ACS Earth and Space Chemistry最新文献

{"title":"Particulate Matter and Total Volatile Organic Compound Emissions Following Surface Cleaning: Comparison of Cleaning Agents and Locations","authors":"Pedro A. F. Souza,&nbsp;Leigh R. Crilley,&nbsp;Yashar E. Iranpour,&nbsp;Jay Dave,&nbsp;Trevor C. VandenBoer* and Tara F. Kahan*,&nbsp;","doi":"10.1021/acsearthspacechem.5c0004610.1021/acsearthspacechem.5c00046","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.5c00046https://doi.org/10.1021/acsearthspacechem.5c00046","url":null,"abstract":"<p >Cleaning activities are essential for maintaining hygiene in indoor environments but can significantly influence indoor air quality (IAQ). We investigated emissions of volatile organic compounds (VOCs) and particulate matter (PM) during cleaning events across various indoor settings including two laboratories, an office, and a residential bathroom, with room volumes ranging from 22 to 206 m³ and air changes rates (ACR) of 0.85–9.14 h^-1. Four cleaning solutions with different active ingredients were evaluated: quaternary ammonium compounds (quats), hydrogen peroxide (H₂O₂), sodium hypochlorite (bleach), and thymol. Cleaning increased PM_2.5 by 0.7–14.5 μg m^–3, depending on location and cleaning solution, with quats generally yielding the greatest increases. Measured total volatile organic compound (TVOC) mixing ratios also increased following cleaning by 10–104 ppbv, with the exception of experiments performed using thymol. We note that sensors such as the photoionization detector (PID) used in this work do not provide quantitative TVOC measurements. In general, greater emissions of PM_2.5 and TVOCs were observed in locations with lower ACR. We also measured PM_2.5 in a lobby, elevator, and public bathroom in a hotel with a number of COVID-positive occupants during routine surface disinfection using a quats-based disinfectant: increases of 5.5–14.2 μg m^–3 were observed. This study demonstrates that emissions other than active ingredients can affect IAQ during surface cleaning, and provides information that may help mitigate harmful effects. It also provides insight into the use and limitations of low-cost sensors (LCS) in determining IAQ impacts from cleaning.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 6","pages":"1622–1632 1622–1632"},"PeriodicalIF":2.9,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.5c00046","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144312422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infrared Irradiation of H2O:CO2 Ice: A Combined Experimental and Computational Study of the Dissipation of CO2 Vibrational Excitations","authors":"Johanna G. M. Schrauwen,&nbsp;Tobias M. Dijkhuis,&nbsp;Sergio Ioppolo,&nbsp;Daria R. Galimberti,&nbsp;Britta Redlich and Herma M. Cuppen*,&nbsp;","doi":"10.1021/acsearthspacechem.5c0003010.1021/acsearthspacechem.5c00030","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.5c00030https://doi.org/10.1021/acsearthspacechem.5c00030","url":null,"abstract":"<p >In interstellar ices, the ice matrix can have a great influence on the chemical reactions. The hydrogen-bonding network in pure water ices facilitates fast energy dissipation that, for example, stabilizes the HOCO complex, a crucial step in the formation of CO₂. To better understand the energy dynamics and its possible influence on the processes in the ice, we investigated a H₂O:CO₂ 1:4 ice mixture exposed to infrared irradiation on-resonance with the CO₂ vibrations. Experimentally, we find changes in the OH stretch of H₂O after irradiating the asymmetric stretch of CO₂ for several minutes with the intense monochromatic light of the FELIX free electron lasers. Using molecular dynamics simulations, we found that an excitation of the asymmetric stretch of CO₂ readily dissipates to other asymmetric stretches in the environment, but only dissipates to the CO₂ libration and H₂O twist modes after roughly 2 ns because of its minimal anharmonicity and coupling with other modes. This is significantly longer than the off-time between laser pulses of 1 ns, suggesting ladder climbing or that the stacking of the excitation boosts the experimentally observed changes. For infrared excitation of the CO₂ bending vibration, the simulations reveal a fast distribution of energy and coupling to the intermolecular interactions that lead to thermal heating of the H₂O vibrational modes. This is not observed on the time scale of the experiments. Still, both simulations and experiments reveal nonthermal annealing of the H₂O component of the mixed ice when exposed to infrared irradiation on-resonance with the CO₂ vibrations.