Chronoamperometry of surface-confined redox couples for irreversible two-step and three-step consecutive reaction mechanisms

Chronoamperometry has been widely employed to determine kinetic rate constants for electron-transfer reactions of surface-confined redox couples. When the mechanism for the transformation is more complicated than a one- electron transfer, deviations can be expected from an exponential decay of the current transient. Theory is presented in this paper for irreversible, two-step and three-step consecutive reaction mechanisms in the form of analytical solutions of the corresponding differential equations. The theory should find application to surface electrode reactions with two-electron 'n- values'.