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采用循环伏安、方波伏安、计时电位和开路计时电位等电化学方法研究了Pr(III)离子在Li Cl-KCl-Bi Cl_3熔体中W电极上的电化学行为。循环伏安和方波伏安的研究表明,Pr在预先沉积的Bi膜电极上发生欠电位沉积是由于生成了Pr-Bi金属间化合物,导致Pr(III)在Bi膜电极上的还原电位比在W电极上还原电位更正。从开路计时电位曲线可以观察到两相共存的Pr-Bi金属间化合物的两个平台。利用开路计时电位计算了723-873 K温度范围内Pr在Pr-Bi合金中的活度和偏摩尔Gibbs自由能以及Pr-Bi金属间化合物的生成Gibbs自由能。通过恒电位电解,在液态Bi电极上得到了Pr-Bi合金,并采用X射线衍射(XRD)和扫描电子显微镜(SEM)附带能量散射谱(EDS)对样品进行了表征,结果表明所得到的Pr-Bi金属间化合物为Pr Bi_2和Pr Bi。
The electrochemical behavior of Pr (III) ions at the W electrode in LiCl-KCl-BiCl_3 melt was investigated by cyclic voltammetry, square wave voltammetry, chronopotentiometry and open-circuit chronopotentiometry. Cyclic voltammetry and square wave voltammetry studies have shown that the pre-deposited Bi film electrode undervolt potential deposition is due to the formation of Pr-Bi intermetallic compounds, resulting in Pr (III) in the Bi membrane electrode potential reduction ratio Reduction potential correction at W electrode. Two platforms of Pr-Bi intermetallic compounds coexisting in two phases can be observed from the open-circuit chronopotential curve. The activity and partial molar Gibbs free energy of Pr in Pr-Bi alloy and the Gibbs free energy of formation of Pr-Bi intermetallic compound in the temperature range of 723-873 K were calculated by using open-circuit chronopotentials. Pr-Bi alloys were obtained on liquid Bi electrodes by potentiostatic electrolysis. The samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The results show that the obtained Pr-Bi intermetallics are Pr Bi 2 and Pr Bi.