Amino acid ionic liquids as efficient catalysts for CO2 capture and chemical conversion with epoxides under metal/halogen/cocatalyst/solvent-free conditions. Issue 9 (12th April 2021)

• Record Type: Journal Article
• Authors: Qu, Ye; Lan, Jianwen; Chen, Yanglin; Sun, Jianmin
• Is Part Of: Sustainable energy & fuels. Volume 5:Issue 9(2021)
• Page Start: 2494
• Page End: 2503
• Publication Date: 2021-04-12
• Subjects: Renewable energy sources -- Periodicals; Fuel cells -- Periodicals; Electric batteries -- Periodicals; Electrochemistry -- Periodicals; 660.297
• DOI: 10.1039/d1se00060h
• Languages: English
• ISSNs: 2398-4902

Abstract

Abstract : Biocompatible amino acid ionic liquids (AAILs) were synthesized and efficiently applied in CO2 capture and catalysis for the coupling reaction of CO2 with epoxides under halogen-, cocatalyst- and organic solvent-free conditions. Abstract : Amino acid ionic liquids (AAILs) are widely considered as biocompatible and biodegradable green absorbents, solvents and catalysts that have been utilized in sustainable chemistry. Several AAILs containing an ether-functionalized imidazole cation and amino acid anion, such as 1-methoxylbutyl-3-methylimidazolium glycine [MOBMIM][Gly], 1-methoxylbutyl-3-methylimidazolium lysine [MOBMIM][Lys], 1-methoxylbutyl-3-methylimidazolium arginine [MOBMIM][Arg] and 1-methoxylbutyl-3-methylimidazolium histidine [MOBMIM][His], were synthesized by the neutralization method and characterized by 1 H NMR, 13 C NMR, FT-IR spectroscopy and elemental analysis in detail. Due to the CO2 affinity of the ether-functionalized imidazole cation and amino acid anion, AAILs were applied in CO2 capture as well as the coupling reaction of CO2 with propylene oxide (PO). Specifically, [MOBMIM][Gly] with the ether-functionalized imidazole cation and glycine anion displayed the highest CO2 capture capacity (2.36 mmol (mmol-IL) −1 ) under the conditions of 50 °C and 0.5 MPa. Additionally, by the synergistic effects of the amino acid anion and ether group functionalized imidazole cation, all AAILs achieved 99% propylene carbonate (PC) selectivity and more than 80% PC yields (110 °C, 2 MPa and 12 h) towards CO2 cycloaddition with PO. More importantly, the as-synthesized AAILs also showed good universality over various epoxides. The presented halogen-free, metal-free, bifunctional and stable AAILs provided a new insight into the application of AAILs in CO2 capture and utilization.