Study of the Electrochemical Behavior and Thermodynamic Properties of Lanthanum Compounds on Inert Mo and Liquid Ga Electrodes in Fused NaCl-2CsCl Eutectic

For extraction of metallic lanthanum from molten NaCl-CsCl-LaCl3 solutions, the electrochemical reduction of La(III) ions on inert Mo and liquid Ga electrodes were explored. Transient electrochemical techniques have been used to explore the reduction mechanism, transport parameters and thermodynamics properties. The obtained results indicate that the electrochemical reaction of La(III) + 3e -> La on inert electrode is a single-stage irreversible process, which controlled by the charge transfer rate. Simultaneously, the diffusion coefficient of [LaCl6](3-) complex ions was obtained at different temperatures. The apparent standard potentials of La3+/La couple and La-Ga alloy vs the temperature were determined. The base thermodynamic properties of lanthanum compounds were calculated. Furthermore, the potentiostatic method of electrolysis was used for the synthesis of La-Ga alloys.