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 6","pages":"1580–1592 1580–1592"},"PeriodicalIF":2.9,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.5c00030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144312308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detailed Investigation of 2,3-Dimethyl-2-butene Ozonolysis-Derived Hydroxyl, Peroxy, and Alkoxy Radical Chemistry","authors":"Benjamin N. Frandsen,&nbsp;Lauri Franzon,&nbsp;Melissa Meder,&nbsp;Dominika Pasik,&nbsp;Emelda Ahongshangbam,&nbsp;Netta Vinkvist,&nbsp;Nanna Myllys,&nbsp;Siddharth Iyer,&nbsp;Matti P. Rissanen,&nbsp;Mikael Ehn and Theo C. Kurtén*,&nbsp;","doi":"10.1021/acsearthspacechem.4c0035510.1021/acsearthspacechem.4c00355","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00355https://doi.org/10.1021/acsearthspacechem.4c00355","url":null,"abstract":"<p >This work investigates the chemistry of peroxy and alkoxy radicals derived from 2,3-dimethyl-2-butene [tetramethylethylene (TME)] ozonolysis. We utilize a combination of computational chemistry and flow reactor chemical ionization mass spectrometry (CIMS) at different temperatures for this study. We particularly focus on the decomposition reactions of alkoxy radicals derived from acetyl peroxy and acetonyl peroxy radicals adding to the TME double bond. The results demonstrate that a great variety of accretion products are formed on the ∼3 s residence time scale of the experiment. The computational chemistry supports the experimental results by inferring assignment of molecular structures to observed mass signals and by explaining the relative concentration of the most abundant peroxides at the different temperatures. Additionally, the computational results suggest that several different unimolecular decomposition pathways are rapid enough to happen on the time scale of the experiment for an acetyl peroxy (APR) + TME-derived alkoxy radical. However, the experimental results tentatively suggest that these alkoxy radicals undergo a methyl β-scission reaction at a competitive rate, despite a more substituted and thus seemingly more favorable β-scission being available. We use computational chemistry to investigate and calculate rate coefficients for the different possible unimolecular decomposition pathways for the APR + TME-derived alkoxy radical and find that the methyl β-scission should be out-competed by the more substituted β-scission, in apparent disagreement with the experimental results. This work is relevant to experimental design, as TME ozonolysis is typically employed as a light-free source of OH radicals in gas phase kinetic experiments. Our findings do not discredit TME ozonolysis as a useful OH radical source; it is important to be aware of possible interferences from TME-derived peroxy and alkoxy radicals if high reactant concentrations are used. Furthermore, the work has principal importance to the investigation of oxidative atmospheric organic chemistry. The radicals investigated here follow <i>a priori</i> unexpected reaction pathways, which demonstrate that these pathways should be considered for other atmospherically relevant organics, where the radicals explored here can serve as a model for future investigations into similar radicals.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 6","pages":"1322–1337 1322–1337"},"PeriodicalIF":2.9,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.4c00355","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144312307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uptake of SO2 into Sulfuric Acid Droplets through the Oxidation by NO2 under Venus-Analogous Conditions","authors":"Soma Ubukata*,&nbsp;Hiroki Karyu*,&nbsp;Hiromu Nakagawa,&nbsp;Shungo Koyama,&nbsp;Rikuto Minamikawa,&nbsp;Takeshi Kuroda,&nbsp;Naoki Terada and Masao Gen*,&nbsp;","doi":"10.1021/acsearthspacechem.5c0001610.1021/acsearthspacechem.5c00016","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.5c00016https://doi.org/10.1021/acsearthspacechem.5c00016","url":null,"abstract":"<p >Sulfur dioxide (SO₂) is the primary sulfur-bearing gas on Venus and plays a pivotal role in its atmospheric chemistry. Observations show that SO₂ concentration decreases by 3 orders of magnitude from the bottom to