Electron-penetration-tunable adsorption strength of oxygen molecules for enhanced hydrogen peroxide electrosynthesis

Electrosynthesis of hydrogen peroxide (H₂O₂) via the two-electron oxygen reduction reaction (2e^- ORR) is a promising alternative to the energy-intensive anthraquinone process. It remains challenging due to the absence of highly selective and active catalysts. Herein, we report the synthesis of graphitic carbon-encapsulated Au nanoparticles (Au@C) featuring tunable core-shell architectures. The optimized catalyst exhibits ∼100 % selectivity for H₂O₂ production across a potential range of 0.2-0.3 V vs. RHE (reversible hydrogen electrode) in acid electrolyte. The evolution rate reaches 5.7 mol g_Au^-1 h^-1 in a flow cell, which lasts 30 h without losing activity. Theoretical calculation and in-situ Raman analysis reveal the electron penetration from the Au core to the surface of the carbon shell, weakening O₂ adsorption and stabilizing the key *OOH intermediate to evolve H₂O₂. This work provides a rational strategy for designing high-performance electrocatalysts toward producing green chemicals.