Interfacial polarized Ptδ- sites drive efficient and direct photocatalytic conversion of methane to formaldehyde by regulating radical species via d-p orbital interactions.

The direct photocatalytic oxidation of inert methane (CH4) to high-value-added oxygenates remains a significant challenge. This study precisely controls generated reactive oxygen species (ROS) types by modulating interfacial electronic interactions in Zn-Ptδ--PS photocatalysts, promoting CH4 conversion into formaldehyde (HCHO). Under ambient conditions, a HCHO production rate reached 3308 μmol·g-1 with a high selectivity of 77%. In situ spectroscopy and theoretical studies demonstrated that the elevated Pt d-band center in Pt-*OOH (* represents the adsorption state) lowered the occupancy of antibonding orbitals, thereby enhancing the interaction between Pt and *OOH, markedly polarizing the OO bond, facilitating its cleavage, and enabling the preferential in situ generation of •OH rather than •OOH. Furthermore, adequate •OH radical accelerated activation of the CH bond in CH4 and induced the cleavage of its OH bond in methanol (CH3OH), promoting HCHO formation. This strategy may guide the rational design of the catalyst's electronic structure to enhance CH4 photocatalytic oxidation.