The Cu Promoter in an Iron−Chromium−Oxide Based Water−Gas Shift Catalyst under Industrial Conditions Studied by in-Situ XAFS
| Autor: | Fernando Morales Cano, Ton V. W. Janssens, Anna Puig-Molina |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
X-ray absorption spectroscopy
Aqueous solution Absorption spectroscopy Inorganic chemistry Iron oxide Water-gas shift reaction Surfaces Coatings and Films Electronic Optical and Magnetic Materials Catalysis X-ray absorption fine structure Metal chemistry.chemical_compound General Energy chemistry visual_art visual_art.visual_art_medium Physical and Theoretical Chemistry |
| Zdroj: | The Journal of Physical Chemistry C. 114:15410-15416 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/jp1035103 |
| Popis: | The chemical state of the Cu promoter (1 wt %) in a Cu-promoted Cr-stabilized iron oxide based water−gas shift catalyst has been studied by in-situ X-ray absorption fine structure (XAFS) at 380 °C and elevated pressures, which is close to the conditions typically applied in industrial processes. The Cu promoter enhances the activity of the catalyst. In this study, the catalyst has been studied as fresh, after use for 2000 h, and after a further wash with an aqueous solution of ammonia. In all three cases, CuO and CuFe2O4-like phases are present; the used catalyst also contains some metallic Cu. X-ray absorption spectroscopy (XAS) shows that upon exposure to a typical feed gas for high-temperature shift containing CO, CO2, H2, and water, both the CuO and the CuFe2O4-phases are reduced to metallic Cu at 250 °C; Cr is present as Cr3+ and is slowly incorporated in the Fe3O4 matrix upon further heating to 380 °C and pressurizing to 12 or 24 bar. Washing a used catalyst with an aqueous solution of ammonia prima... |
| Databáze: | OpenAIRE |
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