Coupling Co–N–C with MXenes Yields Highly Efficient Catalysts for H2O2 Production in Acidic Media

The electrochemical oxygen reduction reaction (ORR) offers a promising method to replace the anthraquinone process for hydrogen peroxide (H2O2) production. However, the efficiency of this process suffers from sluggish kinetics, particularly in an acidic environment. Therefore, employing catalysts with high electroactivity is highly desirable for H2O2 synthesis. Here, an effective strategy for preparing Co-N-C/Ti3C2Tx with high H2O2 selectivity and ORR reactivity is proposed. The acquired Co-N-C/Ti3C2Tx shows excellent H2O2 electrosynthesis performance in acidic media with H2O2 productivity of up to 3200 ppm h-1, superior to state-of-the-art catalysts. Interestingly, a H2O2 concentration of 6.0 wt % was obtained after the stability test, and the Co-N-C/Ti3C2Tx catalyst was found to effectively catalyze organic dye degradation. Further analysis reveals that the enhanced H2O2 electrosynthesis performance originates from the layered structure and the oxygen functional groups of Ti3C2Tx. The layered structure can effectively promote increased exposure of active sites, while the oxygen functional groups will fine-tune the electronic structure of Co atoms, allowing a selective ORR pathway to produce H2O2. This work provides a strategy to design and fabricate highly efficient catalysts for H2O2 production and degradation of organic pollutants.