An electrochemical study of dysprosium（III） on Bi film electrode was carried out in eutectic LiCl-KCI melts by transient and steady state electrochemical techniques.The results of transient electrochemical technique...An electrochemical study of dysprosium（III） on Bi film electrode was carried out in eutectic LiCl-KCI melts by transient and steady state electrochemical techniques.The results of transient electrochemical techniques showed that the reduction of Dy（III） appears at a more positive value than the one detected on W electrode owing to the formation of Bi-Dy intermetallic compounds through electrochemical deposition of Dy on bismuth film electrode.The thermodynamic properties of the formation for Dy-Bi intermetallics were estimated by a steady state electrochemical method in a temperature range of 713-803 K.Furthermore,the electrochemical preparation of Bi-Dy alloys was conducted by galvanostatic electrolysis at different current intensities.The Bi-Dy alloys,characterized by scanning electron microscopy equipped with energy dispersive spectrometry and X-ray diffraction,are comprised of DyBi3/5 and DyBi phases展开更多
The electrochemical reduction mechanism of hafnium ion（IV） was studied in NaC1-KC1-K2HfC16 melts on a molybdenum electrode. The cyclic voltammetry study shows that Hf（IV） is reduced to hafnium metal in double two-...The electrochemical reduction mechanism of hafnium ion（IV） was studied in NaC1-KC1-K2HfC16 melts on a molybdenum electrode. The cyclic voltammetry study shows that Hf（IV） is reduced to hafnium metal in double two-electron process, that is： Hf（IV） ＋ 2e→Hf（II） and Hf（II） ＋ 2e- →Hf, and the electrochemical reduction of Hf（IV） pro- cess was diffusion-controlled. The diffusion coefficients were calculated at several temperatures, and the results obey the Arrhenius law. According to the relationship oflnD versus 1/T, the corresponding activation energy was determined to be 158.8 kJ.mol- x. The square wave voltammetry results further confirm the reduction mechanism of hafnium.展开更多
The mechanism of rare earth metals (Gd and Dy) chloride complexes electroreduction on the tungsten electrode in equimolar NaCl-KCl melt at 973 K has been studied by linear and cyclic voltammetry. Some kinetic paramete...The mechanism of rare earth metals (Gd and Dy) chloride complexes electroreduction on the tungsten electrode in equimolar NaCl-KCl melt at 973 K has been studied by linear and cyclic voltammetry. Some kinetic parameters of processes were calculated. It was shown that the tungsten electrode was indifferent to gadolinium and dysprosium which were reduced on the surface. We found that the discharge mechanism of gadolinium and dysprosium chloride complexes was described by three-electron step when the steady-state conditions of polarization were limited by the mass transfer stage. The conditions of nonstationary polarization made the slowness of the charge transfer stage. The diffusion coefficient of gadolinium and dysprosium ions was calculated, the diffusion coefficient of GdCl3-6 ions was (0.9 ± 0.2) × 10-5 cm2.s-1, and for DYCI3-6 ions, it was (1.60 ± 0.2) × 10-5 сm2.s-1.展开更多
The electrode process of cerium（III） on the Mo electrode in eutectic LiC1-KC1 melt was investigated by electrochemical transient techniques in the temperature range of 673-783 K, respectively. These results unanimou...The electrode process of cerium（III） on the Mo electrode in eutectic LiC1-KC1 melt was investigated by electrochemical transient techniques in the temperature range of 673-783 K, respectively. These results unanimously indicated that the reduction proc- ess of cerium（III） to cerium metal was a single step exchanging three electrons which was controlled by diffusion of cerium（III）. Dif- fusion coefficients （Dce0II）） in eutectic LiC1-KC1 melt were determined by cyclic voltammetry, chronopotentiometry and square wave voltammetry. An empirical diffusion coefficient function depending on temperature was proposed： lnDce（Ⅲ）--2.129-5704/T. The formal potentials （E^θCe（Ⅲy/Ce（0） versus Ag/AgCl reference electrode） at different temperatures were obtained from chronopotentiometry, which were --2.10 V （673 K） and -2.07 V （733 K）, respectively.展开更多
The electrochemical behavior of Pr（Ⅲ） and formation process of Pr-Al intermetallics were investigated by different electrochemical methods. The reduction of Pr（Ⅲ） ion to metallic Pr is an one-step three-electron...The electrochemical behavior of Pr（Ⅲ） and formation process of Pr-Al intermetallics were investigated by different electrochemical methods. The reduction of Pr（Ⅲ） ion to metallic Pr is an one-step three-electrons reaction. The reversibility of Pr（Ⅲ）/Pr（0） system was evaluated by cyclic voltammograms with different scan rates. The co-reduction of Pr（Ⅲ） and Al（Ⅲ） ions formed three different Pr-Al intermetallics at electrode potentials around-1.40,-1.80,and-1.95V vs.Ag/AgCl at 723 K,respectively.Open-circuit chronopotentiometry and electromotive force（emf） measurements were carried out to estimate the relative molar Gibbs energies of Pr for the formation of different Pr-Al intermetallics in the temperature range of 723–843K.The activities of Pr in the Pr-Al intermetallic compounds were calculated.展开更多
