HZSM-5沸石酸性及孔道空间大小调控对丙烷芳构化活性和产物选择性的影响  

Influence of Acidity and Pore Space Regulation of HZSM-5 Zeolite on Propane Aromatization Activity and Product Selectivity

作　　者：马跃[1] 黄羚翔 檀宇航 安海涛 张强[1] 曾鹏晖[1] 朱小春 申宝剑[1] MA Yue;HUANG Lingxiang;TAN Yuhang;AN Haitao;ZHANG Qiang;ZENG Penghui;ZHU Xiaochun;SHEN Baojian(State Key Laboratory of Heavy Oil Processing,College of Chemical Engineering and Environment,China University of Petroleum,Beijing 102249,China)

机构地区：[1]中国石油大学(北京)化学工程与环境学院,重质油全国重点实验室,北京102249

出　　处：《分子催化(中英文)》2025年第2期141-153,I0002,I0003,共15页Journal of Molecular Catalysis(China)

基　　金：国家自然科学基金创新研究群体项目(22021004);国家自然科学基金面上项目(21776304)。

摘　　要：轻烃芳构化产物选择性调控是芳构化催化剂研究的热点和难点.本文以Mg为调控元素考察了HZSM-5沸石酸性及孔道空间大小调控对丙烷芳构化产物选择性的影响.分别采用沸石骨架改性和初湿浸渍法改性法制备了Mg@ZSM-5和Mg/ZSM-5样品并用作丙烷芳构化催化剂.结果表明,Mg物种的不同改性方式对其Mg分布、酸性和孔结构方面产生较大影响.原位合成引入Mg物种后Mg物种均匀分布在催化剂中,Mg@ZSM-5沸石的总酸、B和L酸含量与未改性的HZSM-5比均上升,但是B/L值会显著降低.浸渍法制备的Mg/ZSM-5样品MgO以表面和浅层分布为主,与未改性HZSM-5相比,消除大量B酸位点,同时有效增加了L酸位点分布,整体酸量保持不变.两种含Mg沸石的总孔体积较HZSM-5样品相比均有所下降,孔体积下降使得芳烃产物分布中提升了BTX选择性.沸石B/L值的下降是导致丙烷转化率下降的原因.该酸性的变化还导致与HZSM-5比,Mg@ZSM-5和Mg/ZSM-5催化丙烷芳构化反应时,丙烷的活化温度和芳烃的生成温度均有明显提升.Selective regulation of light hydrocarbon aromatization products is a hot and difficult topic in the research of aromatization catalysts.This article investigates the effects of acidity and pore space control on the selectivity of propane aromatization products in HZSM-5 zeolite using Mg as a regulating element.The samples were prepared by using zeolite framework modification and incipient wetness impregnation methods,respectively,Mg@ZSM-5 and Mg/ZSM-5 samples were obtained and used as a catalyst for propane aromatization.The results indicate that different modification methods have a significant impact on their Mg distribution,acidity,and pore structure.After introducing Mg species through in-situ synthesis,the Mg species were uniformly distributed in the catalyst,the total acid,B and L acid content of Mg@ZSM-5 zeolite increased compared to unmodified HZSM-5,but the B/L value significantly decreased.The Mg/ZSM-5 sample prepared by impregnation method mainly has surface and shallow distribution of MgO,compared with unmodified HZSM-5,it eliminates a large number of B acid sites and effectively increases the amount of L acid sites,while the overall acid content remains unchanged.It is found that total pore volume of both Mg containing zeolites decreased compared to the HZSM-5 sample,and the decrease in pore volume improved the BTX selectivity in the distribution of aromatic products.The results also indicate that the decrease in zeolite B/L ratio is the reason for the decrease in propane conversion rate.The change in acidity also leads an obvious change to the aromatization reaction temperature,compared with HZSM-5,both the propane activation temperature and aromatization temperature of Mg@ZSM-5 and Mg/ZSM-5 increased.

关 键 词：丙烷芳构化 BTX选择性 孔体积 B/L值 Mg改性沸石 

分 类 号：O643.36[理学—物理化学]