Hyper-Crosslinked Polymer-Derived Nitrogen-Doped Hierarchical Porous Carbon as Metal-Free Electrocatalysts for High-Efficiency Oxygen Reduction

The development of N-doped porous carbon from porous organic polymers (POPs), especially low-cost hyper-crosslinked polymers (HCPs) provides an ideal platform for constructing carbon-based metal-free electrocatalysts with tunable chemical compositions and porous structures. However, most of the HCPs do not contain nitrogen, which makes it difficult to fabricate N-doped porous carbon by direct pyrolysis. Herein, a sort of N-doped hierarchically porous carbon using HCPs as a precursor is prepared by simple NH3 activation. The key factors affecting the catalytic performance of the obtained carbon catalysts can be regularly tuned by the pyrolysis temperature and building blocks, which results in an optimal catalyst (Py-NHCP-1000) with abundant nitrogen content, a high surface area (1865 m(2) g(-1)), and rich defects. Remarkably, Py-NHCP-1000 with an outstanding electrocatalytic performance presents a positive shift of 27 mV for E-1/2 relative to commercial Pt/C, and well durable and affordable qualities for the oxygen reduction reaction. Therefore, this work paves an avenue for designing and preparing a kind of affordable and high-efficiency metal-free electrocatalyst from low-cost and scalable HCPs and extending it to other energy storage/conversion materials.

Automated summary

This study prepared N-doped hierarchically porous carbon using NH3 activation and optimized the catalytic performance by tuning key factors such as pyrolysis temperature and building blocks. The obtained Py-NHCP-1000 catalyst showed outstanding performance, positive shift for E-1/2 relative to commercial Pt/C, good durability, and affordability for the oxygen reduction reaction. This work opens up a pathway for designing and preparing affordable and high-efficiency metal-free electrocatalysts from low-cost and scalable HCPs.