Cyclic reciprocal derivative chronopotentiometric behavior of electrode process in the presence of adsorptive reactants: A theoretical study of the electrolysis sequence of adsorptive and diffusing electroactive reactants

Theoretical modeling and analyzing of electrode process in the presence of adsorptive reactants is presented using cyclic reciprocal derivative chronopotentiometry (CRDCP) with symmetrical programmed current applied. Electrode process proposed based on the assumption of the electrolysis sequence of diffusion and adsorbed electroactive species is described as “on first, off last” and denoted as Onfol model. The numerical simulated (dt/dE)–E waves obtained from the analytical potential-time expressions of the Onfol model present peaks during both “diffusion processes” and “adsorption processes”. Influences of maximum surface excess, adsorbed monolayer thickness, adsorption coefficient and current steps on CRDCP characteristic parameters are discussed. CRDCP behavior allows us to distinguish the form of the electroactive species contributing to the system current and electrolysis sequence can therefore be determined.