用富含介孔的硅基材料合成微孔-介孔复合分子筛

以富含介孔的硅基材料为硅源,四乙基氢氧化铵为模板剂,NaAlO2为铝源,调节投料硅铝的摩尔比(n(SiO2)/n(Al2O3)),通过半固相原位合成法,制备了具有不同晶型的微孔-介孔复合分子筛。采用X射线衍射仪分析样品组成,扫描电镜观测样品晶体形态,使用容量吸附分析仪测量样品孔结构。结果表明,所得样品具有微孔-介孔复合结构,在较低硅铝摩尔比条件下(n(SiO2)/n(Al2O3)=20~50),产物主要为β微孔-介孔复合分子筛;硅铝摩尔比较高时(n(SiO2)/n(Al2O3)200),合成产物为ZSM-5微孔-介孔复合分子筛。

Micro -and mesoporous molecular sieves prepared with mesoporous silicon materials

Composite micro - and mesoporous molecular sieves with different crystal form were prepared using mesoporous silicon materials as silicon source,NaAlO2 as Al source and tetraethylammonium hydroxide(TEAOH)as template through semi-solid phase and in-situ synthesis method.The samples were characterized for porosity by N2-sorption;for sample composition by XRD and morphology by SEM.Results showed that all the samples prepared have composite micro - and mesoporous structures.Under conditions of lower SiO2/Al2O3 ratio [n(SiO2)/n(Al2O3)= 20～50],β type micro - and mesoporous composite molecular sieves is the main product;while under conditions of higher SiO2/Al2O3 ratio (higher than 200),ZSM-5 type micro - and mesoporous composite molecular sieves is the main product.