Abstract
Hydrogen peroxide (H₂O₂) is a strategically important oxidant for applications spanning pharmaceuticals, fine chemical synthesis, pulp and textile processing, semiconductor cleaning, and environmental remediation. Despite its green end-use profile—decomposing only to water and oxygen—over 95% of global H₂O₂ production relies on the anthraquinone auto-oxidation (AQ) process, which is energy-intensive, capital-demanding, and dependent on precious-metal catalysts and complex multistep operations.1 These inherent limitations restrict the deployment of H₂O₂ in distributed and on-demand applications, motivating the development of electrochemical alternatives.2
Electrochemical synthesis offers a compelling pathway to directly produce H₂O₂ from water and oxygen under ambient conditions via selective two-electron redox reactions. At the cathode, the two-electron oxygen reduction reaction (2e⁻ ORR) converts O₂ to H₂O₂, while at the anode the two-electron water oxidation reaction (2e⁻ WOR) produces H₂O₂ from water, providing a unique opportunity to generate H₂O₂ at both electrodes simultaneously.3
Here we report the design, fabrication, and operation of a continuous-flow electrochemical reactor that integrates cathodic 2e⁻ ORR and anodic 2e⁻ WOR within a single device. The flow architecture enables independent optimization of mass transport, gas–liquid contact, and electrode kinetics while maintaining strict separation of anodic and cathodic products. By harvesting H₂O₂ from both electrodes, the dual-pathway system substantially increases overall production rates and improves faradaic and energy efficiencies relative to conventional single-reaction electrolysers. Stable operation under industrially relevant current densities is demonstrated, highlighting the robustness of the reactor design.
This dual-electrode H₂O₂ flow reactor represents a scalable and modular platform for decentralized H₂O₂ generation, reducing reliance on centralized AQ plants and hazardous transportation. More broadly, it establishes electrochemical flow technology as a viable route toward sustainable, cost-effective, and environmentally benign oxidant manufacturing for the future chemical industry.
References