Oxygen reduction on iron. Part III. An analysis of the rotating disk-ring electrode measurements in near neutral solutions
Abstract
The kinetics of oxygen reduction were studied on iron in borate and bicarbonate buffered solutions, pH 9.8, using the rotating disk-ring method. Under these conditions O2 reduction occurs both on the oxidized surface and on the oxide-free one, depending on potential. On the oxidized surface the series mechanism was found to be operative. On the oxide-free surface the four-electron reduction was observed, but, due to the very small rate of H2O2 formation with respect to the total reduction current, a reliable distinction between the parallel and series mechanism could not be made. All the rate constants of the O2 and H2O2 reactions on the Fe surface were determined. No catalytic decomposition of H2O2 was found. The kinetics of the O2 reduction reaction is slower on more oxidized surfaces.
Keywords:
oxygen reduction / iron / The kinetics of oxygen reduction / rotating disk-ring methodSource:
Journal of Electroanalytical Chemistry, 1989, 265, 1-2, 179-193Publisher:
- Elsevier
Projects:
- National Science Foundation (U.S.A.), contract No. JFP 522/NSF
- Research Fund of the S.R. Serbia