Mo,W电极在MgCl_2-KCl-NaCl-CaCl_2熔盐中电解镁的钝化行为  

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

作　　者：陈野 叶克 

机构地区：[1]哈尔滨工程大学超轻材料与表面技术教育部重点实验室,黑龙江哈尔滨150001

出　　处：《电化学》2008年第2期197-199,共3页Journal of Electrochemistry

基　　金：国家"863"计划项目(2006AA03Z510)资助

摘　　要：应用循环伏安法和计时电流法研究了Mg(Ⅱ)在MgCl2-KCl-NaCl-CaCl2四元熔盐体系中于(Mo、W)阴极上的放电过程及其钝化行为.结果表明,W电极放电反应的可逆性比Mo电极的好.后者的计时电流曲线偏离线性特征,且其阴极钝化比W严重.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 vohammograms 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 e- lectrode, 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.

关 键 词：熔盐 镁 阴极放电 钝化 

分 类 号：O646.54[理学—物理化学]