Electrochemistry of CeCl3 in molten LiCl-KCl eutectic

The electrochemical properties of CeCl3, dissolved in LiCl-KCl eutectic melt, were investigated by electrochemical techniques, such as cyclic voltammetry and square wave voltammetry on Mo electrode. It was shown that Ce(III) is reduced to Ce(0) based on a three-step mechanism. In a temperature range of 833–923 K, the diffusion coefficient of Ce(III) is lgDCe(III)= −2.49–1704/T determined by means of the Berzins-Delahay equation with two different expressions under reversible and irreversible conditions. The apparent standard potential of a Ce(III)/Ce(0) red-ox system is \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$E_{Ce^{3 + } /Ce^0 }^{0*} $\end{document}=3.551+0.0006132T(K) vs. Cl2/Cl−. Some thermochemical properties of CeCl3 solutions were also derived from the electrochemical measurements, such as the enthalpy, entropy, Gibbs free energies and the activity coefficients of Ce(III). The Gibbs free energy of a dilute solution of CeCl3 in this system was determined to be \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\Delta G_{CeCl_3 }^{0*} $\end{document}/(kJ·mol−1)= −1027.9+0.178T(K) And the activity coefficients, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$\gamma _{CeCl_3 } $\end{document}, range between (7.78–9.14)×10−3. Furthermore, the standard rate constant of kinetic reaction was calculated to be (4.94–9.72)×10−3 cm2/s and the reaction was regarded as a quasi-reversible reaction under the present experimental conditions at 833 K.