Hyper-Crosslinked Polymer-Derived Nitrogen-Doped Hierarchical\nPorous Carbon as Metal-Free Electrocatalysts for High-Efficiency Oxygen\nReduction

Abstract

The\ndevelopment of N-doped porous carbon from porous organic polymers\n(POPs), especially low-cost hyper-crosslinked polymers (HCPs) provides\nan ideal platform for constructing carbon-based metal-free electrocatalysts\nwith tunable chemical compositions and porous structures. However,\nmost of the HCPs do not contain nitrogen, which makes it difficult\nto fabricate N-doped porous carbon by direct pyrolysis. Herein, a\nsort of N-doped hierarchically porous carbon using HCPs as a precursor\nis prepared by simple NH₃ activation. The key factors affecting\nthe catalytic performance of the obtained carbon catalysts can be\nregularly tuned by the pyrolysis temperature and building blocks,\nwhich results in an optimal catalyst (Py-NHCP-1000) with abundant\nnitrogen content, a high surface area (1865 m² g^–1), and rich defects. Remarkably, Py-NHCP-1000 with an outstanding\nelectrocatalytic performance presents a positive shift of 27 mV for <i>E</i>_1/2 relative to commercial Pt/C, and well durable\nand affordable qualities for the oxygen reduction reaction. Therefore,\nthis work paves an avenue for designing and preparing a kind of affordable\nand high-efficiency metal-free electrocatalyst from low-cost and scalable\nHCPs and extending it to other energy storage/conversion materials.