Electrochemistry of Neodymium in an Equimolar NaCl-KCl Melt without and with Addition of Fluoride Ions

• Published in: ECS transactions Vol. 109; no. 14; pp. 29 - 40
• Main Authors: Markovich, Sergey I, Popova, Anna V, Kuznetsov, Sergey A
• Format: Journal Article
• Language: English
• Published: The Electrochemical Society, Inc 30.09.2022
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/10914.0029ecst

The paper presents results of neodymium electrochemical behavior in chloride and chloride-fluoride melts. It was shown that the process of neodymium electroreduction in the NaCl-KCl-NdCl 3 melt proceeds in two stages. It was established by diagnostic criteria of voltammetry that the discharge process of Nd(III) to Nd(II) at a sweep rate in the range of 0.6 ≤ n ≤ 1.0 V s -1 is not complicated by reaction disproportionation. In this study diffusion coefficients, activation energy of diffusion for Nd(III) complexes and standard rate constants of charge transfer for the Nd(III)/Nd(II) redox couple in the NaCl-KCl melt were determined. It was shown that the addition of fluorine anions into the NaCl-KCl-NdCl 3 melt leads to stabilization of the higher oxidation state of neodymium in chloride-fluoride melts and neodymium in the intermediate oxidation state +2 in these melts does not exist.