Cu-based metal-organic framework with dual open metal sites for efficient separation of CO2 from flue gas

Excessive carbon dioxide (CO₂) emissions from flue gases intensify the greenhouse effect. Exploring porous adsorbents with high CO₂/N₂ selectivity is of great significance to reducing the CO₂ content in flue gases. Herein, we report a novel PtS-type metal-organic framework (MOFs), termed ZSTU-21, with narrow pore size and excellent CO₂/N₂ separation performance with dual open copper sites. At 298 K, ZSTU-21 exhibits a CO₂ uptake capacity of 62 cm³ g⁻¹ and a high selectivity of 105 for CO₂/N₂ (CO₂/N₂ = 15/85, v/v). Multicomponent adsorption breakthrough experiments further verified the superior performance of ZSTU-21 MOF in CO₂/N₂ separation. Moreover, the synthesis of ZSTU-21 MOF can be carried out under mild experimental conditions at room temperature, making the process simple and cost-effective, thus laying a solid foundation for its widespread application in CO₂/N₂ separation.