Structure sensitivity of the methanation reaction : H2-induced CO dissociation on nickel surfaces
The dissociation of CO serves both as a model test reaction on single crystals and as a relevant reaction step for industrial methanation. We combined extensive density functional theory calculations, ultra-high vacuum experiments on well-defined single crystals, and catalytic activity measurements...
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Veröffentlicht in: | Journal of catalysis 2008-04, Vol.255 (1), p.6-19 |
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Hauptverfasser: | , , , , , , , , , , , , |
Format: | Artikel |
Sprache: | eng |
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Online-Zugang: | Volltext |
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Zusammenfassung: | The dissociation of CO serves both as a model test reaction on single crystals and as a relevant reaction step for industrial methanation. We combined extensive density functional theory calculations, ultra-high vacuum experiments on well-defined single crystals, and catalytic activity measurements on supported catalysts in a study of the dissociation mechanism of CO on Ni surfaces. We found that this process is highly structure-sensitive and also is sensitive to the presence of hydrogen: Under ultra-high vacuum, with no hydrogen present, the dissociation proceeds through a direct route in which only undercoordinated sites (e.g., steps) are active. Under methanation conditions, the dissociation also proceeds most favorably over undercoordinated sites, but through a COH species. [PUBLICATION ABSTRACT] |
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ISSN: | 0021-9517 1090-2694 |
DOI: | 10.1016/j.jcat.2007.12.016 |