Abstract:Electrochemical behavior of MgCl2 in NaCl-KCl-CaCl2 molten chloride mixture was investigated at 973 K with inert molybdenum electrode. Electrochemical methods such as square wave voltammetry (SWV), cyclic voltammetry (CV), chronoamperometry (CA) and chronopotentiometry (CP) were used to study reaction of Mg2+ on molybdenum electrodes. The results show that Mg2+ undergoes one-step reduction reaction (Mg2++2e=Mg) on molybdenum electrode, which is a reversible reaction controlled by diffusion. Nucleation mechanism of magnesium deposition on molybdenum substrate is instantaneous nucleation, which is consistent with formation and growth mechanism of hemispherical nucleus. The Mg2+ diffusion coefficients calculated by different methods of CV, CP and CA in 973 K are 1.09×10-5, 1.24×10-5 and 3.23×10-5 cm2/s, respectively. The product deposited by cathode at a given potential is Mg metal.