HZSM-5 zeolites undergoing the high-temperature process for boosting the bimolecular reaction in n-heptane catalytic cracking  

作　　者：Chenggong Song Zhenzhou Ma Xu Hou Hao Zhou Huimin Qiao Changchang Tian Li Yin Baitang Jin Enxian Yuan 

机构地区：[1]School of Chemical Engineering,Changchun University of Technology,Changchun,130012,China [2]Department of Chemical and Biomolecular Engineering,North Carolina State University,Raleigh,NC 27606,USA [3]School of Chemistry and Chemical Engineering,Yangzhou University,Yangzhou,225009,China

出　　处：《Chinese Journal of Chemical Engineering》2024年第2期136-144,共9页中国化学工程学报（英文版）

基　　金：the financial support from the National Natural Science Foundation of China(21908010);Jilin Provincial Department of Science and Technology(20220101089JC);the Education Department of Jilin Province(JJKH20220694KJ)。

摘　　要：High-temperature treatment is key to the preparation of zeolite catalysts.Herein,the effects of hightemperature treatment on the property and performance of HZSM-5 zeolites were studied in this work.X-Ray diffraction,N2physisorption,27Al magic angle spinning nuclear magnetic resonance(MAS NMR),and temperature-programmed desorption of ammonia results indicated that the hightemperature treatment at 650℃ hardly affected the inherent crystal and texture of HZSM-5zeolites but facilitated the conversion of framework Al to extra-framework Al,reducing the acid site and enhancing the acid strength.Moreover,the high-temperature treatment improved the performance of HZSM-5 zeolites in n-heptane catalytic cracking,promoting the conversion and light olefins yield while inhibiting coke formation.Based on the kinetic and mechanism analysis,the improvement of HZSM-5 performance caused by high-temperature treatment has been attributed to the formation of extra-framework Al,which enhanced the acid strength,facilitated the bimolecular reaction,and promoted the entropy change to overcome a higher energy barrier in n-heptane catalytic cracking.

关 键 词：HZSM-5 N-HEPTANE Catalytic cracking High-temperature treatment Extra-framework Al 

分 类 号：TE624.41[石油与天然气工程—油气加工工程]