Kumar et al. (2024): The Role of Nonequilibrium Solvent Effects in Enhancing Direct CO2 Capture at the Air–Aqueous Amino Acid Interface

Nitesh Kumar, Vyacheslav S. Bryantsev, Santanu Roy IN: Journal of the American Chemical Society, https://doi.org/10.1021/jacs.4c14612

Direct air capture (DAC) technologies are limited by the poor understanding of the dynamic role of interfaces in modulating the chemisorption of CO₂ from air into solutions. While the reactivity of aqueous amine-based solvents in the bulk environment is strongly inhibited by nonequilibrium solvent effects, promoting DAC at interfaces posits a possibility to reduce the coupling with the solvent and significantly accelerate DAC. Building on an experimentally proven concept to bring an anionic glycine absorbent to the interface through ion-pairing interactions with a positively charged surfactant, the authors establish the fundamental time scales for key elementary steps involved in DAC with rate theory and enhanced-sampling ab initio molecular dynamics simulations. The authors elucidate the mechanism by which water influences the free energy barriers and dynamical crossing-recrossing of those barriers, affecting the reaction rates.

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