Porous liquid metal-organic frameworks with selectively high gas solubility

Porous liquid metal–organic frameworks (MOFs) have recently been discovered rather promising for gas absorption and separation in practical chemical industry processes. In this work, we successfully fabricated a kind of MOF-based porous liquid (i.e., UIO-66-PL) by dispersing the hydrophilic porous filler of UIO-66-NH2 nanoparticles into a specific hydrophilic ionic liquid (IL, [HEMIM][DCA]) through the wet-impregnation method. The obtained UIO-66-PL was a kind of stable porous liquid with well-maintained permanent porosity and liquid-like behavior at room temperature. More importantly, this UIO-66-PL has larger gas absorption capacities than its reference IL hindered solvent as the well-preserved permanent porosity could act as free void space for gas accommodation. Also, IL could serve as a selective gate for target gas to the permanent porosity within UIO-66-PL, i.e., the majority of the permanent porosity in UIO-66-PL is inaccessible to nitrogen, but available for carbon dioxide, demonstrating that this UIO-66-PL could function as a type of fluid selective gas sorbent with high target gas solubility.