摘要
纳米团聚体ZSM-5因具有较高的活性及水热稳定性而被广泛用于催化剂的制备。以水玻璃为硅源、硫酸铝为铝源、正丁胺为模板剂,合成低硅铝比纳米团聚体ZSM-5分子筛。考察了钠硅比、陈化时间、晶种添加量等因素对合成分子筛形貌和晶粒尺寸的影响。采用X射线衍射(XRD)、扫描电镜(SEM)、氮气物理吸附、透射电镜(TEM)和X射线荧光光谱仪(XRF)等手段对样品进行了物性分析。结果表明:钠硅比(氧化钠与二氧化硅物质的量比)大于0.11可以合成出结晶度较好的ZSM-5分子筛,当钠硅比大于0.13时ZSM-5晶粒增大;延长陈化时间有助于降低分子筛的晶粒尺寸,提高晶粒尺寸的均一度,陈化12 h时晶体的平均尺寸约为160 nm;晶种添加量为3%~4%(按总二氧化硅质量计算)时,对样品晶粒尺寸及均匀度的影响较小。
Nano-sized ZSM-5 aggregates are widely used in preparing catalyst because of the higher reactivity and hydrothermal stability.The nano-sized ZSM-5 aggregates with low Si/Al ratio were prepared by hydrothermal synthesis using sodium silicate as silica source,aluminum sulfate as aluminum source and n-butylamine as template.The effect of Na2O/SiO2 ratio,aging time and seed addition amount on the morphology and grain size of the synthesized zeolite were investigated.The sample was analyzed by the means of powder X-ray diffraction,scanning-electron microscopy,N2 adsorption and desorption,transmission electron microscopy and X-ray fluorescence.The results showed that zeolites with good crystallinity can be synthesized at the amount-of-substance of Na2O/SiO2 greater than 0.11,however,when the n(Na2O)/n(SiO2)>0.13,the zeolite crystal size increased.In addition,when the aging time extended,the zeolites crystal particle and uniformity increased,and the average crystal size was approximately 160 nm at aging time of 12 h.There was nearly no effect of seed addition amount(3%~4%)on the crystal size and uniformity of the sample.
作者
常洋
李孝国
侯章贵
米晓彤
尉琳琳
Chang Yang;Li Xiaoguo;Hou Zhanggui;Mi Xiaotong;Wei Linlin(CNOOC Research Institute of Refining and Petrochemicals,Beijing 102209,China)
出处
《无机盐工业》
CAS
CSCD
北大核心
2020年第6期92-95,共4页
Inorganic Chemicals Industry
基金
中国海洋石油集团有限公司课题(CNOOC-KJ 135 FZDXM 00 LH 002 YJY-2017)。
