Kinetics and mechanism of the nickel electrode : II. Acid solutions containing a high concentration of sulphate and nickel ions
The kinetics of the Ni electrode in acid solutions with a high sulphate and nickel ion concentration has been investigated in the range of 25–75°C. The active dissolution and the passive regions and the active-passive transition phenomena have been studied employing different potential perturbation...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 1978 |
| País: | Argentina |
| Institución: | Universidad Nacional de La Plata |
| Repositorio: | SEDICI (UNLP) |
| Idioma: | inglés |
| OAI Identifier: | oai:sedici.unlp.edu.ar:10915/82561 |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/82561 |
| Access Level: | acceso abierto |
| Palabra clave: | Ciencias Exactas Química Cinética química Níquel Electrodos Electroquímica Ácidos Iones |
| Sumario: | The kinetics of the Ni electrode in acid solutions with a high sulphate and nickel ion concentration has been investigated in the range of 25–75°C. The active dissolution and the passive regions and the active-passive transition phenomena have been studied employing different potential perturbation techniques using both still and stirred solutions. Two electrochemical processes are competing within the prepassive film potential region, namely, the active Ni dissolution to Ni(II) ions and the Ni(OH)<sub>2</sub> film formation. Nickel passivation is explained by reaction pathways involving successive electrochemical and chemical steps implying the occurrence of hydroxo- and oxo-species as reactions intermediates. The advanced mechanism is based upon a positively charged Ni surface structure and attributes the onset of the complete passivity to a particular surface oxide species. |
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