On the Key Influence of Amino Acid Ionic Liquid Anions on CO Capture.

Amino acid ionic liquids (AAILs) are promising green materials for CO capture and conversion due to their large chemical structural tunability. However, the structural understanding of the AAILs underlying the CO reaction dynamics remains uncertain. Herein, we examine the steric effects of AAIL anions with various chemical structures on CO capture behavior.

Elucidating the Molecular Mechanism of CO Capture by Amino Acid Ionic Liquids.

Amino acid ionic liquids have received increasing attention as ideal candidates for the CO 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 capture by amino acid ionic liquids through explicit molecular dynamics augmented by well-tempered metadynamics.

On the mechanism of predominant urea formation from thermal degradation of CO-loaded aqueous ethylenediamine.

This study attempts to explain the well-known experimental observation that 1,3-bis(2-aminoethyl)urea (urea) is preferentially formed over the other major product, 2-imidazolidone (IZD), from thermal degradation of aqueous ethylenediamine (EDA) during the CO capture process. This is in direct contrast to the case of monoethanolamine (MEA), preferentially forming oxazolidinone (OZD), rather than urea, which undergoes further reactions leading to more stable products. Given their similar molecular structures, the different preferred degradation pathways of EDA and MEA impose an intriguing question regarding the underlying mechanism responsible for the distinct difference.

Molecular mechanisms for thermal degradation of CO-loaded aqueous monoethanolamine solution: a first-principles study.

Thermal degradation of aqueous monoethanolamine (MEA), a benchmark solvent, in CO2 capture processes still remains a challenge. Here, we present molecular mechanisms underlying thermal degradation of MEA based on ab initio molecular dynamics simulations coupled with metadynamics sampling. Isocyanate formation via dehydration of carbamic acid (MEACOOH) is predicted to be highly probable and more kinetically favorable than the competing cyclization-dehydration reaction to 2-oxazolidinone (OZD), albeit not substantially.