Interfacial force engineering unlocks mass transfer in the oxygen reduction reaction

The efficiency of oxygen reduction reactions (ORR) that involve gaseous reactants is often limited by sluggish reactant mass transport, which is fundamentally impeded by the structured interfacial hydration shell at the catalyst surface. Here, we demonstrate that this limitation can be overcome by physically disrupting the hydration shell. To achieve this, we propose and implement an interfacial force engineering strategy that systematically generates a gradient of bubble-electrode interfacial forces ranging from 60.8 to 275.7 μN. The engineered electrode exhibits a 7.1-fold increase in H₂O₂ production yield, accompanied by a Faradaic efficiency of 92.5% for the two-electron oxygen reduction pathway. Multiscale simulations reveal that the enhanced interfacial force expels structured water molecules at the interface, thereby creating a local oxygen-rich environment at the catalytic surface. This work highlights interfacial force as an important physical parameter for regulating gas transport at electrocatalytic interfaces, providing a new perspective for designing systems beyond conventional mass-transport limitations.