Hierarchically porous N-doped carbon nanoflakes: Large-scale facile synthesis and application as an oxygen reduction reaction electrocatalyst with high activity

Hierarchically porous N-doped carbon nanoflakes (HPNCNFs) were facilely synthesized on a large scale via pyrolysis of 1,8-diaminonaphthalene (DAN)/FeCl3·6H2O mixture under Ar followed by acid leaching. Both pyrolysis temperature and the amount of Fe species have strong influence on catalyst activity. It suggests that the presence of large excess Fe species not only is key to nanoflake formation but also serves as a mesopore-forming agent. The HPNCNF-900 catalyst, obtained at 900 °C with a mass ratio 1:5 of DAN to FeCl3·6H2O, was found to exhibit superhigh oxygen reduction reaction activity and excellent durability in alkaline media outperforming the state-of-the-art Pt/C catalyst at a moderate loading.