Interfacial modulation promoted C-C coupling in selective methane oxidation to ethanol

Selective methane oxidation to ethanol remained a formidable challenge. Herein, MOF-derived In₂O₃ was synthesized via MIL-68(In) pyrolysis. The optimized In₂O₃-500 achieved an ethanol yield of 10.8 mmol·g⁻¹·h⁻¹ under full-spectrum illumination. These performances were attributed to carboxylate type C-O related interfacial modulation, which enriched surface electron density and promoted C-C coupling. During derivation, precursor derived carbon species were retained as carboxylate type C-O related structures and interacted with the In-O framework, inducing surface charge redistribution. Compared with In₂O₃-400, which retained residual MOF structures, and highly crystalline In₂O₃-600, which exhibited severe charge recombination, In₂O₃-500 exhibited a higher surface electron density and enhanced ·OH and ·CH₃ generation, thereby promoting the stepwise oxidation of *CH₃ to *CH₃O and *CH₂O. The enriched *CH₂O and *CH₃ intermediates further facilitated C–C coupling to form ethanol. These findings highlighted the role of electron-rich surfaces in steering methane conversion toward ethanol.