Adjusting the active site of single Co atoms on CeO2 via cyano functional groups for selective H2O2 electrosynthesis at high yield

The electrocatalytic two−electron oxygen reduction reaction (2e−ORR) offers a promising alternative to the traditional energy−intensive anthraquinone oxidation process for in situ synthesis of hydrogen peroxide (H 2 O 2 ). However, constructing a novel catalyst to enhance the H 2 O 2 selectivity remains a significant challenge in the field. In this work, we propose a novel strategy for charge regulation involving the axial attachment of an electron−withdrawing cyano group (−C N) to enhance the performance of Co single−atom catalysts in the 2e−ORR. This strategy is validated through the preparation of −C N modified single−atom Co doped cerium dioxide (CeO 2 ) catalysts using an electrochemical in situ reconstruction method. The optimized catalyst demonstrated 97 % H 2 O 2 selectivity and 11.2 mol g cat. −1 h −1 yield in 0.1 M KOH solution, outperforming the majority of reported catalysts. Both calculations and in−situ experiments revealed that the introduction of the −C N group facilitates the transition of electrons around the Co atom from a localized to a delocalized state, thus optimizes the adsorption energy of the *OOH intermediate to boost 2e−ORR performance. This study not only provides new insights into the targeted optimization of catalytic performance through −C N group modification but also offers significant theoretical and experimental foundations for the design of highly efficient 2e−ORR catalysts. The Ce−Co PBA undergoes electrochemical in−situ reconstruction to form Co single-atom doped CeO 2 modified with −C N functional groups, which showed good performances in 2e−ORR for electrosynthesis of H 2 O 2 . • Co and −C N integrated into CeO 2 create a high-performance 2e−ORR catalyst. • The −C N modification optimizes *OOH adsorption, enhancing 2e−ORR performance. • −C N − modified catalyst shows 97 % H 2 O 2 selectivity, 11.2 mol g cat. −1 h −1 yield. • The study examined −C N's effect on catalyst electronic structure and performance.