Thermodynamics of oxygen electrode of porous platinum in contact with solid oxide electrolyte at high oxygen pressures

Thermodynamics of oxygen electrodes from porous platinum in contact with solid electrolyte of the composition 0.90ZrO2+0.06Sc2O3+0.04Y2O3 was studied in the temperature range of 733-973 K and oxygen pressures of 0.02-4.9 MPa. It is shown that potential of the electrode studied deviates from its thermodynamical value in the course of platinum oxidation (oxide reduction). Oxidation (oxide reduction) of platinum proceeds slowly enough and covers not more than 10 % of the total mass of platinum in the cell. Assessment of total area of platinum contact with electrolyte and size of single contact were made on the basis of data on platinum oxidation rate and potential deviation from equilibrium value