Boosting hydrogen peroxide production in formic acid-driven oxygen reduction via regulating the microenvironment of reaction interfaces

The two-electron oxygen reduction driven by formic acid based on metal catalysts is a promising approach for H₂O₂ synthesis under mild conditions. However, in conventional catalytic systems, the concentration of reactant O₂ at the solid/liquid diphase reaction interface is generally low, which restricts the reaction kinetics and the yield of H₂O₂. Inspired by the natural non-wetting surfaces, we describe here a catalytic system with an air–liquid–solid triphase interface microenvironment for efficient H₂O₂ generation in formic acid-driven oxygen reduction. The triphase system was fabricated by immobilizing Pt-decorated TiO₂ (Pt-TiO₂), a model catalyst on a hydrophobic porous carbon substrate. Such a triphase system allows sufficient O₂ to be rapidly delivered from the air phase, greatly enhancing its concentration at the reaction zone. We found the H₂O₂ formation rate constant was increased by more than 10-fold in comparison with a conventional solid/liquid diphase catalytic system. In addition, the design principle is applicable to a wide range of catalysts. This work provides an exploratory platform for the further development of high-efficiency H₂O₂ generation systems.