Electrochemical Behavior of Zirconium in an in-situ Preparing LiCl−KCl−ZrCl4 Molten Slat

Abstract

The electrochemical behavior of zirconium was investigated in an in-situ preparing LiCl−KCl−ZrCl4 molten slat at 773 K by cyclic voltammetry, chronopotentiometry, and open circuit chronopotentiometry. The concentration of ZrCl4 in the salt is shown to have a great influence on the reduction process of zirconium. Two reduction steps at about −1.05 and −1.25 V due to Zr(IV)/Zr(II) and subsequently Zr(IV)/Zr and Zr(II)/Zr are observed at the lower concentration of ZrCl4 (0.28 wt.%). At the medium concentration of ZrCl4 (0.75 wt.% and 1.25 wt.%), another reduction step at −1.60 V corresponding to ZrCl/Zr is observed, indicating that Zr(IV) would reduce to ZrCl expecting for Zr at −1.25 V. What’s more, the reduction of Zr(II) to ZrCl is also observed at −1.40 V at the higher concentration of ZrCl4 (1.80 wt.%). In the anodic dissolution process, Zr firstly oxidizes to Zr(II) and Zr(IV), and then Zr(II) further oxidizes to Zr(IV).