High-Current-Density H₂O₂ Synthesis Toward Paired Electrolytic Upgrading of Ethylene Glycol

The high-efficiency electrosynthesis of hydrogen peroxide (H₂O₂) via two-electron oxygen reduction reaction (2e^- ORR) represents a promising alternative to the traditional anthraquinone process. However, achieving high selectivity, industrial-grade stability, and on-site utilization of H₂O₂ remains a significant challenge. Here, we designed a single-atom catalyst, CoNPC, featuring a Co-N/P co-coordination structure, tailored for high-current-density H₂O₂ electrosynthesis and relevant paired valorization of ethylene glycol. The P modulation optimized the electronic structure of Co centers, leading to enhanced selectivity (> 90%) and stable H₂O₂ production for over 140 h at a high current density of -200 mA cm^-2. In situ spectroscopic studies and theoretical calculations revealed that the P heteroatom plays a critical role in optimizing *OOH binding energy, thereby facilitating the 2e^- ORR process. The electrogenerated H₂O₂ was further utilized in a Fenton-like process to oxidize ethylene glycol to formic acid. By coupling this cathodic reaction with anodic EG electrooxidation, we demonstrated a paired electrolysis system that enables simultaneous value-added products at both sides. This work not only offers a robust strategy for the design of single-atom catalysts on industrial H₂O₂ electrosynthesis but also pioneers an energy-efficient paired electrolysis system for waste utilization.