Spatially programmed regioisomeric conjugated microporous polymers modulating zinc sites for selective CO2 photoreduction to CH4†

Abstract

Conjugated microporous polymers show great potential for photocatalytic CO₂ reduction into value-added products. However, their catalytic activity and selectivity remain significantly limited due to poor charge separation efficiency and the lack of suitable active sites. Herein, we propose a topology-driven dipole programming strategy that synergistically decouples atomic-level electronic configuration control from spatially resolved active site engineering. Crucially, the regioisomer-dependent π-topology governs light-harvesting ability, dipole polarization hierarchy, and directional charge transport networks. As a result, the designed Zn-TPA-BPy-1, featuring dipole polarization fields and Zn–N₂O₂ sites, exhibits exceptional photocatalytic CO₂ conversion activity, with a CH₄ evolution rate of 753.18 μmol g⁻¹ h⁻¹ and a high selectivity of 89.7%. Experimental and theoretical results reveal that asymmetric dipole arrays lower the energy barrier for *COOH and *CO intermediates while stabilizing *CHO intermediates through dynamic charge compensation, which contribute to the high activity and selectivity. This finding offers new insights into designing polymer-photocatalysts by subtle structural modulation for CO₂ conversion.