Potentiostatic response when reactant and product are adsorbed at an electrode expanding with any power law or at a DME (expanding sphere electrode model)

Abstract

Equations for a potentiostatic reversible reaction with an adsorption process following Henry's isotherm have been derived for an electrode expanding according to the law A( t) = A 0 t z , where A( t) is the area of the electrode. Hence, these equations can be applied both for a stationary plane electrode and for a DME (expanding plane electrode model) by making z = 0 and z = 2 3 , respectively. In addition, we have also derived the corresponding equations when we adopt for the DME the more rigorous expanding sphere electrode model, which allows us to carry out a comparison with the results obtained with the simplified model (expanding plane). Finally, our equations can also be readily converted to the corresponding equations for the adsorption controlled by diffusion only of surface-active species when they are not involved in a charge transfer reaction.