Pyrolyzed Cobalt Corrole as a Potential Non-Precious Catalyst for Fuel Cells

Non-precious metal catalysts of the oxygen reduction reaction are highly favored for use in polymer electrolyte fuel cells (PEFC) because of their relatively low cost. Here, a new carbon-black-supported pyrolyzed Co-corrole (py-Co-corrole/C) catalyst of the oxygen reduction reaction (ORR) in a PEFC cathode is demonstrated to have high catalytic performance. The py-Co-corrole/C at 700 degrees C exhibits optimized ORR activity and participates in a direct four-electron reduction pathway for the reduction of O2 to H2O. The H2-O2 PEFC test of py-Co-corrole/C in the cathode reveals a maximum power density of 275 mW cm-2, which yields a higher performance and a lower Co loading than previous studies of Co-based catalysts for PEFCs. The enhancement of the ORR activity of py-Co-corrole/C is attributable to the four-coordinated Co-corrole structure and the oxidation state of the central cobalt.