This work presents an electrochemical extraction of cerium and synthesization of Al–Ce alloy in LiCl–KCl melts on Mo and Al electrodes by chlorination of CeO2 using AlCl3 at 873 K. The cyclic voltammogram on Mo electrodes in LiCl–KCl–CeO2 melt showed no obvious reduction wave other than the reduction of Li(I). After the addition of AlCl3, the signals of the reaction of Ce(ⅡI)/Ce(0) and the synthesization of Al–Ce and Al–Li alloys were investigated by cyclic voltammetry, square-wave voltammetry, open-circuit chronopotentiometry and chronopotentiometry. These results indicated that AlCl3 can chloridize CeO2 and that it is possible to extract cerium and form Al–Ce and Al–Li–Ce alloys in LiCl–KCl–CeO2–AlCl3 melts. According to potentiostatic electrolysis, only the Al4 Ce layer coated the Al electrodes. According to galvanostatic electrolysis, Al–Ce(Al4Ce, Al3 Ce, and Al92Ce8), Al2Li3, and Al phases were formed on Mo electrodes, and the content of cerium in the Al–Li–Ce alloys was more than 17 wt%.
An electrochemical study of dysprosium(III) on Bi film electrode was carried out in eutectic LiCl-KCI melts by transient and steady state electrochemical techniques.The results of transient electrochemical techniques showed that the reduction of Dy(III) appears at a more positive value than the one detected on W electrode owing to the formation of Bi-Dy intermetallic compounds through electrochemical deposition of Dy on bismuth film electrode.The thermodynamic properties of the formation for Dy-Bi intermetallics were estimated by a steady state electrochemical method in a temperature range of 713-803 K.Furthermore,the electrochemical preparation of Bi-Dy alloys was conducted by galvanostatic electrolysis at different current intensities.The Bi-Dy alloys,characterized by scanning electron microscopy equipped with energy dispersive spectrometry and X-ray diffraction,are comprised of DyBi_(3/5) and DyBi phases.
Shanshan WangBaicong WeiMei LiWei HanMilin ZhangXiaoguang YangYang Sun
在843 K LiCl-KCl-CeCl_3熔盐中活性铝电极上,研究了Ce(Ⅲ)离子的电化学行为和欠电位沉积Al-Ce合金。对比循环伏安曲线发现,在Al电极上Ce(Ⅲ)/Ce反应的氧化还原电势比在Mo惰性电极上更正;开路计时电位在金属铝和铈的沉积平台之间出现2个平台,这表明Ce(Ⅲ)在A1活性电极上可以生成两种金属间化合物。以上结果在电化学机理上说明Ce(Ⅲ)离子可以在Al电极上欠电位沉积形成金属间化合物。在该实验条件下通过恒电位电解,在Al电极上得到了Al-Ce合金,验证了电化学分析的结果。经XRD表征,证实形成了AlCe和AlCe_3两种合金,结合Al-Ce合金相图分析了只产生这两种合金的原因;结合开路电位计算了生成这两种合金的标准吉布斯自由能变值。经SEM和EDS表征,证明了铈在Al电极表面分布,并形成厚度均一约28μm的Al-Ce合金镀层。
