Bulk and surface properties of highly dispersed VOx/ZrO2, VOx/SiO2 and VOx/TiO2/SiO2 systems and their relevance for propane oxidation
- Highly dispersed vanadium-doped metal oxides such as VOx/ZrO2, VOx/SiO2 and VOx/TiO2/SiO2 with vanadium contents between 0 and 25 mole% were prepared by special bulk preparation methods (coprecipitation and solgel, followed by freeze-drying). Bulk and surface properties of the obtained mixed oxide solid solutions were thoroughly investigated by different analytical methods (Raman and FTIR spectroscopy, TPD, H2-TPR, oxygen isotope measurements etc.). Moreover, the catalytic behaviour of the oxides was studied for the example of the oxidative dehydrogenation (ODH) of propane to propylene. Independent of the preparation method, the catalytic behaviour of vanadium-doped ZrO2 and TiO2 phases is very similar. Both metal oxide solid solutions are very active in propane ODH whereas the catalytic activity of VOx/SiO2 is relatively low. On the other hand, the reduction of the catalytic activity is accompanied by an improved selectivity for the formation of propylene. The correlation between theHighly dispersed vanadium-doped metal oxides such as VOx/ZrO2, VOx/SiO2 and VOx/TiO2/SiO2 with vanadium contents between 0 and 25 mole% were prepared by special bulk preparation methods (coprecipitation and solgel, followed by freeze-drying). Bulk and surface properties of the obtained mixed oxide solid solutions were thoroughly investigated by different analytical methods (Raman and FTIR spectroscopy, TPD, H2-TPR, oxygen isotope measurements etc.). Moreover, the catalytic behaviour of the oxides was studied for the example of the oxidative dehydrogenation (ODH) of propane to propylene. Independent of the preparation method, the catalytic behaviour of vanadium-doped ZrO2 and TiO2 phases is very similar. Both metal oxide solid solutions are very active in propane ODH whereas the catalytic activity of VOx/SiO2 is relatively low. On the other hand, the reduction of the catalytic activity is accompanied by an improved selectivity for the formation of propylene. The correlation between the catalytic activity and the acidity of the oxide systems is discussed. Oxidation experiments with 18O2 clearly show that the ODH reaction occurs according to the Marsvan Krevelen mechanism.…
MetadatenAutor*innen: | K. Scheurell, E. Hoppe, Klaus-Werner Brzezinka, E. Kemnitz |
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Dokumenttyp: | Zeitschriftenartikel |
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Veröffentlichungsform: | Verlagsliteratur |
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Sprache: | Englisch |
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Titel des übergeordneten Werkes (Englisch): | Journal of materials chemistry |
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Jahr der Erstveröffentlichung: | 2004 |
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Verlag: | Royal Society of Chemistry |
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Verlagsort: | Cambridge |
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Jahrgang/Band: | 14 |
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Ausgabe/Heft: | 16 |
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Erste Seite: | 2560 |
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Letzte Seite: | 2568 |
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Freie Schlagwörter: | Catalytic activity; Coprecipation; Oxygen mobility; Propan oxidation; Sol-gel-method; Solid solutions; Vanadium-doped metal oxides |
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DOI: | 10.1039/b402924k |
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ISSN: | 0959-9428 |
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ISSN: | 1364-5501 |
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Verfügbarkeit des Dokuments: | Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access") |
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Bibliotheksstandort: | Sonderstandort: Publica-Schrank |
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Datum der Freischaltung: | 19.02.2016 |
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Referierte Publikation: | Ja |
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Datum der Eintragung als referierte Publikation: | 30.09.2004 |
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