Electrodeposition of Zn‐Ni Alloys in Sulfate Electrolytes: II. Reaction Modeling
| Autor: | Oswaldo E. Barcia, F. J. Fabri Miranda, Oscar R. Mattos, R. Wiart |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Reaction mechanism
Renewable Energy Sustainability and the Environment Chemistry Inorganic chemistry chemistry.chemical_element Zinc Electrolyte Condensed Matter Physics Electrochemistry Surfaces Coatings and Films Electronic Optical and Magnetic Materials Catalysis chemistry.chemical_compound Materials Chemistry Sulfate Polarization (electrochemistry) Electrode potential |
| Zdroj: | Journal of The Electrochemical Society. 144:3449-3457 |
| ISSN: | 1945-7111 0013-4651 |
| DOI: | 10.1149/1.1838031 |
| Popis: | A reaction model has been developed to account for the mechanism of Zn-Ni alloys deposition from acidic sulfate electrolytes. The heterogeneous reactions imply the presence of four adsorbates: (i) ZnNi ad + which catalyzes nickel deposition, (ii) the intermediate H ad involved in hydrogen evolution which occurs at low polarizations on nickel-rich deposits, (iii) the intermediate adion Zn ad + acting as a catalyst for the deposition of the zinc-rich δ-phase which prevails at high polarizations, and (iv) the anionic species Zn/NiSO 4,ad 2- which inhibits the formation of the δ-phase. In the transition region of intermediate polarizations, an increase in the interfacial pH facilitates the chemical incorporation of S in deposits, which is catalyzed by the anionic adsorbate. The model validity has been confirmed by comparison with experimental polarization curves, electrode impedance measurements, and analyses of the deposit structures and compositions. |
| Databáze: | OpenAIRE |
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