the top of the cloud layers. However, this SO₂ depletion cannot be explained by gas-phase chemistry alone, suggesting a missing SO₂ sink within the cloud layers. Here, we show for the first time that SO₂ uptake and subsequent oxidation within droplets could serve as an additional sink in the Venusian cloud layers. We performed laboratory experiments to examine the uptake of SO₂ by sulfuric acid (H₂SO₄) droplets of ∼10 μm in the presence of nitrogen dioxide (NO₂) as an oxidant. We find that the size growth of H₂SO₄ droplets occurs only when both SO₂ and NO₂ are present, indicating the SO₂ oxidation by NO₂ in H₂SO₄ droplets. The growth rate increases with NO₂ concentration, and the reactive uptake coefficient of SO₂, γ_SO₂, is parameterized by the number density of NO₂ (cm^–3), <i>n</i>_NO₂, as log₁₀γ_SO₂ = 0.572 × log₁₀<i>n</i>_NO₂ – 15.03. Numerical simulations suggest that γ_SO₂= 10^–7 is required to reproduce the observed SO₂ concentration at the top of the cloud layer. Our results underscore that the reactive uptake of SO₂ by H₂SO₄ droplets may play an important role in SO₂ depletion in the cloud layers, warranting future observations of oxidants in the Venusian atmosphere.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 6","pages":"1525–1533 1525–1533"},"PeriodicalIF":2.9,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.5c00016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144312447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infrared Irradiation of H₂O:CO₂ Ice: A Combined Experimental and Computational Study of the Dissipation of CO₂ Vibrational Excitations.","authors":"Johanna G M Schrauwen, Tobias M Dijkhuis, Sergio Ioppolo, Daria R Galimberti, Britta Redlich, Herma M Cuppen","doi":"10.1021/acsearthspacechem.5c00030","DOIUrl":"10.1021/acsearthspacechem.5c00030","url":null,"abstract":"<p><p>In interstellar ices, the ice matrix can have a great influence on the chemical reactions. The hydrogen-bonding network in pure water ices facilitates fast energy dissipation that, for example, stabilizes the HOCO complex, a crucial step in the formation of CO₂. To better understand the energy dynamics and its possible influence on the processes in the ice, we investigated a H₂O:CO₂ 1:4 ice mixture exposed to infrared irradiation on-resonance with the CO₂ vibrations. Experimentally, we find changes in the OH stretch of H₂O after irradiating the asymmetric stretch of CO₂ for several minutes with the intense monochromatic light of the FELIX free electron lasers. Using molecular dynamics simulations, we found that an excitation of the asymmetric stretch of CO₂ readily dissipates to other asymmetric stretches in the environment, but only dissipates to the CO₂ libration and H₂O twist modes after roughly 2 ns because of its minimal anharmonicity and coupling with other modes. This is significantly longer than the off-time between laser pulses of 1 ns, suggesting ladder climbing or that the stacking of the excitation boosts the experimentally observed changes. For infrared excitation of the CO₂ bending vibration, the simulations reveal a fast distribution of energy and coupling to the intermolecular interactions that lead to thermal heating of the H₂O vibrational modes. This is not observed on the time scale of the experiments. Still, both simulations and experiments reveal nonthermal annealing of the H₂O component of the mixed ice when exposed to infrared irradiation on-resonance with the CO₂ vibrations.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 6","pages":"1580-1592"},"PeriodicalIF":2.9,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12183729/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamic Constraints on the Citric Acid Cycle and Related Reactions in Ocean World Interiors.","authors":"Seda Işık, Mohit Melwani Daswani, Emre Işık, Jessica M Weber, Nazlı Olgun Kıyak","doi":"10.1021/acsearthspacechem.4c00371","DOIUrl":"10.1021/acsearthspacechem.4c00371","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Icy ocean worlds in our solar system have attracted significant interest for their astrobiological and biogeochemical potential due to the predicted presence of global subsurface liquid water oceans, the presence of organics in Enceladus and Titan, and plausible sources of chemical energy available for life therein. A difficulty in placing quantitative constraints on the occurrence and effectiveness of biogeochemical reactions favorable