摘要
采用弱碱性的Na_(2)SiO_(3)介质对ZSM-5沸石进行选择性改性处理,主要是脱硅降解,用处理后的沸石从其原来结构单元中脱除的硅物种和Na_(2)SiO_(3)物种中的硅共同作为硅源,以十六烷基三甲基溴化铵(CTAB)作为合成沸石分子筛的模板剂,保持弱碱性环境,水热法合成了ZM分子筛,其结构中含有ZSM-5沸石单元。采用XRD、SEM、TEM和NH3-TPD等手段对碱处理的ZM沸石进行表征。结果表明:碱处理后的ZSM-5沸石具有类似于MCM-41的规整一维六方直孔道介孔结构,具有更高的酸中心密度、B酸中心比例和强酸中心比重,优化了沸石ZSM-5的脱硅降解处理条件。Na_(2)SiO_(3)体系在硅铝沸石脱硅降解时具有缓冲效应。
ZSM-5 zeolite was mainly desilicated with alkalescent Na_(2)SiO_(3)solution as medium.ZM molecular sieve with ZSM-5 structural units in the pore walls was hydrothermally synthesized by processing of zeolite from its original structure unit in the removal of silicon species and Na_(2)SiO_(3)silicon as silicon source,together with hexadecyl trimethyl ammonium bromide(CTAB)as template agent of synthetic zeolite molecular sieves in the weak alkaline environment,and the alkali treated ZM zeolite was characterized by X-ray diffraction(XRD),ammonia temperature programmed desorption(NH3-TPD),scanning electron microscopy(SEM)and transmission electron microscope(TEM).The results showed that The alkali treated ZSM-5 zeolite had a regular one-dimensional hexagonal mesoporous structure similar to MCM-41,and hah higher acid center density,B acid center ratio and strong acid center ratio.The desilication degradation conditions of ZSM-5 zeolite were optimized.The Na_(2)SiO_(3)system had buffer effect in the desilication of aluminosilicate zeolites.
作者
吕浩东
蒙亮亮
邹洁
于海涛
徐睿
王伟
LYU Hao-dong;MENG Liang-liang;ZOU Jie;YU Hai-tao;XV Rui;WANG Wei(Yinchuan University of Energy,Yinchuan Ningxia 750105,China)
出处
《当代化工》
CAS
2023年第1期56-61,共6页
Contemporary Chemical Industry
基金
宁夏重点研发计划项目(项目编号:2018YBZD0763)
宁夏高校科研项目资助(项目编号:NGY2020122)
国家大学生创新创业训练计划项目(项目编号:202013820001)。
