- Treffer 1 von 1
Zitieren Sie bitte immer diesen URN: urn:nbn:de:kobv:b43-474793
Identifying the location of Cu ions in nanostructured SAPO-5 molecular sieves and its impact on the redox properties
- Combining X-ray Absorption Fine Spectroscopy (XAFS) with Anomalous Small-Angle X-ray Scattering (ASAXS) determines the location of Cu2+ ions in silicoaluminophosphate (SAPO-5) frameworks prepared by hydrothermal crystallization or impregnation. As expected, for the hydrothermally prepared sample, incorporation in the SAPO-5 framework was observed. For the first time preferential location of Cu2+ ions at the inner and outer surfaces of the framework is determined. Temperature-Programmed Reduction (TPR) and X-ray Photoelectron Spectroscopy (XPS) investigations demonstrated that such Cu2+ is stable in an argon (Ar) atmosphere up to 550 °C and can only be reduced under a hydrogen atmosphere. In contrast, Cu2+ deposited by impregnation on the pure SAPO-5 framework can be easily reduced to Cu+ in an Ar atmosphere. At lower Cu amounts, mononuclear tetrahedrally coordinated Cu species were formed which are relatively stable in the monovalent form. In contrast, at higher Cu amounts, CuOCombining X-ray Absorption Fine Spectroscopy (XAFS) with Anomalous Small-Angle X-ray Scattering (ASAXS) determines the location of Cu2+ ions in silicoaluminophosphate (SAPO-5) frameworks prepared by hydrothermal crystallization or impregnation. As expected, for the hydrothermally prepared sample, incorporation in the SAPO-5 framework was observed. For the first time preferential location of Cu2+ ions at the inner and outer surfaces of the framework is determined. Temperature-Programmed Reduction (TPR) and X-ray Photoelectron Spectroscopy (XPS) investigations demonstrated that such Cu2+ is stable in an argon (Ar) atmosphere up to 550 °C and can only be reduced under a hydrogen atmosphere. In contrast, Cu2+ deposited by impregnation on the pure SAPO-5 framework can be easily reduced to Cu+ in an Ar atmosphere. At lower Cu amounts, mononuclear tetrahedrally coordinated Cu species were formed which are relatively stable in the monovalent form. In contrast, at higher Cu amounts, CuO particles were found which change easily between the mono- and bivalent species.…
Autor*innen: | Jörg RadnikORCiD, T. T. H. Dang, S. Gatla, V. S. Raghuwanshi, D. Tatchev, A. Hoell |
---|---|
Dokumenttyp: | Zeitschriftenartikel |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | RSC Advances |
Jahr der Erstveröffentlichung: | 2019 |
Organisationseinheit der BAM: | 6 Materialchemie |
6 Materialchemie / 6.1 Oberflächen- und Dünnschichtanalyse | |
Veröffentlichende Institution: | Bundesanstalt für Materialforschung und -prüfung (BAM) |
Verlag: | RSC |
Jahrgang/Band: | 9 |
Ausgabe/Heft: | 12 |
Erste Seite: | 6429 |
Letzte Seite: | 6437 |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Freie Schlagwörter: | Anomalous Small Angle X-ray Scattering; Molecular sieves; Nanostructured material; X-ray Photoelectron Spectroscopy; X-ray absorption Fine Spectroscopy |
Themenfelder/Aktivitätsfelder der BAM: | Chemie und Prozesstechnik |
DOI: | 10.1039/c8ra10417d |
URN: | urn:nbn:de:kobv:b43-474793 |
ISSN: | 2046-2069 |
Verfügbarkeit des Dokuments: | Datei für die Öffentlichkeit verfügbar ("Open Access") |
Lizenz (Deutsch): | Creative Commons - CC BY - Namensnennung 4.0 International |
Datum der Freischaltung: | 04.03.2019 |
Referierte Publikation: | Ja |
Datum der Eintragung als referierte Publikation: | 29.03.2019 |
Schriftenreihen ohne Nummerierung: | Wissenschaftliche Artikel der BAM |