Isotopic studies on the degradation of acetaldehyde on anatase surfaces
| Autor: | Stephanie Melchers, Detlef W. Bahnemann, Jenny Schneider |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Reaction mechanism
Anatase Chemistry Acetaldehyde 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Mass spectrometry Photochemistry 01 natural sciences Catalysis 0104 chemical sciences chemistry.chemical_compound Adsorption Photocatalysis Isotopologue 0210 nano-technology |
| Zdroj: | Catalysis Today. 340:318-322 |
| ISSN: | 0920-5861 |
| DOI: | 10.1016/j.cattod.2018.10.016 |
| Popis: | Herein, we studied the role of bridging oxygen (Obr2−) in the photocatalytic degradation reaction of gaseous acetaldehyde under anaerobic conditions. Ti16O2 and the isotopologues Ti18O2 were treated with acetaldehyde in the dark and upon UV illumination and at the reactor outlet the evolved C16O2 and C18O16O were monitored by mass spectrometry (MS). Ti16O2 exhibited a constant C18O16O/C16O2 ratio in the dark and upon UV illumination. In the dark the C18O16O/C16O2 ratio obtained with Ti18O2 was similar to the ratio monitored with Ti16O2, while upon UV illumination the ratio increased evincing an incorporation of Obr2− into the formation of CO2. Accordingly, a following reaction mechanism could be derived: upon UV illumination the generated holes are trapped by the bridging oxygens forming Obr −, which then react with adsorbed acetaldehyde forming acetate that is decomposed into CO2 and CH4. The remaining oxygen vacancy is replenished by an oxygen atom supplied by adsorbed water. This is, to the best of our knowledge, the first time that the crucial role of Obr2− within the photocatalytic process has been described for a gas phase reaction. |
| Databáze: | OpenAIRE |
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