Spectroelectrochemistry of EuCl3 in Four Molten Salt Eutectics; 3 LiCl−NaCl, 3 LiCl−2 KCl, LiCl−RbCl, and 3 LiCl−2 CsCl; at 873 K
文摘
Key electrochemical properties affecting pyroprocessing of nuclear fuel were examined in four eutectic melts using Eu3+/2+ as a representative probe. We report the electrochemical and spectroelectrochemical behavior of EuCl3 in four molten salt eutectics (3 LiCl−NaCl, 3 LiCl−2 KCl, LiCl−RbCl and 3 LiCl−2 CsCl) at 873 K. Cyclic voltammetry was used to determine the reduction potential for Eu3+/2+ and the applied potentials for spectroelectrochemistry. Single step chronoabsorptometry and thin-layer spectroelectrochemistry were used to obtain the number of electrons transferred, reduction potentials and diffusion coefficients for Eu3+ in each eutectic melt. The reduction potentials determined by thin-layer spectroelectrochemistry were essentially the same as those obtained using cyclic voltammetry. The diffusion coefficient for Eu3+ was the largest in the 3 LiCl−NaCl melt, showed a negative shift in the 3 LiCl−2 KCl melt, and was the smallest in the LiCl−RbCl and 3 LiCl−2 CsCl eutectic melts. The basic one-electron reversible electron transfer for Eu3+/2+ was not affected by melt composition.