Electrosynthesis of hydrogen peroxide with anion exchange membrane-free resin wafer reactors

Abstract Porous solid electrolyte (PSE) reactors have attracted worldwide interest in H₂O₂ electrosynthesis and other electrochemical processes (e.g., CO₂ reduction). However, scaling up PSE reactors for industrial applications faces several challenges, including the difficulty in uniformly packing PSE (typically resin microspheres) in large reactors, the high pressure drop across the reactor, and the limited durability of anion exchange membranes (AEM). Here, to address these challenges, we fabricated robust PSE wafers with both high ion conductivity and porosity by pre-molding resin microspheres, conductive binder, and pore-forming agent. These pre-molded wafers can be easily installed in reactors, thereby simplifying the reactor assembly and scalability. Moreover, due to their high porosity, the PSE wafers dramatically reduced the pressure drops across the reactor by a factor of ~ 5–7 compared to resin microsphere-packed beds. Consequently, the wafer reactors could be stably operated without the need of an AEM for preventing electrode flooding, circumventing the barrier to long-term stability of PSE reactors. By addressing these bottlenecks, the wafer reactor provide a robust and scalable platform for practical H₂O₂ electrosynthesis.