Heterogeneous electron-transfer rate constants for Fe(H2O)63+/2+ at metal oxide electrodes

The title redox couple, in noncoordinating perchlorate medium, has been used to probe the electrochemical behavior of different IrO 2 -based electrodes; pure oxide electrodes, as well as IrO 2 -SnO 2 mixtures, have been investigated. The obtained results show that the electrode material strongly affects the electrochemical response. A tentative explanation, based on the different point of zero charge of the considered oxides, is presented.