Abstract
The CO-tolerance of a carbon-supported Pt/Mo-oxide (Pt/MoOx/C) anode in proton-exchange membrane fuel cells was examined by electrochemical impedance spectroscopy. A pseudo-inductive loop was clearly observed only for a Pt/MoOx/C anode at low anodic polarizations, which indicates the onset of the electro-oxidation of adsorbed CO (COad) on the Pt/MoOx/C catalyst. The CO-tolerance of Pt/MoOx/C at low anodic polarizations is mainly ascribed to the combination of the electro-oxidation of COad and the removal of CO by the water-gas shift reaction depending on the operating conditions.
