The Effect of Protonated Ethionine Adsorption on Bi(III) Electroreduction in Chlorate(VII) Solutions with Varied Water Activity

摘要

The Bi(III) electroreduction in the presence of the ethionine (Et) was studied under its different protonation and changes of water activity. In order to determine adsorption and kinetic parameters, the following were applied: DC polarography, square wave voltammetry (SWV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The influence of ethionine on the double-layer parameters at the electrode/chlorate (VII) interface and multistep Bi(III) ion electroreduction was found. The multistep Bi(III) electroreduction process is controlled by the kinetics of the formation of active Bi–Et complexes on the electrode surface. The size of the catalytic effect is connected with the equilibrium of the reaction creating active complexes before the successive transition of electrons. Graphical Abstract ?.