Electrochemical characterization of sintered magnetite electrode in LiOH solution

In relation to the mitigation of flow assisted corrosion (FAC) occurring at the carbon steel materials at power plants, magnetite powder was sintered into pellets and used to construct electrodes for electrochemical property measurements in LiOH solutions at ambient conditions. Measurements indicated adsorption of hydroxide ions on the magnetite surface. Slow cathodic scanning removed the adsorbed OH− and returned the electrode surface to its original state. It is proposed that the cause of cyclic voltammetric (CV) peaks is the reduction of H2O involving the conduction band edge (EC) and valence band edge (EV) of the magnetite. Negative polarization by the CV produced hydrogen atoms and injected them into the magnetite body; these were oxidized when the sweep was reversed and then dissipated at the magnetite surface by contact with OH− ions. Results support the interaction of magnetite energy levels with adsorbed species, rather than the dissolution of magnetite.