Anion‐Shielded Porous Organic Cages for High‐Performance Xenon/Krypton Separation

Abstract

Abstract The separation of Xe and Kr poses a significant industrial challenge. Herein, we demonstrate an anionic shielding strategy that effectively spatially confines anions within the cage's cavities, constructing unprecedented individually positively charged channel‐based adsorbents for Xe/Kr separation. Building on this approach, the obtained POC‐TG Cl achieved high Xe uptake (75.1 cm 3 g −1 ), remarkably IAST selectivity (23.4), and a record‐breaking dynamic selectivity of 15.4 among porous organic materials. These results achieve a superior trade‐off between adsorption capacity and selectivity compared to all reported Xe‐selective adsorbents. Notably, this is the first Xe/Kr adsorbent to use organic cations as binding sites, offering a new category of adsorbents for Xe/Kr separation. Theoretical calculations and in situ spectroscopic characterizations reveal that the presence of cationic sites accounts for the high performance of POC‐TG Cl . Moreover, unlike conventional ionic materials that are easily affected by water and ion interference, POC‐TG Cl , with its hydrophobic surface and anionic shielding, can effectively prevent the competitive adsorption of water and potential ion exchanges, enabling efficient ppm‐level Xe capture from nuclear waste off‐gas. Our work not only develops high‐performance adsorbents for Xe/Kr separation, but also provides a solution for constructing pure positively charged channels based porous materials for various application.