Covalent organic framework-based catalysts for efficient CO2 utilization reactions

Anthropogenic CO2 emissions threaten the synergy between human society and the natural environment. To mitigate CO2 emissions, several CO2 utilization techniques have been proposed. Covalent organic frameworks (COFs), a promising class of porous crystalline materials, have been extensively explored for efficient CO2 utilization owing to their unique features. In particular, well-designed COFs with diverse active sites provide great opportunities to realize CO2 conversion. Herein, we review recent progresses in the design, synthesis, and catalytic mechanisms of COF-based functional materials for CO2 utilization reactions such as photo/electrocatalytic CO2 reduction, cycloaddition, carboxylation, and hydrogenation. We thoroughly evaluate and discuss photocatalytic CO2 reduction reactions using pristine and metalated COFs; CO2 electroreduction and carboxylation reactions using different metal-based COFs; and CO2 cycloaddition reactions using non-metalated, metalated, and ionic liquid-functionalized COFs. Finally, the challenges and prospects of CO2 utilization using COF-based catalysts are highlighted.