Potential-pH Diagrams of Iron in Concentrated Aqueous LiBr Solutions at 25°C

Potential-pH diagrams of iron are developed in aqueous LiBr solutions with concentrations of 400 g/L, 700 g/L, 850 g/L, and 992 g/L LiBr at 25°C, which are common concentrations in different parts of absorption machines. Comparison of the potential-pH diagrams of iron in the absence and the presence of concentrated aqueous LiBr solutions shows that the corrosion area at acid, neutral, and weak alkaline pH extends to lower potentials and higher pH values with the increase of LiBr concentration, as a result of formation of the aqueous species FeBr₂(aq) and FeBr₃(aq) and destabilization of the solid species Fe, Fe(OH)₂(s), Fe₃O₄, and Fe₂O₃.