Electrochemical Monitoring of Ni Corrosion Induced by Water in Eutectic LiCl-KCl

The corrosion of metallic nickel was studied in eutectic LiCl-KCl at 773 K while bubbling argon into the salt with a fixed concentration of H2O. The corrosion process was monitored electrochemically by using continuous open circuit potentiometry (OCP) and intermittent cyclic voltammetry (CV). The OCP of the Ni rod increased with time while H2O was bubbling into the molten salt. CV measurement results were consistent with a proposed mechanism which results in formation of NiCl2 based on matching the potentials of observed oxidation/reduction peaks. OCP reached a maximum plateau after prolonged bubbling, likely due to hydrolysis of the NiCl2. No solubility for NiO was measured in the eutectic LiCl-KCl, thus Ni concentrations in the salt stop rising once there is a balance between NiCl2 generation from corrosion and dissipation via hydrolysis. (C) The Author(s) 2018. Published by ECS.