Electrochemical reactions with adsorption of the reactants and electrosorption. Simple analytical solutions for a Henry isotherm

Abstract A theoretical treatment of an electrochemical reaction O + ne− R with adsorption of the reactants is presented when the adsorption, at equilibrium, obeys a Henry isotherm. A simple analytical solution, valid for any degree of adsorption of O and or R, is established for a polarographic wave. In LSV, for slow sweep rates and weak adsorption, both the cathodic and anodic peaks have a ‘diffusional’ character; for high sweep rates and strong adsorption, they are both of a ‘surface’ nature. In the intermediate case, one peak has a ‘diffusional’ character (deposition process), while the other is of a ‘surface’ nature (redissolution process). Expressions of the peak potentials are given i…