Self-assembly SnO2/COF catalysts for improved electro-synthesis of hydrogen peroxide

Abstract

Electrochemical oxygen reduction reaction (ORR) via a two-electron pathway offers a sustainable route for on-site hydrogen peroxide (H2O2) production. However, achieving stable H2O2 production at industrial-scale current densities continues to pose significant challenges. In this study, 10%SnO2/COF catalysts synthesized via self-assembly approach exhibited both high performance and robust stability. In the neutral solution, a yield of 11,873 mg/(L•h) could be achieved at a high current density of 125 mA/cm2, with Faraday Efficiency exceeding 80% maintained throughout a 60-hour stability test. Through a series of experiments and in situ tests, it was concluded that the hierarchical porous structure of COF enhances the mass transfer of oxygen, while the strong interaction between SnO2 nanoparticles and COF promotes the 2-electron (2e-) reaction pathway. This interaction also accelerates the desorption of hydrogen peroxide and enhances its accumulation rate. This research provides a thought to design efficient catalysts for production H2O2 via electrochemical 2e- ORR.