Theoretical studies of large amplitude alternating current voltammetry for a reversible surface-confined electron transfer process coupled to a pseudo first-order electrocatalytic process

Novel characteristics associated with separated dc and ac harmonic components deduced from large amplitude alternating current voltammograms have been identified theoretically for the case where a surface confined electron transfer component is reversible and the coupled catalytic reaction involving dissolved substrate is pseudo first order. The assumptions that the surface confined process is Nernstian and the substrate concentration remains constant enable an analytical solution of current/time/frequency relationships to be obtained for the dc and all ac components. Equations derived reveal that while the catalytic reaction may modify the shape and current magnitude of the dc component, the shape of ac components remains invariant, and the influence on the magnitude is less for the higher ac harmonics. Thus, recent experimental observations that the Fourier transformed large amplitude ac method enables separation of electron transfer and catalytic processes in biologically important processes and ready measurements of reversible potentials, are confirmed theoretically. (c) 2006 Elsevier B.V. All rights reserved.