Effects of Amino Acids Protonation on Double-Layer Parameters of the Electrode/Chlorates(VII) Interface, as well as Kinetics and Mechanism of Bi(III) Ion Electroreduction in the Aspect of the “Cap–Pair” Effect

Abstract

It was found that both water activity and the presence of differently protonated homocysteine (HCE), homocystine (HCY) and ethionine (ET) affect on double layer parameters at the electrode/chlorates(VII) interface and multi-step Bi(III) ion electroreduction. The catalytic activity of amino acids increases in the order ET< HCY < HCE of large water activity (2 molndm-3 chlorate(VII)). For higher concentrations of chlorates(VII) (4 and 6 molndm-3 chlorate(VII)) there is observed a comparable effect of studied amino acids on the Bi(III) ions electroreduction rate particulary in the case of HCE and HCY. The mechanism of the catalytic effects of amino acids is associated with the formation of active complexes under specific conditions present on the electrode surface.