Interfacial charge‐regulated peroxide pathway enables visible‐light‐driven oxidative coupling of methane to ethane

Controlling oxygen activation while suppressing overoxidation remains a central challenge in photocatalytic oxidative coupling of methane (OCM) under mild conditions. Herein, we report an interfacial charge‐regulated strategy for selective visible‐light‐driven methane coupling to ethane over an In 2 O 3 ‐synergized Au/TiO 2−x photocatalyst. The introduction of In 2 O 3 establishes a built‐in electric field at the In 2 O 3 /Au/TiO 2−x heterointerface, enhancing charge separation and driving directional photogenerated electron migration along the pathway of In 2 O 3 → TiO 2−x → Au and resulting in electron‐enriched Au sites under irradiation. These sites fundamentally alter the oxygen activation pathway by promoting the formation of mild peroxide species (O 2 2− ) while suppressing highly oxidative oxygen species. The resulting O 2 2− species activate CH 4 to form *CH 3 intermediates, which undergo selective C–C coupling on Au. As a result, the catalyst achieves an ethane formation rate of 304.6 ± 7.6 μmol·g −1 ·h −1 with 99.4% selectivity under visible‐light irradiation. The rate increases to 32.9 ± 0.5 mmol·g −1 ·h −1 under full‐spectrum irradiation.