Stability Enhancement of ZSM-5 Zeolite in Olefin Aromatization by Alkali Treatment:Comparison of Medium

• 作者: Chen Xiaobo An Zhiyuan Zhu Chao Yan Hao Liu Yibin Feng Xiang Jin Xin Yang Chaohe
• 来源期刊: 中国炼油与石油化工（英文版）
• 年，卷（期）: 2020,（4）
• 所属期刊栏目: Catalyst Research
• 页码范围: 63-72
• 页数: 10页
• 语种: 英文

摘要

ZSM-5 zeolite samples with a SiO2/Al203 ratio of 40 were synthesized by a hydrothermal method,and treated by 0.3 M tetrapropyl ammonium hydroxide(TPAOH)and 0.3 M sodium hydroxide(NaOH)solution separately to create hollow structures.The synthesized ZSM-5 zeolite and treated ZSM-5 zeolite samples were evaluated for aromatization of 1-hexene in a continuous flow reactor.The prepared ZSM-5 zeolite samples were characterized by XRD,SEM,TEM,NMR,XPS,and other analyses.The results showed that the alkali treatment formed mesopores and hollow structures in the ZSM-5 crystals without destroying the topological structure.The acid amount of ZSM-5 zeolite was also increased after alkali treatment.Compared with the ZSM-5 zeolite treated by TPAOH,the ZSM-5 zeolite treated by NaOH had more mesopores and a higher total acid amount but a lower strong acid amount,resulting in higher aromatics yields and catalytic stability for 1-hexene aromatization.The characterization of spent ZSM-5 zeolites suggested that the spent treated ZSM-5 zeolites contained less coke,leading to a smaller reduction of micropore surface area and volume than in the spent parent ZSM-5,which contributed to the stability enhancement.