A New Approach for the Preparation of Variable Valence Rare Earth Alloys from Nano Rare Earth Oxides at a Low Temperature in Molten Salt

Author(s)

Milin Zhang
Yongde Yan
Wei Han
Xing Li
Zhiyao Hou
Yang Tian
Ke Ye
Lihong Bao
Xiaodong Li, University of South Carolina - ColumbiaFollow
Zhijian Zhang

Document Type

Article

Abstract

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 °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 insquare 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.

Publication Info

Published in RSC Advances, Volume 2, Issue 4, 2012, pages 1585-1591.

Rights

©RSC Advances 2012, Royal Society of Chemistry.

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This article was first published by the Royal Society of Chemistry and can be found at http://dx.doi.org/10.1039/C1RA00285F

Zhang, M., Yan, Y., Han, W., Li, D., Hou, Z., Tian, Y., Ye, K., Bao, L., Li, X., & Zhang, Z. (21 February 2012). A New Approach for the Preparation of Variable Valence Rare Earth Alloys from Nano Rare Earth Oxides at a Low Temperature in Molten Salt. RSC Advances, 2(4), 1585 – 1591. http://dx.doi.org/10.1039/C1RA00285F