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/Ti₃C₂T_x with high H₂O₂ selectivity and ORR reactivity is proposed. The acquired Co-N-C/Ti₃C₂T_x 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/Ti₃C₂T_x 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 Ti₃C₂T_x. 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.