| Autor: |
Lucy J. Oblonsky, Hugh S. Isaacs, Mary P. Ryan |
| Rok vydání: |
2000 |
| Předmět: |
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| Zdroj: |
Corrosion Science. 42:229-241 |
| ISSN: |
0010-938X |
| Popis: |
In situ X-ray absorption near edge structure (XANES) was used to study the formation and galvanostatic reduction of passive films that form on Fe in 1 and 0.1 M acetate solutions of pH 4.5–7.5. Passivation at anodic potentials was accompanied by dissolution of Fe; a small amount of dissolution at pH 5.5–7.5 and significantly more dissolution at pH 4.5. Passive film thickness was approximately 40–50 A and did not vary with pH. Nevertheless, the duration of the potential decay during galvanostatic reduction at −1 μA cm −2 increased substantially with pH from 380 s at pH 4.5 to 2500 s at pH 7.5. At the knee of the potential decay curve, a burst of dissolution occurred where the reduced passive film and remainder of the metallic Fe sample dissolved. The plot of the plateau potential versus pH had a slope of −94 mV/pH unit. The products of the reduction were Fe 3 O 4 and Fe 2+ . |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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