for life and metabolism in ocean worlds is the paucity of thermodynamic data for the relevant reactions for pressure, temperature and compositional conditions pertaining to ocean worlds, in addition to uncertainties in the estimation of such conditions. Here, we quantify the thermodynamic viability and energetics of various reactions of interest to metabolism at pressures and temperatures relevant to ocean worlds Enceladus, Europa, Titan and Ganymede, and conditions relevant to the Lost City Hydrothermal Field for comparison. Specifically, we examine the tricarboxylic acid cycle (also known as TCA, Krebs cycle, or citric acid cycle) and a plausible precursor prebiotic network of reactions leading to the TCA cycle. We use DEWPython, a program based on the deep earth water (DEW) model (which is a high pressure and high temperature extension of the HelgesonKirkhamFlowers equation of state used to calculate thermodynamic properties of ions and complexes in aqueous solutions), to compute the equilibrium constants and the Gibbs free energy changes for given reactions, as a function of pressure and temperature. Using instantaneous concentrations of inorganics and organics from terrestrial microbial experiments and those derived from the Cassini mission for Enceladus, we calculate chemical affinities of reactions in the network. We carry out similar calculations using the SUPCRT model for lower pressures and temperatures. Together, the two models span temperatures between 0 and 1200 °C and pressures between 1 bar and 60 kbar. We found that across the majority of oceanic pressuretemperature profiles, certain TCA cycle species, such as citrate and succinate, accumulate, while others, including fumarate and oxaloacetate, exhibit a diminishing trend. This observation suggests that the internal conditions of ocean worlds may not thermodynamically favor a unidirectional TCA cycle, thereby implying an additional source of energy (e.g., metabolites) to overcome energy bottlenecks. Notably, we find similar bottlenecks at the Lost City Hydrothermal Field, which is undoubtedly inhabited by organisms. In the prebiotic network, we found that pyruvate and acetate exhibit remarkable stability and accumulate in substantial quantities, thereby feeding the TCA cycle through the production of citrate. In this case the oxaloacetate bottleneck within the TCA cycle is bypassed via the prebiotic pathway. We also found that the formation of all TCA cycle species from inorganic compounds (CO&lt;sub&gt;2&lt;/sub&gt; + H&lt;sub&gt;2&lt;/sub&gt;) is highly favored","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 6","pages":"1392-1412"},"PeriodicalIF":2.9,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12183719/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energetics of Neodymium Titanate Glass Made on Earth and in Space","authors":"Laura Bonatti,&nbsp;Tamilarasan Subramani,&nbsp;Stephen K. Wilke,&nbsp;Richard Weber and Alexandra Navrotsky*,&nbsp;","doi":"10.1021/acsearthspacechem.5c0001110.1021/acsearthspacechem.5c00011","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.5c00011https://doi.org/10.1021/acsearthspacechem.5c00011","url":null,"abstract":"<p >Space exploration presents an increased need for manufacturing materials beyond Earth due to spacecraft launch costs and logistical challenges of long missions. Differences in convection, buoyancy, and sedimentation under microgravity conditions compared to those at the Earth’s surface have the potential to impact the properties of manufactured materials. In order to better understand microgravity effects on melt-quenched glass, this study explores the energetics of crystallization of neodymium titanate glass (83TiO₂-17Nd₂O₃, “NT”), a potential material for advanced optical applications. Differential scanning calorimetry (DSC) reveals no significant thermodynamic differences between NT manufactured on Earth and aboard the International Space Station (ISS). The glass transition and crystallization temperatures are remarkably similar for glasses made on Earth and in space, consistent with their similar atomic structures. Additional research to investigate the critical cooling rates and behavior of glasses is needed to optimize glass processing in low gravity and to identify glass systems that benefit the most from the additional control of heat and mass transfer during processing.