Self-Optimized Reconstruction of Metal–Organic Frameworks Introduces Cation Vacancies for Selective Electrosynthesis of Hydrogen Peroxide

Abstract

The electrocatalytic synthesis of hydrogen peroxide (H₂O₂) through the two-electron oxygen reduction pathway represents a green production process that has gained increasing importance. Nevertheless, there is a dearth of efficacious catalysts to attain high activity under industrial current density. In this study, we present a strategy for cation vacancy generation through metal–organic frameworks self-optimized reconfiguration for the efficient electrosynthesis of H₂O₂ under industrial current densities in solid-electrolyte cell. The ZIF-ZC91@Co(OH)₂-V_Co electrocatalyst exhibits significant H₂O₂ selectivity of 97.8%, and the H₂O₂ productivity is up to 24.53 mol g_catalyst⁻¹ h⁻¹ with a direct and continuous output of ∼3.36 wt% H₂O₂ aqueous solutions under industrial current density (400 mA cm⁻²). Impressively, the ZIF-ZC91@Co(OH)₂-V_Co possesses superb long-term durability for over 220 h and can output H₂O₂ aqueous solution with a concentration of ∼8.03 wt% in the pilot experiment. Theoretical calculations confirm that the introduction of modest cation vacancies optimizes the adsorption strength of *OOH intermediate and reduces both thermodynamic and kinetic barriers, thus balancing the selectivity of the two-electron oxygen reduction. This work provides valuable insights into the rapid, eco-friendly synthesis of H₂O₂ and the rational design of highly active catalysts.