Filtschew, Anastasia ; Hess, Christian (2024)
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, 2018, 237
doi: 10.26083/tuprints-00028219
Article, Secondary publication, Postprint
Text
107-Unravelling the mechanism of NO and NO 2 storage in ceria....pdf Copyright Information: CC BY-NC-ND 4.0 International - Creative Commons, Attribution NonCommercial, NoDerivs. Download (4MB) |
Item Type: | Article |
---|---|
Type of entry: | Secondary publication |
Title: | Unravelling the mechanism of NO and NO₂ storage in ceria: The role of defects and Ce-O surface sites |
Language: | English |
Date: | 5 December 2024 |
Place of Publication: | Darmstadt |
Year of primary publication: | 23 June 2018 |
Place of primary publication: | Amsterdam |
Publisher: | Elsevier |
Journal or Publication Title: | Applied Catalysis B: Environment and Energy |
Volume of the journal: | 237 |
Collation: | 40 Seiten |
DOI: | 10.26083/tuprints-00028219 |
Corresponding Links: | |
Origin: | Secondary publication service |
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. |
Uncontrolled Keywords: | Ceria, NOx storage mechanism, In situ Raman, Defects, NOx adsorber |
Status: | Postprint |
URN: | urn:nbn:de:tuda-tuprints-282193 |
Classification DDC: | 500 Science and mathematics > 540 Chemistry |
Divisions: | 07 Department of Chemistry > Eduard Zintl-Institut > Physical Chemistry |
Date Deposited: | 05 Dec 2024 13:37 |
Last Modified: | 06 Dec 2024 08:50 |
URI: | https://tuprints.ulb.tu-darmstadt.de/id/eprint/28219 |
PPN: | 524412766 |
Export: |
View Item |