Poly(ionic liquid)s-loaded metal-organic framework gel for CO2 capture and cycloaddition catalytic conversion

Combining ionic liquids (ILs) with metal–organic frameworks (MOFs) functionalizes the MOF pores and provides numerous active sites including Lewis acidic sites and hydrogen bond donors in the resulting heterogeneous composites, making them promising materials for CO 2 capture and conversion. Despite this potential, the prevalent microporosity in most MOFs severely restricts mass transfer. To address this limitation, it is essential to introduce hierarchical porosity into MOFs since it can enhance CO 2 capture and conversion by facilitating mass transfer and molecular diffusion. In this work, a hierarchical porous gel of UiO-66-NH 2 (denoted as HP-UiO-66-NH 2 ) was prepared through a simple sol-gel process, exhibiting micropores within the particles, mesopores between the particles, as well as multiple catalytic sites. Subsequently, poly(ionic liquid)s (PILs) were introduced into the porous framework to successfully construct PILs-MOFs gel materials (HP-MOF@PILs). A comprehensive evaluation was conducted on the synthesized materials regarding their ability to adsorb CO 2 , their catalytic performance in CO 2 cycloaddition with epichlorohydrin, and their recyclability. Benefiting from the synergistic advantages of its hierarchically porous structure and the strong CO 2 and epoxide activation ability of nucleophilic Br ions in PILs, HP-MOF@PIL-2 demonstrated exceptional catalytic performance and achieved high efficiency for the cycloaddition of CO 2 with epichlorohydrin under mild conditions (80 °C, 0.1 MPa, 24 h) without requiring co-catalysts or solvents, showcasing its role as a potential and eco-friendly catalyst in CO 2 conversion processes.