Electrochemical Behavior and Extraction of Holmium on Cu Electrode in LiCl-KCl Molten Salt
Electrochemical Behavior and Extraction of Holmium on Cu Electrode in LiCl-KCl Molten Salt
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DOI：
10.1149/2.0101714jes
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发表时间：
2017
影响因子：
3.9
通讯作者：
W. Han;Zhuyao Li;Mei Li;X. Hu;Xiaoguang Yang;Milin Zhang;Yang Sun
中科院分区：
文献类型：
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作者：
W. Han;Zhuyao Li;Mei Li;X. Hu;Xiaoguang Yang;Milin Zhang;Yang Sun
采用瞬态电化学技术研究了Ho（III）在Cu电极上的电化学行为。循环伏安和方波伏安实验表明，由于Cu-Ho金属间化合物的形成，Ho（III）在Cu电极上的沉积电位向正方向移动。根据开路计时电位法的结果，计算了773− 893 K温度下各Cu-Ho金属间化合物的标准摩尔吉布斯自由能、生成焓和生成熵等热力学数据。在773 K下，在铜电极上进行了恒电位和恒电流电解从熔盐中提取钬的实验。在-2.15 V恒电位电解20 h后，Ho的萃取率可达99.37%。采用X射线衍射（XRD）、扫描电子显微镜（SEM）和能谱仪（EDS）对萃取产物的物相组成和形貌进行了表征。结果表明，在电化学萃取过程中，生成了Cu0.99Ho0.01、Cu 5 Ho和Cu 2 Ho金属间化合物。研究了外加电位对Cu-Ho层形成速率的影响。
The electrochemical behavior of Ho (III) on Cu electrode was analyzed by transient electrochemical techniques. Cyclic voltammetry and square wave voltammetry experiments indicated that the deposition potential of Ho (III) shift toward more positive values on Cu electrode because of the formation of Cu-Ho intermetallic compounds. According to the results of open circuit chronopotentiometry, the thermodynamic data, such as standard molar Gibbs free energy, enthalpy and entropy of formation for each Cu-Ho intermetallics were calculated in the temperature of 773− 893 K. Moreover, potentiostatic and galvanostatic electrolysis was conducted to extract holmium from molten slat on Cu electrode at 773 K. The extraction efficiency of Ho was found to be about 99.37% by potentiostatic electrolysis at− 2.15 V for 20 h. The phase composition and morphology of the extraction products were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDS). The results revealed that Cu-Ho intermetallic compounds, Cu 0.99 Ho 0.01, Cu 5 Ho and Cu 2 Ho were formed during electrochemical extraction. The effect of the applied potential on the formation rate of Cu-Ho layer was investigated.