The Electrochemical Behavior of Tellurium Tetrachloride in LiCl-KCl Eutectic Molten Salt at 450 oC

Cyclic voltammetry CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy measurements were carried out in 1 and 5 wt% TeCl4 containing LiCl-KCl eutectic molten salt at 450 degrees C using tungsten and glassy carbon as working electrodes. Reduction of Te(IV) to Te(0) occurred in three steps at potentials more negative than -0.4 V-Ag/AgCl. The Te(0) was further reduced to Te2- at more negative potentials. Formation of Te2- was observed at potentials more negative than -2.2 V-Ag/AgCl. Diffusivities of Te4+, Te2+, and Te2- and their formal potentials were estimated from the CV data. The diffusion coefficients of Te4+, Te2+ and Te2- were 0.9 x 10(-5), 3.8 x 10(-5), and 1.5 x 10(-5) cm(2) s(-1), respectively in the 1 wt% TeCl4 containing LiCl-KCl molten salt. The diffusivity of Te species generally decreased with increase in the concentration of TeCl4.

Automated summary

This study investigated cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy measurements in LiCl-KCl eutectic molten salt containing different concentrations of TeCl4. The diffusivity of Te species generally decreased with an increase in the concentration of TeCl4, as observed from the experiments conducted with tungsten and glassy carbon working electrodes at 450 degrees C.