Oxygen Transfer on Substituted ZrO₂, Bi₂O₃, and CeO₂ Electrolytes with Platinum Electrodes: I. Electrode Resistance by D-C Polarization

The electrode behavior of Pt-sputtered and PT-gauze electrodes on ZrO2-Y2O3, Bi2O3-Er2O3, and CeO2-Gd2O3 solid electrolyteswas investigated by means of d-c measurements in the temperature region of 770–1050 K and in the oxygen partialpressure region of 10–5 – 1 atm O2 using N2-O2 mixtures. On these different materials the same electrode morphology wasrealized and was preserved during the subsequent experiments. The electrode process is strongly influenced by the natureof the electrolyte. The electrode resistance for Pt electrodes on Bi2O3-Er2O3 was found to be many times lower than onZrO2-Y2O3 and CeO2-Gd2O3. On zirconia- and ceria-based materials diffusion of atomic oxygen on the Pt electrode is therate-determining step in the electrode process, whereas for bismuth sesquioxide-based materials diffusion on the oxidesurfaces is rate determining.