以微孔口沸石为硅铝源,通过碱处理和以十六烷基三甲基溴化铵为模板剂,合成了具有较强酸性的六方结构介孔分子筛材料β-MCM-41,并采用XRD、N2吸附脱附、FT-IR、”A1MASNMR、HRTEM和水热处理等手段对其进行了结构表征,采用NH_3TPD对其进行了酸性表征。实验结果表明,B-MCM-41具有明显强于常规介孔分子筛的酸性,且在C10^+混合芳烃加氢脱烷基化反应中表现出了良好的催化性能。这主要是由于碱溶液将口沸石降解为沸石结构单元,在表面活性剂作用下五元环次级结构单元被引入了介孔铝硅酸盐B-MCM-41的结构。
With alkalitreated beta zeolite as the sources of silicon and aluminum and cetyltrimethylammonium bromide (CTAB) as template, mesoporous aluminosilicates with hexagonal structure denoted as B-MCM-41 were synthesized. The structure and acidity of B-MCM-41 were characterized by XRD, N2 adsorption-desorption, FTIR, 27A1 MAS NMR, HRTEM and NH3-TPD. Compared with conventional mesoporous aluminosilicates materials, B-MCM-41 synthesized in this way exhibits enhanced acidity and higher activity for catalytic dealkylation of C1o aromatic hydrocarbon. B,MCM-41 mesoporous structure may be built in the presence of a cationic surfactant template via the assembly of the dissolved fragments such as five member secondary structural units which are formed from the dissolution of preformed beta zeolite in a caustic solution.