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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。
The electrochemical behavior of Ce (Ⅲ) ions and the underpotential deposition of Al-Ce alloy were investigated on the active aluminum electrode in 843 K LiCl-KCl-CeCl 3 molten salt. In contrast to the cyclic voltammetry, the redox potential of the Ce (III) / Ce reaction on the Al electrode was found to be more correct than on the Mo inert electrode; the open circuit chronopotentials showed two platforms between the metal aluminum and cerium deposition platforms, indicating Ce (Ⅲ) can generate two kinds of intermetallic compounds on the A1 active electrode. The above results show that the electrochemical mechanism of Ce (Ⅲ) ions can be deposited on the Al electrode underpotential formation of intermetallic compounds. The Al-Ce alloy was obtained on the Al electrode by potentiostatic electrolysis under the experimental conditions, which verified the result of electrochemical analysis. XRD characterization confirmed the formation of AlCe and AlCe_3 two alloys, combined with Al-Ce alloy phase diagram analysis of the reasons for the only two alloys; combined with the open circuit potential calculation of the two alloys generated by the standard Gibbs free energy change value. The SEM and EDS characterization demonstrated that cerium was distributed on the surface of Al electrode and formed Al-Ce alloy coating with a uniform thickness of about 28μm.