模板剂对全硅MCM-41介孔分子筛结构的影响

Effects of Different Templating Agent on the Structure of Silica MCM-41 Mesoporous Molecular Sieves

分别采用十六烷基三甲基溴化铵和十六烷基三乙基溴化铵作为模板剂,硅溶胶为硅源,用水热晶化法在碱性(NaOH)介质中合成了MCM-41介孔分子筛样品.通过XRD、N2吸附-脱附、TG-DTA、IR等测试手段对这两种样品进行了对比表征分析.考察了两种不同模板剂对其晶体结构、比表面及孔径大小的影响.实验结果表明,相对于十六烷基三甲基溴化铵做模板剂,采用大头基的十六烷基三乙基溴化铵可以合成较大孔径和孔容(分别为4.72nm和1.14cm3·g-1)的MCM-41介孔分子筛,而且具有较窄的孔径分布,因此对于合成大孔径的介孔分子筛MCM-41,十六烷基三乙基溴化铵是一种很好的模板剂.

Using cetyltriethylammonium bromide and cetyltrimethylammonium bromide as templating agent respectively,and silicasol as silica source,the mesoporous molecular sieves MCM 41 were synthesized by hydrothermal method in basic media.The synthesized samples were characterized by XRD、 N2 adsorption desorption、 TG DTA and IR.The effects of different templating agent on the crystalline structure 、 pore diameter and pore size distribution of synthesized silica MCM 41 were investigated.The experimental results show that the templated by cetyltriethylammonium bromide,compared with those templated by cetyltrimethylammonium bromide,have larger pore diameter and pore volume with 4.72 nm and 1.14 cm3· g- 1 respectively and narrower pore size distribution.For the preparation of large pore mesoporous MCM 41,cetyltriethylammonium bromide is a more effective templating agent than cetyltrimethylammonium bromide.