posted on 2024-04-09, 08:30authored byCongcong Ni, Zhiheng Fan, Ning Deng, Xin Huang
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.