低浓度表面活性剂条件下合成含β沸石次级结构单元的介孔分子筛  

SYNTHESIS OF MESOPOROUS MOLECULAR SIEVES WITH SECONDARY BUILDING UNITS OF β ZEOLITE AT LOW SURFACTANT CONCENTRATION

作　　者：李玉平[1] 张伟[2] 霍全[2] 窦涛[2] 谢克昌[1] 

机构地区：[1]太原理工大学教育部和山西省煤科学与技术重点实验室,山西太原030024 [2]太原理工大学精细化工研究所,山西太原030024

出　　处：《石油学报（石油加工）》2006年第3期40-45,共6页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家自然科学基金项目(20476060);国家重大基础研究973项目(2004CB217806)资助

摘　　要：在表面活性剂浓度很低(n(CTAB)/n(SiO2)=0.05,n(CTAB)/n(H2O)=8.3×10-4)的合成体系中,从具有β沸石次级结构单元的溶胶前驱体出发,在碱性条件下合成了高度规整六方排列的介孔分子筛。采用XRD、N2吸附-脱附、FT-IR、HRTEM、DTG、NMR和水热处理等手段,表征了样品的结构特征和性能。结果表明,以低浓度表面活性剂为模板,可以得到孔壁含β沸石次级结构单元的高度有序的介孔分子筛;铝元素主要以四配位状态存在于介孔分子筛骨架中。与普通MCM-41相比,此法合成的样品呈现较高的水热稳定性,主要是由于沸石次级结构单元进入分子筛孔壁,提高了骨架的聚合度和孔壁的厚度。Mesoporous molecular sieves with the structure of MCM-41 have been synthesized in alkaline situation, by using the cationic surfactants of low concentration （n （CTAB）/n （SiO2） = 0.05, n（CTAB）/n（H2O）=8.3 × 10^-4） as template and the gel contaning secondary building units of β zeolite as precursors. The ordered mesoporous materials were characterized by XRD, N2 adsorption and desorption, FT-IR, HRTEM, DTG, NMR and hytrothermal treatment methods. The results indicated that the samples had ordered hexagonal structure with β zeolite secondary units in its pore walls,which are thicker than the walls of MCM-41 synthesized by normal hydrothermal ways. The synthesized materials were superior to conventional MCM 41 with respect to their higher hydrothermal stability. The retention of zeolite-like connectivity of tetrahedral AlO4 and SiO4 units upon assembling the nanoclusters into mesostructured materials and thicker framework pore walls contributed to the good hydrothermal stability greatly.

关 键 词：介孔分子筛 Β沸石 次级结构单元 水热稳定性 

分 类 号：O643[理学—物理化学]