Journal of Electroanalytical Chemistry, Vol.391, No.1-2, 111-118, 1995
Oxygen Reduction on Copper Chromium Manganites - Effect of Oxide Composition on the Reaction-Mechanism in Alkaline-Solution
The electrocatalytic oxygen reduction reaction (ORR) in 1 M KOH at 25 degrees C on Teflon-bonded Cr-(1-x)CuxMn2O4 + graphite electrodes with x = 0, 0.5, 0.75, 0.9 and 1 has been studied using the rotating-ring-disk technique. All manganites exhibited spinel structure with tetragonal distortion. The reaction rate depends on the [Mn4+]/[Cu2+ + Cr3+ + Mn3+] surface ratio. The ORR occurs through "interactive" and "parallel" pathways depending on the oxide composition parameter x. The most active oxide Cr0.25Cu0.75Mn2O4 shows the lowest OCP and the highest kinetic S-1 parameter.
Keywords:RING-DISK ELECTRODES;MIXED-OXIDE;ELECTROCATALYTIC REDUCTION;KINETIC-PARAMETERS;SPRAY PYROLYSIS;MANGANESE IONS;SURFACE-AREA;EVOLUTION;CO3O4;FILMS