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DOE OSTI · 1876879

Quantifying the anion effect of gas solubility within ionic liquids using the solvation affinity index

Liu, Xiaoyang·Turner, C. Heath
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Abstract

The solubility of gas molecules within ionic liquids (ILs) is strongly dictated by the anion effect and the free volume effect, and of these two influences, the anion effect can be challenging to predict. We evaluate a wide range of different gas solutes (O 2 , NH 3 , CH 4 , H 2 S, SO 2 , Ar, H 2 , N 2 , CO 2 ) in different ILs, and we find that the solubility is strongly correlated to one of three different IL properties, which can be directly calculated from the anion electrostatic potential (ESP) surfaces. Thus, the solutes can be grouped into three fundamental types, leading to a general descriptor, the solvation affinity index (SAI), which can identify the affinity between a wide range of gas solutes and IL solvents. The SAI of nine common industrial gases with 47 common anions are generated. Furthermore, this can provide a fast approach for pre-screening IL solvents or even for ILs embedded within porous supports.

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Liu, Xiaoyang, Turner, C. Heath. 2022-07-02. Quantifying the anion effect of gas solubility within ionic liquids using the solvation affinity index. https://doi.org/10.1016/j.ces.2022.117851

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