Photocatalytic Coupling of CH₄ and CO₂ to Ethanol on Asymmetric Ce−O−Zn Sites

Abstract Partial oxidation of methane (CH₄) to value‐added products is significantly challenging due to the highly inert chemical property of CH₄ at ambient conditions and easy over‐oxidation into carbon dioxide (CO₂) or carbon monoxide (CO) at elevated temperatures and pressures. Targeting this challenge, the efficient photocatalytic coupling of CO₂ and CH₄ into ethanol is demonstrated, using a cerium (Ce)‐doped zinc oxide (ZnO) photocatalyst with abundant Ce─O─Zn units. Under light illumination, CO₂ is adsorbed on the Ce atoms and photo‐reduced to CO, and CH₄ is captured by the Zn atoms and photo‐oxidized to hydroperoxymethane (CH₃OOH). The close proximity of Ce and Zn atoms on the Ce─O─Zn units allowed to further efficiently couple the as‐formed CO and CH₃OOH into ethanol. Without additional Oxygen (O₂) oxidant or sacrificial regent, the ethanol production rate reached 580 µmol g⁻¹ h⁻¹, substantially exceeding previously reports on photocatalytic CH₄ oxidation. This work features to convert two greenhouse gases into value‐added chemicals with adjacent and asymmetric reaction sites, suggesting attractive potentials for CH₄ and CO₂ utilization.