Fast faradaic processes observed during the potentiodynamic polarization of polycrystalline palladium in acid electrolyte
Two almost reversible electrochemical systems are detected during the potentiodynamic anodization of polycrystalline palladium in 1 M H2SO4 and 1 M HClO<sub>4</sub> by applying the triangular modulated triangular potential sweep technique. The first electrochemical system which appears i...
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| Autores principales: | , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
1984
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/84114 |
| Aporte de: |
| Sumario: | Two almost reversible electrochemical systems are detected during the potentiodynamic anodization of polycrystalline palladium in 1 M H2SO4 and 1 M HClO<sub>4</sub> by applying the triangular modulated triangular potential sweep technique. The first electrochemical system which appears in the 0.7–0.9 V range (vs. RHE) corresponds to the reaction Pd+H<sub>2</sub>O=PdOH+H<sup>+</sup>+e<sup>−</sup> whose reversible potential is estimated as 0.80±0.02 V and the average half-life time of PdOH species is estimated as 6×10<sup>−3</sup> s.
The second electrochemical system appears when the anodizing potential sweep extends to the oxygen evolution potential region. The appearance of the second electrochemical system is accompanied by a change in colour of the electrode surface, a shift of the current-potential curve of the oxygen evolution reaction and an increase in thickness of the oxide anodic layer. The reversible response is tentatively assigned to the PdO<sub>2</sub>/PdO<sub>3</sub> redox couple. |
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