(140f) A Molecular Simulation Study on CO2 and a Deep Eutectic Solvent in Slit Nanopores

 

Yan Shen and Francisco R. Hung

Department of Chemical Engineering, Northeastern University, Boston, MA 02115

Molecular dynamics (MD) simulations were performed to study systems of CO₂ and deep eutectic solvents (DESs) in the bulk and inside slit-like nanopores. The porous materials considered were graphite and rutile, while the DES studied was composed of choline chloride and ethylene glycol with a 1:2 molar ratio; different amounts of DES inside the nanopores were considered. Our work was motivated by previous studies exploring the use of bulk DESs in CO₂ capture^{1, 2}, as DESs share many of the physical and chemical properties of room temperature ionic liquids (ILs) while being considerably cheaper and (mostly) nontoxic. On the other hand, recent reports^3-5 have studied the “oversolubility” phenomenon, where gas molecules exhibit larger solubility in solvents that are confined within a nanoporous material, as compared to the gas solubility in the bulk solvents. Our results show that the properties of the DES-CO₂ systems in the bulk are significantly different from those of the same systems confined in the nanopores. For the confined systems, the chemical composition of the pore walls, and the amounts of DES inside the nanopores have a great impact on the behavior of CO₂ molecules. Detailed comparisons of the properties of all systems will be presented and discussed.

References:

1. García, G.; Atilhan, M.; Aparicio, S. The Journal of Physical Chemistry C 2015, 119, (37), 21413-21425.

2. García, G.; Aparicio, S.; Ullah, R.; Atilhan, M. Energy & Fuels 2015, 29, (4), 2616-2644.

3. Bratko, D.; Luzar, A. Langmuir 2008, 24, (4), 1247-1253.

4. Clauzier, S.; Ho, L. N.; Pera-Titus, M.; Coasne, B.; Farrusseng, D. Journal of the American Chemical Society 2012, 134, (42), 17369-17371.

5. Ho, N. L.; Perez-Pellitero, J.; Porcheron, F.; Pellenq, R. J. M. The Journal of Physical Chemistry C 2012, 116, (5), 3600-3607.