Engineering macroporous catalyst layer with fluorinated interface for industrial current density H2O2 electrosynthesis

On-site electrochemical synthesis of hydrogen peroxide (H 2 O 2 ) for advanced oxidation processes is a promising technology, yet its practical application is hindered by poor performance at industrial-scale current densities (>500 mA cm −2 ). This limitation stems from severe mass transport bottlenecks for both oxygen and protons. Here, we report a strategy to overcome this dual challenge by designing a self-stratified porous catalyst layer (D-CL) using a volatile fluorinated additive. The additive's evaporation creates abundant macropores that enhance O 2 permeation, while residual -CF x fragments restructure the interfacial water network from rigid tetrahedrally coordinated water to flexible doubly hydrogen-bonded water configurations. This tailored interface weakens hydrogen bonding, facilitating rapid proton transport and mitigating local pH increases. This synergistic design enables a high H 2 O 2 Faradaic efficiency of ∼60% and a production rate of 8.0 mmol cm −2  h −1 at 0.8 A cm −2 , demonstrating a robust pathway for practical environmental remediation applications.