Interface‐Engineering‐Induced C−C Coupling for C ₂ H ₄ Photosynthesis from Atmospheric‐Concentration CO ₂ Reduction

Producing ethylene (C₂H₄) from carbon dioxide (CO₂) photoreduction under mild conditions is primarily restricted by the difficulty of C-C coupling. Herein, we designed highly active metal atom clusters anchored on semiconductor nanosheets, which established heteroatom sites on the interface to steer C-C coupling, realizing air-concentration CO₂ photoreduction into C₂H₄ in pure water. As an example, the Pd nanoclusters loaded on ZnO nanosheets are prepared, demonstrated by the X-ray photoelectron spectroscopy and high-angle annular dark-field image. In situ Fourier transform infrared spectroscopy confirms the C-C coupling step over the Pd-ZnO nanosheets, while quasi in situ X-ray photoelectron spectroscopy illustrates the active sites of Pd and Zn atoms on the Pd-ZnO nanosheets during CO₂ photoreduction. Density functional theoretical calculations unveil the transition state energy barrier of C-C coupling of CO* and COH* intermediates are only 0.998 eV, hinting the easy C-C coupling to produce C₂ fuels. Therefore, the Pd-ZnO nanosheets realize C₂H₄ photosynthesis by atmospheric-concentration CO₂ reduction with the formation rate of 1.03 μmol g^-1 h^-1, while the ZnO nanosheets only acquired the carbon monoxide product.