物理化学学报 >> 2016, Vol. 32 >> Issue (10): 2538-2544.doi: 10.3866/PKU.WHXB201607202

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NaCl-KCl熔盐体系中AlF3氟化Tb4O7电化学制备Al-Tb合金

韩伟*(),季男,李梅*(),王珊珊,杨晓光,张密林,颜永得   

  • 收稿日期:2016-05-19 发布日期:2016-09-30
  • 通讯作者: 韩伟,李梅 E-mail:weihan@hrbeu.edu.cn;meili@hrbeu.edu.cn
  • 基金资助:
    国家自然科学基金(21271054,11575047,21173060);国家自然科学基金重大研究计划(91326113,91226201);和中央高校基本科研业务经费资助项目(HEUCF2016012)

Electrochemical Formation of Al-Tb Alloys from Tb4O7 Fluorinated by AlF3 in NaCl-KCl Melts

Wei HAN*(),Nan JI,Mei LI*(),Shan-Shan WANG,Xiao-Guang YANG,Mi-Lin ZHANG,Yong-De YAN   

  • Received:2016-05-19 Published:2016-09-30
  • Contact: Wei HAN,Mei LI E-mail:weihan@hrbeu.edu.cn;meili@hrbeu.edu.cn
  • Supported by:
    The project was supported by the National Natural Science Foundation of China(21271054,11575047,21173060);Major Research Plan of the National Natural Science Foundation of China(91326113,91226201);and Fundamental Research Funds for the Central Universities, China(HEUCF2016012)

摘要:

在NaCl-KCl-Tb4O7-AlF3体系中为了制备Al-Tb合金,首先对熔盐中的上清液和沉淀物进行了分析,X射线衍射(XRD)结果确定了Tb4O7能被AlF3氟化生成TbF3。采用一系列的电化学方法对NaCl-KCl-AlF3-Tb4O7体系在Mo电极上的电化学行为进行了研究。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的研究结果表明Tb(III)在预先沉积的Al电极上发生欠电位沉积。在不同条件下进行恒电流电解制备了Al-Tb合金,并对所得合金样品进行XRD和扫描电镜-能量散射谱(SEM-EDS)表征。结果表明在-2.5 A进行恒电流电解得到的Al-Tb合金是由Al和Al3Tb两相组成。采用电感耦合等离子体-原子发射光谱仪(ICP-AES)对实验所得沉积物的组成进行分析,研究了电解条件对合金组成和电流效率的影响。在电流强度为-1.5 A进行恒电流电解2 h,电流效率可达76.5%。

关键词: 电化学行为, Tb4O7, 共还原, NaCl-KCl熔盐, Al-Tb合金, 电流效率

Abstract:

To prepare Al-Tb alloys from Tb4O7 assisted by AlF3 in NaCl-KCl melts, we initially studied the effect of AlF3 on the dissolution of Tb4O7 by analyzing the supernatant and bottom salts. X-ray diffraction (XRD) results revealed that Tb4O7 was fluorinated by AlF3 to form TbF3. The electrochemical behavior of the NaCl-KCl-AlF3-Tb4O7 system was investigated using a Mo electrode at 1073 K. Cyclic voltammetry (CV), square wave voltammetry (SWV), chronopotentiometry (CP) and open circuit chronopotentiometry (OCP) analyses indicated that the under-potential deposition of Tb(III) occurred on pre-deposited Al. The co-deposition of Al-Tb alloys was investigated by galvanostatic electrolysis under different conditions. These samples were characterized by XRD and scanning electron microscopy and energy dispersive spectrometry (SEM-EDS). The Al-Tb alloy obtained by galvanostatic electrolysis at -2.5 A consisted of Al and Al3Tb phases. The effects of the electrolysis conditions on the composition of the alloy and current efficiency were studied by analyzing the compositions of the Al-Tb alloys by inductively coupled plasma-atomic emission spectrometer (ICP-AES). The current efficiency could reach 76.5% under the conditions of galvanostatic electrolysis at -1.5 A for 2 h.

Key words: Electrochemical behavior, Tb4O7, Co-reduction, NaCl-KCl melt, Al-Tb alloy, Current efficiency

MSC2000: 

  • O646