Electrochemical and thermodynamic properties of ytterbium and formation of Zn–Yb alloy on liquid Zn electrode

The electrochemical behavior of Yb(III) in LiCl–KCl–YbCl3 melts on W and liquid Zn electrodes was studied at 813 K. On the W electrode, the diffusion coefficient of Yb(III) was determined to be 3.38 × 10−5 cm2 s−1. The apparent standard Gibbs energy of the reaction: YbCl2+1/2Cl2→YbCl3 in LiCl–KCl melts was calculated. On the liquid Zn electrode, the results from cyclic voltammetry, square wave voltammetry and open circuit chronopotentiometry indicated that two electrochemical signals corresponding to the formation of two kinds of Zn–Yb intermetallic compounds were observed. Ytterbium was extracted in the form of Zn–Yb alloys by galvanostatic electrolysis on liquid Zn electrode. The results from XRD show that three kinds of Zn-Yb intermetallic compounds were formed. Moreover, the different phases of Zn–Yb alloys could be controlled by adjusting the concentrations of YbCl3.