Mechanism of the Combined Electroreduction of Dy³⁺ and Fe³⁺ Ions in the KCl–NaCl–CsCl Eutectic Melt at 823 K

Abstract—The kinetic laws of Fe³⁺ ion electroreduction in the KCl–NaCl–CsCl eutectic melt at 823 K are determined. The potentials of metallic iron and dysprosium formation on the inert tungsten electrode in the KCl–NaCl–CsCl molten system are found to differ by approximately 1.5 V. In the case of the combined presence of Fe³⁺ and Dy³⁺ ions in the KCl–NaCl–CsCl eutectic melt, a certain depolarization of dysprosium ion electroreduction occurs on the metallic iron preliminary deposited at the tungsten electrode to form iron- and dysprosium-based intermetallic phases of different compositions. The dissolution potentials of the different intermetallic phases Dy_xFe_y are determined by open circuit chronopotentiometry.