Acta Phys. -Chim. Sin. ›› 2016, Vol. 32 ›› Issue (7): 1708-1714.doi: 10.3866/PKU.WHXB201604143

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Electrochemical Behavior of Pr(Ⅲ) Ions on a Bi-Coated W Electrode in LiCl-KCl Melts

Tao JIANG1,Shu-Ming PENG1,*(),Mei LI2,Ting-Ting PEI2,Wei HAN2,*(),Yang SUN2,Mi-Lin ZHANG2   

  1. 1 Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, Sichuan Province, P. R. China
    2 Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, P. R. China
  • Received:2016-02-26 Published:2016-07-08
  • Contact: Shu-Ming PENG,Wei HAN E-mail:weihan@hrbeu.edu.cn

Abstract:

The electrochemical behavior of Pr(Ⅲ) ions was studied on a Bi-coatedWelectrode in LiCl-KCl melts by a series of techniques, such as cyclic voltammetry, square wave voltammetry, and open circuit chronopotentiometry. From the cyclic voltammogram and square wave voltammogram, the underpotential deposition of Pr(Ⅲ) on pre-deposited Bi (i.e., a Bi-coated W electrode) occurs, owing to the formation of Pr-Bi intermetallic compounds, resulting in the electrochemical reduction of Pr(Ⅲ) at less cathodic potentials than that on an inert W electrode. Using the open circuit chronopotentiometry technique, two plateaus, corresponding to the co-existence of two phases of Pr-Bi intermetallic compound, were observed. Thermodynamic properties, such as the activities and relative partial molar Gibbs energies of Pr in the Pr-Bi alloys as well as Gibbs energies of the formation for the Pr-Bi intermetallic compounds, were estimated from the open circuit potential measurement in the temperature range of 723-873 K. Pr-Bi alloys were produced on the liquid Bi pool electrode by potentiostatic electrolysis, and were characterized by X-ray diffraction (XRD) and scanning electronic microscopy with energy-dispersive spectrometry (SEM-EDS). The results indicated that the intermetallic LiClcompounds, PrBi2 and PrBi, were obtained.

MSC2000: 

  • O646