Reconfiguration of Electrostatic Interactions within an Ultramicroporous Metal–Organic Framework Enables CO2 Separation

Developing highly efficient adsorbents for CO₂ separation is significant in solving environmental challenges, but the trade-off between regenerability and selectivity undoubtedly limits their practical applications. Here, an ultramicroporous zinc metal–organic framework (Zn-MOF, termed as 1a) with decent CO₂-affinity pore cavities is synthesized to enhance electrostatic interactions between CO₂ and the pore surface for efficient CO₂ purification from CO₂/N₂ and CO₂/CH₄ binary gas mixtures, in which the reconfiguration of electrostatic interactions within the 1a leads to a lower desorption temperature and high regenerability. Single-component gas adsorption isotherms indicate that 1a possesses a higher CO₂ capacity of 33.7/62.1 cm³ g^–1 (0.1/1 bar) at 298 K. Theoretical calculations suggest that the framework is electrostatically compatible with CO₂ and can boost CO₂ separation through multiple electrostatic interactions. Further, highly efficient separations of CO₂/CH₄ and CO₂/N₂ have been achieved and verified by column breakthrough tests.