Electrochemical properties of yttrium on W and Pb electrodes in LiCl–KCl eutectic melts

Abstract

Cyclic voltammetry, square wave voltammetry, linear polarization, chronopotentiometry and chronoamperometry were performed to investigate the electrochemical properties of Y(III) on W and Pb electrodes in LiCl–KCl eutectic melts. The diffusion coefficient of Y(III) measured by various techniques was in the order of 10⁻⁵. The nucleation of Y on W electrode was found to comply with the instantaneous nucleation mechanism. With increasing temperature, the exchange current densities increased and the charge-transfer resistances decreased, and exchange current densities are distinctly larger on liquid Pb electrode compared with W electrode. In addition, the co-deposition mechanism of Y(III) and Pb(II) on W electrode was also studied and four Pb–Y intermetallics could be detected. The feasibility of extraction metallic Y from the melts was explored by co-deposition on W electrode and under-potential deposition on liquid Pb electrode and the extracted products consisted of Pb₃Y and Pb phases.