| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 55361 | Catalysis Today | 2012 | 5 Pages |
The evolution of supported silver species of a pre-calcined Ag/Al2O3 catalyst was monitored upon thermal treatment under an air flow enriched with 3000 ppm of ethanol (EtOH) using transmission electron microscopy and UV–visible and X-ray absorption spectroscopies. A special focus is put on the application of in situ Quick-XAS that permits to acquire high quality spectra at the Ag K-edge with a good time resolution (30 s), thus informing in real time on the transformations of the silver species. While the reduction of silver under Air/EtOH flow is shown to possibly occur at room temperature, the process is strongly accelerated by heating, most of the silver being indeed reduced at ca. 78 °C, a temperature which corresponds to the ethanol boiling point. The possible impact of this silver sensitivity on the behavior of silver–alumina catalysts in reactions such as the selective catalytic reduction (SCR) of NOx in presence of ethanol is addressed.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (154 K)Download as PowerPoint slideHighlights► Real time in situ monitoring of state silver in Ag/Al2O3 catalysts by Quick-XAS. ► Reduction of the highly dispersed cationic silver species by ethanol. ► Active sites transformation in the course of reaction (SCR of NOx).
