Photocatalytic Asymmetric C‐C Coupling for CO ₂ Reduction on Cu‐Zn Bimetallic Catalysts with Dipole‐Limiting Effects

Abstract The photocatalytic reduction of CO ₂ to multicarbon products such as ethylene remains a challenge due to the difficulty in achieving efficient C‐C coupling. This study proposes a novel Cu‐Zn bimetallic catalyst, CuZn‐E‐d‐MOF, synthesized by grafting ethylenediaminetetraacetic acid (EDTA) onto a defect‐rich Ti‐MOF framework (d‐Ti‐BPDC). The catalyst exhibits excellent photocatalytic CO ₂ reduction performance, with an ethylene yield of 308.72 µmol g ⁻¹ h ⁻¹ and an electron selectivity of 98.4%. The Cu‐Zn dual sites enhance the adsorption and activation of CO ₂ intermediates through asymmetric charge distribution and the formation of a dipole‐limited domain field (DLDF), facilitating multi‐electron transfer and C‐C coupling. Density functional theory (DFT) calculations show that Cu ²⁺ /Cu ⁺ pairs stabilize *CO intermediates and promote C─C bond formation, while Zn enhances orbital hybridization, improving electron transfer between Cu‐Zn sites and *CO‐*CO intermediates. In situ FTIR analysis confirms the formation of the *CO‐*CO coupling intermediate, elucidating the high selectivity for C ₂ products. This work highlights the role of asymmetric bimetallic sites and localized electric fields in CO ₂ photoreduction, providing a promising strategy for efficient multicarbon product synthesis.