Microenvironment Engineering of Catalytic Pockets in Copper Paddle-Wheel-Based Hypercrosslinked Microporous Polymers for Highly Selective CO2 Photoreduction

Abstract

Precise modulation of the local microenvironment surrounding metal active centers constitutes a powerful strategy for optimizing the performance of photocatalytic CO2 reduction. In this work, a series of hypercrosslinked microporous polymers incorporating paddle-wheel copper benzoate moieties were rationally designed and synthesized. By introducing para-substituted styrene comonomers with distinct functional groups (-NH2, -CH3, -CO2H, -CF3), the microenvironment surrounding Cu active sites was delicately and systematically regulated. Benefiting from significantly improved photogenerated charge separation efficiency and favorable surface hydrophobicity, poly(Cu2(VB)4-co-VBTF)-3 exhibits a CO production rate of 21.8 μmol g-1 h-1 with nearly 100% CO selectivity under gas-solid conditions without any sacrificial agent, representing a 3.6-fold activity enhancement compared with the Cu2(VB)4 monomer. This microenvironment engineering strategy offers a new avenue for the precise design of metal active sites in porous polymeric photocatalysts and provides important insights for developing efficient solar-driven CO2 conversion technologies.