Iron Oxide Clusters as Electron Donors Under Light Enhance Oxygen Reduction Kinetics at Atomically Dispersed Fe for Photocatalytic CH₄ Partial Oxidation

Photocatalytic CH₄ oxidation to CH₃OH emerges as a promising strategy to sustainably utilize natural gas and mitigate the greenhouse effect. However, there remains a significant challenge for the synthesis of methanol by using O₂ at low temperature. Inspired by the catalytic structure in soluble methane monooxygenase (MMO) and the corresponding reaction mechanism, we prepared a biomimetic photocatalyst with the decoration of Fe₂O₃ nanoclusters and satellite Fe single atoms immobilized on carbon nitride. The catalyst demonstrates an excellent CH₃OH productivity of 5.02 mmol ⋅ g_cat⁻¹ ⋅ h⁻¹ with CH₃OH selectivity of 98.5 %. Mechanism studies reveal that the synergy between Fe₂O₃ nanoclusters and Fe single atoms establishes a dual-Fe site as MMO for O₂ activation and subsequent CH₄ partial oxidation. Moreover, the light excitation of Fe₂O₃ nanoclusters with a relative narrow band gap could deliver the electrons and protons to atomic Fe that facilitating the oxygen reduction kinetics for the robust of CH₃OH synthesis.