Kinetics of anodic dissolution of Zr in acidic fluoride media

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• 作者：M. S. Amrutha ; Ramanathan Srinivasan
• 关键词：Anodic dissolution ; HF ; Potentiodynamic polarization ; Reaction mechanism ; Zr
• 刊名：Journal of Solid State Electrochemistry
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：21
• 期：1
• 页码：91-102
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Physical Chemistry; Electrochemistry; Energy Storage; Characterization and Evaluation of Materials; Analytical Chemistry; Condensed Matter Physics;
• 出版者：Springer Berlin Heidelberg
• ISSN：1433-0768
• 卷排序：21

文摘

The kinetics of anodic dissolution of Zr in hydrofluoric acid (HF) was investigated using potentiodynamic polarization experiments. At lower potentials, an active region with a rapid increase in current with the potential was observed and at higher potentials, a large passivation current plateau was observed. The current decreased only slightly with potential in the passive region. Scanning electron micrographs confirmed that the passivation is incomplete in the region where current exhibits a plateau and x-ray photoelectron spectroscopic analysis showed that oxides and oxyfluorides are present on the surface. A four-step mechanism with two adsorbed intermediate species was evaluated and the model captures the essential characteristics of the polarization plots. The results suggest that \( {HF}_2^{-} \) species participates in the chemical dissolution step and actual HF participates in the electrochemical dissolution step.