Redox Potential Measurements of Cr(II)/Cr Ni(II)/Ni and Mg(II)/Mg in Molten MgCl2–KCl–NaCl Mixture

The redox potential of Ni(II)/Ni, Cr(II)/Cr, and Mg(II)/Mg in MgCl2–KCl–NaCl (Magnak chloride) were studied utilizing chronopotentiometry (CP) method in a three-electrode electrochemical cell. Four different CrCl2 concentrations from 873 K to 1073 K, three NiCl2 concentrations from 773 K to 1073 K, and two MgCl2 concentrations from 823 K to 1073 K have been measured. The activity coefficients were calculated referring to a supercooled potential accordingly. The empirical equation of formal potential will be of great significance for the fundamental thermodynamic prediction in high-temperature Magnak chloride systems where corrosion product impurities are present.