A new approach for the preparation of variable valence rare earth alloys from nano rare earth oxides at a low temperature in molten salt

作者：Zhang, Milin^*; Yan, Yongde; Han, Wei; Li, Xing; Hou, Zhiyao; Tian, Yang; Ye, Ke; Bao, Lihong; Li, Xiaodong; Zhang, Zhijian

来源：RSC Advances, 2012, 2(4): 1585-1591.

DOI：10.1039/c1ra00285f

• Chronopotentiometry
• Electrochemical behaviors
• Electrochemical techniques
• Energy dispersions
• Low temperatures
• Potentiostatic electrolysis
• Square wave voltammetry
• Underpotential deposition

The solubility of RE2O3 (RE = Eu, Sm, and Yb) with variable valence in molten salts is extremely low. It is impossible to directly obtain variable valence metals or alloys from RE2O3 using electrolysis in molten salts. We describe a new approach for the preparation of variable valence rare earth alloys from nano rare earth oxide. The excellent dispersion of nano-Eu2O3 in LiCl-KCl melts was clearly observed using a luminescent feature of Eu3 as a probe. The ratio of solubility of nano-Sm2O3/common Sm2O3 is 16.98. Electrochemical behavior of RE2O3 on a molybdenum and Al electrode in LiCl-KCl melts containing AlCl3 at 480 degrees C was investigated by different electrochemical techniques, such as cyclic voltammetry (CV), square wave voltammetry, and chronopotentiometry. Prior to the reduction peak of Al, the reduction peaks of Sm(III)/Sm(II), Yb(III)/Yb(II), and Eu(III)/Eu(II) were observed at about -0.85, -0.45, and 0.39 V in square wave voltammetry, respectively. The underpotential deposition of RE on pre-deposited aluminum leads to the formation of Al-RE alloy. The structure, morphology, and energy dispersion analysis of the deposit obtained by potentiostatic electrolysis are analyzed. Al2Sm and Al3Sm alloys were successfully obtained from nano-Sm2O3.

• 出版日期2012
• 单位哈尔滨工程大学