Rational Design of Hierarchical, Porous, Co‐Supported, N‐Doped Carbon Architectures as Electrocatalyst for Oxygen Reduction

Abstract Developing highly active nonprecious‐metal catalysts for the oxygen reduction reaction (ORR) is of great significance for reducing the cost of fuel cells. 3D‐ordered porous structures could substantially improve the performance of the catalysts because of their excellent mass‐diffusion properties and high specific surface areas. Herein, ordered porous ZIF‐67 was prepared by forced molding of a polystyrene template, and Co‐supported, N‐doped, 3D‐ordered porous carbon (Co‐NOPC) was obtained after further carbonization. Co‐NOPC exhibited excellent performance for the ORR in an alkaline medium with a half‐wave potential of 0.86 V vs. reversible hydrogen electrode (RHE), which is higher than that of the state‐of‐the‐art Pt/C (0.85 V vs. RHE). Moreover, the substantially improved catalytic performance of Co‐NOPC compared with Co‐supported, N‐doped carbon revealed the key role of its hierarchical porosity in boosting the ORR. Co‐NOPC also exhibited a close‐to‐ideal four‐electron transfer path, long‐term durability, and resistance to methanol penetration, which make it promising for large‐scale application.