Metallo-deuteroporphyrins derived multi-layered hollow carbon spheres electrocatalysts for highly efficient oxygen reduction reaction

Abstract

The development of low-cost, highly efficient and stable non-precious metal electrocatalyst for the oxygen reduction reaction (ORR) substituting Pt has attracted much attention. Herein, we developed a promising structural platform for the fabrication of carbon nanospheres functionalized with hollow nanostructures of M-NHCS (M = Fe, Co and Mn) based on metallo-deuteroporphyrins (MDP). Benefited from the multi-layered active sites and hollow substrate with more exposed active surface area, convenient channels for the transport of electrons, the resulting Fe-NHCS electrocatalysts exhibit enhanced electrocatalytic performance in ORR with an onset potential of 0.90 V (versus RHE), and a high selectivity in the direct 4-electron pathway. The Fe-NHCS electrocatalysts also show a good methanol tolerance superior to Pt/C catalysts and an extremely high stability with only 13.0 mV negative after 5000 cycles in alkaline media. Experiments have verified that maintaining the multi-layered Fe−N−C active sites and hollow substrate were essential to deliver the high performance for ORR. The work opens new avenues for utilizing MDP-based materials in future energy conversion applications.