Abstract: The cathodic behavior of Cr(II) ion at W electrode in NaCl?KCl molten salts at a temperature of 710℃ was investigated by cyclic voltammetry, square wave voltammetry, chronopotentiometry. The results indicates that the reduction process of Cr(II) to Cr at W electrode was a one step process: Cr2++2e?=Cr. The reduction of Cr(II) is a quasi-reversible process controlled by diffusion mass transfer. The diffusion coefficients of Cr(II) calculated by the data of cyclic voltammetry and chronopotentiometry, is 1.27?10?5 and 2.24?10?5 cm2/s, respectively. Potentiostatic electrolysis performed on the W electrode proved the feasibility of electrodepositing metallic chromium in the molten NaCl?KCl?CrCl2 system.

Key words: molten salt, chromium, electrochemical behavior, diffusion coefficients, potentiostatic electrolysis

摘要： 通过循环伏安、方波伏安、计时电位等电化学方法对710℃下NaCl?KCl熔盐体系中Cr2+在钨电极上的电化学行为进行了研究. 结果表明，Cr2+在W电极上发生一步还原反应Cr2++2e?=Cr，是由扩散控速的准可逆反应，循环伏安法和计时电位法计算的扩散系数分别为1.27?10?5和2.24?10?5 cm2/s，表明在该体系中在W电极上恒压电解制备金属铬是可行的.

关键词: 熔盐, 铬, 电化学行为, 扩散系数, 恒压电解