Electrochemical behavior of Pb–Ag–Nd alloy during pulse current polarization in H 2 SO 4 solution
| Autor: | Xiao-cong Zhong, Xiao-ying Yu, Li Jie, Fei Li, Liangxing Jiang, Yexiang Liu |
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| Rok vydání: | 2015 |
| Předmět: |
Tafel equation
Materials science Alloy Metals and Alloys Analytical chemistry Oxygen evolution engineering.material Geotechnical Engineering and Engineering Geology Condensed Matter Physics Electrochemistry Anode Materials Chemistry engineering Constant current Polarization (electrochemistry) Current density |
| Zdroj: | Transactions of Nonferrous Metals Society of China. 25:1692-1698 |
| ISSN: | 1003-6326 |
| DOI: | 10.1016/s1003-6326(15)63774-8 |
| Popis: | The anodic layer and oxygen evolution behavior of Pb–Ag–Nd alloy during pulse current polarization and constant current polarization in 160 g/L H 2 SO 4 solution was comparatively investigated by chronopotentiometry, SEM, XRD, EIS and Tafel techniques. The results show that the anodic layer on Pb–Ag–Nd alloy formed through pulse current polarization is more intact and presents fewer micro-holes than that formed through constant current polarization. This could be attributed to the low current density period, which works as a ‘recovery period’. During this period, the oxygen evolution reaction is less intense, which benefits the recovery of porous anodic layer. Pb–Ag–Nd anode also shows a lower anodic potential during pulse current polarization, which is in accordance with its smaller charge transfer resistance and smaller Tafel slope coefficient at high over-potential region. The lower anodic potential could be ascribed to the higher concentration of PbO 2 in the anodic layer, which promotes the formation of more reactive sites for the oxygen evolution reaction. |
| Databáze: | OpenAIRE |
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