User-assisted methodology targeted for building structure interpretable QSPR models for boosting CO2 capture with ionic liquids

Task-specific ionic liquid (IL) is an emerging class of compounds that may be environmentally friendly. Properly selected, these compounds may be green alternative to amine solutions and can replace them in post-combustion carbon dioxide (CO2) capture processes on an industrial scale. However, owing to the vast diversity of ions and their possible combinations, laboratory research is time consuming and expensive. Therefore, computational methods are preferred for assessing their potential applications. In this study, three quantitative structure-property relationship models based on six distinct descriptors were created to predict Henry's law constant (HLC) of CO2 in 62 ILs. The statistical parameters of multiple linear regression, logistic regression, and partial least squares models were satisfactory. In all cases, the coefficients of determination (R-2) exceeded 0,90, and both external and internal validation proved them to be reliable and predictive with Q(2) and R-pred(2) values exceeding 0,90 and 0,87, respectively. Three of the descriptors were attributed to cations, and three were attributed to anions. In contrast to many other models, the descriptors were chosen in a manner that ensured their interpretability. Each of the six descriptors was analyzed for its influence on HLC. On this basis, guidelines for designing the structure of ionic liquids with increased CO2 absorption capacity were developed. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

As an environmentally friendly alternative, ionic liquids are potential candidates for carbon capture processes. Computational methods are preferred for assessing their potential applications due to the time-consuming and expensive nature of laboratory research. In this study, three quantitative structure-property relationship models were created to predict the Henry's law constant of CO2 in 62 ionic liquids. The models showed satisfactory statistical parameters and provided guidelines for designing ionic liquids with increased CO2 absorption capacity.