{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T09:57:03Z","timestamp":1790675823060,"version":"4.1.0"},"reference-count":37,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T00:00:00Z","timestamp":1790640000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000266","name":"EPSRC","doi-asserted-by":"publisher","award":["EP\/N024672\/1"],"award-info":[{"award-number":["EP\/N024672\/1"]}],"id":[{"id":"10.13039\/501100000266","id-type":"DOI","asserted-by":"publisher"}]},{"award":["EP\/N024672\/1"],"award-info":[{"award-number":["EP\/N024672\/1"]}],"id":[{"id":"https:\/\/ror.org\/0439y7842","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Amine regeneration is the most energy-intensive step in amine-based post-combustion carbon capture (PCCC), and reducing its energy demand is essential for improving the overall efficiency of the capture process. In Part I of this series, static electric fields were shown to stabilize CO2 absorption products and increase the energy requirements for amine regeneration. In Part II, we investigate whether the fundamentally different response to time-dependent infrared laser excitation could provide molecular mechanisms for reducing the energy demand of amine regeneration. Nonequilibrium Ehrenfest electron\u2013nuclear dynamics simulations were performed for aqueous zwitterion, carbamate, and bicarbonate systems representative of CO2 capture by monoethanolamine (MEA) and triethanolamine (TEA), using a benchmarked density functional tight-binding framework. Pulsed and continuous-wave infrared laser excitation was applied at frequencies corresponding to selected molecular vibrational modes. Laser-induced heating was strongly mode selective, with the CCO2\u2013OCO2\u2013CCO2 bending mode consistently producing the largest overall temperature increase across all three systems. However, the modes producing the strongest total-system heating were not necessarily those that preferentially deposited vibrational kinetic energy into the CO2\u2013amine species rather than the surrounding water. Preferential energy deposition was strongly system dependent, being greatest for the symmetric CCO2\u2013OCO2 stretch in the zwitterion, the CCO2\u2013NMEA stretch in the carbamate, and the CCO2\u2013OOH stretch in the bicarbonate. Infrared laser excitation also produced pronounced mode-dependent structural and energetic perturbations of the regeneration-relevant CCO2\u2013NMEA and CCO2\u2013OOH bonds, including increases in their mean lengths and energies, broadening of their bond-length and bond-energy distributions, and increased probabilities of sampling transient elongated-bond configurations. Importantly, the strongest bond perturbations did not always result from direct excitation of the monitored bond, consistent with vibrational coupling and energy redistribution. These results identify three complementary effects that may contribute to infrared-assisted amine regeneration: efficient total-system heating, preferential energy deposition into the CO2\u2013amine species, and mode-selective structural and energetic perturbations of bonds involved in CO2 retention. Because no single vibrational mode maximizes all three effects across the investigated systems, selecting an excitation frequency is inherently a multi-objective problem. The findings provide a molecular-level basis for investigating infrared-assisted regeneration strategies, although their potential to reduce process-level energy consumption remains to be established.<\/jats:p>","DOI":"10.3390\/molecules31193475","type":"journal-article","created":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T09:10:54Z","timestamp":1790673054000},"page":"3475","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Electric Field Effects on Amine Regeneration in Post-Combustion Carbon Capture\u2014Part II: Mode-Selective Infrared Laser Excitation Probed by Nonequilibrium Ehrenfest Electron-Nuclear Dynamics"],"prefix":"10.3390","volume":"31","author":[{"given":"Nasser D.","family":"Afify","sequence":"first","affiliation":[{"name":"Institute for Materials and Processes, School of Engineering, The University of Edinburgh, Edinburgh EH9 3FB, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xianfeng","family":"Fan","sequence":"additional","affiliation":[{"name":"Institute for Materials and Processes, School of Engineering, The University of Edinburgh, Edinburgh EH9 3FB, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martin B.","family":"Sweatman","sequence":"additional","affiliation":[{"name":"Institute for Materials and Processes, School of Engineering, The University of Edinburgh, Edinburgh EH9 3FB, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1016\/j.ijggc.2015.06.017","article-title":"Recent Progress and New Developments in Post-Combustion Carbon-Capture Technology with Amine Based Solvents","volume":"40","author":"Liang","year":"2015","journal-title":"Int. J. Greenh. Gas Control"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1016\/j.apenergy.2017.02.012","article-title":"Microwave Swing Regeneration of Aqueous Monoethanolamine for Post-Combustion CO2 Capture","volume":"192","author":"McGurk","year":"2017","journal-title":"Appl. Energy"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1039\/b811608c","article-title":"The Energy Penalty of Post-Combustion CO2 Capture & Storage and Its Implications for Retrofitting the U.S. Installed Base","volume":"2","author":"House","year":"2009","journal-title":"Energy Environ. