Dissolution of Metal Organic Cage in Deep Eutectic Solvent: A Solution for Preparing Type II Porous Liquids

Porous liquids represent an innovative class of materials that combine the porosity of porous solids with the dynamic fluidity of liquids, garnering significant interest. However, the preparation of type II porous liquids is often hindered by complex methodologies and stringent requirements for both the porous host and the sterically hindered solvent. Herein, we present a simple and universal approach to prepare type II porous liquids, utilizing the metal organic cage ZrT-1-OH as the porous host and deep eutectic solvents (DES) as the sterically hindered solvent, respectively. Through hydrogen bonding interactions, ZrT-1-OH dissolves efficiently in DES, resulting in porous liquids with low viscosity. These porous liquids exhibit enhanced CO₂ sorption performance and demonstrate potential for selective gas separations of CO₂/N₂ and CH₄/N₂. Given the diversity of available porous organic cages and the high tunability of DES compositions, this approach offers a promising and universal pathway for the design and preparation of type II porous liquids.