高等学校化学学报 ›› 2014, Vol. 35 ›› Issue (12): 2662.doi: 10.7503/cjcu20140405

• 物理化学 • 上一篇    下一篇

LiCl-KCl熔盐体系中镨(Ⅲ)在镍电极上的电化学行为

李梅, 李炜, 韩伟(), 张密林, 颜永得   

  1. 哈尔滨工程大学材料科学与化学工程学院, 教育部超轻材料与表面技术重点实验室, 哈尔滨 150001
  • 收稿日期:2014-04-28 出版日期:2014-12-10 发布日期:2014-11-29
  • 作者简介:联系人简介: 韩 伟, 男, 博士, 教授, 博士生导师, 主要从事熔盐电化学研究. E-mail:weihan@hrbeu.edu.cn
  • 基金资助:
    国家自然科学基金(批准号: 21271054, 21173060)、 国家自然科学基金重大研究计划项目(批准号: 91326113, 91226201)和中央高校基本科研业务经费(批准号: HEUCF201403001)资助

Electrochemical Behavior of Pr(Ⅲ) in the LiCl-KCl Melt on a Ni Electrode

LI Mei, LI Wei, HAN Wei*(), ZHANG Milin, YAN Yongde   

  1. Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China
  • Received:2014-04-28 Online:2014-12-10 Published:2014-11-29
  • Contact: HAN Wei E-mail:weihan@hrbeu.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(Nos.21271054, 21173060), the Major Research Plan of the National Natural Science Foundation of China(Nos.91326113, 91226201) and the Fundamental Research Funds for the Central Universities, China(No.HEUCF201403001)

摘要:

采用循环伏安、 方波伏安、 计时电位和开路计时电位等电化学方法研究了Pr(Ⅲ)离子在共晶LiCl-KCl熔盐中Ni电极上的电化学行为及Pr-Ni合金化机理. 结果表明, Pr(Ⅲ)离子的电化学还原过程为三电子转移的一步反应. 与惰性Mo电极上的循环伏安曲线相比, Pr(Ⅲ) 离子在活性Ni电极的循环伏安曲线上还出现了4对氧化还原峰, 表明Pr(Ⅲ)离子在Ni电极上发生欠电位沉积, 是由于生成不同的Pr-Ni金属间化合物. 采用X射线衍射仪和扫描电子显微镜-能谱仪等对恒电位电解的产物进行了表征. 结果表明, 在不同电位下进行恒电位电解时, 每个电位上只得到一种Pr-Ni金属间化合物, 分别为PrNi2, PrNi3, Pr2Ni7和PrNi5.

关键词: 电化学行为, 欠电位沉积, 恒电位电解, 镨-镍金属间化合物

Abstract:

The electrochemical behavior of Pr(Ⅲ) on a Ni electrode in the LiCl-KCl melt and the alloying mechanism of Pr-Ni alloys were investigated by cyclic voltammetry, square wave voltammetry, chronopoten-tiometry and open-circuit chronopotentiometry. Cyclic voltammetry and square wave voltammetry experiments indicate that the reduction of Pr(Ⅲ) ions into Pr metal occur in a single step with three electrons exchanged. Compared with the cyclic voltammograms on an inert Mo electrode, four reduction peaks are observed, which indicates the under-potential deposition of Pr(Ⅲ) on the reactive Ni electrode due to the formation of Pr-Ni intermetallic compounds. The Pr-Ni alloys obtained by potentiostatic electrolysis were characterized by X-ray diffraction(XRD) and scanning electron micrograph-energy dispersive spectrometry(SEM-EDS). The results show that only one Pr-Ni intermetallic compound, i.e. PrNi2, PrNi3, Pr2Ni7 or PrNi5, is obtained at each potential, respectively. This process can also be used for other electrochemical formation of lanthanide-Ni alloys.

Key words: Electrochemical behavior, Under-potential deposition, Potentiostatic electrolysis, Pr-Ni intermetallic compound

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