Kinetics and mechanism of the electrochemical reduction of molecular oxygen on platinum in KOH: influence of preferred crystallographic orientation
The oxygen electroreduction reaction has been studied at both preferred oriented and conventional polycrystalline platinum rotating disc electrodes in x m KOH (0.05 ⩽ x ⩽ 3.0) aqueous solutions under oxygen saturation at 25°C. At low current densities, Tafel lines with slope -0.060 V decade⁻¹ have b...
| Autores: | , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1994 |
| País: | Argentina |
| Recursos: | Universidad Nacional de La Plata |
| Repositorio: | SEDICI (UNLP) |
| Idioma: | inglés |
| OAI Identifier: | oai:sedici.unlp.edu.ar:10915/146265 |
| Acesso em linha: | http://sedici.unlp.edu.ar/handle/10915/146265 |
| Access Level: | acceso abierto |
| Palavra-chave: | Química Platinum Electrode Oriented Surface Rotate Disc Electrode Prefer Crystallographic Orientation Oxygen Electroreduction |
| Resumo: | The oxygen electroreduction reaction has been studied at both preferred oriented and conventional polycrystalline platinum rotating disc electrodes in x m KOH (0.05 ⩽ x ⩽ 3.0) aqueous solutions under oxygen saturation at 25°C. At low current densities, Tafel lines with slope -0.060 V decade⁻¹ have been obtained at all platinum electrodes. At high current densities, higher Tafel slopes ranging from -0.18 to -0.40 V decade⁻¹ have been observed, depending on the type of preferred oriented Pt and KOH concentration. Rotating ring-disc electrode data have shown that a higher amount of H₂O₂ is produced on one type of preferred oriented surface at all KOH concentrations. A complex reaction scheme has been used to evaluate the electrochemical rate constants of the reaction steps at three platinum electrodes. |
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