Physico-chemical Properties of the Molten CuCl–CuCl2 System: Experiment, Thermodynamics and Molecular Dynamics Simulations

Abstract

The molten CuCl–CuCl2 system was studied by means of the maximum bubble pressure method, thermodynamics and molecular dynamics simulations at temperatures of 835, 866, 905 and 943 K. The equilibrium constant of CuCl2 decomposition has been determined with thermodynamic simulation. The density and molar volume of the CuCl–CuCl2 system were established as a function of composition. Some evidence of ideality of CuCl–CuCl2 solutions was observed. The molar volumes of pure liquid CuCl2 are equal to 44.64, 46.23, 46.55 and 46.81 cm3·mol−1 at 835, 866, 905 and 943 K, correspondingly. Radial distribution functions, coordination numbers, self-diffusion coefficients and trajectories of motion were obtained by molecular dynamics simulation. For this reason a new pair potential for Cu2+–Cl− pair has been designed. The coordination number of Cu2+ by Cl− is about 4. This value corresponds to literature data with regards to this coordination. The self-diffusion coefficients are close to diffusion coefficients measured in molten salts solutions.