文献类型：期刊文献

英文题名：Investigation on electrochemical behaviors of Ni(II) impurity in LiCl-KCl melt

作者：Liu, Zhaoting[1];Lu, Guimin[1];Yu, Jianguo[1]

机构：[1]East China Univ Sci & Technol, Natl Engn Res Ctr Integrated Utilizat Salt Lake, Shanghai 200237, Peoples R China

年份：2021

卷号：268

外文期刊名：SEPARATION AND PURIFICATION TECHNOLOGY

收录：;EI(收录号：20211510196776);WOS:【SCI-EXPANDED(收录号:WOS:000647784900009)】；

基金：The authors acknowledge the financial support provided by the National Natural Science Foundation of China (Grant U20A20147).

语种：英文

外文关键词：Electrochemical behavior; Standard rate constant; Nucleation mechanism; Exchange current density

摘要：This work concerned the electrochemical behaviors of Ni(II) in LiCl-KCl melt at the temperature of 673 K. The methods of Cyclic voltammetry (CV), square wave voltammetry (SWV) and open circuit chronopotentiometry (OCP) were used during the investigation. The semi-integral curve derived from CV measurements showed that the reduction of Ni(II) was a quasi-reversible process. And the standard reaction rate constant of the order approximate to 10(-3) cm s(-1) , determined by Nicholson method, placed the redox reaction of Ni in the quasi-reversible range per Matsuda-Ayabe criteria. The apparent standard potential and activity coefficient of Ni(II) were studied by EMF measurements. According to the standard apparent potentials at different temperatures, the values of enthalpy and entropy changes were -269.293 kJ mol(-1) and 0.0965 kJ mol(-1) K-1, respectively. CA results showed that deposition of metal Ni on the tungsten cathode was an instantaneous nucleation process. Additionally, the diffusion coefficients calculated by semi-integral technique showed that the temperature dependence was consistent with Arrhenius' law. And the activation energy for diffusion of Ni(II) is 57.87 kJ mol(-1). Finally, the exchange current density of Ni on tungsten electrode was explored by linear polarization method.