Exploring the atmospheric chemistry of O&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; and assessing the  maximum turnover number of ion catalysed H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; formation

Abstract. It has recently been demonstrated that the O2SO3− ion forms in the atmosphere as a natural consequence of ionizing radiation. Here, we present a density functional theory-based study of the reactions of O2SO3− with O3. The most important reactions are (a) oxidation of O2SO3− to O3SO3− and (b) cluster decomposition into SO3, O2 and O3−. The former reaction is highly exothermic and the nascent O3SO3− will rapidly decompose into SO4− and O2. If the origin of O2SO3− is SO2 oxidation by O3−, the latter reaction closes a catalytic cycle wherein SO2 is oxidized to SO3. The relative rates between the two major sinks for O2SO3− is assessed, thereby providing a measure of the maximum turnover number of ion catalysed SO2 oxidation, i.e. how many SO2 can be oxidized per free electron. The rate ratio between reactions (a) and (b) is significantly altered by the presence or absence of a single water molecule, but reaction (b) is in general much more probable. Although we are unable to assess the overall importance of this cycle in the real atmosphere due to the unknown influence of CO2 and NOx, we roughly estimate that ion induced catalysis may contribute with several percent of H2SO4 levels in typical CO2 free and low NOx reaction chambers, e.g. the CLOUD chamber at CERN.

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Exploring the atmospheric chemistry of O<sub>2</sub>SO<sub>3</sub><sup>−</sup> and assessing the maximum turnover number of ion-catalysed H<sub>2</sub>SO<sub>4</sub> formation

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-3695-2013 ◽

2013 ◽

Vol 13 (7) ◽

pp. 3695-3703 ◽

Cited By ~ 17

Author(s):

N. Bork ◽

T. Kurtén ◽

H. Vehkamäki

Keyword(s):

Atmospheric Chemistry ◽

Density Functional ◽

Relative Rate ◽

Natural Consequence ◽

Turnover Number ◽

So2 Oxidation ◽

Functional Theory ◽

Reaction Chambers ◽

Real Atmosphere ◽

Single Water Molecule

Abstract. It has recently been demonstrated that the O2SO3− ion forms in the atmosphere as a natural consequence of ionizing radiation. Here, we present a density functional theory-based study of the reactions of O2SO3− with O3. The most important reactions are (a) oxidation to O2SO3− and (b) cluster decomposition into SO3, O2 and O3−. The former reaction is highly exothermic, and the nascent O2SO3− will rapidly decompose into SO4− and O2. If the origin of O2SO3− is SO2 oxidation by O3−, the latter reaction closes a catalytic cycle wherein SO2 is oxidized to SO3. The relative rate between the two major sinks for O2SO3− is assessed, thereby providing a measure of the maximum turnover number of ion-catalysed SO2 oxidation, i.e. how many SO2 can be oxidized per free electron. The rate ratio between reactions (a) and (b) is significantly altered by the presence or absence of a single water molecule, but reaction (b) is in general much more probable. Although we are unable to assess the overall importance of this cycle in the real atmosphere due to the unknown influence of CO2 and NOx, we roughly estimate that ion-induced catalysis may contribute with several percent of H2SO4 levels in typical CO2-free and low NOx reaction chambers, e.g. the CLOUD chamber at CERN.

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Theoretical study on the chemical formation mechanism of a β-myrcene ozonolysis reaction under atmospheric conditions

Canadian Journal of Chemistry ◽

10.1139/v2012-050 ◽

2012 ◽

Vol 90 (8) ◽

pp. 708-715 ◽

Cited By ~ 5

Author(s):

Yuyang Zhao ◽

Jing Bai ◽

Chenxi Zhang ◽

Chen Gong ◽

Xiaomin Sun

Keyword(s):

