| Autor: | Patrick Gélin, Gérard Thomas, Nicolas Sergent, Laurent Périer-Camby, Hélène Praliaud |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Thermogravimetric analysis
Tin dioxide Inorganic chemistry Analytical chemistry chemistry.chemical_element Infrared spectroscopy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Oxygen 0104 chemical sciences chemistry.chemical_compound Adsorption chemistry 13. Climate action Specific surface area Physical and Theoretical Chemistry 0210 nano-technology Tin Carbon monoxide |
| Zdroj: | Journal of Thermal Analysis and Calorimetry. 72:1117-1126 |
| ISSN: | 1388-6150 |
| DOI: | 10.1023/a:1025084129973 |
| Popis: | The interactions of CO with a high specific surface area tin dioxide was investigated by FTIR spectroscopy and thermogravimetric analysis. FTIR study of CO interactions have shown that CO can adsorb on cus (coordinatively unsaturated sites) Sn4+ cation sites (band at 2201 cm-1). In addition, CO reacts with surface oxygen atoms. This leads to the partial reduction of SnO2 surface and to the formation of ionised oxygen vacancies together with the release of free electrons, which are responsible for the loss of transmission. Formed CO2 can chemisorb on specific surface sites: on basic sites to form carbonates species and on acidic sites (Sn4+-CO2 species) which is in competition with the formation of Sn4+-CO species. TG experiment have shown that the reduction of SnO2 by CO at 400°C occurs in two steps. First, the reduction of SnO2 surface, which is a quick phenomenon. This has allowed to evaluate that more than 12% of reducible surface oxygens can react with CO, essentially because of the presence of a large amount of surface hydroxyl groups. The second step of the reduction of SnO2 would be the progressive reduction of SnO2 bulk by the slow diffusion of oxygen atoms from the bulk to the surface. |
| Databáze: | OpenAIRE |
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