Imidazole tailored deep eutectic solvents for CO₂ capture enhanced by hydrogen bonds

Abstract

Deep eutectic solvents (DESs) have emerged as promising alternative candidates for CO2 capture in recent years. In this work, several novel DESs were firstly prepared to enhance CO2 absorption. Structural and physical properties of DESs were investigated, as well as their absorption performance of CO2. A distinct depression in the melting point up to 80 K of DESs was observed compared with that of BMIMCl. The observed red shifts of the C2H group in an imidazolium ring and its chemical shifts downfield in NMR spectra are indicative of a hydrogen bond interaction between BMIMCl and MEA. In particular, CO2 uptake in MEA : ILs (4 : 1) at room temperature and atmospheric pressure is up to 21.4 wt%, which is higher than that of 30 wt% MEA (13%). A hydrogen bond related mechanism was proposed in which ILs act as a medium to improve CO2 uptake through hydrogen bonds. Finally, the firstly reported overall heat of CO2 absorption is slightly higher than that of 30 wt% MEA, implying that the hydrogen bonds of DESs contribute to the overall heat of CO2 absorption. This study reveals that the heat of CO2 absorption can be tailored by the proper molar ratio of MEA and ILs.

Screening Deep Eutectic Solvents for CO2 Capture With COSMO-RS

“…Shukla et al reported that the CO 2 solubility in DES depends on the HB interactions between HBA and HBD (Shukla and Mikkola, 2018). Cao et al indicated that the formation of HB between HBA and HBD enhanced the CO 2 solubility in DESs (Cao et al, 2015). In addition, Atilhan et al investigated the interactions between DES and SO 2 by the quantum chemistry, confirming a dominant VdW interaction between DES and SO 2 (Atilhan et al, 2019).…”

A Reversed Photosynthesis‐like Process for Light‐Triggered CO2 Capture, Release, and Conversion

“…[3] Moreover, treatment of the waste alkaline solution is an energy intensive process, which may causes econdary pollution to the environment. Recent progresses suggest that some green sorbents, for example, zeolites, [4] zeolitic imidazolate framework, [5][6][7][8] metal-organic framework, [9][10][11][12][13] ionic liquids, [14][15][16][17][18][19][20] base-containing, or porousp olymers, [21][22][23][24][25][26][27][28][29][30][31][32] carbonbased materials, [33,34] are very promising for CO 2 capturew ithout environmental pollution. However, the regeneration of these sorbents upon removing CO 2 has to involve endothermic processes,s till relying on the consumptiono ff ossil fuels.…”

Bifunctional imidazole‐PTSA deep eutectic solvent for synthesizing long‐chain ester IBIBE in reactive extraction

“…Traditional DESs are usually composed of hydrogen bond acceptor (HBA, e.g., quaternary ammonium salt or quaternary phosphonium salt) and hydrogen bond donor (HBD, e.g., organic acid or alcohol), where hydrogen bond between them makes the freezing points of the resultant DESs decrease greatly . Owing to the simple preparation as well as low cost and easy control, DESs have been increasingly applied to organic synthesis, electrochemistry, extraction separation, and gas absorption …”