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 6","pages":"1277–1281 1277–1281"},"PeriodicalIF":2.9,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144312444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermodynamic Constraints on the Citric Acid Cycle and Related Reactions in Ocean World Interiors","authors":"Seda Işık*,&nbsp;Mohit Melwani Daswani*,&nbsp;Emre Işık,&nbsp;Jessica M. Weber and Nazlı Olgun Kıyak,&nbsp;","doi":"10.1021/acsearthspacechem.4c0037110.1021/acsearthspacechem.4c00371","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.4c00371https://doi.org/10.1021/acsearthspacechem.4c00371","url":null,"abstract":"&lt;p &gt;Icy ocean worlds in our solar system have attracted significant interest for their astrobiological and biogeochemical potential due to the predicted presence of global subsurface liquid water oceans, the presence of organics in Enceladus and Titan, and plausible sources of chemical energy available for life therein. A difficulty in placing quantitative constraints on the occurrence and effectiveness of biogeochemical reactions favorable for life and metabolism in ocean worlds is the paucity of thermodynamic data for the relevant reactions for pressure, temperature and compositional conditions pertaining to ocean worlds, in addition to uncertainties in the estimation of such conditions. Here, we quantify the thermodynamic viability and energetics of various reactions of interest to metabolism at pressures and temperatures relevant to ocean worlds Enceladus, Europa, Titan and Ganymede, and conditions relevant to the Lost City Hydrothermal Field for comparison. Specifically, we examine the tricarboxylic acid cycle (also known as TCA, Krebs cycle, or citric acid cycle) and a plausible precursor prebiotic network of reactions leading to the TCA cycle. We use DEWPython, a program based on the deep earth water (DEW) model (which is a high pressure and high temperature extension of the Helgeson─Kirkham─Flowers equation of state used to calculate thermodynamic properties of ions and complexes in aqueous solutions), to compute the equilibrium constants and the Gibbs free energy changes for given reactions, as a function of pressure and temperature. Using instantaneous concentrations of inorganics and organics from terrestrial microbial experiments and those derived from the Cassini mission for Enceladus, we calculate chemical affinities of reactions in the network. We carry out similar calculations using the SUPCRT model for lower pressures and temperatures. Together, the two models span temperatures between 0 and 1200 °C and pressures between 1 bar and 60 kbar. We found that across the majority of oceanic pressure─temperature profiles, certain TCA cycle species, such as citrate and succinate, accumulate, while others, including fumarate and oxaloacetate, exhibit a diminishing trend. This observation suggests that the internal conditions of ocean worlds may not thermodynamically favor a unidirectional TCA cycle, thereby implying an additional source of energy (e.g., metabolites) to overcome energy bottlenecks. Notably, we find similar bottlenecks at the Lost City Hydrothermal Field, which is undoubtedly inhabited by organisms. In the prebiotic network, we found that pyruvate and acetate exhibit remarkable stability and accumulate in substantial quantities, thereby feeding the TCA cycle through the production of citrate. In this case the oxaloacetate bottleneck within the TCA cycle is bypassed via the prebiotic pathway. We also found that the formation of all TCA cycle species from inorganic compounds (CO&lt;sub&gt;2&lt;/sub&gt; + H&lt;sub&gt;2&lt;/sub&gt;) is highly favored t","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 6","pages":"1392–1412 1392–1412"},"PeriodicalIF":2.9,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsearthspacechem.4c00371","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144312445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IR-Induced CO Photodesorption from Pure CO Ice and CO on Amorphous Solid Water.","authors":"Laura Slumstrup, John D Thrower, Johanna G M Schrauwen, Thanja Lamberts, Emily R Ingman, Domantas Laurinavicius, Jessalyn DeVine, Jeroen Terwisscha van Scheltinga, Julia C Santos, Jennifer A Noble, Gabi Wenzel, Martin R S McCoustra, Wendy A Brown, Harold Linnartz, Liv Hornekær, Herma M Cuppen, Britta Redlich, Sergio Ioppolo","doi":"10.1021/acsearthspacechem.5c00040","DOIUrl":"10.1021/acsearthspacechem.5c00040","url":null,"abstract":"<p><p>Carbon