Electrochemical properties of α-Fe + Fe3C nanocrystalline composites in acidic environments

Regularities of the physicochemical behavior of α-Fe + Fe3C nanocomposites in a concentration range of cementite from 9 to 92 wt % in sulfate and chloride solutions are studied. Nanocrystalline state (∼40 nm) is found to intensify the active dissolution of α-Fe + Fe3C alloys and not noticeably affect the hydrogen evolution in acidic environments. With an increase in the cementite content or when it forms a reticular structure, the catalytic activity of α-Fe + Fe3C nanocrystalline composites with respect to the hydrogen evolution increases. Cementite manifests a higher overpotential of dissolution in both sulfate and chloride solutions.