含氟体系中合成高品质的MCM-48介孔分子筛

Synthesis of mesoporous MCM-48 molecular sieves of high quality in a fluorine-containing system

摘要: 在含氟体系中以正硅酸乙酯和十六烷基溴化铵作为硅源和模板剂,合成高质量的MCM-48。主要考察了各种影响合成MCM-48的因素,得到的产物分别用XRD,TEM和N₂吸附-脱附技术进行表征。结果表明,合成高质量MCM-48的条件是温度为393 K,时间为24 h,CTAB/Si比为0.65;得到的MCM-48具有较大的比表面积(130 5 m²/g),孔径分布比较集中(2.416 nm)。

Abstract: Mesoporous MCM-48 molecular sieves were synthesized in a fluorinecontaining system using tetraethylorthosilicate (TEOS) as silica source and cetyltrimethylammonium bromide (CTAB) as template. To investigate the influence of various factors for synthesis on the structure and properties of the MCM-48 molecular sieves obtained, they were characterized by Xray diffraction (XRD), N₂ adsorptiondesorption and transmission electron microscopy (TEM). The results showed that under the optimal conditions, i.e. a CTAB/Si ratio of 0.65 and crystallization at 393 K for 24 h, the assynthesized MCM-48 exhibits high crystallinity with a specific surface area of 1 305 m²/g and an average pore size of 2.416 nm.