Hydrophobic porous ionic liquids for efficient CO ₂ capture and conversion from humid flue gas under ambient conditions

Abstract

Here, we propose the hydrophobic porous ionic liquids (PILs) for CO ₂ capture and conversion from humid flue gas. Specifically, silver was introduced onto the surface of ZIF‐90 and the resultant material was incorporated into the hydrophobic ionic liquids (ILs) to form Type III PILs. The obtained LADDA‐PIL exhibited an exceptional CO ₂ absorption capacity and CO ₂ /N ₂ (15/85) selectivity of 2021, surpassing nearly all previously reported porous liquids. Dynamic breakthrough experiments confirmed that LADDA‐PIL successfully captured CO ₂ from humid flue gas. Moreover, the π‐interaction between silver in LADDA‐PIL and the alkynyl group enabled high‐yield carboxylative cyclization of CO ₂ with propargylic alcohols at ambient temperature. Density functional theory calculations and molecular dynamics simulations revealed that the hydrophobic ILs act as an effective H ₂ O barrier, while the NH ₂ moiety of the ILs facilitates CO ₂ transport and conversion. This study offers a promising strategy for energy‐efficient carbon capture under humid conditions.