Promoted absorption of CO at high temperature by cuprous‐based ternary deep eutectic solvents

Achieving efficient dissolution of carbon monoxide (CO) in the solvent is very helpful for the implementation of carbonylation reaction at ambient pressure. However, almost all of common solvents show very low solubilities of CO at high temperature. Herein, a series of cuprous‐based ternary deep eutectic solvent (DES) was prepared by mixing imidazolium hydrochloride with CuCl and ZnCl 2 . The ternary DES [BimH]Cl‐CuCl‐1.0ZnCl 2 exhibited very large CO absorption capacity (0.075 mol mol −1 , 1 bar) even at a high temperature (353.2 K), which is superior to all of the reported absorbents. Moreover, the ternary DES [BimH]Cl‐CuCl‐1.0ZnCl 2 could further promote the reactive absorption of CO to conduct the aminocarbonylation reaction effortlessly at ambient pressure, and thus the targeted products benzamides were obtained in 70–97 yields. We believe that this finding opens a new way to design advanced solvents for efficient capture of CO at high temperature.