The role of catalytic reactions in the generating of electrode potentials in chemically irreversible gas mixtures

The formation of steady-state potential at an electrode of solid-electrolyte electrochemical cell placed in chemically irreversible gas mixture is discussed; the potential emerges due to the change in the gas activities at the electrode, caused by the passing of catalytic reaction. This mechanism of potential change is analyzed theoretically for a catalytically asymmetrical gas-diffusion cell located in a CH₄ + CO + CO₂ gas mixture. Experimental studies demonstrated an agreement between the experimental results and theoretical considerations. Dependence of the potential changing rate on the kinetics of the methane catalytic oxidation is revealed experimentally.