Rate Constants ◽

Potential Energy Surfaces ◽

Density Functional ◽

Single Point ◽

State Theory ◽

Tunneling Effect ◽

Atmospheric Conditions ◽

Functional Theory ◽

Real Atmosphere ◽

Energy Surfaces

Density functional theory (DFT) was used to study the β-myrcene ozonolysis reaction. The reactants, intermediates, transition states, and products were optimized at the MPWB1K/6–31G(d,p) level. The single-point energies were performed at the MPWB1K/6–311+G(3df,2p) level. The profiles of the potential energy surfaces were constructed and the rate constants of the reaction steps were analyzed. The possible reaction mechanisms for the ozonolysis intermediates in real atmosphere are also discussed. Based on quantum chemistry information, the rate constants were calculated using Rice–Ramsperger–Kassel–Marcus (RRKM) theory and the canonical variational transition-state theory (CVT) with small curvature tunneling effect (SCT). Arrhenius equations of rate constants over the temperature range of 200–800 K are provided, and the lifetimes of the reaction species in the troposphere were estimated according to rate constants.

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The Under-Explored Possibilities of Ground State Carbonyl Photochemistry

10.26434/chemrxiv.12950822.v1 ◽

2020 ◽

Author(s):

Keiran Rowell ◽

Scott Kable ◽

Meredith J. T. Jordan

Keyword(s):

Atmospheric Chemistry ◽

Ground State ◽

Density Functional ◽

Reaction Pathway ◽

Photon Absorption ◽

Functional Theory ◽

Volatile Organic ◽

Hybrid Density Functional ◽

Maximum Photon ◽

Carbonyl Species

Carbonyls are among the most abundant volatile organic compounds in the atmosphere, and their C=O chromophores allow them to photolyse. However, carbonyl photolysis reactions are not restricted to the excited state: the C=O chromophore allows relaxation to, and reaction on, the ground state, following photon absorption. <div><br></div><div>In this paper, the energetic thresholds for eight ground state reactions across twenty representative carbonyl species are calculated using double-hybrid density functional theory. Most reactions are found to be energetically accessible within the maximum photon energy available in the troposphere, but are absent in contemporary atmospheric chemistry models. </div><div><br></div><div>Structure–activity relationships are then elucidated so that the significance of each reaction pathway for particular carbonyl species can be predicted based upon their class. The calculations here demonstrate that ground state photolysis pathways are ubiquitous in carbonyls and should not be ignored in the analysis of carbonyl photochemistry.</div>

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The promoting mechanism of doping Mn, Co, and Ce on gas adsorption property and anti-SO2 oxidation over γ-Fe2O3 (001) surface: a density functional theory study

Colloids and Surfaces A Physicochemical and Engineering Aspects ◽

10.1016/j.colsurfa.2021.127218 ◽

2021 ◽

pp. 127218

Author(s):

Chaoyue Xie ◽

Yunlan Sun ◽

Baozhong Zhu

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Gas Adsorption ◽

Adsorption Property ◽

Density Functional Theory Study ◽

So2 Oxidation ◽

Functional Theory

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Revisiting the reactivity between HCO and CH3 on interstellar grain surfaces

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa484 ◽

2020 ◽

Vol 493 (2) ◽

pp. 2523-2527 ◽

Cited By ~ 4

Author(s):

J Enrique-Romero ◽

S Álvarez-Barcia ◽

F J Kolb ◽

A Rimola ◽

C Ceccarelli ◽

...

