It is critical to improve carbon capture efficiency while reducing costs to popularize carbon capture and storage. Considering the green chemistry and engineering objectives, this study theoretically explores the CO 2 absorption capacity of 1,533,528 hydrogen-bonded mixtures, i.e., deep eutectic solvents in a broad sense. Exhaustive statistical thermodynamic calculations well explain the experimental reports; it is confirmed that deep eutectic solvents containing ionic compounds have higher CO 2 selective absorption capacity than those composed of non-ionic species. Quantitative evaluation of hydrogen-bonding interaction also predicts that the capacity is higher when the ionic compounds work as hydrogen-bonding donors. This is because the trace ionic species weaken the hydrogen-bonding network in the mixtures to improve CO 2 physisorption.

Improving the carbon capture efficiency with reducing the cost is mandatory for popularizing carbon capture, utilization, and storage (CCUS). Considering the objectives of green chemistry and engineering, here we show a theoretical exploration of the CO2-absorbing capacity of a set of 1,527,030 deep eutectic solvents (DESs). Comprehensive statistical thermodynamic calculations followed the previous experiments that DESs, including choline chloride, would have better CO2-absorbing capacity than those composed of non-ionic hydrogen bonding species in the case that choline chloride is used as a hydrogen-bonding acceptor. Quantitative evaluation of hydrogen-bonding interaction also indicated that the CO2-absorbing capacity would increase further when choline chloride is used as a hydrogen- bonding donor.