Passivation Behaviors of Mo,W Electrodes in MgCl_2-KCl-NaCl-CaCl_2 Molten Salt for Electrolysis of Magnesium

Authors

CHEN Ye, Key Laboratory of Superlight Materials and Surface Technology,Ministry of Education,Harbin Engineering University,Harbin 150001,China;
YE Ke, Key Laboratory of Superlight Materials and Surface Technology,Ministry of Education,Harbin Engineering University,Harbin 150001,China;

Abstract

The discharge process and passivation behaviors of Mg(Ⅱ) on cathode(Mo、W) in MgCl2-KCl-NaCl-CaCl2 molten salt system had been investigated by means of cyclic voltammetry and chronoamperometry.The composition of molten salt was MgCl(10%)+CaCl(20%)+NaCl(60%)+KCl(10%)(by mass) and the temperature of electrolysis was 725 ℃.The deposition potential of Mo was 37 mV more negative than that of W,while the peak current was sharper than Mo according to the voltammograms at 0.05 V/s,indicating that the passivation on Mo cathode is easier than W.The formation of MgO impurities during the electrolysis could cause the cathode passiration.However,the reversibility on the discharge reaction of W cathode was better than Mo electrode,and the reduction peak potential of W electrode almost unchanged with the scan rate.The I～t-1/2 curves demonstrated a positive linear relationship on W electrode,but deviated from the linear characteristics on Mo electrode due to the passivation.

Keywords

molten salt, magnesium, cathode discharge, passivation

DOI Link

https://doi.org/10.61558/2993-074X.1890

Publication Date

2008-05-28

Online Available Date

2008-05-28

Revised Date

2008-05-28

Received Date

2008-05-28

Recommended Citation

CHEN Ye, YE Ke. Passivation Behaviors of Mo,W Electrodes in MgCl_2-KCl-NaCl-CaCl_2 Molten Salt for Electrolysis of Magnesium[J]. Journal of Electrochemistry, 2008 , 14(2): 197-199.
DOI: 10.61558/2993-074X.1890
Available at: https://jelectrochem.xmu.edu.cn/journal/vol14/iss2/17