Structure Investigation and Dibenzothiophene Hydrodesulfurization Properties of Fe-Substituted Ni–Si Intermetallics

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• 作者：Xiao Chen ; Junhu Wang ; Kaixuan Yang ; Changgong Meng ; Christopher T. Williams ; Changhai Liang
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：December 31, 2015
• 年：2015
• 卷：119
• 期：52
• 页码：29052-29061
• 全文大小：670K
• ISSN：1932-7455

文摘

Development of highly active and sulfur-tolerant catalysts for deep hydrodesulfurization (HDS) is of great importance in petroleum refining. Here, the discovery of Fe-substituted Ni–Si intermetallic catalysts (Ni_1–xFe_xSi₂) that efficiently removes dibenzothiophene (DBT) by HDS is reported. The structure of the catalyst was identified through X-ray diffraction, M?ssbauer spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results showed that Fe atoms substituted Ni atoms in Ni_1–xFe_xSi₂ catalysts, which preferentially bond with Ni to form alloy and combine with Si to form silicide. The DBT activity for the Ni_1–xFe_xSi₂ has the following order: Ni_0.75Fe_0.25Si₂ > NiSi₂ > Ni_0.50Fe_0.50Si₂ ≈ Ni_0.25Fe_0.75Si₂ ≈ Fe–Si. The positive synergistic effect on HDS activity can be correlated to that the formation of Ni–Fe and Fe–Si bonds makes the metal site to have high d-electron density, which promotes the hydrogenation activity. Comparison with the fresh and spent catalysts revealed the stability and sulfur resistance of these catalysts. The present findings suggest that Fe-substituted Ni–Si intermetallics catalysts provide a good starting point for a new catalyst development in the HDS field.