Zirconium Oxide-Based Compounds as Non-Pt Cathode for Polymer Electrolyte Fuel Cell

Zirconium oxide-based compounds without partial oxidation of zirconium carbonitride were investigated as non-platinum cathode for polymer electrolyte fuel cell. Zirconium oxide-based compounds were prepared by solution-precipitation method and heat-treated at different temperature. In X-ray diffraction patterns tetragonal ZrO2 peaks decreased whereas monoclinic ZrO2 peaks increased with increasing temperature. Onset potential for oxygen reduction reaction (ORR) of the specimen heat-treated at 1000 degrees C reached 0.90 V vs. RHE indicating that the specimen had definite ORR activity. The increase of ORR activity may be explained by the increase of Zr3+ and / or oxygen vacancies due to the transformation of ZrO2 from tetragonal to monoclinic structure from the XRD results.