Reactivity of Ionic Liquid-Based Phenolate Zwitterions for CO Capture in the Aqueous Phase.

Ideal liquid sorbents, such as phenolate zwitterions, represent a novel and promising technology for CO capture. To enhance their design and reactivity with CO, two types of substituents, electron-donating groups (EDGs) and electron-withdrawing groups (EWGs) were investigated. Using density functional theory (DFT) with a large basis set, their effectiveness as reactivity modulators was assessed through energy decomposition analysis, noncovalent interaction, natural bond orbitals (NBO), evaluation of reaction energy barriers, and pK. EDGs, in general, enhance phenolate reactivity and stability, highlighting their potential in the design of advanced zwitterionic sorbents for CO capture. Conversely, EWGs demonstrated mixed effects, providing lower CO capture effectiveness but enhancing recyclability of the phenolates. In summary, our findings provide a framework to investigate substituent efficacy and design next-generation carbon capture materials.