物理化学学报 >> 2007, Vol. 23 >> Issue (10): 1525-1530.doi: 10.1016/S1872-1508(07)60077-1

研究论文 上一篇    下一篇

铁阳极在浓NaOH溶液中的极化特征

何伟春; 邵海波; 陈权启; 王建明; 张鉴清   

  1. 浙江大学化学系, 杭州 310027; 河南工业大学材料科学与工程学院, 郑州 450007; 中国科学院金属腐蚀与防护国家重点实验室, 沈阳 110015
  • 收稿日期:2007-06-01 修回日期:2007-07-09 发布日期:2007-10-01
  • 通讯作者: 邵海波 E-mail:shaohb@zju.edu.cn;weichunhex@163.com

Polarization Characteristic of Iron Anode in the Concentrated NaOH Solution

HE Wei-Chun; SHAO Hai-Bo; CHEN Quan-Qi; WANG Jian-Ming; ZHANG Jian-Qing   

  1. Department of Chemistry, Zhejiang University, Hangzhou 310027, P. R. China; College of Material Science and Engineering, Henan University of Technology, Zhengzhou 450007, P. R. China; State Key Laboratory for Corrosion and Protection, Chinese Academy of Sciences, Shenyang 110015, P. R. China
  • Received:2007-06-01 Revised:2007-07-09 Published:2007-10-01
  • Contact: SHAO Hai-Bo E-mail:shaohb@zju.edu.cn;weichunhex@163.com

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摘要： 使用极化曲线、电解曲线对纯铁电极在浓NaOH 溶液中的极化过程进行了研究. 结果表明, 碱溶液温度越高, 碱浓度越低,电流密度越高, 铁阳极越容易发生钝化;但在某些情况下, 铁电极出现钝化的现象很微弱甚至观察不到.电解法制备高铁酸盐的适宜条件为, 温度25-35 ℃, 极化电流密度≤4.7 mA·cm-2, 碱浓度≥ 14.5 mol·L-1. 用电化学阻抗谱(EIS)研究了上述极化过程中电极表面的阻抗变化情况, 据此描述了铁阳极在浓NaOH溶液中超钝化区极化时的阶段特征.

关键词: 铁阳极, 钝化, 高铁酸盐, 电解曲线, 电化学阻抗谱, 电流效率

Abstract: Polarization curve, electrolysis curve, and electrochemical impedance spectroscopy (EIS) were adopted to study the polarization of iron electrode in the concentrated NaOH solution. The results showed that passivation of the iron anode occured more easily at higher temperature, lower alkaline concentration, and greater current density. However, the passivation phenomenon of the iron electrode might become too weak to see under some conditions. The conditions were as follows: temperature 25-35 ℃, current density ≤ 4.7 mA·cm-2, alkaline concentration ≥ 14.5mol·L-1. EIS was used to investigate the impedance change of the electrode surface during the above polarization process. Next, the step characteristic of the iron anode polarization during its super-passivation range in theconcentrated NaOH solution was described.

Key words: Iron anode, Passivation, Ferrate(Ⅵ), Electrolysis curve, EIS, Current efficiency