Photocatalytic Acetic Acid Production with High Selectivity from Conversion of CH ₄ and CO Under Mild Conditions

Abstract Solar‐driven direct carbonylation of CH ₄ to value‐added C ₂ chemicals, such as acetic acid (CH ₃ COOH), offers a promising pathway toward carbon neutrality under mild conditions, but the performance is largely impeded by the ineffective activation of C─H bond and limited control over CH ₃ ‒CO coupling. Here, we report that through rational surface decoration of Pd nanoparticles (NPs) and oxygen vacancy (V _O ), selective photocatalytic CH ₃ COOH production is realized on WO ₃ nanosheets from co‐conversion of CH ₄ and CO at room temperature and ambient pressure. Under light irradiation, the optimal Pd/V _O ‐WO ₃ photocatalyst exhibits efficient CH ₃ COOH production with a yield rate of 52.7 µmol g ⁻¹ h ⁻¹ and a selectivity of 63.7% in the presence of H ₂ O ₂ oxidant. Combined in situ spectroscopies and computational calculations reveal that V _O serves as the active site for CH ₄ adsorption, while Pd NPs facilitates the activation of H ₂ O ₂ into ·OH radicals to promote CH ₄ dissociation to ^* CH ₃ intermediate, thus leading to subsequent CH ₃ ‒CO coupling for CH ₃ COOH production over Pd/V _O ‐WO ₃ . This work paves a new path into photocatalytic CH ₄ carbonylation to targeted C ₂₊ products under mild conditions via synergistic active sites.