摘要
分别以铝酸钠、异丙醇铝、硫酸铝、硝酸铝、氯化铝为铝源,采用水热法合成一系列HZSM-5分子筛,并将其应用于甲醇和正己烷耦合裂解反应中.运用X射线衍射(XRD)、扫描电镜(SEM)、氨程序升温脱附(NH 3-TPD)、N 2吸附脱附和热重(TG)分析等方法对分子筛进行表征,研究不同铝源对HZSM-5分子筛物理化学性质的影响.结果表明:不同铝源合成的HZSM-5分子筛在酸性、晶粒大小及孔道结构等方面存在较大差异;丰富的介孔、适中的酸量有利于提高正己烷的转化率、低碳烯烃的选择性以及催化剂的稳定性.其中,以铝酸钠为铝源合成的HZSM-5分子筛在甲醇和正己烷耦合裂解反应中呈现较好的催化性能,反应8 h内正己烷平均转化率达92.93%,低碳烯烃平均选择性为60.28%,具有较强的抗积碳能力.
Using sodium aluminate,aluminum isopropanol,aluminum sulfate,aluminum nitrate,and aluminum chloride as aluminum sources,a series of HZSM-5 zeolites were synthesized with a hydrothermal method,and applied to the coupled cracking reaction of n-hexane with methanol.The zeolites were characterized with X-ray diffraction(XRD),scanning electron microscopy(SEM),NH 3 temperature-programed desorption(NH 3-TPD),and N 2 adsorption-desorption and thermal gravimetric(TG)analysis to investigate the influence of aluminum sources on the physical and chemical properties.The results showed that different aluminum sources resulted in various acidity property,crystalline size,and porous structure of HZSM-5 zeolite;abundant mesopores and moderate amount of acid were beneficial to enhancing the conversion fraction of n-hexane,selectivity of light olefins,and stability of catalyst.Among the HZSM-5 zeolites,the one synthesized with sodium aluminate presented superior catalytic performance with the average conversion fraction of n-hexane of 92.93%and light olefins average selectivity of 60.28%within 8 h reaction time,and showed strong anti-carbon deposition ability in the coupled cracking reaction of n-hexane with methanol.
作者
董焕能
徐显明
代跃利
汲永刚
张永军
王叶霏
连奕新
DONG Huanneng;XU Xianming;DAI Yueli;JI Yonggang;ZHANG Yongjun;WANG Yefei;LIAN Yixin(National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361102,China;Daqing Petrochemical Research Center,PetroChina Company Limited,Daqing 163000,China)
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2022年第5期823-830,共8页
Journal of Xiamen University：Natural Science
关键词
铝源
HZSM-5分子筛
酸量
多级孔
低碳烯烃
aluminum source
HZSM-5 zeolite
acid amount
hierarchical pore
light olefin
