Protic ionic <scp>liquid‐based</scp> deep eutectic solvents with multiple hydrogen bonding sites for efficient absorption of <scp>NH₃</scp>

Abstract

Abstract The emerging of ionic liquids (ILs) provides an efficient and sustainable way to separate and recover NH 3 due to their unique properties. However, the solid or highly viscous ILs are not suitable for traditional scrubbing. Therefore, an effective strategy was proposed by combining the protic ILs (PILs) with acidic H and low viscous ethylene glycol (EG) to form IL‐based deep eutectic solvents (DESs) for NH 3 absorption. The results indicated that these PIL‐based DESs not only have fast absorption rate, but also exhibit exceptional NH 3 capacity and excellent recyclability. The highest mass capacity of 211 mg NH 3 /g DES was achieved by [Im][NO 3 ]/EG with molar ratio of 1:3, and was higher than all the reported ILs and IL‐based DESs, which was originated from multiple hydrogen bonding between acidic H and hydroxyl groups of the DESs and NH 3 . This work will provide useful idea for designing IL‐based solvents for NH 3 separation applications.