Screen ammonium‐based deep eutectic solvents for <scp> CO ₂ </scp> capture: Extended <scp>UNIFAC</scp> ‐ <scp>DES</scp> , calibrated <scp>COSMO</scp> ‐ <scp>RS</scp> , and experiment

Abstract CO 2 solubility in deep eutectic solvent (DES) is a critical property to indicate the competence of using DESs for carbon capture. This work presents a systematic screening framework with computational and experimental procedures to identify the promising ammonium‐based DESs for CO 2 absorption. First, 1556 CO 2 solubility data points are collected to regress UNIFAC‐DES interaction parameters to extend the applicability of UNIFAC in DESs. Meanwhile, the data are utilized to calibrate the COSMO‐RS model for enhancing accuracy. Then, 3192 hypothetical DESs are generated by rules. Their CO 2 solubilities are predicted using the two newly obtained models to produce two lists of top candidates. The melting points and viscosities of the candidates that appear in the two lists repeatedly are estimated and finally four ethylenecyanohydrin‐based DESs are identified. With two DESs verified via experiment, their superiority over the best reference DES is proved. Their absorption mechanisms are analyzed through quantum chemistry calculations.