Development of Zirconium Based Non-Platinum Cathode for Polymer Electrolyte Fuel Cell

Zirconium based compounds (ZrOxNy) have been investigated as a new cathode of polymer electrolyte fuel cells without platinum. The ZrOxNy film were prepared by the radio frequency magnetron sputtering method under Ar + O2 + N2 atmosphere with heating the sputtered material. The effect of the heat treatment on both the catalytic activity for the oxygen reduction reaction (ORR) and the properties of ZrOxINI, has been examined. The solubility of ZrOxNy was less than 5x10-8 mol dm -3 in 0.1 mol dm -3 sulfuric acid at 30 deg C under atmospheric condition. This indicated that ZrOxNy had a high chemical stability in acidic media. The ORR current density on ZrOxNy which was heated at 800 deg C was about 30 times larger than that on ZrOxNy deposited at 50 deg C. It was found that heating the sputtered material during the deposition was very effective to increase the catalytic activity for ORR. The higher temperature of heat treatment caused the change of crystalline structure and the increase of the crystallinity of ZrOxNy.