文献类型：期刊文献

英文题名：Surface Si decoration of ultrafine NaFeMn-Si catalyst enabling high Fe-phase electron density for effectively converting syngas to aromatics

作者：Li, Minzhe[1,2];Zhang, Zhen[2];Song, Guiyao[1];Nawaz, Muhammad Asif[1];Wang, Zihao[1];Chen, Zhongwei[2];Liu, Dianhua[1]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Univ Waterloo, Waterloo Inst Sustainable Energy, Waterloo Inst Nanotechnol, Dept Chem Engn, Waterloo, ON N2L 3G1, Canada

年份：2022

卷号：433

外文期刊名：CHEMICAL ENGINEERING JOURNAL

收录：;EI(收录号：20220411516247);WOS:【SCI-EXPANDED(收录号:WOS:000790216600007)】；

基金：Acknowledgment This work was supported by the National Key R&D Program of China (2017YFB0602204) .

语种：英文

外文关键词：Syngas to aromatics; Fe-based composite catalyst; Ultrafine crystal; Surface Si decoration; Electron density

摘要：Effectively converting syngas to aromatics attracts widespread attention for its potential value in alleviating the scarcity of oil resources, while the promising catalysts composited with Fe-based oxides and zeolites are typically plagued by lower aromatics selectivity. Herein, ultrafine NaFeMn-Si catalyst is designed via the surface deco-ration of SiO2-Na2SiO3 on the crystal surface by a unique post-modification strategy. Experiments and calcula-tions demonstrate that surface decoration of Si reduces the NaFeMn-Si crystal size to 6.7 nm by potently preventing agglomeration, which greatly enlarges the active surface area to promote the catalytic activity. Moreover, the in situ formed surface Na2SiO3, which is converted from Na2O under the synergism between Si and Na species, remarkably weakens binding force of -SiO3 in comparison with -O bond. Thereby, the electron delocalization of Na is enhanced by releasing the outer electron to Fe, significantly increasing the electron density of Fe phase. This elaborate modification strategy effectively modulates the adsorption and dissociation of H-2 and CO molecules, which facilitates the formation of iron carbide as the active center, not only improving the intermediary olefin/paraffin ratio to achieve a superior catalytic performance of 64% aromatic selectivity with 90% CO conversion, but also providing an appealing and instructive design guidance for the aromatics synthesis over Fe-based composite catalysts.