Simultaneous Photon‐Phonon Co‐driven Coupling of Methanol to Ethanol Over CoO _x /S _v ‐CdS

Abstract Ethanol, an environmentally friendly and versatile fuel, finds wide applications in pharmaceuticals, chemicals, and food industries. The present production route from methanol derived from biomass or coal offers an ideal alternative pathway for ethanol synthesis. However, the conventional thermal catalytic methods require high temperatures (>200 °C) and multi‐step reactions. Herein, coupling photons and phonons, a direct one‐step and rather efficient approach has been developed for methanol to ethanol synthesis operated under very mild conditions. The surface‐engineered CoO x /S v ‐CdS catalyst achieves an exceptional ethanol production rate of 13.45 µmol h −1 (2.69 mmol g −1 h −1 ) at 100 °C under visible light irradiation (>420 nm). Such high activity also remains long time (>25 h). Fundamentally, an effective dual‐radical coupling mechanism is proposed, in which CoO x sites capture holes to activate C─H bonds to generate ·CH 2 OH radicals. In parallel, Cd in CdS acts as an electron acceptor for C─O bond breaking to produce ·CH 3 radicals, followed by radical coupling to synthesize ethanol. This work further discusses the function of photons and phonons and presents an efficient simultaneous photon‐phonon co‐driven catalytic system for the C─C coupling.