Guidelines for improving resistance to CO2 of materials for solid state electrochemical systems
| Autor: | Andrei V. Kovalevsky, Duncan P. Fagg, Jorge R. Frade, Vladislav V. Kharton, J.F. Monteiro, A.D. Brandão |
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| Rok vydání: | 2011 |
| Předmět: |
Alkaline earth metal
Materials science Carbonation Solid-state Oxide Ionic bonding Mineralogy General Chemistry Condensed Matter Physics Electrochemistry chemistry.chemical_compound chemistry Chemical engineering visual_art visual_art.visual_art_medium General Materials Science Ceramic Electroceramics |
| Zdroj: | Solid State Ionics. 192:16-20 |
| ISSN: | 0167-2738 |
| Popis: | Alkali earth oxides are present in many ionic and mixed conductors with a potential application in solid state electrochemical or electroceramic devices. Hence, study has been made of the relative risks of carbonation of selective materials based on thermodynamic predictions, with emphasis on ATiO 3 electroceramics, with A = Ca, Sr, Ba, and proton conductors based on AMO 3 perovskites with A = Sr or Ba and M = Ce or Zr. Predictions show that slight A-site deficiency lowers the activity of alkali earth oxide and enhances resistance to CO 2 ; this is confirmed by experimental findings. Thermodynamic predictions also indicate that the high stability of (Ba,Sr)TiO 3 and (Ba,Sr)ZrO 3 perovskites contributes to attain reasonable resistance to CO 2 , in spite of the ready carbonation of BaO and SrO. However, these materials show wide gap between the upper and lower limits of resistance to CO 2 . This gap provides interpretation for the effects of powder preparation and/or ceramic processing on resistance to CO 2 . It is also shown that the lower and upper limits of resistance to CO 2 correlate with the structural tolerance factor of these perovskites. |
| Databáze: | OpenAIRE |
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