Efficient conversion of H2S into mercaptan alcohol by tertiary-amine functionalized ionic liquids

This work develops a novel way of H 2 S resource into mercaptan alcohol mediated by tertiary-amine functionalized protic ionic liquids. • Novel way of H 2 S resource utilization into mercaptan alcohol was developed. • The mechanism of H 2 S conversion mediated ionic liquids was proposed. • The reaction separation coupling process was proposed. The resource utilization of hydrogen sulfide (H 2 S) is of great significance in natural gas chemical industry. Described herein have developed a novel method mediated in tertiary amine-functionalized ionic liquids (ILs) to convert H 2 S into mercaptan alcohols with enols. The effect of ILs, substrate scope, and regeneration experiments have been investigated. It is found that the conversion of 3-methyl-2-buten-1-ol by H 2 S can reach 52% with a 50% (mol) catalyst loading of bis(2-dimethylaminoethyl) ether methoxyacetate within 12 h at 90 °C. The reaction mechanism was speculated based on theoretical calculation. Besides, a plausible reaction–separation-integrated strategy was further proposed. This work reveals an effective insight into the capture and catalytic conversion of H 2 S to high valuable mercaptan alcohol, which makes the utilization method of H 2 S resource universal and has the potentiality for industrial application.