Inhibiting Joule Heating to Enhance the Hydrogen Peroxide Electrosynthesis Efficiency at Industrial Level Current Density

Hydrogen peroxide (H2O2) electrosynthesis by an oxygen reduction reaction has been widely studied, but the inverse correlation between faradaic efficiency and industrial level current density is still difficult to solve. Here, we demonstrated the significant impact of generated OH– and Joule heating on the electrosynthesis efficiency of hydrogen peroxide (H2O2). Concurrent OH– production with H2O2 during oxygen reduction (O2 + 2H2O + 2e– → H2O2 + 2OH–) created locally alkaline environments, resulting in H2O2 self-decomposition at pH > 10, which was further facilitated by Joule heating in the interfacial regions of cathodes. Theoretical models were established to accurately simulate the trend of H2O2 electrosynthesis under the action of byproducts. By suppressing the electrolysis byproducts, excellent H2O2 yield of 170 mg h–1 cm–2 was obtained at 300 mA cm–2 with faradaic efficiency of 89.3%, even using commercial catalysts. This study contributes valuable insights into achieving a breakthrough in H2O2 selectivity at the ampere-level current density.