CO2 chemisorption at ambient temp. on a via-chloride anatase prepn. was investigated by microgravimetry and IR spectroscopy. Besides a CO2 species linearly held at surface acidic sites, different types of carbonate-like species were formed, revealing the existence of surface basic sites. The nature of surface carbonates varied on varying the sample activation temp. The overall chemisorbed amt. was quite small, indicating that very little surface basicity can be evidenced by a soft acid like CO2. The activity of surface oxygens depends strongly on the hydration degree, as well as on the preadsorption of polar mols., indicating that anatase surface basicity is influenced by the overall polarity of the surface layer.
Tipologia ministeriale: | Articolo su rivista |
Appare nelle tipologie: | 1.1 Articolo su rivista |