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"381","DOI":"10.1016\/j.egypro.2012.06.053","article-title":"Techno Economic Evaluation of Amine Based CO2 Capture: Impact of CO2 Concentration and Steam Supply","volume":"23","author":"Husebye","year":"2012","journal-title":"Energy Procedia"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"2137","DOI":"10.1021\/am507465f","article-title":"Amine-Based CO2 Capture Technology Development from the Beginning of 2013\u2014A Review","volume":"7","author":"Dutcher","year":"2015","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"745","DOI":"10.4209\/aaqr.2012.05.0132","article-title":"A Review of CO2 Capture by Absorption and Adsorption","volume":"12","author":"Yu","year":"2012","journal-title":"Aerosol Air Qual. Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"126903","DOI":"10.1016\/j.energy.2023.126903","article-title":"Analysis of the Energy Consumption in Solvent Regeneration Processes Using Binary Amine Blends for CO2 Capture","volume":"270","author":"He","year":"2023","journal-title":"Energy"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1652","DOI":"10.1126\/science.1176731","article-title":"Amine Scrubbing for CO2 Capture","volume":"325","author":"Rochelle","year":"2009","journal-title":"Science"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1016\/j.ijggc.2019.04.013","article-title":"Novel Non-Aqueous MEA Solutions for CO2 Capture","volume":"86","author":"Bougie","year":"2019","journal-title":"Int. J. Greenh. Gas Control"},{"key":"ref_10","first-page":"e5","article-title":"Progress in Modeling of Carbon Capture Technologies","volume":"1","author":"Chen","year":"2025","journal-title":"Camb. Prism. Carbon Technol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"150954","DOI":"10.1016\/j.cej.2024.150954","article-title":"Review on Post-Combustion CO2 Capture by Amine Blended Solvents and Aqueous Ammonia","volume":"488","author":"Du","year":"2024","journal-title":"Chem. Eng. J."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"204513","DOI":"10.1063\/1.5022585","article-title":"Molecular Dynamics Simulation of Microwave Heating of Liquid Monoethanolamine (MEA): An Evaluation of Existing Force Fields","volume":"148","author":"Afify","year":"2018","journal-title":"J. Chem. Phys."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"024508","DOI":"10.1063\/1.5001928","article-title":"Classical Molecular Dynamics Simulation of Microwave Heating of Liquids: The Case of Water","volume":"148","author":"Afify","year":"2018","journal-title":"J. Chem. Phys."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1016\/j.ijggc.2018.10.008","article-title":"Microwave Regeneration of Monoethanolamine Aqueous Solutions Used for CO2 Capture","volume":"79","author":"Bougie","year":"2018","journal-title":"Int. J. Greenh. Gas Control"},{"key":"ref_15","first-page":"100728","article-title":"Evaluating Regeneration Performance of Amine Functionalized Solid Sorbents for Direct Air CO2 Capture Using Microwave","volume":"26","author":"Nokpho","year":"2024","journal-title":"Mater. Today Sustain."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"024503","DOI":"10.1063\/1.5110399","article-title":"Preferential Heating of Aqueous Amine Solutions Using Infrared Radiation at Selected Vibrational Frequencies: A Molecular Dynamics Study","volume":"151","author":"Afify","year":"2019","journal-title":"J. Chem. Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1091","DOI":"10.1038\/nchem.2651","article-title":"Oriented Electric Fields as Future Smart Reagents in Chemistry","volume":"8","author":"Shaik","year":"2016","journal-title":"Nat. Chem."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2142","DOI":"10.1038\/s41467-018-04481-5","article-title":"Molecular Polarizability Anisotropy of Liquid Water Revealed by Terahertz-Induced Transient Orientation","volume":"9","author":"Zalden","year":"2018","journal-title":"Nat. Commun."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Afify, N.D., Fan, X., and Sweatman, M.B. (2026). Electric Field Effects on Amine Regeneration in Post-Combustion Carbon Capture\u2014Part I: Static Electric Fields as a Reference Mechanistic Baseline. Molecules, 31.","DOI":"10.3390\/molecules31091422"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Gonz\u00e1lez, L., and Lindh, R. (2020). Quantum Chemistry and Dynamics of Excited States, Wiley.","DOI":"10.1002\/9781119417774"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"8554","DOI":"10.1021\/acs.jpclett.1c02020","article-title":"Minimizing the Time-Dependent Density Functional Error in Ehrenfest Dynamics","volume":"12","author":"Lacombe","year":"2021","journal-title":"J. Phys. Chem. Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"4454","DOI":"10.1021\/acs.jctc.9b01217","article-title":"A Real-Time Time-Dependent Density Functional Tight-Binding Implementation for Semiclassical Excited State Electron\u2013Nuclear Dynamics and Pump\u2013Probe Spectroscopy Simulations","volume":"16","author":"Aradi","year":"2020","journal-title":"J. Chem. Theory Comput."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"4901","DOI":"10.1021\/ct400123t","article-title":"Extensions the Time-Dependent Density Functional Tight-Binding Approach","volume":"9","author":"Aradi","year":"2013","journal-title":"J. Chem. Theory Comput."},{"key":"ref_24","unstructured":"Ramachandran, K.I., Deepa, G., and Namboori, K. (2008). Computational Chemistry and Molecular Modeling, Springer."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e1493","DOI":"10.1002\/wcms.1493","article-title":"Extended tight-binding Quantum Chemistry Methods","volume":"11","author":"Bannwarth","year":"2021","journal-title":"WIREs Comput. Mol. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"124101","DOI":"10.1063\/1.5143190","article-title":"DFTB+, a Software Package for Efficient Approximate Density Functional Theory Based Atomistic Simulations","volume":"152","author":"Hourahine","year":"2020","journal-title":"J. Chem. Phys."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1989","DOI":"10.1021\/acs.jctc.7b00118","article-title":"A Robust and Accurate Tight-Binding Quantum Chemical Method for Structures, Vibrational Frequencies, and Noncovalent Interactions of Large Molecular Systems Parametrized for All Spd-Block Elements (Z = 1\u201386)","volume":"13","author":"Grimme","year":"2017","journal-title":"J. Chem. Theory Comput."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1652","DOI":"10.1021\/acs.jctc.8b01176","article-title":"GFN2-XTB\u2014An Accurate and Broadly Parametrized Self-Consistent Tight-Binding Quantum Chemical Method with Multipole Electrostatics and Density-Dependent Dispersion Contributions","volume":"15","author":"Bannwarth","year":"2019","journal-title":"J. Chem. Theory Comput."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1648","DOI":"10.1080\/00268976.2013.813595","article-title":"Manipulation of Molecules with Electromagnetic Fields","volume":"111","author":"Lemeshko","year":"2013","journal-title":"Mol. Phys."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"12654","DOI":"10.1073\/pnas.0803010105","article-title":"Chemical Dynamics of Vibrationally Excited Molecules: Controlling Reactions in Gases and on Surfaces","volume":"105","author":"Crim","year":"2008","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"12725","DOI":"10.1021\/jp9604812","article-title":"Bond-Selected Chemistry: Vibrational State Control of Photodissociation and Bimolecular Reaction","volume":"100","author":"Crim","year":"1996","journal-title":"J. Phys. Chem."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Crim, F.F., Sinha, A., Hsiao, M.C., and Thoemke, J.D. (1991). Mode-and Bond-Selected Bimolecular Reaction of Water, Springer.","DOI":"10.1007\/978-94-011-2642-7_15"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"615","DOI":"10.1126\/science.aau7742","article-title":"Tilting a Ground-State Reactivity Landscape by Vibrational Strong Coupling","volume":"363","author":"Thomas","year":"2019","journal-title":"Science"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2157","DOI":"10.1002\/jcc.21224","article-title":"PACKMOL: A Package for Building Initial Configurations for Molecular Dynamics Simulations","volume":"30","author":"Andrade","year":"2009","journal-title":"J. Comput. Chem."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"931","DOI":"10.1021\/ct100684s","article-title":"DFTB3: Extension of the Self-Consistent-Charge Density-Functional Tight-Binding Method (SCC-DFTB)","volume":"7","author":"Gaus","year":"2011","journal-title":"J. Chem. Theory Comput."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1117","DOI":"10.1080\/00268979600100761","article-title":"Explicit Reversible Integrators for Extended Systems Dynamics","volume":"87","author":"Martyna","year":"1996","journal-title":"Mol. Phys."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"61509","DOI":"10.1063\/1.4996559","article-title":"Ultrafast Dynamics Induced by the Interaction of Molecules with Electromagnetic Fields: Several Quantum, Semiclassical, and Classical Approaches","volume":"4","author":"Antipov","year":"2017","journal-title":"Struct. Dyn."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/19\/3475\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T09:11:44Z","timestamp":1790673104000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/19\/3475"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,29]]},"references-count":37,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2026,10]]}},"alternative-id":["molecules31193475"],"URL":"https:\/\/doi.org\/10.3390\/molecules31193475","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,29]]}}}