首页|SrCl2-KCl-MgCl2熔体中氯化镁的电化学行为和镁锶共沉积机理

SrCl2-KCl-MgCl2熔体中氯化镁的电化学行为和镁锶共沉积机理

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采用循环伏安法、方波伏安法、开路电位等电化学手段评估SrCl2-KCl共晶体系中MgCl2的电化学行为和Mg、Sr共沉积机理.在SrCl2-KCl体系中,Mg(Ⅱ)在钨电极的还原属于一步两电子的准可逆过程;Mg、Sr的电化学共沉积过程形成两种Mg-Sr金属间化合物.基于计时电流法探索共沉积过程的成核类型随过电位的演变关系,结果显示,电极表面的成核模式依赖于基体材料和电极反应产物.所有过电位下对应的前期成核归因于Mg(Ⅱ)的还原.当Mg和Sr共同沉积时,首先是Mg(Ⅱ)在电极表面还原,形成Mg核,随后同时进行Sr(Ⅱ)在Mg表面欠电位沉积和Mg的沉积.此外,随着SrCl2-KCl体系中MgCl2浓度的增加,Mg-Sr共沉积过程中的电流密度相应增加.
Electrochemical behavior of MgCl2 and co-deposition mechanisms of Mg and Sr in SrCl2-KCl-MgCl2 melt
The electrochemical behavior of MgCl2 and the co-deposition mechanisms of Mg and Sr in the SrCl2-KCl eutectic system were evaluated using various electrochemical techniques,including cyclic voltammetry(CV),square wave voltammetry(SWV),and open-circuit potential(OCP)analysis.It was observed the Mg(Ⅱ)reduction on the tungsten electrode in SrCl2-KCl melt occurred in a single-step process involving the transfer of two electrons,exhibiting a quasi-reversible mode.The electrochemical co-deposition of Mg and Sr in the SrCl2-KCl-MgCl2 melt involved the formation of two types of Mg-Sr intermetallic compounds.The evolution in the co-deposition mechanism of the nucleation type with changing overpotential was explored through chronoamperometry(CA).It is shown that the nucleation pattern on the electrode surface was depended on the substrate materials and the electrode reaction products.Early-stage nucleation was attributed to Mg(Ⅱ)reduction under all overpotential conditions.With the co-deposition of Mg and Sr,Mg(Ⅱ)was reduced to form the Mg nucleus on the electrode surface,followed by underpotential deposition of Sr(Ⅱ)on the Mg surface accompanied by Mg deposition simultaneously.Additionally,increasing MgCl2 concentration in the SrCl2-KCl melt resulted in a higher current density during the Mg-Sr co-deposition process.

MgCl2electrochemical behaviordiffusion coefficientnucleation mechanismco-deposition

赵佳、闫艺航、张皓、高华阳、张烨、路贵民

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华东理工大学国家盐湖资源综合利用工程技术研究中心,上海 200237

华东理工大学钾锂战略资源国际联合实验室,上海 200237

华东理工大学化工学院,上海 200237

氯化镁 电化学行为 扩散系数 成核机理 共沉积

National Natural Science Foundation of China

U20A20147

2024

中国有色金属学报(英文版)
中国有色金属学会

中国有色金属学报(英文版)

CSTPCD
影响因子:1.183
ISSN:1003-6326
年,卷(期):2024.34(7)