LiCl-KCl共晶熔盐为乏燃料干法后处理中电解精炼过程常用的电解质,其对结构材料的腐蚀主要受熔盐中杂质的影响,通过熔盐纯化降低其腐蚀性是解决干法后处理材料腐蚀问题的重要手段之一。研究中使用电解法对LiCl-KCl盐进行纯化,通过循环...LiCl-KCl共晶熔盐为乏燃料干法后处理中电解精炼过程常用的电解质,其对结构材料的腐蚀主要受熔盐中杂质的影响,通过熔盐纯化降低其腐蚀性是解决干法后处理材料腐蚀问题的重要手段之一。研究中使用电解法对LiCl-KCl盐进行纯化,通过循环伏安电化学方法监测纯化过程,并使用电感耦合原子发射质谱(Inductively Coupled Plasma Mass Spectrometry,ICP-MS)测量LiCl-KCl盐纯化前后杂质元素含量。同时在773K、氩气环境下开展Inconel 600在纯化前后LiCl-KCl熔盐中500h的浸泡腐蚀实验,使用扫描电镜(Scanning Electron Microscopy,SEM)、X射线衍射仪(X-ray Diffractometer,XRD)对腐蚀后试样进行表征。结果显示:电解纯化对LiCl-KCl盐内金属离子杂质的去除效果显著,有效减缓了高温熔盐对Inconel 600的腐蚀。展开更多
A comprehensive electrochemical assessment of Fe^(2+)behavior in a MgCl_(2)−NaCl−KCl melt was reported,involving cyclic voltammetry(CV),square wave voltammetry(SWV),and chronoamperometry(CA)analyses.Reduction of Fe^(2...A comprehensive electrochemical assessment of Fe^(2+)behavior in a MgCl_(2)−NaCl−KCl melt was reported,involving cyclic voltammetry(CV),square wave voltammetry(SWV),and chronoamperometry(CA)analyses.Reduction of Fe^(2+)in MgCl_(2)−NaCl−KCl was observed to occur in a single step involving two electrons,exhibiting quasi-reversible behavior.The diffusion coefficient of Fe^(2+)(5.75×10^(-5)cm^(2)/s)in this system was experimentally determined at 973 K,with an associated diffusion activation energy of 25.06 kJ/mol in the range of 973−1048 K,and an estimated standard rate constant for Fe^(2+)/Fe of around 1×10^(-3)cm/s.The nucleation of Fe on the tungsten electrode in the MgCl_(2)−NaCl−KCl molten salt is insensitive to temperature and overpotential.It is found that the nucleation mode is related to the concentration of Fe^(2+)surrounding the electrode and evolves from an instantaneous to a progressive process,accompanied by a deterioration of magnesium electrolysis due to Fe impurities.展开更多
The alloying process of Mg-La in NaCl-KCl-MgCl_(2)-LaCl_(3)(NKML)melts during electroreduction was elucidated using electrochemical techniques and deep potential molecular dynamics(DPMD)simulations.In the NKML system,...The alloying process of Mg-La in NaCl-KCl-MgCl_(2)-LaCl_(3)(NKML)melts during electroreduction was elucidated using electrochemical techniques and deep potential molecular dynamics(DPMD)simulations.In the NKML system,the Mg^(2+)/La^(3+)electrodeposition on the tungsten(W)electrode at 973 K was found to be a one-step process.The nucleation of metal ions on the electrode surface followed an instantaneous nucleation mode and was not influenced by the alloying process.The redox potential and underpotential deposition behavior of the metal ions in the NKML system were accurately predicted by the DPMD simulations,confirming the alloying process of the Mg-La.Additionally,scanning electron microscopy with energy dispersive spectroscopy(SEM-EDS)analysis results confirmed that the cathodic deposits consisted of a bright phase and a dark phase,corresponding to the Mg-La alloys and Mg,respectively.The distribution of electrolytic products suggests that the cathodic deposit initially favors the Mg phase,with the Mg-La alloy forming more easily when the Mg source in the melt is depleted.展开更多
The reduction mechanism of Ir in the NaCl-KCl-IrCl3 molten salt was investigated by cyclic voltammetry and chronopotentiometry, and Ir film was deposited effectively on platinum in potentiostatic mode. The morphology ...The reduction mechanism of Ir in the NaCl-KCl-IrCl3 molten salt was investigated by cyclic voltammetry and chronopotentiometry, and Ir film was deposited effectively on platinum in potentiostatic mode. The morphology and constitution of Ir film were examined by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD）. It is found that the reduction mechanism of Ir（III） is a three-electron step and electro reaction is a reversible diffusion controlled process; the diffusion coefficients of Ir（III） at 1083, 1113, 1143 and 1183 K are 1.56×10-4, 2.23×10-4, 2.77×10-4 and 4.40×10-4 cm2/s, respectively, while the activation energy of the electrode reaction is 102.95 kJ/mol. The compacted Ir film reveals that the applied potential greatly affects the deposition of Ir, the thickness of Ir film deposited at the potential of reduction peak is the highest, the temperature of the molten salt also exerts an influence on deposition, the film formed at a lower temperature is thinner, but more micropores would occur on film when the temperature went too high.展开更多
