Comparison of the Temperature Dependence of CO-Poisoning for Different Anode Electrodes in a Polymer Electrolyte Fuel Cell

摘要

The CO-tolerance of a commercial Pt and two different RRu anode electrodes, so-called PtRu-type A (50:50 atom% Pt and Ru) and PtRu-type B (40:60 atom% Pt and Ru) has been examined using AC-impedance spectroscopy along steady-state current-voltage curves. A simple mathematical model has been derived in order to extract important kinetic parameters for CO-poisoning on different anode electrodes. The RRu-type B electrode demonstrated the best CO-tolerance. An inductive behavior in the low frequency region of the impedance spectra for the Pt and the PtRu-type A electrode proved to be characteristic for CO-poisoning but the impedance spectra of the PtRu-type B electrode did not show any inductive behavior and its surface coverage of CO extracted from the fitting of the experimental data to the model was lower than the surface CO-coverage of the two other electrodes.