Electrode Potentials of Cells with an Electrolyte Based on Zirconium Dioxide in Gas Mixtures N2+ O2+ CO2+ CO: A Platinum Electrode

Steady-state potentials of various platinum electrodes are measured in cells containing electrolyte ZrO₂+ Y₂O₃(10 mol %) in the temperature range 673–773 K in binary equilibrium gas mixtures N₂+ O₂and CO + CO₂, as well as in four-component nonequilibrium gas mixtures N₂+ O₂+ CO₂+ CO containing 0–3 vol % CO and 0–10 vol % O₂. Adding CO to a gas mixture makes the electrode potential deviate from equilibrium, which is explained by chemisorption of CO on the electrode. The oxygen, which is adsorbed on platinum, interacts with CO; as a result, CO₂undergoes desorption and the surface concentration of CO drops.