Kinetics of electroreduction of peroxodisulfate anions on electrochemically polished single crystal Cd(0001) electrode has been studied using impedance spectroscopy. The influence of the electrode potential, the electrolyte as well as reactant concentrations on the kinetic parameters has been established. The fitting analysis of results demonstrates the influence of adsorption of the base electrolyte as well as reactant components (Na+ or ion complex at more negative electrode potentials and S2O82- or reaction intermediates at less negative surface charge densities) on the electroreduction rate of the S2O82- anions. (c) 2005 Elsevier B.V. All rights reserved.