XANES study of Li-MgO and Li-La2O3-MgO catalysts for oxidative coupling of methane
To characterize the defect sites in the near-surface and bulk phase of Li-MgO and Li-La2O3-MgO, XANES at Mg K-edge and La L3-edge was applied. For Li-MgO, it can be suggested that Li doping at a low content (2.5 wt%) brings about the formation of defect species only in the near-surface. This is due...
| Veröffentlicht in: | Journal of synchrotron radiation. - 1994. - 8(2001), Pt 2 vom: 01. März, Seite 593-5 |
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| Weitere Verfasser: | , , , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2001
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| Zugriff auf das übergeordnete Werk: | Journal of synchrotron radiation |
| Schlagworte: | Journal Article |
| Zusammenfassung: | To characterize the defect sites in the near-surface and bulk phase of Li-MgO and Li-La2O3-MgO, XANES at Mg K-edge and La L3-edge was applied. For Li-MgO, it can be suggested that Li doping at a low content (2.5 wt%) brings about the formation of defect species only in the near-surface. This is due to the localization of doped Li ions in the surface, and thus the catalytically active species containing [Li+ O-] type center exist in the surface region. After OCM reaction, the detect species are formed in the near-surface over MgO and Li-MgO. By addition of La2O3 to Li-MgO (La/(Mg+La)=0.25), the structural change during the reaction is almost suppressed in the surface. In addition, the Li-La2O3-MgO shows higher C2 selectivity than Li-MgO |
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| Beschreibung: | Date Completed 06.09.2001 Date Revised 05.06.2019 published: Print Citation Status PubMed-not-MEDLINE |
| ISSN: | 1600-5775 |