Nitrogen-Doped Porous Carbon Nanosheets Derived from Coal Tar Pitch as an Efficient Oxygen-Reduction Catalyst

Abstract

High value-added processing and manufacturing of coal tar pitch (CTP), an abundant and cheap byproduct of the coal industry, is a crucial issue worldwide. Herein, novel nitrogen-doped porous carbon nanosheets (N-PCN) were fabricated by selecting CTP and ferric chloride (FeCl3) as the carbonaceous source and mild activating agent, respectively. Due to the synergistic effects of the unique flaky graphitic structure, hierarchical porosity, high nitrogen-doping contents, and trace of Fe-containing sites, N-PCN exhibited excellent oxygen-reduction (ORR) electrocatalytic activity in alkaline medium. Linear sweep voltammetry (LSV) testing results for N-PCN showed that the diffusion-limited current density was as high as 5.8 mA cm–2 and the half-wave potential was 0.85 V (vs RHE), both better than commercial 20 wt % Pt/C. Moreover, N-PCN showed an ideal methanol tolerance and catalytic stability, indicating its potential application as cathode catalysts in direct methanol fuel cells (DMFCs).