Electrochemical behavior of Y(III) and preparation of Y-Ni intermetallic compounds in molten LiCl-KCl salts

Abstract The work concerned the electrochemical behaviors of Y(III) on W and Ni electrodes in molten LiCl-KCl salts by a series of electrochemical techniques. The electrochemical reaction of Y(III) to Y(0) proceeded in a one-step reduction process with the exchange of three electrons, Y(III)+3e − →Y(0). Compared with the cyclic voltammogram and square wave voltammogram obtained on W electrode, the reduction potential of Y(III) on Ni electrode was observed at less negative potential than the one of Y(III) to give pure Y metal on W electrode, which revealed the occurrence of underpotential deposition of Y(III) on Ni electrode. Electromotive force (emf) measurements were performed to calculate the relative partial molar Gibbs energies and activities of Y in Y-Ni alloys. The standard Gibbs energies of formation for different Y-Ni intermetallic compounds were also estimated. The different Y-Ni alloys were formed by potentiostatic electrolysis at different potentials and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS). It was found that four intermetallic compounds, YNi 5 , Y 2 Ni 7 , YNi 3 and YNi 2 , were selectively produced by controlling applied potential.