Novel hydrodesulfurization catalysts derived from a rhodium carbonyl complex
| Autor: | Yuji Oomori, Jeayoung Lee, Franck Dumeignil, Atsushi Ishihara, Eika W. Qian, Kou Miyazaki, Toshiaki Kabe |
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| Rok vydání: | 2004 |
| Předmět: |
Process Chemistry and Technology
Inorganic chemistry chemistry.chemical_element Heterogeneous catalysis Sulfur Catalysis Rhodium Metal chemistry.chemical_compound Reaction rate constant chemistry Dibenzothiophene visual_art visual_art.visual_art_medium Physical and Theoretical Chemistry Hydrodesulfurization |
| Zdroj: | Journal of Molecular Catalysis A: Chemical. 209:155-162 |
| ISSN: | 1381-1169 |
| Popis: | The first part of this work aimed at optimizing Rh based HDS catalysts by modification of the precursor nature as well as the selection of an adequate pre-activation method. Further, the combination of the Rh catalysts with Ru catalysts was also investigated. Although no obvious synergetic effect was observed, the combined Rh-Ru catalysts exhibited higher activities than the single metal-based ones. Among all the prepared catalysts, the RhCs/Al2O3 catalysts prepared from the rhodium carbonyl precursor with a ratio Rh/Cs=1–2 exhibited the most interesting catalytic performance. The effect of the Rh loading on the activity of these catalysts was studied. An increase in activity was observed when the Rh loading increased up to 0.5 wt.% but further Rh addition did not lead to any noticeable effect on the catalytic performance. Whilst the prepared catalysts exhibited a gross activity inferior to that of a classical CoMo system, their specific activity calculated per mole of metal was considerably higher than the one obtained for the latter conventional system. Furthermore, the conversion of the 4 wt.% Rh catalyst was about twice as high as the one of a 4 wt.% Ru catalyst. Therefore, in order to elucidate the interesting catalytic properties of such Rh based catalysts, 35 S radioactive tracer DBT HDS experiments were performed. We found that for 4 wt.% Rh, kRE, the H2S release rate constant, was almost the same as the one obtained for the 4 wt.% Ru catalyst. However, S0 was significantly higher on the Rh catalyst than on the Ru catalyst (+70%). This indicated that the high activity was due to the formation of a great quantity of active sites (labile sulfur atoms). |
| Databáze: | OpenAIRE |
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