ELECTRODE-KINETICS OF FE(III) FE(II) REDOX COUPLE ON AN ELECTRODEPOSITED RUTHENIUM ELECTRODE/

The heterogeneous electron transfer in Fe(CN)6(4-/3-) and aquo complex es of Fe3+/2+ redox couples have been investigated on a ruthenized pla tinum electrode in 0.5 mol dm-3 sulphuric acid solution. Qualitative v oltammetric data measured on a rotating disc electrode showed that a r uthenized platinum layer was a good electronic conductor, which did no t block electron transfer in either direction of Fe(CN)6(4-/3-) redox couple. Quantitative electrode kinetic data were obtained using aquo c omplexes of Fe3+/2+ redox couple on a freshly deposited ruthenium elec trode and on an electrode activated to the state of enhanced oxygen ev olution from acid solution. The heterogeneous electron transfer rate c onstant of 3.9 x 10(-5) cm s-1 on the unactivated electrode increased by 30% in the case of the activated electrode.