以纯天然矿物为硅铝原料水热合成ZSM-5分子筛

以纯化硅藻土和热活化高岭土为硅铝原料,在水热条件下一步合成纯相ZSM-5分子筛。考察分子筛合成参数对产物的影响,得到合成ZSM-5分子筛的适宜条件:硅藻土与高岭土质量比32∶1,晶化温度170℃,晶化时间48 h,合成体系pH=13. 0。采用XRD、SEM及N2吸附-脱附等对样品进行表征。结果表明,最适宜条件下合成的ZSM-5分子筛晶型完整,具有与工业ZSM-5分子筛相似的六棱柱形貌以及相近的总比表面积和总孔容。

Hydrothermal synthesis of ZSM-5 zeolite from nature silicon-aluminum clay

Pure ZSM-5 zeolites were synthesized by conventional hydrothermal method using purified diatomite and heat-activated kaolin as silicon-aluminum raw materials.The effects of synthesis conditions of ZSM-5 zeolites were examined.The optimum conditions were as follows:the mass ratio of diatomite to kaolin was 32∶1,the crystallization temperature was 170 ℃,the crystallization time was 48 h,and the pH was 13.0.The obtained materials were characterized by XRD,SEM and N₂ adsorption-desorption.The results indicated that the high purity ZSM-5 zeolites synthesized under the optimum conditions have the same regular hexagonal prism morphology as commercial ZSM-5 zeolites.The as-synthesized products with high degree of crystallinity also had large total specific surface area and pore volume.