Electrocatalysis and inductive effects at the gas, Pt/stabilized zirconia interface

Analysis of the gas, Pt/yttria-stabilized zirconia electrode shows that electrocatalyzed reactions can ocur at both the anode and the cathode. These reactions are promoted by the onset of electronic conductivity in the electrolyte subsurface. Such conductivity can result from either native or added electronic defects, which become active under appropriate experimental conditions pertaining to oxygen partial pressure or electrode polarization. Transition from pure ionic to mixed (ionic + electronic) subsurface and conductivity is reflected by a sharp decrease in the corresponding overvoltage and by a drastic modification of the electrode impedance spectra in terms of magnitude and frequency distribution.