Investigations of carbon-supported CoPd3 catalysts as oxygen cathodes in PEM fuel cells

The oxygen reduction reaction (ORR) has been studied on platinum free, palladium-based electrocatalysts in acid media. Polycrystalline electrodes were prepared by electrodeposition on a polycrystalline gold substrate using a dual ligand approach at room temperature. The surface morphology and approximate surface composition of the electrodeposits were confirmed by scanning electron microscopy and energy dispersive X-ray spectroscopy. The electrodeposits showed performance for the ORR similar to polycrystalline platinum under identical conditions, despite an observed 50 mV cathodic shift in the peak potential. Carbon supported CoPd3 electrocatalysts also showed high catalytic activity for oxygen reduction in a 5 cm2 fuel cell.