HOMOGENEOUS AND HETEROGENEOUS CATALYTIC REACTIONS IN COBALT OXIDE GRAPHITE AIR ELECTRODES .1. CHEMICAL-KINETICS OF PEROXIDE DECOMPOSITION BY CO(II) IONS IN ALKALINE-SOLUTIONS

This paper considers the role played by dissolved cobaltous ions in concentrated alkaline solutions in the homogeneous decomposition of H2O2 and its significance to oxygen reduction in alkaline media. Dissolved cobaltous ions, in the form of HCoO2 − in concentrated alkaline solutions, show a very high catalytic activity for the decomposition of H2O2 even at a concentration of 1 ppm. The homogeneous decomposition of peroxide is not a simple first-order reaction as reported in literature but is a 1.2 order reaction. It is suggested that kinetics of decomposition of H2O2 in the presence of Co3O4 is controlled by the homogeneous catalytic reaction of the HCoO2 − ions, the heterogeneous redox reaction between HCoO2 − ions in solution, and the Co3+ ions in the cobalt oxide spinel lattice sites. © 1990, The Electrochemical Society, Inc. All rights reserved.