Controllably tailoring external surface sites of nanosheet HZSM-5 for maximizing light olefins in catalytic cracking of n-decane  

作　　者：Tiantian Zhu Hairui Liang Bofeng Zhang Yajie Tian Guozhu Liu 

机构地区：[1]Key Laboratory for Green Chemical Technology of Ministry of Education,School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China [2]Henan Province Engineering Research Center of Catalytic Reaction,College of Chemistry and Chemical Engineering,Henan University,Kaifeng 475004,China

出　　处：《Chinese Journal of Chemical Engineering》2021年第10期276-285,共10页中国化学工程学报（英文版）

基　　金：Financial supports by the National Natural Science Foundation of China(21776210 and 22008055)。

摘　　要：A series of triphenylethoxysilane(TPEOS)-modified nanosheet HZSM-5 catalysts(ZN-x,x=4%,8%and16%,mass)were synthesized by chemical liquid deposition to selectively change external acidity distributions.TPEOS modification was found to passivate some external Br?nsted and Lewis acid sites by37.8%,in which Br?nsted acid sites(BAS)were found more easily sacrificed by breaking the surface Al AO bond of bridging hydroxyl groups and forming Si AOASi bonds.The selectivity of ZN-8 catalyst for light olefins(ethylene,propylene and butene)in n-decane catalytic cracking is up to 26%(450℃,WHSV=10.95 h^(-1)),which is ca.78%higher than that of parent one.The better performance was attributed to the appropriate external acid density in ZN-8,which inhibits bimolecular hydrogen transfer reaction of light olefins on the adjacent acid sites,resulting in more olefins,few coke precursors and thus an excellent catalytic stability.

关 键 词：Nanosheet HZSM-5 Acid properties Surface modification Catalysis DEACTIVATION FIXED-BED 

分 类 号：TQ221.2[化学工程—有机化工] TQ426[一般工业技术—材料科学与工程] TB383.1