Coordination-Assisted Photothermal Catalysis over Metalloporphyrin 3D COFs for Efficient CO2 Cycloaddition

The development of catalytic systems that leverage solar energy to drive chemical transformations under mild conditions represents a promising pathway for sustainable CO2 utilization. Herein, we report a series of metalloporphyrin-based three-dimensional covalent organic frameworks (MTTEP-COFs; M = Co, Zn) designed for the efficient photothermal cycloaddition of CO2 with epoxides. Due to its pronounced donor–acceptor (D–A) character, CoTTEP-COF achieves a rapid photothermal response (ΔT = 34 °C within 5 min) and superior charge separation, enabling 76% conversion of styrene oxide to the corresponding cyclic carbonate with >99% selectivity under ambient pressure. This performance significantly surpasses its Zn-based counterpart and molecular analogs. Mechanistic studies combining experiments and DFT calculations reveal a coordination-assisted photo-activation mechanism: the Co center forms coordination with epoxides, promoting photogenerated charge separation; the inherent D–A structure enhances photothermal conversion and suppresses carrier recombination; photothermal synergy accelerates reaction kinetics while facilitating substrate activation. This work not only presents a high-performance and stable photothermal catalyst but also provides new insights into the design of advanced catalytic systems that integrate light harvesting, charge dynamics, and molecular coordination for sustainable CO2 utilization.