Ru-Pyrochlores: Compositional Tuning for Electrochemical Stability as Cathode Materials for IT-SOFCs
| Autor: | Olivier Mentré, Séverine Bellayer, Martine Frere, Léon Gengembre, Marlu César Steil, Sylvie Daviero-Minaud, G. Ehora |
|---|---|
| Přispěvatelé: | Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces (LEPMI ), Institut de Chimie du CNRS (INC)-Institut National Polytechnique de Grenoble (INPG)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2008 |
| Předmět: |
Materials science
General Chemical Engineering [CHIM.MATE]Chemical Sciences/Material chemistry 02 engineering and technology General Chemistry Electrolyte 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Cathode 0104 chemical sciences law.invention Dielectric spectroscopy Chemical engineering X-ray photoelectron spectroscopy law Electrode Materials Chemistry 0210 nano-technology Polarization (electrochemistry) Solid solution |
| Zdroj: | Chemistry of Materials Chemistry of Materials, American Chemical Society, 2008, 20 (24), pp. 7425-7433. ⟨10.1021/cm801942c⟩ |
| ISSN: | 1520-5002 0897-4756 |
| DOI: | 10.1021/cm801942c |
| Popis: | International audience; Using XRD, impedance spectroscopy, and XPS, it was shown that both Bi2Ru2O7 and Pb2Ru2O6.5, generally announced as attractive electrode materials for IT-SOFCs, chemically react with CGO. In addition, a never-mentioned time-instability under electrochemical measurements with YZS as electrolyte mediates the polarization tests. For Pb2Ru2O6.5, long time experiments (stabilization time > 900 h, previously to complementary electrochemical tests), yields strong increasing of the resistance polarization. Concerning Bi2Ru2O7, a partial transformation into Bi3Ru3O11 is observed after impedance measurements. The investigation of the Bi2−xMxRu2O7−δ (M = Sr, Pb) solid solutions was performed with the aim to improve the catalytic/electric properties. For low x values, it shows a time and chemical stabilization of the electrode/electrolyte cells, able to preserve high electrode performances of these materials. For higher substitution, the chemical/electrochemical instability reappears. According to our polarization measurements versus oxygen pressure and temperature in the so-called “stabilized” samples, the electrode performance appears limited by the diffusion of adsorbed oxygen on the triple point boundary. It is fully compatible with the metallic behavior checked in all the series. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|