Giving physical insight into the Butler-Volmer model of electrode kinetics: Application of asymmetric Marcus-Hush theory to the study of the electroreductions of 2-methyl-2-nitropropane, cyclooctatetraene and europium(III) on mercury microelectrodes

► Quantitative application of the asymmetric Marcus-Hush kinetic model is reported. ► Electroreductions of 2-methyl-2-nitropropane, cyclooctatetraene and Eu3+ are studied. ► Symmetric MH fits cyclic and square wave voltammetry in all cases. ► Kinetic parameters are obtained leading to physical insight of electroactive species. ► Physical interpretation for the Butler-Volmer transfer coefficient is proposed.