CO₂ photoreduction with high selectivity of C₂H₄ production on conjugated microporous polymer with Cu single atoms

Selective conversion of CO2 to fuels and chemicals has been considered one of the key challenges in the photocatalytic CO2 reduction reaction. The multi-electron reduction reaction requires the design of photocatalysts that can adsorb CO2 and transfer electrons. Herein, Cu single atoms are confined in a conjugated microporous polymer (CMP) to construct Cun@CMP photocatalyst for CO2 reduction to produce C2H4 and CH4. By adjusting Cu loading, Cu-0.012@CMP exhibited a high performance with production yields of 236.81 mu mol center dot g(-1)center dot h(-1) for C2H4, and 78.2 % selectivity for C2H4 formation. DFT calculations displayed the band structure and confirmed Cu-N together with characterization. The in situ DRIFTS revealed *CH2 and *C2H4 as key reaction intermediates to form CH4 and C2H4, respectively. The synergy effect in Cu single-atoms and CMP contributed greatly to C-C coupling and interfacial charge transfer, thus achieving excellent activity for conversion of CO2 to C-1/C-2. This work highlights the potential for constructing Cu single atoms on CMP to produce highly selective C2H4.