoporous molecular sieve Al-MCM-41 is prepared in ammonia water by hydrothermal crystallization,using cetyltrimethyl ammonium bromide(CTABr) as structural template agent,tetraethyl orthosilioate(TOES) as silica source and aluminum chlorhydrexusp(AlCl3·6H2O) as aluminum source.The effects of the ratio of reaction substances and the synthesis conditions on the crystal structure of Al-MCM-41 are studied by X-ray diffraction characterization.The synthesized samples are characterized by nitrogen adsorption and infrared spectra analysis.The results show that the mesoporous molecular sieve of high crystallinity,uniform mesopore distribution and great specific surface area can be synthesized when the ammonia concentration of the reaction system is 5~10 mol/L,the substance amount ratio of CTABr to TOES is 0.3,and the crystallizing time is 72 h at 120 ℃.