The selective removal of H₂S from CO₂-contained gaseous mixture is an important and challenging task for natural gas industry. Herein, 1-ethyl-3-methylimidazolium chloride ([Emim]Cl) + imidazole DESs were examined as the physical solvents for H₂S and CO₂ absorption. The solubilities of gases were determined systematically, and the Henry’s constants of gases, ideal selectivities of gas pair, enthalpy changes of gas absorption were calculated. The variations of H₂S and CO₂ solubilities with [Emim]Cl contents in DESs show different trends. In addition, the H₂S solubilities in the [Emim]Cl + imidazole DESs are much higher than those of CO₂. The results were compared with other liquid solvents, and [Emim]Cl + imidazole DESs enable extremely high efficiency for H₂S absorption and large selectivity towards CO₂. The molecular dynamics (MD) simulations and density functional theory (DFT) calculations were then systematically carried out to explain the results obtained. It is demonstrated that the strong interaction was found between the H of H₂S and Cl⁻ of [Emim]Cl, which contributes to the excellent performance of [Emim]Cl + imidazole DESs in separation of H₂S from CO₂.

从含有CO ₂的气体混合物中选择性去除 H ₂ S是天然气工业的一项重要且具有挑战性的任务。在此，研究了 1-乙基-3-甲基咪唑氯化物 ([Emim]Cl) + 咪唑 DES 作为 H ₂ S 和 CO ₂吸收的物理溶剂。系统地测定了气体的溶解度，计算了气体的亨利常数、气体对的理想选择性、气体吸收焓变。H ₂ S 和CO ₂溶解度随DESs中[Emim]Cl含量的变化表现出不同的趋势。此外，[Emim]Cl + 咪唑 DESs 中H ₂ S 的溶解度远高于 CO ₂. 将结果与其他液体溶剂进行比较，[Emim]Cl + 咪唑 DESs 具有极高的 H ₂ S 吸收效率和对 CO _{2 的}高选择性。然后系统地进行分子动力学 (MD) 模拟和密度泛函理论 (DFT) 计算以解释所获得的结果。结果表明，H ₂ S的H和[Emim]Cl 的Cl ^-之间存在强相互作用，这有助于[Emim]Cl + 咪唑DESs 在从CO ₂中分离H ₂ S 方面具有优异的性能。