Experimental and Molecular Simulation Investigation of Enhanced CO2 Solubility in Hybrid Adsorbents

• Published in: Langmuir Vol. 26; no. 16; pp. 13287 - 13296
• Main Authors: Ho, Ngoc Linh, Porcheron, Fabien, Pellenq, Roland J.-M
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 17.08.2010
• Subjects: Interfaces: Adsorption, Reactions, Films, Forces
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la1015934

Hybrid adsorbents are prepared by confining physical solvents (propylene carbonate, N-methyl-2-pyrrolidone) within the porosity of a solid support (alumina) using both wet and dry impregnation methods. The resulting hybrid solids are analyzed using characterization methods (N2 adsorption isotherm, TGA) to ensure that a proper confinement of the solvent has been achieved. The hybrid adsorbents are then subsequently assessed for CO2 capture by performing solubility measurements. An enhanced CO2 solubility is observed with regard to the ones in the bulk solvent and in the raw solid. In a next step, grand canonical Monte Carlo simulations have been performed on a slit pore model to understand the microscopic mechanisms yielding the apparition of enhanced solubility. The presence of solvent molecules favors the layering of CO2 within the pore, and the resulting local density profile is then markedly increased compared to one found in the raw adsorbent as more carbon dioxide molecules can be accommodated into the pore volume.