Catalytic activity of zirconium oxynitride prepared by reactive sputtering for ORR in sulfuric acid

Zirconium oxynitride (ZrO(x)N(y)) prepared by the reactive sputtering method under O(2) and N(2) atmosphere was evaluated as a nonplatinum cathode catalyst for polymer electrolyte fuel cells. The ZrO(x)N(y) prepared at p(Ar)=0.886 Pa, p(N2)=0.41 Pa, and p(O2)=1.7 mPa with a substrate temperature of 800 degrees C during the film formation had a superior catalytic activity for the oxygen reduction reaction (ORR) in sulfuric acid. The onset potential for the ORR had a maximum of 0.8 V vs a reversible hydrogen electrode. The thin-film X-ray diffraction analysis and ionization potential measurement revealed that the ZrO(x)N(y) with a high catalytic activity for the ORR contained the Zr(2)ON(2) crystalline structure. (C) 2008 The Electrochemical Society.