Preparation and characterization of titanium oxynitrides with high specific surface areas
| Autor: | Chae-Ho Shin, Guy Bugli, Gérald Djéga-Mariadassou |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Chemistry
chemistry.chemical_element Aerogel Crystal structure Atmospheric temperature range Condensed Matter Physics Isothermal process Electronic Optical and Magnetic Materials Inorganic Chemistry Lattice constant Chemical engineering Specific surface area Materials Chemistry Ceramics and Composites Organic chemistry Gas composition Physical and Theoretical Chemistry Titanium |
| Zdroj: | Journal of Solid State Chemistry. 95:145-155 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/0022-4596(91)90384-t |
| Popis: | Titania was reacted with ammonia between 890 and 1120 K to produce titanium oxynitride. The degree of nitridation and the specific surface area of the final solid products depend upon various factors such as gas composition, space velocity of the synthesis gas, heating rate, temperature and duration of isothermal treatment, and structure and texture of the starting material (commercial titania powder (P25, Degussa), titania aerogel or rhodium-titania aerogel). The influence of some of these parameters was investigated in the present study. Optimized operating conditions yielded specific surface areas ranging from 58 to 87 m 2 g −1 depending on the starting material. The pore size distribution was centered on a 15–17 nm range. Titanium oxynitride crystallized in a face-centered cubic lattice. Above 70% nitridation, the X-ray diffraction data showed the presence of only one fcc phase; its lattice parameter increased with the nitrogen content, from a value close to that of fcc TiO, to a value approaching the parameter of fcc δ-TiN. Before exposure to air, samples had to be passivated in a flowing mixture of 1 vol% O 2 in He to prevent a rapid oxidation of the bulk. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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