Interface‐Engineering‐Induced C–C Coupling for C2H4 Photosynthesis from Atmospheric‐Concentration CO2 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 nanosheet, which established heteroatom sites on the interface to steer C−C coupling, realizing air‐concentration CO2 photoreduction into C2H4 in pure water for the first time. 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 first 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.