| Autor: |
Keith R. McCrea, John W. Logan, Wes W. C. Quigley, Paul A. Aegerter, Mark E. Bussell, Garth J. Simpson, David D. Ziegler, Samantha Glazier |
| Rok vydání: |
1996 |
| Předmět: |
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| Zdroj: |
Journal of Catalysis. 164:109-121 |
| ISSN: |
0021-9517 |
| Popis: |
Mo2C/Al2O3and Mo2N/Al2O3catalysts have been synthesized and characterized by X-ray diffraction, pulsed chemisorption (CO and O2) and infrared (IR) spectroscopy, and temperature programmed desorption (TPD) measurements. Thiophene hydrodesulfurization (HDS) activities were measured for alumina-supported Mo carbide and nitride catalysts as well as a sulfided Mo/Al2O3catalyst, all with a 10 wt% Mo loading. The HDS activities (μmol Th/mol Mo/s) of the catalysts after 24 h at 693 K were found to increase according to the trend sulfided Mo < γ-Mo2N < β-Mo2C, and provide further evidence that carbide and nitride catalysts have the potential to replace sulfided Mo catalysts in commercial HDS reactors. X-ray diffraction analysis of fresh and tested 30 wt% Mo2C/Al2O3and Mo2N/Al2O3catalysts indicates that the bulk structure of the carbide (β-Mo2C) and nitride (γ-Mo2N) particles is retained, while IR spectroscopy of adsorbed CO indicates that the surface of the carbide and nitride particles becomes sulfided under reaction conditions. A model is proposed for the structure of the active catalytic surface of the alumina-supported Mo carbide and nitride catalysts in which a thin layer of highly dispersed sulfided Mo is present on the surfaces of the carbide and nitride particles. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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