The electrochemical behaviour of magnesium（Ⅱ） and the formation mechanism of Mg-Ni alloys on Ni electrode were studied in LiCl-KCl eutectic using various electrochemical techniques. Cyclic voltammogram and square-w...The electrochemical behaviour of magnesium（Ⅱ） and the formation mechanism of Mg-Ni alloys on Ni electrode were studied in LiCl-KCl eutectic using various electrochemical techniques. Cyclic voltammogram and square-wave voltammogram revealed that under-potential deposition of magnesium occurred on Ni electrode because Mg-Ni alloy compounds were formed. The thermodynamic properties of the Mg-Ni intermetaUics, Mg2Ni and MgNi2, were determined using open circuit chronopotentiometry in the temperature range of 8186893 K. Moreover, the Mg-Ni alloys were produced by potentiostatic and galvanostatic electrolysis under different conditions and characterized by means of scanning electron microscopy（SEM） equipped with energy dispersive spectrometry（EDS） and X-ray diffraction（XRD）. The experimental results indicate that Mg-Ni intermetaUic compounds can be selectively produced by potentiostatic electrolysis.展开更多
This work presents the results of joint electroreduction of tetrafluorborate and cerium-ions, and determines the conditions of electrochemical synthesis of cerium borides in KCl-NaCl melts at the 973 K on tungsten ele...This work presents the results of joint electroreduction of tetrafluorborate and cerium-ions, and determines the conditions of electrochemical synthesis of cerium borides in KCl-NaCl melts at the 973 K on tungsten electrode by the linear and cyclic voltammetry. Based on the current-voltage studies the optimal modes of cerium boride electrodeposition were found.展开更多
基金Project supported by the National Natural Science Foundation of China(11675044,11575047,21790373,21271054,21173060)the Major Research plan of the National Natural Science Foundation of China(91326113,91226201)
文摘An electrochemical study of dysprosium（III） on Bi film electrode was carried out in eutectic LiCl-KCI melts by transient and steady state electrochemical techniques.The results of transient electrochemical techniques showed that the reduction of Dy（III） appears at a more positive value than the one detected on W electrode owing to the formation of Bi-Dy intermetallic compounds through electrochemical deposition of Dy on bismuth film electrode.The thermodynamic properties of the formation for Dy-Bi intermetallics were estimated by a steady state electrochemical method in a temperature range of 713-803 K.Furthermore,the electrochemical preparation of Bi-Dy alloys was conducted by galvanostatic electrolysis at different current intensities.The Bi-Dy alloys,characterized by scanning electron microscopy equipped with energy dispersive spectrometry and X-ray diffraction,are comprised of DyBi3/5 and DyBi phases
基金financially supported by the National Natural Science Foundation of China(No.51204021)the National Science and Technology Plan of China(No.2012BAB10B10)
文摘The electrochemical reduction mechanism of hafnium ion（IV） was studied in NaC1-KC1-K2HfC16 melts on a molybdenum electrode. The cyclic voltammetry study shows that Hf（IV） is reduced to hafnium metal in double two-electron process, that is： Hf（IV） ＋ 2e→Hf（II） and Hf（II） ＋ 2e- →Hf, and the electrochemical reduction of Hf（IV） pro- cess was diffusion-controlled. The diffusion coefficients were calculated at several temperatures, and the results obey the Arrhenius law. According to the relationship oflnD versus 1/T, the corresponding activation energy was determined to be 158.8 kJ.mol- x. The square wave voltammetry results further confirm the reduction mechanism of hafnium.
文摘The mechanism of rare earth metals (Gd and Dy) chloride complexes electroreduction on the tungsten electrode in equimolar NaCl-KCl melt at 973 K has been studied by linear and cyclic voltammetry. Some kinetic parameters of processes were calculated. It was shown that the tungsten electrode was indifferent to gadolinium and dysprosium which were reduced on the surface. We found that the discharge mechanism of gadolinium and dysprosium chloride complexes was described by three-electron step when the steady-state conditions of polarization were limited by the mass transfer stage. The conditions of nonstationary polarization made the slowness of the charge transfer stage. The diffusion coefficient of gadolinium and dysprosium ions was calculated, the diffusion coefficient of GdCl3-6 ions was (0.9 ± 0.2) × 10-5 cm2.s-1, and for DYCI3-6 ions, it was (1.60 ± 0.2) × 10-5 сm2.s-1.
