N-doped hierarchical porous metal-free catalysts derived from covalent triazine frameworks for the efficient oxygen reduction reaction†
The oxygen reduction reaction (ORR) is a core reaction in energy conversion and storage devices. Herein, nitrogen-doped hierarchical micro/mesoporous carbon ORR catalysts derived from covalent triazine frameworks (CTFs) were prepared based on a rational bottom-up strategy. Benefiting from its high specific surface area (1925 m2 g−1), hierarchical micro/mesoporous structure (0–12 nm), three-dimensional conductive network and high pyridinic N and graphitic N content, the optimal CTF-Super P-10 composite catalyst exhibits an onset potential of 0.981 V and a half-wave potential of 0.883 V, with a high limiting current density of around 5.31 mA cm−2 under alkaline conditions. It shows a dominant four-electron pathway, strong stability, and better methanol tolerance than commercial Pt/C in both alkaline conditions and acidic conditions, highlighting a promising strategy for designing high performance metal-free ORR catalysts.