Electrochemistry and Spectroelectrochemistry of Europium(III) Chloride in 3LiCl-2KCl from 643 to 1123 K

The electrochemical and spectroelectrochemical behavior of europium(III) chloride in a molten salt eutectic, 3LiCl-2KCl, over a temperature range of 643-1123 K using differential pulse voltammetry, cyclic voltammetry, potential step chronoabsorptometry, and thin-layer spectroelectrochemistry is reported. The electrochemical reaction was determined to be the one-electron reduction of Eu3+ to Eu2+ at all temperatures. The redox potential of Eu3+/2+ shifts to more positive potentials, and the diffusion coefficient for Eu3+ increases as temperature increases. The results for the number of electrons transferred, redox potential, and diffusion coefficient are in good agreement between the electrochemical and spectroelectrochemical techniques. This research extends our ability to develop a spectroelectrochemical sensor for lanthanides and actinides into molten salt media.