无有机胺体系中高硅ZSM-5沸石的一步合成

One-Step Synthesis of High-Silica ZSM-5 in the Absence of Organic Amine

在无有机胺模板剂和不加晶种体系中,采用较低晶化温度(130℃),在水热体系中一步合成了形貌均一的板块状高硅ZSM-5沸石(nSiO2/nAl2O3>90)。系统地考察了合成体系中原料的物质的量之比对合成ZSM-5沸石的影响。通过X射线衍射(XRD),傅里叶红外光谱(FT-IR),扫描电镜(SEM),低温氮气吸附/脱附和固体核磁共振(29Si MAS NMR)等技术手段对合成的ZSM-5沸石进行了物化表征。结果表明,当原料的物质的量之比nC2H5OH/nSiO2=2.8、nNa2O/nSiO2=0.14和nSiO2/nAl2O3=150时,可合成具有高结晶度的ZSM-5纯相沸石。比表面积和微孔孔容分别为409 m^2·g^-1和0.14 cm^3·g^-1,其骨架nSiO2/nAl2O3达到96.4。

The plate-like high-silica ZSM-5 zeolite(nSiO2/nAl2O3>90)with uniform morphology was synthesized by hydrothermal method at a lower crystallization temperature(130℃)in the absence of organic amine and seed.The effects on ratio of the amount of substance of reactants on the synthesis of high-silica ZSM-5 zeolite were systematically investigated.The synthesized high-silica ZSM-5 zeolite was characterized by XRD,FT-IR,SEM,N2 adsorption/desorption and ^29Si MAS NMR techniques.Results confirmed that the synthesized ZSM-5 zeolite(nC2H5OH/nSiO2=2.8,nNa2O/nSiO2=0.14,nSiO2/nAl2O3=150)exhibited high crystallinity of the product.The specific surface area and micropore volume were 409 m^2·g^-1 and 0.14 cm^3·g^-1.^29Si MAS NMR analysis showed that the nSiO2/nAl2O3 was 96.4.