Porous nitrogen/halogen dual-doped nanocarbons derived from imidazolium functionalized cationic metal-organic frameworks for highly efficient oxygen reduction reaction

Heteroatom-doped carbon materials as alternative catalysts for oxygen reduction reaction (ORR) have drawn increasing attention due to their tunable chemical and electronic structures for achieving high activity and stability. However, there still remains a great challenge to fabricate porous heteroatoms dual-doped carbons with uniformly doping in a facile and controllable way. Herein, imidazole/imidazolium-functionalized metal-organic frameworks (MOFs) are employed as precursors and templates to achieve porous nitrogen and halogen dual-doped nanocarbons. Among these carbon materials, the as-prepared nitrogen/bromine dual-doped catalyst BrNC-800 exhibits the best ORR performance with a positive half-wave potential at 0.80 V (vs. RHE) in 0.1 mol L-1 KOH, which is comparable to the benchmark commercial 20 wt% Pt/C catalyst. BrNC-800 shows excellent long term stability and methanol tolerance. This work provides a facile approach to fabricate highly efficient heteroatoms dual-doped carbon catalysts for energy conversion.