Selective water oxidation to H₂O₂: from laboratory to scaled-up applications

Hydrogen peroxide (H₂O₂) is a benchmark green oxidant, widely employed in water treatment, bleaching, and selective oxidation processes. The conventional production of H 2 O 2 is largely reliant on the large-scale and highly centralized anthraquinone process, which also involves safety issues related to transportation and handling of large volumes of explosive peroxide solutions, and a disadvantageous environmental footprint. Among the electrochemical methods, synthesis of H 2 O 2 via two-electron (2e⁻) water oxidation offers an alternative approach, suitable for decentralized and on-demand production powered by renewable energy, with a reduced carbon footprint and safety advantages. Recent advances in anodic electrocatalysis and flow-reactor engineering have begun to demonstrate continuous operation at industrially relevant current densities, highlighting the potential of this route for modular and distributed chemical manufacturing. This work critically examines recent progress in material development, reactor design, operational strategies, techno-economic considerations, and sustainability aspects. Particular attention is given to catalyst durability, degradation pathways under high current densities, and strategies to preserve selectivity during long-term operation. Emphasis is placed on overcoming the unique challenges posed by selectivity, stability, mass transport, and system integration for the scalable deployment of the technology. Emerging modular reactor architectures and recent scale-up demonstrations are discussed to illustrate practical design principles, energy efficiency targets, and cost drivers relevant to real-world implementation. Finally, an outlook is presented regarding future R&D avenues toward reliable, economically viable, and industrially scalable H₂O₂ generation.