不同Lewis酸度的AlCl₃-NaCl体系中Sm(II)的电化学行为及化学物种

Electrochemical Behaviour and Chemical Species of Sm(II) in AlCl -NaCl with Different Lewis Acidity.

作者信息

Chen Jiazhuang, Zhong Yuke, Liu Yalan, Zhang Lei, Li Mei, Han Wei, Chai Zhifang, Shi Weiqun

机构信息

Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China.

Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, China.

出版信息

Chemistry. 2022 Jul 26;28(42):e202200443. doi: 10.1002/chem.202200443. Epub 2022 Jun 16.

DOI:10.1002/chem.202200443

PMID:35608191

Abstract

AlCl -NaCl was utilized as an electrolyte in this work due to its low melting point and Lewis acidity, in which samarium exists in two oxidation states, Sm(III) and Sm(II), resulting in unique electrochemical behaviours. Sm metal dissolves in AlCl -NaCl melt to form SmCl , which is verified by electrochemical and spectroscopic techniques. As the Lewis acidity of the melt increases, the diffusion coefficient of Sm(II) gradually increases, and the activation energy of diffusion decreases. Moreover, an additional co-reduction peak of Sm and AlCl is observed to be more positive than that of Al(0)/Al(III) in Lewis basic melt, which may be tightly correlated with the variation of Sm(II) coordination in AlCl -NaCl melt and ligand variation from Cl to AlCl and Al Cl as the Lewis acidity of the AlCl -NaCl melt increases, according to the in situ electronic absorption spectra of Sm in this melt.

摘要

在本工作中，AlCl₃-NaCl因其低熔点和路易斯酸性而被用作电解质，其中钐以两种氧化态Sm(III)和Sm(II)存在，导致独特的电化学行为。钐金属溶解在AlCl₃-NaCl熔体中形成SmCl₃，这已通过电化学和光谱技术得到证实。随着熔体路易斯酸性的增加，Sm(II)的扩散系数逐渐增大，扩散活化能降低。此外，在路易斯碱性熔体中观察到Sm和AlCl₃的一个额外的共还原峰比Al(0)/Al(III)的更正向，根据该熔体中Sm的原位电子吸收光谱，这可能与AlCl₃-NaCl熔体中Sm(II)配位的变化以及随着AlCl₃-NaCl熔体路易斯酸性增加配体从Cl变为AlCl₄⁻和Al₂Cl₇⁻密切相关。