Facilitating H⁺ ion heterolysis using lattice strained Pd-tipped Au nanorods for direct H₂O₂ synthesis in pure water

Direct H2O2 synthesis (DHS) from H-2 and O-2 over Pd catalyst is a potentially rewarding strategy to replace the industrial anthraquinone method, but the sluggish hydrogenation process seriously impedes production efficiency in pure water. Here, we report a lattice strained Pd catalyst which is formed on Au nanorods (NRs) tips by taking advantage of curvature. The lattice strained Pd tipped Au NRs (PTA) is found to be able to facilitate the H+ ion heterolysis, in particular with light illumination, thereby remarkably enhancing the DHS performance. The lattice strain effect together with light-induced hot electrons enables a production rate of 0.12 mol/g/h for H2O2 generation, which is 3.11 and 3.56 times higher than that of no light assistance or strain effect ones, respectively. Finally, a porous PTA film was assembled, which achieves a H2O2 concentration of similar to 2.3% within 24 h that is expected to make for direct medical use (< 3%).