Evolution of Zn Species on Zn/HZSM‐5 Catalyst under H2 Pretreated and its Effect on Ethylene Aromatization,ChemCatChem

当前位置： X-MOL 学术 › ChemCatChem › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Evolution of Zn Species on Zn/HZSM‐5 Catalyst under H2 Pretreated and its Effect on Ethylene Aromatization
ChemCatChem ( IF 3.8 ) Pub Date : 2019-07-18 , DOI: 10.1002/cctc.201900596
Jie Gao _{1,

2} , Chunlei Wei ₁ , Mei Dong ₁ , Guofu Wang ₁ , Zhikai Li ₁ , Zhangfeng Qin ₁ , Jianguo Wang _{1,

2} , Weibin Fan ₁

Affiliation

Aromatization reaction is of importance in producing aromatics, accompanied by the generation of abundant H₂, which may influence the reaction by interacting with the catalyst. In this work, Zn‐containing ZSM‐5 prepared by impregnation was treated in H₂ atmosphere at different temperatures, and the evolution in structure, acidity, and Zn species distribution were studied. The catalyst's performance in ethylene aromatization was also evaluated. The results show that the H₂ atmosphere enabled the reconstruction of ZnO microparticles and the reformation of Brønsted acid sites on Zn/HZSM‐5 below 200 °C. At an elevated temperature (300 °C), Zn⁺ species were produced by the reduction of [ZnOZn]²⁺ as confirmed by in‐situ Zn K‐edge extended X‐ray absorption fine structure (EXAFS) study and density functional theory (DFT) calculation. After H₂ pretreatment at 300 °C, the increase in the amount of ZnOH⁺ species increased the selectivity of Zn‐containing ZSM‐5 for aromatics from 62 % to 67 %.

中文翻译：

氢气预处理下Zn / HZSM-5催化剂上锌形态的演变及其对乙烯芳构化的影响

芳香化反应在产生芳族化合物中很重要，并伴有大量H ₂的生成，而H ₂可能通过与催化剂相互作用而影响反应。在这项工作中，将通过浸渍制备的含锌ZSM-5在H ₂气氛中于不同温度下进行了处理，并研究了其结构，酸度和锌物种分布的演变。还评估了催化剂在乙烯芳构化中的性能。结果表明，在200°C以下，H ₂气氛使ZnO微粒得以重建，并且Zn / HZSM-5上的Brønsted酸位得以重新形成。在高温（300°C）下，通过还原[ZnOZn] ²⁺产生了Zn ⁺物种。如原位Zn K边缘扩展X射线吸收精细结构（EXAFS）研究和密度泛函理论（DFT）计算所证实。在300°C下进行H ₂预处理后，ZnOH ⁺物种数量的增加将含锌的ZSM-5对芳烃的选择性从62％提高到67％。

更新日期：2019-07-18

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南