monoxide (CO) is a key component of the icy mantles that form on the surfaces of dust grains in the interstellar medium. In dense molecular clouds, where grain temperatures are around 10 K, CO freezes out as a nonpolar layer on top of H₂O ice. This CO plays an important role in the formation of complex organic molecules (COMs) through reactions with hydrogen atoms. Interstellar grains are also exposed to photons and charged particles that can both drive chemical reactions and promote desorption of molecules, providing an important link between the solid state reservoir of molecules and the gas phase. While several studies have considered UV photon driven desorption mechanisms, the UV component of the interstellar radiation field is strongly attenuated within dense clouds, with the internal cloud field being dominated by IR photons. We have used the FELIX IR Free Electron Laser (FEL) FEL-2 to irradiate a few monolayer film of CO deposited on the top of amorphous solid water (ASW) and compared the CO desorption yields to those obtained for a pure CO film. Infrared spectroscopy, combined with mass spectrometric detection of desorbing CO molecules, reveals that excitation of vibrational modes in the underlying ASW leads to significant CO desorption. This is in contrast to direct excitation of the stretching mode of CO which results in only inefficient desorption. The desorption efficiencies we derive indicate that energy transfer within ices on interstellar grains might provide an important route to IR photon-induced desorption of volatile species, such as CO.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 6","pages":"1607-1621"},"PeriodicalIF":2.9,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12184678/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144482511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IR-Induced CO Photodesorption from Pure CO Ice and CO on Amorphous Solid Water","authors":"Laura Slumstrup,&nbsp;John D. Thrower*,&nbsp;Johanna G. M. Schrauwen,&nbsp;Thanja Lamberts,&nbsp;Emily R. Ingman,&nbsp;Domantas Laurinavicius,&nbsp;Jessalyn DeVine,&nbsp;Jeroen Terwisscha van Scheltinga,&nbsp;Julia C. Santos,&nbsp;Jennifer A. Noble,&nbsp;Gabi Wenzel,&nbsp;Martin R. S. McCoustra,&nbsp;Wendy A. Brown,&nbsp;Harold Linnartz,&nbsp;Liv Hornekær,&nbsp;Herma M. Cuppen,&nbsp;Britta Redlich and Sergio Ioppolo*,&nbsp;","doi":"10.1021/acsearthspacechem.5c0004010.1021/acsearthspacechem.5c00040","DOIUrl":"https://doi.org/10.1021/acsearthspacechem.5c00040https://doi.org/10.1021/acsearthspacechem.5c00040","url":null,"abstract":"<p >Carbon monoxide (CO) is a key component of the icy mantles that form on the surfaces of dust grains in the interstellar medium. In dense molecular clouds, where grain temperatures are around 10 K, CO freezes out as a nonpolar layer on top of H₂O ice. This CO plays an important role in the formation of complex organic molecules (COMs) through reactions with hydrogen atoms. Interstellar grains are also exposed to photons and charged particles that can both drive chemical reactions and promote desorption of molecules, providing an important link between the solid state reservoir of molecules and the gas phase. While several studies have considered UV photon driven desorption mechanisms, the UV component of the interstellar radiation field is strongly attenuated within dense clouds, with the internal cloud field being dominated by IR photons. We have used the FELIX IR Free Electron Laser (FEL) FEL-2 to irradiate a few monolayer film of CO deposited on the top of amorphous solid water (ASW) and compared the CO desorption yields to those obtained for a pure CO film. Infrared spectroscopy, combined with mass spectrometric detection of desorbing CO molecules, reveals that excitation of vibrational modes in the underlying ASW leads to significant CO desorption. This is in contrast to direct excitation of the stretching mode of CO which results in only inefficient desorption. The desorption efficiencies we derive indicate that energy transfer within ices on interstellar grains might provide an important route to IR photon-induced desorption of volatile species, such as CO.</p>","PeriodicalId":15,"journal":{"name":"ACS Earth and Space Chemistry","volume":"9 6","pages":"1607–1621 1607–1621"},"PeriodicalIF":2.9,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144312446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}