Large-amplitude fourier transformed high-harmonic alternating current cyclic voltammetry: Kinetic discrimination of interfering faradaic processes at glassy carbon and at boron-doped diamond electrodes

Significant advantages of Fourier transformed large-amplitude ac higher (second to eighth) harmonics relative to responses obtained with conventional small-amplitude ac of dc cyclic voltammetric methods have been demonstrated with respect to (i) the suppression of capacitive background currents, (ii) the separation of the reversible reduction of [Ru(NH₃)₆] ³⁺ from the overlapping irreversible oxygen reduction process under conditions where aerobic oxygen remains present in the electrochemical cell, and (iii) the kinetic resolution of the reversible [Ru(NH₃) ₆]^3+/2+ process in mixtures of [Fe(CN)₆,] ^3- and [Ru(NH₃)₆]³⁺ at appropriately treated boron-doped diamond electrodes, even when highly unfavorable [Fe(CN)₆]^3- to [Ru(NH₃)₆] ³⁺ concentration ratios are employed. Theoretical support for the basis of kinetic discrimination in large-amplitude higher harmonic ac cyclic voltammetry is provided.