Hydrodesulfurization properties of rhodium phosphide: Comparison with rhodium metal and sulfide catalysts

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• 作者：John R. Hayes ; Richard H. Bowker ; Amy F. Gaudette ; Mica C. Smith ; Cameron E. Moak ; Charles Y. Nam ; Thomas K. Pratum ; Mark E. Bussell
• 关键词：Hydrodesulfurization ; HDS ; Dibenzothiophene ; Rhodium ; Rhodium phosphide
• 刊名：Journal of Catalysis
• 出版年：2010
• 出版时间：15 December 2010
• 年：2010
• 卷：276
• 期：2
• 页码：249-258
• 全文大小：982 K

文摘

Silica-supported rhodium phosphide (Rh₂P/SiO₂) catalysts were prepared and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ³¹P solid-state NMR spectroscopy, X-ray photoelectron spectroscopy (XPS), and chemisorption measurements. XRD and TEM analysis of a 5 wt. % Rh₂P/SiO₂ catalyst confirmed the presence of well-dispersed Rh₂P crystallites on the silica support having an average crystallite size of 10 nm. NMR spectroscopy showed unsupported and silica-supported Rh₂P to be metallic and XPS spectroscopy yielded a surface composition of Rh_1.94P_1.00 that is similar to that expected from the bulk stoichiometry. The 5 wt. % Rh₂P/SiO₂ catalyst exhibited a higher dibenzothiophene (DBT) hydrodesulfurization (HDS) activity than did Rh/SiO₂ and sulfided Rh/SiO₂ catalysts having a similar Rh loading and was also more active than a commercial NiMo/Al₂O₃ catalyst. The Rh₂P/SiO₂ catalyst showed excellent stability over a 100 h DBT HDS activity measurement and was more S tolerant than the Rh/SiO₂ catalyst. The Rh₂P/SiO₂ catalyst strongly favored the hydrogenation pathway for DBT HDS, while the Rh/SiO₂ and sulfided Rh/SiO₂ catalysts favored the direct desulfurization pathway.