Dissolution Behavior of an Iron–Aluminum Double Anode and the Physicochemical Properties of the Dissolution Products

The electrochemical behavior of an iron–aluminum double anode is studied in aqueous sodium chloride solutions. With no applied current, such a double anode has the form of a short-circuited galvanic couple and its surface is nearly equipotential, with the potential being intermediate between the open circuit potentials of individual aluminum and iron electrodes. At low polarization, the applied current almost entirely flows through the aluminum component of the double anode, while at higher polarization the fraction of current through the aluminum component falls and tends to a limiting value that is around twice as high as that for the iron component. This can enable us to control the dissolution rates of aluminum and iron electrodes upon their simultaneous oxidation in a synthesis of metal oxide precursors with a required phase composition by adjusting the ratio of the electrode surface areas.