The charge transfer reactions between a Pt catalyst and yttria-stabilized zirconia (YSZ) support have been studied electrochemically during CO oxidation over a range of gas phase compositions and temperatures typical of automotive exhaust. From a combination of electrochemical and reaction-rate measurements, a model for the participation of the support in the oxidation reactions is derived. It is estimated from the model that the contribution of the charge transfer reactions occurring at the three-phase interface between Pt, YSZ and the gas phase, to the total rate of CO oxidation is negligible under steady operating conditions (gas phase composition and temperature). However, under cyclic conditions typical of those encountered in automotive exhaust, these charge transfer reactions can lead to an enhancement (≈ 10% at 828 K) in the rate of CO oxidation.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering