Highly Durable Graphene Nanosheet Supported Iron Catalyst for Oxygen Reduction Reaction in PEM Fuel Cells

A novel NPMC using pyrimidine-2,4,5,6-tetramine sulfuric acid hydrate (PTAm) as a nitrogen precursor and graphene nanosheets as catalyst supports was prepared and characterized. We investigate the effect of different pyrolysis temperatures on the catalysts' ORR activity along with detailed surface analysis to provide insight regarding the nature of the ORR active surface moieties. The NPMC sample heat treated at 800 degrees C was found to display optimal ORR activity and H2O selectivity, specifically, an onset potential of 0.853V vs RHE, a half-wave potential of 0.682 V vs RHE, and a H2O selectivity of ca. 99.9%. High stability through an accelerated durability testing (ADT) protocol was demonstrated and attributed to the high graphitic content of the catalyst support material. This novel NPMC demonstrates promising electrocatalyst activity and superior durability over commercial Pt/C catalyst for ORR under the studied conditions, rendering graphene nanosheets as an ideal replacement to traditional nanostructured carbon support materials. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.062201jes]