Faradaic Impedance of Polarized Porous Electrodes

The a‐c impedance characteristics of polarized porous gas‐diffusion electrodes are calculated on the basis of a simplified dual‐layer model. It is shown that the consideration of a region within the electrode wherein simultaneous diffusion and reaction occur can result in either an inductive or capacitive reactance, depending on the magnitudes of dimensionless frequency and d‐c current density parameters. The absence of such a region, which corresponds to the limiting case at high reaction rates, results in capacitive reactance only.