Highly efficient H2S absorption and conversion by cyclohexanone-enhanced ionic liquid composite systems

Functionalized ionic liquid-cyclohexanone composites are proposed and designed. • An excellent H₂S uptake (7.34 mol·kg −1 at 313.2 K and 1.0 bar) is achieved. • Carbonyl and acetate are responsible for superior H₂S uptake. • Conversion of H 2 S into thiols and catalysts recovery by water extraction. Traditional functionalized ionic liquids (ILs) require tedious structural derivatization to boost separation yet suffer from high synthetic cost and poor industrial scalability. Herein, a facile cyclohexanone (Cyc)-based composite strategy was proposed relying on reversible H 2 S absorption enabled by carbonyl moieties instead of conventional functional-group derivatization. Four commercial ILs were blended with Cyc to construct IL − Cyc systems for efficient selective H 2 S capture and catalytic valorization. Among these candidates, [Emim][Ac] − Cyc delivered a high H 2 S uptake of 7.34 mol·kg −1 at 313.2 K and 1.0 bar. Combined spectroscopic characterizations, quantum chemical calculations and molecular dynamics simulations verified that synergistic interactions between acetate and carbonyl sites account for superior H 2 S affinity. Moreover, [Emim][Ac] − Cyc efficiently catalyzed the addition of H 2 S to epoxides for thiol synthesis, with catalyst recyclability realized by water extraction. This work provides guidance for the design of low-cost desulfurization materials toward sustainable H 2 S resource utilization. This work presents IL–Cyc composites for efficient H 2 S capture and catalytic conversion. Download: Download high-res image (150KB) Download: Download full-size image