The electrochemical behaviors of La(III) on W and Zn-coated W electrodes was investigated, respectively, in the LiCl-KCl eutectic by cyclic voltammetry (CV) and open circuit chronopotentiometry (OCP). On an inert W electrode, the reduction of La(III) takes place at about -2.11 V in a single soluble-insoluble electrochemical step La(III)/La(0). In contrast, the electrochemical reduction of La(III) on a Zn-coated W electrode was observed at less cathodic potentials than at the inert W electrode. The potential shift was mainly caused by the formation of La-Zn intermetallic compounds, in which the activity of La was largely decreased compared to that in pure La metal. From CV results, six peaks corresponding to the formation of La-Zn intermetallic compounds were observed. By the OCP technique, eight plateaus corresponding to the co-existence of two phases of La-Zn intermetallic compound such as LaZn-LaZn2, LaZn2-LaZn4, LaZn4-LaZn5, LaZn5-La3Zn22, La3Zn22-La2Zn17, La2Zn17-LaZn11, LaZn11-LaZn13 and LaZn13-Zn were observed. The formation energy of each La-Zn intermetallic compound, and the overall formation constant were estimated from OCP measurements at 723 K. X-ray diffraction (XRD) and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS) were employed to characterize the potentiostatic and galvanostatic electrolysis products. The presences of LaZn, LaZn2, LaZn5 and La2Zn17 in the electrolysis products were identified. (C) 2015 Elsevier Ltd. All rights reserved.