文摘
A nitrogen-doped vesicle-like porous carbon with well-integrated dual iron-based catalytic sites was developed through direct pyrolysis of inexpensive and abundant precursors. Benefiting from the mesoporous structures with synchronous construction of Fe–Nx and Fe/Fe3C@NC sites, the optimized catalyst exhibited outstanding performance for the oxygen reduction reaction (ORR) in alkaline media, even superior to the commercial Pt/C catalyst. Detailed characterizations revealed that Fe/Fe3C@NC sites can make major catalytic contributions in basic media, whereas the Fe–Nx sites were found to play an indispensable role for ORR in acidic media.