Coupling Co-N-C with MXenes Yields Highly Efficient Catalysts for H 2 O 2 Production in Acidic Media.

The electrochemical oxygen reduction reaction (ORR) offers a promising method to replace the anthraquinone process for hydrogen peroxide (H 2 O 2 ) 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 H 2 O 2 synthesis. Here, an effective strategy for preparing Co-N-C/Ti 3 C 2 T x with high H 2 O 2 selectivity and ORR reactivity is proposed. The acquired Co-N-C/Ti 3 C 2 T x shows excellent H 2 O 2 electrosynthesis performance in acidic media with H 2 O 2 productivity of up to 3200 ppm h -1 , superior to state-of-the-art catalysts. Interestingly, a H 2 O 2 concentration of 6.0 wt % was obtained after the stability test, and the Co-N-C/Ti 3 C 2 T x catalyst was found to effectively catalyze organic dye degradation. Further analysis reveals that the enhanced H 2 O 2 electrosynthesis performance originates from the layered structure and the oxygen functional groups of Ti 3 C 2 T 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 H 2 O 2 . This work provides a strategy to design and fabricate highly efficient catalysts for H 2 O 2 production and degradation of organic pollutants.