Bo-Hak Yoon

High Resolution Image Download MS PowerPoint Slide Amino acid ionic liquids have received increasing attention as ideal candidates for the CO 2 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 2 capture by amino acid ionic liquids through explicit ab initio molecular dynamics augmented by well-tempered met

Amino acid ionic liquids (AAILs) are promising green materials for CO 2 capture and conversion due to their large chemical structural tunability. However, the structural understanding of the AAILs underlying the CO 2 reaction dynamics remains uncertain. Herein, we examine the steric effects of AAIL anions with various chemical structures on CO 2 capture behavior. Based on ab initio free-energy sampling, we assess reaction mechanisms for carbamate formation via a two-step reaction pathway with a

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), al

Abstract The reaction kinetics and molecular mechanisms of CO 2 absorption using nonaqueous and aqueous monoethanolamine (MEA)/methyldiethanolamine (MDEA)/2‐amino‐2‐methy‐1‐propanol (AMP) solutions were analyzed by the stopped‐flow technique and ab initio molecular dynamics (AIMD) simulations. Pseudo first‐order rate constants ( k 0 ) of reactions between CO 2 and amines were measured. A kinetic model was proposed to correlate the k 0 to the amine concentration, and was proved to perform well fo

Monoethanolamine (MEA) is the most studied and used to be considered as benchmark solvent for CO2 capture. CO2 absorption in aqueous MEA is well known to produce ion pairs such as carbamate (MEACOO–) and protonated amine (MEAH+), following a stepwise reaction mechanism involving a zwitterionic intermediate (MEA+COO–). Contrastingly, thermal degradation of MEA has been thought to occur through carbamic acid (MEACOOH) formation under stripper conditions. This raises a fundamental question regardin

Based on first-principles simulations, we present that carbamate formation can be kinetically more favorable than bicarbonate formation at high stripping temperatures (>400 K) from the reaction between CO2 and 2-amino-2-methyl-1-propanol (AMP) in aqueous solution, while the latter tends to be predominant during CO2 capture at low absorber temperatures (<330 K). This finding offers explanation for the intriguing observation of oxazolidinone formation as the major product of AMP degradation, which

Abstract This study presents the impact of the side chains in 1‐ n ‐alkylimidazolium ionomers with varying side chain lengths (C n H 2n+1 where n = 1, 4, 10, 16) on Cu‐catalyzed electrochemical CO 2 reduction reaction (CO 2 RR). Longer side chains suppress the H 2 and CH 4 formation, with the n ‐hexadecyl ionomer ( n = 16) showing the greatest reduction in kinetics by up to 56.5% and 60.0%, respectively. On the other hand, C 2 H 4 production demonstrates optimal Faradaic efficiency with the n ‐d

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. Thermal degradation of both EDA and MEA tends to proceed mainly via formation of

Thermal degradation of aqueous piperazine (PZ) for CO2 capture is experimentally known to yield a major product N-(2-aminoethyl)piperazine (AEP) and a minor product pair 1,1′-(1,2-ethanediyl)bis-piperazine (PEP) plus ethylenediamine (EDA), although the two reactions exhibit no substantial difference in thermodynamic favorability. This raises a question on factors affecting the rates of key reactions involved in PZ thermal degradation. Herein, we present the underlying mechanisms of PZ degradatio

Deep eutectic solvents (DESs) offer promise for CO 2 capture due to their tunability and low cost, yet their development is constrained by limited predictive accuracy for CO 2 solubility. In this work, we present the first machine learning framework that integrates quantum chemical descriptors for solubility prediction. We compiled 2287 experimental measurements from 119 DESs over wide temperature (293.15–353.15 K) and pressure (26.3–7620 kPa) ranges. Through density functional theory (DFT) calc