Filtschew, Anastasia ; Hess, Christian (2018)
Unravelling the mechanism of NO and NO₂ storage in ceria: The role of defects and Ce-O surface sites.
In: Applied Catalysis B: Environment and Energy, 237
doi: 10.1016/j.apcatb.2018.06.058
Artikel, Bibliographie
Dies ist die neueste Version dieses Eintrags.
Kurzbeschreibung (Abstract)
Ceria is an important NOₓ storage material often used in combination with barium or zirconia. To elucidate the NO and NO₂ storage mechanism in ceria we employed in situ Raman spectroscopy coupled with simultaneous FT-IR gas-phase analysis. The Raman spectra reveal new information about the dynamics of the surface and bulk structure of ceria upon NOₓ exposure at 30 °C besides the identification of nitrite and nitrate adsorbates. In particular, Raman spectra provide direct evidence of the involvement of Ce-O surface sites so far not accessible by spectroscopic methods. These Ce-O sites play a key role for NOₓ storage, as their amount strongly influences the NOₓ storage capacity. A reduction of ceria prior to NOₓ exposure resulted in a lower NOₓ storage capacity, as long as no strong oxidizing agent (e.g. NO₂) was present to form new Ce-O sites. In the case of NO storage at 30 °C, new reaction pathways are postulated that describe the activation of gas-phase oxygen for ionic nitrite transformation and formation of new NOₓ adsorption sites. However, it is shown that the activated oxygen species is not a peroxide, as no correlation was found between the peroxides and formed nitrate and nitrite species. Based on our results, a mechanism for NO and NO₂ storage in ceria was formulated.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2018 |
| Autor(en): | Filtschew, Anastasia ; Hess, Christian |
| Art des Eintrags: | Bibliographie |
| Titel: | Unravelling the mechanism of NO and NO₂ storage in ceria: The role of defects and Ce-O surface sites |
| Sprache: | Englisch |
| Publikationsjahr: | 23 Juni 2018 |
| Ort: | Amsterdam |
| Verlag: | Elsevier |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Applied Catalysis B: Environment and Energy |
| Jahrgang/Volume einer Zeitschrift: | 237 |
| DOI: | 10.1016/j.apcatb.2018.06.058 |
| Zugehörige Links: | |
| Kurzbeschreibung (Abstract): | Ceria is an important NOₓ storage material often used in combination with barium or zirconia. To elucidate the NO and NO₂ storage mechanism in ceria we employed in situ Raman spectroscopy coupled with simultaneous FT-IR gas-phase analysis. The Raman spectra reveal new information about the dynamics of the surface and bulk structure of ceria upon NOₓ exposure at 30 °C besides the identification of nitrite and nitrate adsorbates. In particular, Raman spectra provide direct evidence of the involvement of Ce-O surface sites so far not accessible by spectroscopic methods. These Ce-O sites play a key role for NOₓ storage, as their amount strongly influences the NOₓ storage capacity. A reduction of ceria prior to NOₓ exposure resulted in a lower NOₓ storage capacity, as long as no strong oxidizing agent (e.g. NO₂) was present to form new Ce-O sites. In the case of NO storage at 30 °C, new reaction pathways are postulated that describe the activation of gas-phase oxygen for ionic nitrite transformation and formation of new NOₓ adsorption sites. However, it is shown that the activated oxygen species is not a peroxide, as no correlation was found between the peroxides and formed nitrate and nitrite species. Based on our results, a mechanism for NO and NO₂ storage in ceria was formulated. |
| Freie Schlagworte: | Ceria, NOx storage mechanism, In situ Raman, Defects, NOx adsorber |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| Fachbereich(e)/-gebiet(e): | 07 Fachbereich Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Physikalische Chemie |
| Hinterlegungsdatum: | 12 Dez 2024 11:50 |
| Letzte Änderung: | 12 Dez 2024 11:56 |
| PPN: | 524554374 |
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| Suche nach Titel in: | TUfind oder in Google |
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Unravelling the mechanism of NO and NO₂ storage in ceria: The role of defects and Ce-O surface sites. (deposited 05 Dez 2024 13:37)
- Unravelling the mechanism of NO and NO₂ storage in ceria: The role of defects and Ce-O surface sites. (deposited 12 Dez 2024 11:50) [Gegenwärtig angezeigt]
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