材料科学
开裂
ZSM-5型
催化作用
复合材料
烯烃纤维
乙烯
微晶
化学工程
沸石
化学
有机化学
聚合物
冶金
工程类
作者
Lei Han,Ruoyu Wang,Peng Wang,Yuchen Sha,Aiguo Zheng,Qiuqiao Jiang,Mudi Xin,Haitao Song,Wei Lin
出处
期刊:Fuel
[Elsevier]
日期:2023-06-01
卷期号:341: 127688-127688
标识
DOI:10.1016/j.fuel.2023.127688
摘要
Featuring engineerable reaction pathway, ordered hierarchical cracking over core–shell structured zeolites ([email protected]) plays a pivotal role in achieving the high-efficient conversion of low-value oil fractions into important petrochemical building blocks such as ethylene and propylene. However, the synthesis of [email protected] zeolite composites with specific desirable textures is technically challenging. Herein, a novel embryo seed-breeding (ESB) approach was developed to synthesize polycrystalline [email protected] core–shell composites ([email protected]) for boosted light olefin production. For the first time, [email protected] composites composed of a polycrystalline ZSM-5 core and a submicron-sized Beta shell was reported, which shows enhanced inner-diffusion properties and improved hydrothermal stabilities than that of conventional [email protected] composites. In [email protected]B-catalyzed reations, bulky molecules undergone a preliminary cracking into intermediate products within the Beta shell, followed by the direct diffusion into the micropores of the ZSM-5 core where they could be cracked selectively into ethylene and propylene. Compared with physically mixed zeolites and hierarchical ZSM-5, [email protected] composites showed the highest conversion and yield of ethylene and propylene in the cracking reaction of both decalin and practical industrial heavy oil. The superior catalytic activity of [email protected] can be attributed to the high accessibility of acid sites and the ordered hierarchical cracking space derived from the core–shell structure.
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