Reduction Kinetics of Praseodymiun Chloride in the Equimolar NaCl-KCl Melt

The interest in molten salt systems with rare-earth metals (REM) is caused by their use in many industries. This is due to the ability when introducing even small amounts of REM into other metals to give the latter unique properties. The surface metal treatment is a promising method for the formation of such coatings. Although current less diffusion coatings are formed without the application of an electric current, the process of coating formation has an electrochemical nature since it includes the stage of REM ion reduction. Since REMs and their alloys are promising materials, it is necessary to comprehensively study the processes of cathode reduction of REM ions in molten salt electrolytes. These problems for rare-earth metals under high-temperature conditions have not been sufficiently studied. In this work we have determined the kinetic parameters (transport coefficients, heterogeneous constants of the charge transfer rate) of cathode reduction of praseodymium ion in the equimolar NaCl-KCl melt by chronopotentiometry and chronovoltamperometry. The dependences of the kinetic parameters on temperature and the rare-earth metal chloride concentration are presented. A mechanism is proposed for the reduction of the complex in the equimolar NaCl-KCl melt

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