Electrochemical measurement of solubility product of metal oxides in liquid metals by coulometric titration of oxygen

Giacomo Gregori, Alexander Aerts, Kristof Gladinez, Kris Rosseel, Thomas Doneux, Jun Lim

Research outputpeer-review


We propose a new electrochemical method for the measurement of the solubility product of the oxide of a metal impurity, in a liquid metal solvent that is less easily oxidized than the metal impurity. When a known amount of oxygen is continuously added into the liquid metal by coulometric titration, the dissolved metal impurity reacts with the added dissolved oxygen, forming a metal oxide. By measuring the concentration of dissolved oxygen in the liquid metal solvent during the titration, the solubility product of the impurity metal oxide in the liquid metal solvent can be derived. From this solubility product, using thermochemical data of the known chemical species involved in the oxidation reaction, i.e. Sieverts’ constant of dissolved oxygen in the liquid metal solvent and the Gibbs free energy of formation of the impurity metal oxide, the elemental solubility of the metallic impurity element in the liquid metal solvent can be derived as well. In this work, we validate the method by measuring the solubility product of magnetite (Fe3O4) in molten lead-bismuth eutectic alloy (LBE), in the temperature range of 723–826 K.
Original languageEnglish
Article number141202
Number of pages7
JournalElectrochimica Acta
StatePublished - 10 Nov 2022

Cite this