Ag‐ZnO Nanoflowers Enable Highly Selective Photocatalytic Conversion of CH ₄ to CH ₃ OH at Atmospheric Pressure: Unraveling Reactive Interfaces and Intermediate Control

Abstract At atmospheric pressure, the main challenge in the photocatalytic oxidation of CH ₄ to CH ₃ OH is to absorb and activate the inert C─H bond while preventing excessive oxidation of CH ₃ OH. In this study, metal‐supported ZnO nanoflowers (Ag‐ZnO) are designed to produce abundant active interfacial oxygen sites for CH ₄ oxidation at atmospheric pressure, with a CH ₃ OH yield reaching 1300 µmol g _cat ⁻¹ h ⁻¹ and the selectivity is 94%. DFT calculation and in situ analysis show that the addition of Ag regulates the electron state density and band center of O, which is beneficial to the adsorption of CH ₄ , and decreases the dissociation energy barrier of C─H bond at O _L (Lattice oxygen) site. The further selective conversion of ·CH ₃ to CH ₃ OH involves two different pathways: one pathway consists of the oxidation of ·CH ₃ by O _L , and the other pathway is the combination of ·CH ₃ and ·OH generated from dissolved O ₂ (0.28 m m ) in water. Notably, in the photochemical flow device, the yield of CH ₃ OH is increased to 5200 µmol g _cat ⁻¹ h ⁻¹ and the selectivity is close to 100%. This work offers valuable insights into reactive interfaces, morphological engineering, and the control of intermediate evolution toward selective conversion of CH ₄ to oxygenates at atmospheric pressure.