Active site design enables industrial scale H₂O₂ electrosynthesis with metal-free catalysts.

Abstract

The electrosynthesis of hydrogen peroxide (H₂O₂) via a two-electron oxygen reduction reaction enables decentralized H₂O₂ production. While metal-free carbon catalysts are sustainable and low-cost, their performance is hindered by poorly defined active sites and uncontrolled defect states. Here, we resolve these challenges through active site design and catalyst screening using fluorine (F) and nitrogen (N) codoped carbons as model materials. Statistical analysis combined with density functional theoretical calculations reveals that F-induced structural modification and defect passivation optimize OOH* binding, with F-doping and adjacent F atoms predominantly lowering abs ΔG(OOH*). Experimental results confirm that semi-ionic C-F bonds passivate defects in nitrogen-doped carbon, enhancing catalytic activity and durability. The resulting (N, F)-codoped carbon achieves nearly 100% H₂O₂ selectivity at 0.5-0.65 V versus the reversible hydrogen electrode and maintains > 95% across 0.01-0.65 V versus the reversible hydrogen electrode. In an electrolyzer, (N, F)-codoped carbon exhibits an H₂O₂ yield rate of 74.35 mol g_cat.^-1 h^-1 and sustains 300 mA cm^-2 for 105 hours with ~95% faradaic efficiency. Coupling the two-electron oxygen reduction reaction with methanol oxidation further reduces cell voltage and enhances productivity. This work provides a means to design efficient catalysts for industrial H₂O₂ electrosynthesis.