The Role of Solid Electrolytes in Suppressing Joule Heating Effect for Scalable H _<b>2</b> O _<b>2</b> Electrosynthesis

Abstract

The electrosynthesis of hydrogen peroxide (H2O2) via oxygen reduction has the potential to revolutionize traditional chemical synthesis. However, this objective is often hindered by the decline in energy efficiency during large-scale production, a guiding metric for the economic feasibility of H2O2 electrosynthesis. This study identifies Joule heating as the primary contributor to efficiency loss as it accelerates H2O2 decomposition and induces substantial voltage drops. Thermal and impedance analyses reveal that Joule heating can be significantly suppressed by enhancing electrolyte conductivity and optimizing reactor structure to reduce internal resistance. Among these strategies, structural optimization shows a bottleneck in reducing internal resistance, while electrolyte conductivity enhancement is the key to further improvement. To balance electrosynthesis performance with environmental sustainability, a Na2SO4-strongly acidic cation exchange resin (SAC) composite solid electrolyte is proposed, significantly reducing the use of salt-based liquid electrolytes. This approach enables efficient and stable H2O2 production at an industrial current density, providing a feasible pathway for its scalable application.