Electrochemical generation of ferrate on SnO2-Sb2O3/Ti electrodes in strong concentration basic condition

The excellent over-potential with respect to the OER in strong basic solution of the SnO2-Sb2O3/Ti anode was applied to the investigation of the electrochemical behaviour of the redox couple FeO42-/FeO2-. The results proved that ferrate could be generated by the electrochemical path without any side reaction of OER on the electrode of SnO2-Sb2O3/Ti. At the same time, the formation of Fe(III) species, which formed a redox couple with FeO42- in strong basic solution, was confirmed as exclusively FeO2-. The generation of FeO2- and the ionization of Fe(III) hydroxide in very high concentration basic environment were explored and discussed. The results proved that acidity and acidic ionization of Fe(III) hydroxide play an un-neglected role for the safe rechargeable super-iron battery. Furthermore the mechanism of electrochemical generation of ferrate was investigated and exhibited as the mechanism of CEC. The relative barriers for the manufacture of secondary super-iron battery were discussed. (C) 2004 Elsevier B.V. All rights reserved.