Co–C–N Oxygen Reduction Catalysts Prepared by Combinatorial Magnetron Sputter Deposition
- 1 January 2007
- journal article
- Published by The Electrochemical Society in Journal of the Electrochemical Society
- Vol. 154 (4) , A275-A282
Abstract
Thin-film libraries of CoxC1−x−yNyCoxC1−x−yNy ( 0<x<0.10700.003<y<0.3890.003Ar∕N2Ar∕N2 gas mixture followed by subsequent heat-treatment at 700, 800, or 1000°C1000°C in N2N2 atmosphere. By increasing the nitrogen partial pressure during sputtering, the nitrogen content was increased significantly in the as-sputtered libraries and more nitrogen remained in the libraries after heat-treatment. The catalytic activities of the libraries towards the oxygen reduction reaction (ORR) were studied using the rotating ring-disk electrode (RRDE) technique. CoxC1−x−yNyCoxC1−x−yNy libraries heat-treated at 800°C800°C with 0.004<x<0.1050.0040.026<y<0.0970.0260.1M0.1M HClO4HClO4 solution at room temperature. The heating temperature that induces the onset of catalytic activity coincides with the temperature at which both substantial nitrogen release from the originally amorphous films and the formation of graphitic carbon and β-Co occurs. This temperature varies significantly with both the Co and N content in the films. The production of H2O2H2O2 and the corrosion stability of the libraries are also discussed.Keywords
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