基金supported by the National Basic Research Program of China (2007CB209900)
文摘The electrode process of cerium（III） on the Mo electrode in eutectic LiC1-KC1 melt was investigated by electrochemical transient techniques in the temperature range of 673-783 K, respectively. These results unanimously indicated that the reduction proc- ess of cerium（III） to cerium metal was a single step exchanging three electrons which was controlled by diffusion of cerium（III）. Dif- fusion coefficients （Dce0II）） in eutectic LiC1-KC1 melt were determined by cyclic voltammetry, chronopotentiometry and square wave voltammetry. An empirical diffusion coefficient function depending on temperature was proposed： lnDce（Ⅲ）--2.129-5704/T. The formal potentials （E^θCe（Ⅲy/Ce（0） versus Ag/AgCl reference electrode） at different temperatures were obtained from chronopotentiometry, which were --2.10 V （673 K） and -2.07 V （733 K）, respectively.
基金Project supported by the Fundamental Research Funds for the Central Universities(HEUCF201403001)the National Natural Science Foundation of China(21507118)
文摘The electrochemical behavior of Pr（Ⅲ） and formation process of Pr-Al intermetallics were investigated by different electrochemical methods. The reduction of Pr（Ⅲ） ion to metallic Pr is an one-step three-electrons reaction. The reversibility of Pr（Ⅲ）/Pr（0） system was evaluated by cyclic voltammograms with different scan rates. The co-reduction of Pr（Ⅲ） and Al（Ⅲ） ions formed three different Pr-Al intermetallics at electrode potentials around-1.40,-1.80,and-1.95V vs.Ag/AgCl at 723 K,respectively.Open-circuit chronopotentiometry and electromotive force（emf） measurements were carried out to estimate the relative molar Gibbs energies of Pr for the formation of different Pr-Al intermetallics in the temperature range of 723–843K.The activities of Pr in the Pr-Al intermetallic compounds were calculated.
基金supported by the High Technology Research and Development Program of China(2011AA03A409)National Natural Science Foundation of China(21103033,21101040,91226201)+2 种基金China Postdoctoral Science Foundation(2013T60344)Fundamental Research Funds for the Central Universities,China(HEUCF201310012)Foundation for University Key Teacher of Heilongjiang Province of China(1253G016)~~
基金supported by the National Natural Science Foundation of China (21271054, 21173060)Major Research Plan of the National Natural Science Foundation of China (91326113, 91226201)Fundamental Research Funds for the Central Universities, China (HEUCF201403001)~~
基金Supported by the National Natural Science Foundation of China（Nos.11675044, 11575047, 21790373 and 21271054）, the Major Research Plan of the National Natural Science Foundation of China（Nos. 91326113, 91226201） and the Fundnmental Research Funds for the Central Universities, China（No.HEUCFP201790）.
文摘The electrochemical behaviour of magnesium（Ⅱ） and the formation mechanism of Mg-Ni alloys on Ni electrode were studied in LiCl-KCl eutectic using various electrochemical techniques. Cyclic voltammogram and square-wave voltammogram revealed that under-potential deposition of magnesium occurred on Ni electrode because Mg-Ni alloy compounds were formed. The thermodynamic properties of the Mg-Ni intermetaUics, Mg2Ni and MgNi2, were determined using open circuit chronopotentiometry in the temperature range of 8186893 K. Moreover, the Mg-Ni alloys were produced by potentiostatic and galvanostatic electrolysis under different conditions and characterized by means of scanning electron microscopy（SEM） equipped with energy dispersive spectrometry（EDS） and X-ray diffraction（XRD）. The experimental results indicate that Mg-Ni intermetaUic compounds can be selectively produced by potentiostatic electrolysis.
文摘This work presents the results of joint electroreduction of tetrafluorborate and cerium-ions, and determines the conditions of electrochemical synthesis of cerium borides in KCl-NaCl melts at the 973 K on tungsten electrode by the linear and cyclic voltammetry. Based on the current-voltage studies the optimal modes of cerium boride electrodeposition were found.
基金National Natural Science Foundation of China(51441003)Qinghai Natural Science Foundation(2015-ZJ-931Q)+1 种基金Research Foundation of Jimei University(ZQ2021052)National Key Research and Development Program(2020YFE0100100)。
