A simple and rigorous methodology to establish the relationship between the faradaic equilibrium polarization resistance of an
electrocatalytic reaction with the elementary kinetic parameters involved in the reaction mechanism is proposed. It was derived
through an alternative method, which avoided the differentiation of the corresponding current-overpotential dependence. This
formalism includes the cases where both, reactants and products, exhibit diffusion contributions. It is demonstrated that the
equilibrium polarization resistance is the sum of both, faradaic and diffusion, contributions. Each diffusion term has a linear
variation with the inverse of the limiting diffusion current density of the species involved. This behavior was exemplified with
two different experimental data sets for the hydrogen electrode reaction, obtained on a rotating disc and microelectrodes,
respectively.

• A Simple Method to Establish the Relationship Between the Equilibrium Polarization Resistance and the Elementary Kinetic Parameters of an Electrocatalysed Reaction