@article{TEXTUAL, recid = {6803}, author = {Yoon, Bohak and Voth, Gregory A.}, title = {Elucidating the Molecular Mechanism of CO&lt;sub&gt;2&lt;/sub&gt; Capture by Amino Acid Ionic Liquids}, journal = {Journal of the American Chemical Society}, address = {2023-07-13}, number = {TEXTUAL}, abstract = {Amino acid ionic liquids have received increasing attention as ideal candidates for the CO<sub>2</sub> chemisorption process. However, the underlying molecular mechanisms, especially those involving proton transfer, remain unclear. In this work, we elucidate the atomistic-level reaction mechanisms responsible for carbamate formation during CO<sub>2</sub> capture by amino acid ionic liquids through explicit ab initio molecular dynamics augmented by well-tempered metadynamics. The resulting ab initio free-energy sampling reveals a two-step reaction pathway in which a zwitterion, initially formed from the reaction between the anion of serine and CO<sub>2</sub>, undergoes a kinetically facile intermolecular proton transfer to the O atom of the COO– moiety in the nearby serine. Further analysis reveals that the significantly reduced free-energy barriers are attributed to enhanced intermolecular interaction between the zwitterion and serine, thus facilitating the kinetic favorability of the proton transfer, which governs the overall CO<sub>2</sub> capture mechanism. This work provides valuable insight into the important mechanistic and kinetic features of these reactions from explicit condensed phase ab initio MD free-energy sampling of the CO<sub>2</sub> capture process.}, url = {http://knowledge.uchicago.edu/record/6803}, }