<scp>Efficient</scp> H ₂ S capture and conversion by deep eutectic solvents via dual physicochemical synergistic effects

Abstract For the selective removal of H 2 S from natural gas, five deep eutectic solvents (DESs) were designed and synthesized by combining functionalized ionic liquids (ILs) bearing dual tertiary amine sites with high‐boiling‐point solvents. The thermodynamic parameters for the dissolution of H 2 S and CO 2 in [C 4 ‐PMDTA]Br‐ME were calculated using variable temperature measurements of solubility and the Krichevsky–Kasarnovsky (K–K) equation. These DESs demonstrate superior H 2 S performance and H 2 S/CO 2 selectivity over other DESs. Nuclear magnetic resonance, quantum chemical calculations, and molecular dynamics simulation reveal that the efficient capture and separation of H 2 S originate from the synergistic effect between the protonation of tertiary amine sites and hydrogen‐bonding interactions. More importantly, the H 2 S activated by tertiary amine sites can be efficiently converted into high‐value‐added thiol products under mild reaction conditions, and DESs can be recovered by water washing extraction. These functionalized DESs offer a promising alternative for the capture and conversion of H 2 S.