Preparation of electron-rich Fe-based catalyst via electronic structure regulation and its promotion to hydrodesulfurization of dibenzothiophene

• Published in: Applied catalysis. B, Environmental Environmental, 2020-07, Vol.269, p.118779, Article 118779
• Main Authors: Liu, Xuandong, Liu, Jinjia, Li, Lei, Zhang, Xinyue, Sun, Houxiang, Guo, Rong, Ren, Shenyong, Guo, Qiaoxia, Wen, Xiao-Dong, Shen, Baojian
• Format: Article
• Language: English
• Subjects: Acidity; Bimetals; Bonding strength; Catalysts; CeO2-x; Cerium oxides; Dibenzothiophene; Electronic structure; Electronic structure regulation; Electrons; Fe-based catalysts; Hydrodesulfurization; Industrial applications; Iron; Lewis acid; Pyrrhotite; Species; Sphalerite; Sulfidation; Sulfur; Sulfur removal; Zincblende
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2020.118779

[Display omitted] •CeO2-x makes Fe-S/FeZn-S bonds weaker and facilitates the formation of sulfur vacancies or coordinatively unsaturated sites.•Weak Fe-O bonds caused by CeO2-x result in high sulfidation degree of Fe/FeZn sulfide catalysts.•Higher dispersion of Fe species is achieved by the anchoring effect due to the strong EMSI.•The main active phases of pure Fe-based and FeZn bimetallic catalysts are Fe1-xS and FeZnS, respectively.•Better HDS brought by CeO2-x are attributed to electron-rich Fe species but not the variation of acidity. In this work, the sulfur removal rates of CeO2-x modified Fe/FeZn catalysts are increased by 5 %–20 %, attributed to the electron-rich Fe species but not the variation of acidity. The main active phases of pure Fe-based and FeZn bimetallic catalysts are pyrrhotite (Fe1-xS) and ferroan sphalerite (FeZnS), respectively. The results of characterizations and DFT calculations show that strong electron-donating effect of CeO2-x on Fe species can promote the dispersion of Fe species and weaken the Fe-O and Fe-S/FeZn-S bonds, resulting in higher sulfidation degrees and more active sites of Fe/FeZn catalysts. Besides, weak Al−OH peaks caused by CeO2-x could also increase the sulfidation degrees of Fe/FeZn catalysts. Furthermore, HYD/DDS ratios of Fe-based catalysts are reduced by CeO2-x because of the electron-rich Fe species and decrease of Lewis acid sites. This promising work has great potential for the industrial application of environmentally friendly and economical Fe-based catalysts in HDS field.