Rational design of single-atom catalysts for efficient H2O2 production via a four-step strategy†

Electrocatalysis presents an efficient and eco-friendly approach for the two-electron oxygen reduction reaction (2e⁻ ORR) to produce hydrogen peroxide (H₂O₂). However, challenges persist in enhancing catalyst activity and refining design strategies. In this study, a general four-step strategy is introduced to develop efficient single-atom catalysts (SACs) for H₂O₂ production based on transition metals and nonmetals embedded into γ-graphyne monolayers (TM–NM–GY) through first-principles calculations. Our results indicate that the intrinsic activity for the 2e⁻ ORR can be properly and handily evaluated using the robust intrinsic electronegativity descriptor. On this foundation, we propose two strategies of B doping and creating C vacancies (v) to further enhance catalytic activity. Remarkably, Ni–B–GY and Ag–v–GY exhibit exceptional selectivity, stability, and activity with overpotentials as low as 0.08 V and 0.15 V, respectively, approaching the ideal limit of H₂O₂ catalysts. Mechanistic investigations reveal that B doping facilitates electron transfer and strengthens the hybridization between Ni 3d and O 2p orbitals, leading to stronger adsorption strength of *OOH and thus enhancing the 2e⁻ ORR catalytic performance. These findings not only present several promising SAC candidates for H₂O₂ production, but also pave the way for the rational design of highly efficient SACs for various catalytic reactions.