LI Duichun;XING Bin;LIU Hongyan;LIU Ping;WANG Baojun;LI Ruifeng;

• 1:College of Chemistry and Chemical Engineering
• 2:Taiyuan University of Technology
• 3:College of Chemistry and Chemical Engineering
• 4:Shanxi Datong University

Abstract：

In order to clarify the effect of molecular sieve on the catalytic activity and product selectivity of MTO reaction,density functional theory including dispersion correction( GGA-PBE-D2) has been employed to study the effect of acidic strength on the activity and selectivity of methanol-to-olefins( MTO) conversion over Fe,Co and Ni modified SAPO-34 zeolites.The relationship between acidic strength and catalytic activity of different Me APO-34 zeolites was discussed.The deprotonation energy was calculated to measure the acidic strength of different Me APO-34 zeolites,and the energy barrier and reaction heat of different MTO reaction steps over Me APO-34 zeolites were calculated to compare the activity and selectivity. Results show that the acidic strength order is Fe APO-34 > Co APO-34 > SAPO-34>Ni APO-34.The catalytic activity of ethylene formation is in order of Fe APO-34≈Ni APO-34>Co APO-34,and the catalytic activity order of propene formation is Fe APO-34≈Co APO-34>Ni APO-34.The introduced of Ni atoms into the SAPO-34 zeolite framework can enhance the selectivity towards ethylene compared with that of Fe and Co atoms,however,the introduced of Fe and Co atoms into the SAPO-34 zeolite framework has higher selectivity towards propene than that of Ni atom.

Key Words： Fe,Co and Ni modification;SAPO-34 zeolite;MTO reaction;density functional theory;Br■nsted acidic strength

Abstract:

Keywords:

Foundation: 山西省留学回国人员科研资助项目(2016-104)

Authors: LI Duichun;XING Bin;LIU Hongyan;LIU Ping;WANG Baojun;LI Ruifeng;

DOI: 10.13226/j.issn.1006-6772.18071302

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