Preparation, characterization of ZrOxNy/C and its application in PEMFC as an electrocatalyst for oxygen reduction

In this paper, a noble-metal-free electrocatalyst based on carbon-supported zirconium oxynitride (ZrOxNy/C) was prepared by ammonolysis of carbon-supported zirconia (ZrO2/C) at 950 degrees C and investigated as cathode electrocatalyst towards oxygen reduction reaction (ORR) in PEMFCs. The electrocatalyst was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. The catalytic activity of the catalyst towards ORR was investigated by using the rotating disk electrode (RDE) technique in an O-2-saturated 0.5 M H2SO4 solution. The ZrOxNy/C electrocatalyst presented attractive catalytic activity for ORR. The onset potential of ZrOxNy/C electrocatalyst for oxygen reduction was 0.7 V versus RHE and the four-electron pathway for the ORR was achieved on the surface of ZrOxNy/C electrocatalyst. The ZrOxNy/C electrocatalyst showed a comparatively good cell performance to ORR in PEMFCs, especially when operated at a comparatively high temperature. (c) 2007 Elsevier B.V. All rights reserved.