Efficient Neutral H₂O₂ Electrosynthesis from Favorable Reaction Microenvironments via Porous Carbon Carrier...

The efficient electrosynthesis of hydrogen peroxide (H₂O₂) via two-electron oxygen reduction reaction (2e^- ORR) in neutral media is undoubtedly a practical route, but the limited comprehension of electrocatalysts has hindered the system advancement. Herein, we present the design of model catalysts comprising mesoporous carbon spheres-supported Pd nanoparticles for H₂O₂ electrosynthesis at near-zero overpotential with approximately 95 % selectivity in a neutral electrolyte. Impressively, the optimized Pd/MCS-8 electrocatalyst in a flow cell device achieves an exceptional H₂O₂ yield of 15.77 mol g_catalyst ^-1 h^-1, generating a neutral H₂O₂ solution with an accumulated concentration of 6.43 wt %, a level sufficiently high for medical disinfection. Finite element simulation and experimental results suggest that mesoporous carbon carriers promote O₂ enrichment and localized pH elevation, establishing a favorable microenvironment for 2e^- ORR in neutral media. Density functional theory calculations reveal that the robust interaction between Pd nanoparticles and the carbon carriers optimized the adsorption of OOH* at the carbon edge, ensuring high active 2e^- process. These findings offer new insights into carbon-loaded electrocatalysts for efficient 2e^- ORR in neutral media, emphasizing the role of carrier engineering in constructing favorable microenvironments and synergizing active sites.