▎ 摘 要
The development of robust metal-free catalysts for electrochemical oxygen reduction reaction (ORR) is a great challenge due to the large energy barriers for the intermediate *OO- formation. In this work, an ionic liquid (IL) modified N/S co-doped graphene oxide (IL-SNG) was synthesized and explored as a metal-free ORR catalyst in alkaline conditions. Compared to the electrode without IL modification (SNG), the onset and half-wave potentials of IL-SNG were positively shifted by 130 and 110 mV, respec-tively. The IL and co-doping effects enable IL-SNG a comparable activity to that of Pt/C catalyst in alkaline solution. In addition to impressive activity, IL-SNG exhibits a superior tolerance to methanol and excel-lent long-term stability over Pt/C under the identical conditions, enabling it a potential candidate for ORR in alkaline conditions. DFT calculation shows that IL enhances O-2 adsorption and stabilizes the high-energy *OO- intermediate by forming ion pairs and therefore boosts the catalytic activity. (C) 2021 Elsevier Ltd. All rights reserved.