Mesoporous Boron‐Doped Carbon with Curved B ₄C Active Sites for Highly Efficient H ₂O ₂ Electrosynthesis in Neutral Media and Air‐Supplied Environments

Abstract

Hydrogen peroxide (H ₂O ₂) electrosynthesis via the 2e ⁻ oxygen reduction reaction (ORR) is considered as a cost‐effective and safe alternative to the energy‐intensive anthraquinone process. However, in more practical environments, namely, the use of neutral media and air‐fed cathode environments, slow ORR kinetics and insufficient oxygen supply pose significant challenges to efficient H ₂O ₂ production at high current densities. In this work, mesoporous B‐doped carbons with novel curved B ₄C active sites, synthesized via a carbon dioxide (CO ₂) reduction using a pore‐former agent, to simultaneously achieve excellent 2e ⁻ ORR activity and improved mass transfer properties are introduced. Through a combination of experimental analysis and theoretical calculations, it is confirmed that the curved B ₄C configuration, formed by mesopores in the carbon, demonstrates superior selectivity and activity for 2e ⁻ ORR due to its weaker interaction with *OOH intermediates compared to planar B ₄C in neutral media. Moreover, the mesopores facilitate oxygen supply and suppress the hydrogen evolution reaction, achieving a Faradaic efficiency of 86.2% at 150 mA cm ⁻² under air‐supplied conditions, along with an impressive O ₂ utilization efficiency of 93.6%. This approach will provide a route to catalyst design for efficient H ₂O ₂ electrosynthesis in a practical environment.