文摘LiCl-KCl共晶熔盐为乏燃料干法后处理中电解精炼过程常用的电解质,其对结构材料的腐蚀主要受熔盐中杂质的影响,通过熔盐纯化降低其腐蚀性是解决干法后处理材料腐蚀问题的重要手段之一。研究中使用电解法对LiCl-KCl盐进行纯化,通过循环伏安电化学方法监测纯化过程,并使用电感耦合原子发射质谱(Inductively Coupled Plasma Mass Spectrometry,ICP-MS)测量LiCl-KCl盐纯化前后杂质元素含量。同时在773K、氩气环境下开展Inconel 600在纯化前后LiCl-KCl熔盐中500h的浸泡腐蚀实验,使用扫描电镜(Scanning Electron Microscopy,SEM)、X射线衍射仪(X-ray Diffractometer,XRD)对腐蚀后试样进行表征。结果显示:电解纯化对LiCl-KCl盐内金属离子杂质的去除效果显著,有效减缓了高温熔盐对Inconel 600的腐蚀。
基金the financial support provided by the National Key R&D Program of China(No.2022YFB3709300).
文摘A comprehensive electrochemical assessment of Fe^(2+)behavior in a MgCl_(2)−NaCl−KCl melt was reported,involving cyclic voltammetry(CV),square wave voltammetry(SWV),and chronoamperometry(CA)analyses.Reduction of Fe^(2+)in MgCl_(2)−NaCl−KCl was observed to occur in a single step involving two electrons,exhibiting quasi-reversible behavior.The diffusion coefficient of Fe^(2+)(5.75×10^(-5)cm^(2)/s)in this system was experimentally determined at 973 K,with an associated diffusion activation energy of 25.06 kJ/mol in the range of 973−1048 K,and an estimated standard rate constant for Fe^(2+)/Fe of around 1×10^(-3)cm/s.The nucleation of Fe on the tungsten electrode in the MgCl_(2)−NaCl−KCl molten salt is insensitive to temperature and overpotential.It is found that the nucleation mode is related to the concentration of Fe^(2+)surrounding the electrode and evolves from an instantaneous to a progressive process,accompanied by a deterioration of magnesium electrolysis due to Fe impurities.
基金support from the National Natural Science Foundation of China(No.U20A20147).
文摘The alloying process of Mg-La in NaCl-KCl-MgCl_(2)-LaCl_(3)(NKML)melts during electroreduction was elucidated using electrochemical techniques and deep potential molecular dynamics(DPMD)simulations.In the NKML system,the Mg^(2+)/La^(3+)electrodeposition on the tungsten(W)electrode at 973 K was found to be a one-step process.The nucleation of metal ions on the electrode surface followed an instantaneous nucleation mode and was not influenced by the alloying process.The redox potential and underpotential deposition behavior of the metal ions in the NKML system were accurately predicted by the DPMD simulations,confirming the alloying process of the Mg-La.Additionally,scanning electron microscopy with energy dispersive spectroscopy(SEM-EDS)analysis results confirmed that the cathodic deposits consisted of a bright phase and a dark phase,corresponding to the Mg-La alloys and Mg,respectively.The distribution of electrolytic products suggests that the cathodic deposit initially favors the Mg phase,with the Mg-La alloy forming more easily when the Mg source in the melt is depleted.
文摘The reduction mechanism of Ir in the NaCl-KCl-IrCl3 molten salt was investigated by cyclic voltammetry and chronopotentiometry, and Ir film was deposited effectively on platinum in potentiostatic mode. The morphology and constitution of Ir film were examined by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD）. It is found that the reduction mechanism of Ir（III） is a three-electron step and electro reaction is a reversible diffusion controlled process; the diffusion coefficients of Ir（III） at 1083, 1113, 1143 and 1183 K are 1.56×10-4, 2.23×10-4, 2.77×10-4 and 4.40×10-4 cm2/s, respectively, while the activation energy of the electrode reaction is 102.95 kJ/mol. The compacted Ir film reveals that the applied potential greatly affects the deposition of Ir, the thickness of Ir film deposited at the potential of reduction peak is the highest, the temperature of the molten salt also exerts an influence on deposition, the film formed at a lower temperature is thinner, but more micropores would occur on film when the temperature went too high.
