An experimental comparison of the Marcus–Hush and Butler–Volmer descriptions of electrode kinetics applied to cyclic voltammetry. The one electron reductions of europium (III) and 2-methyl-2-nitropropane studied at a mercury microhemisphere electrode

Abstract

We present a comparative experimental evaluation of the Butler–Volmer and Marcus–Hush models using cyclic voltammetry at a microelectrode. Numerical simulations are used to fit experimental voltammetry of the one electron reductions of europium (III) and 2-methyl-2-nitropropane, in water and acetonitrile, respectively, at a mercury microhemisphere electrode. For Eu (III) very accurate fits to experiment were obtained over a wide range of scan rates using Butler–Volmer kinetics, whereas the Marcus–Hush model was less accurate. The reduction of 2-methyl-2-nitropropane was well simulated by both models, however Marcus–Hush required a reorganisation energy lower than expected.