Electrode polarization at the O2(g), Pd/YSZ interface

The polarization phenomena of the O2–Pd–YSZ interface were studied as a function of oxygen partial pressure (1–100 kPa) and temperature (400–550°C) in the double chamber reactor cell: Pd|YSZ|Pd. The steady-state current–overpotential characteristics can be analyzed with a Butler–Volmer type of equation. The apparent anodic and cathodic charge transfer coefficients are found close to 0.5 and the activation energy of the exchange current was found to be about 107 kJ/mol. Based on the experimental results, a charge transfer reaction model, is proposed.