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

作　　者：HAN Wei ZHAO Qiang WANG Ji LI Mei LIU Wenlai ZHANG Milin YANG Xiaoguang SUN Yang 韩伟;赵强;王季;李梅;刘文凯;张密林;杨晓光;孙杨(Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China)

机构地区：Key Laboratory of Superlight Materials and Surfbce Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engi- neering University, Harbin 150001, China

出　　处：《Journal of Rare Earths》2017年第1期90-97,共8页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(21271054,11575047,21173060,11675044),the Major Research Plan of the National Natural Science Foundation of China(91326113,91226201);the Fundamental Research Funds for the Central Universities(HEUCF2016012)

摘　　要：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.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.

关 键 词：electrochemical formation Y-Ni intermetallic compounds Ni electrode potentiostatic electrolysis thermodynamic properties rare earths 

分 类 号：TG146.45[一般工业技术—材料科学与工程]