Hierarchical micro/mesoporous nitrogen-doped carbons derived from hypercrosslinked polymers for highly efficient oxygen reduction reaction

Abstract

Exploring highly efficient non-Pt oxygen reduction reaction (ORR) electrocatalysts is an inevitable trend in the progress of various sustainable energy storage and conversion technologies. Herein, we prepare three kinds of hierarchical porous carbons, derived from hypercrosslinked polyaniline (HCP-An), polypyrrole (HCP-Py) and polymethylbenzene (HCP-MB) through a facile Friedel-Crafts reaction, among which NPC-An-900 exhibits outstanding ORR catalytic performance combining high surface area, good conductivity and high nitrogen-doped content. The hypercrosslinked polyaniline ensures micro-/mesoporous skeleton and prevents collapse during the pyrolysis process for NPC-An-900 with a high surface area of 2938.31 m2 g−1 and hierarchical micro-/mesoporous structure (1–8 nm). High nitrogen-doping content of NCP-An-900 is up to 7.02 at.% with pyridinic N as the main nitrogen doped type of 48.5% of the total nitrogen content. NPC-An-900 manifests an onset potential of 0.96 V (vs. RHE) with a high limiting current density of −5.31 mA cm−2 (superior to the commercial Pt/C of −5.20 mA cm−2) and excellent stability with current retention of 96.2% over 7.5 h. Furthermore, the extraordinary tolerance against methanol corrosion would also indicate its potential practical applications. This simple and universal synthesis strategy can be widely applied in the preparation of other porous heteroatom-doped carbons derived functional polymers towards energy storage and conversion.