Meliorated oxygen reduction reaction of polymer electrolyte membrane fuel cell in the presence of cerium-zirconium oxide

摘要

Oxygen Reduction Reaction (ORR) kinetics is known to be one of the major bottle necks in PEM Fuel Cell performance. Several attempts are being made to enhance the ORR. Inspite of several attempts Pt in the vicinity of high surface area oxide catalysts seems to be the best choice although some alloy catalyst have shown good performance in half cell studies and single cell studies. We are investigating methods to improve the performance of PEM fuel cell especially in low air flow conditions which is the condition that will arise in surge power requirements. We have found that oxygen reduction reaction (ORR) performance of Pt/C can be increased in the presence of cerium-zirconium oxides especially Ceo.sZro.2O2 (CZO) in the cathode catalyst layer. Ceo.sZro.2O2 was prepared by co-precipitation method and the formation is confirmed by the XRD results. An XPS study of Ce 3d emission spectra dominated by atomic multiplet effects in core level spectroscopy of Ce0.8Zr0.2O2-Pt/C are studied from which the possible oxidation states of Ce on Ce0.8Zr0.2O2-Pt/C surface are examined. The ORR improvement in the CZO added electrodes have been studied using chronoammperometry and fuel cell testing.