In situ metallization of 2D COFs with acid/base site synergistic effects for boosting one-pot CO2 conversion

Abstract

Covalent organic frameworks (COFs) with permanent porosity, high structural stability and framework modifiability offer unique superiority for heterogeneous catalysis. Herein, we propose an in situ metallization strategy to construct a series of metal-functionalized 2D COFs (M/COFs, M = Co, Ni and Zn). The 2D matrix provides inherent accessible Lewis base sites, along with the introduced metal species acting as Lewis acid sites. These active sites with synergistic effects boost the catalytic CO₂ conversion performance of these materials. Our results show that these M/COFs efficiently convert CO₂ and olefins into cyclic carbonates through one-pot tandem catalysis. Specifically, Co/COFs achieve nearly complete styrene conversion and 85% yield of styrene carbonate without a co-catalyst at 80 °C and 1 bar. Simulation results further reveal the higher interaction energy of Co/COFs and guests and elucidate the underlying catalytic mechanisms of COF catalysts before and after modification. This work provides both scientific and applicational insights into designing high-performance metal-functionalized materials for optimal tandem catalytic performance.