文献类型：期刊文献

英文题名：Electrochemical behavior of SO?2? in chloride molten salt electrolysis

作者：Du, Yushuang[1,2]; Sun, Ze[1,2]; Jia, Xiaoqiang[3]; Lu, Guimin[1,2]

机构：[1] National Engineering Research Center for Integrated Utilization of Salt Lake Resources, East China University of Science and Technology, Shanghai, 200237, China; [2] Joint International Laboratory for Potassium and Lithium Strategic Resources, East China University of Science and Technology, Shanghai, 200237, China; [3] Inner Mongolia Moris Energy Materials Co., Ltd, Ordos, 014399, China

年份：2025

卷号：541

外文期刊名：Electrochimica Acta

收录：EI(收录号：20253719164175)

语种：英文

外文关键词：Boron compounds - Cyclic voltammetry - Electrodeposition - Electron transitions - Energy dispersive spectroscopy - Magnesium compounds - Nucleation - Potassium chloride - Reduction - Sulfur compounds - Thermoanalysis - X ray diffraction

摘要：Electrolysis in chloride molten salts is widely recognized as a key method for producing reactive metals such as Na, K, Mg, Ca, and selected rare earth elements. Sulfate (SO?2?) impurities are known to significantly influence the electrolysis process and often reduce current efficiency. In this study, the electrochemical behavior of SO?2? was investigated in a eutectic MgCl?–KCl system through the addition of MgSO?. Cyclic voltammetry (CV) and square wave voltammetry (SWV) identified two new irreversible cathodic peaks, corresponding to electron transfer numbers of approximately 4 and 2, respectively. Chronoamperometry (CA) showed that these processes followed instantaneous and progressive 3D nucleation mechanisms. Open circuit potential (OCP) and chronopotentiometry (CP) measurements exhibited three distinct plateaus, suggesting a staged reduction sequence. A novel multi-step reduction mechanism of SO?2? → SO? → S? → MgS was proposed and experimentally supported for the first time, based on energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and thermodynamic analysis. This work clarifies the stepwise reduction of SO?2? in chloride molten salts and offers practical insights for improving metal electrodeposition processes under sulfate-containing conditions. ? 2025 Elsevier Ltd