Electrochemical behavior of Y(III) and preparation of Y-Ni intermetallic compounds in molten LiCl-KCl salts

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• 作者：Wei HAN (韩 伟) ; ^{weihan@hrbeu.edu.cn} ; Qiang ZHAO (赵 强) ; Ji WANG (王 季) ; Mei LI (李 梅) ; ^{meili@hrbeu.edu.cn} ; Wenlai LIU (刘文凯) ; Milin ZHANG (张密林) ; Xiaoguang YANG (杨晓光) ; Yang SUN (孙 杨)
• 关键词：electrochemical formation ; Y-Ni intermetallic compounds ; Ni electrode ; potentiostatic electrolysis ; thermodynamic properties ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：35
• 期：1
• 页码：90-97
• 全文大小：4097 K
• 卷排序：35

文摘

The work concerned the electrochemical behaviors of Y(III) on W and Ni electrodes in molten LiCl-KCl salts by a series of electrochemical techniques. The electrochemical reaction of Y(III) to Y(0) proceeded in a one-step reduction process with the exchange of three electrons, Y(III)+3e−→Y(0). Compared with the cyclic voltammogram and square wave voltammogram obtained on W electrode, the reduction potential of Y(III) on Ni electrode was observed at less negative potential than the one of Y(III) to give pure Y metal on W electrode, which revealed the occurrence of underpotential deposition of Y(III) on Ni electrode. Electromotive force (emf) measurements were performed to calculate the relative partial molar Gibbs energies and activities of Y in Y-Ni alloys. The standard Gibbs energies of formation for different Y-Ni intermetallic compounds were also estimated. The different Y-Ni alloys were formed by potentiostatic electrolysis at different potentials and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS). It was found that four intermetallic compounds, YNi5, Y2Ni7, YNi3 and YNi2, were selectively produced by controlling applied potential.