Keyword(s):

Water Molecule ◽

Energy Barrier ◽

Density Functional ◽

High Energy ◽

Functional Theory ◽

Radical Coupling ◽

High Energy Barrier ◽

Single Water Molecule ◽

Complex Organic

ABSTRACT The formation of interstellar complex organic molecules is currently thought to be dominated by the barrierless coupling between radicals on the interstellar icy grain surfaces. Previous standard density functional theory (DFT) results on the reactivity between CH3 and HCO on amorphous water surfaces showed that the formation of CH4 + CO by H transfer from HCO to CH3 assisted by water molecules of the ice was the dominant channel. However, the adopted description of the electronic structure of the biradical (i.e. CH3/HCO) system was inadequate [without the broken-symmetry (BS) approach]. In this work, we revisit the original results by means of BS-DFT both in gas phase and with one water molecule simulating the role of the ice. Results indicate that the adoption of BS-DFT is mandatory to describe properly biradical systems. In the presence of the single water molecule, the water-assisted H transfer exhibits a high energy barrier. In contrast, CH3CHO formation is found to be barrierless. However, direct H transfer from HCO to CH3 to give CO and CH4 presents a very low energy barrier, hence being a potential competitive channel to the radical coupling and indicating, moreover, that the physical insights of the original work remain valid.

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Influence of water on the CH3O˙ + O2 → CH2O + HO2˙ reaction

Physical Chemistry Chemical Physics ◽

10.1039/c9cp00720b ◽

2019 ◽

Vol 21 (28) ◽

pp. 15734-15741 ◽

Cited By ~ 9

Author(s):

Subhasish Mallick ◽

Amit Kumar ◽

Brijesh Kumar Mishra ◽

Pradeep Kumar

Keyword(s):

Density Functional Theory ◽

Electronic Structure ◽

Water Molecule ◽

Density Functional ◽

Electronic Structure Calculations ◽

Functional Theory ◽

Influence Of Water ◽

Single Water Molecule ◽

Structure Calculations

Electronic structure calculations employing density functional theory have been used to study the effect of a single water molecule on the CH3O˙ + O2 → CH2O + HO2˙ reaction.

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The Under-Explored Possibilities of Ground State Carbonyl Photochemistry

10.26434/chemrxiv.12950822 ◽

2020 ◽

Author(s):

Keiran Rowell ◽

Scott Kable ◽

Meredith J. T. Jordan

Keyword(s):

Atmospheric Chemistry ◽

Ground State ◽

Density Functional ◽

Reaction Pathway ◽

Photon Absorption ◽

Functional Theory ◽

Volatile Organic ◽

Hybrid Density Functional ◽

Maximum Photon ◽

Carbonyl Species

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Highly Accurate Many-Body Potentials for Simulations of N2O5 in Water: Benchmarks, Development, and Validation

10.26434/chemrxiv.13613678 ◽

2021 ◽

Author(s):

Vinicius Cruzeiro ◽

Eleftherios Lambros ◽

Marc Riera ◽

Ronak Roy ◽

Francesco Paesani ◽

...

Keyword(s):

Density Functional Theory ◽

Atmospheric Chemistry ◽

Short Range ◽

Density Functional ◽

Coupled Cluster ◽

Many Body ◽

Functional Theory ◽

High Level ◽

Three Body ◽

Many Body Interactions

<div><div><div><p>Dinitrogen pentoxide (N2O5) is an important intermediate in the atmospheric chemistry of nitrogen oxides. Although there has been much research, the processes that govern the physical interactions between N2O5 and water are still not fully understood at a molecular level. Gaining quantitative insight from computer simulations requires going beyond the accuracy of classical force fields, while accessing length scales and time scales that are out of reach for high-level quantum chemical approaches. To this end we present the development of MB-nrg many-body potential energy functions for simulations of N2O5 in water. This MB-nrg model is based on electronic structure calculations at the coupled cluster level of theory and is compatible with the successful MB-pol model for water. It provides a physically correct description of long-range many-body interactions in combination with an explicit representation of up to three-body short-range interactions in terms of multidimensional permutationally invariant polynomials. In order to further investigate the importance of the underlying interactions in the model, a TTM-nrg model was also devised. TTM- nrg is a more simplistic representation that contains only two-body short-range interactions represented through Born-Mayer functions. In this work an active learning approach was employed to efficiently build representative training sets of monomer, dimer and trimer structures, and benchmarks are presented to determine the accuracy of our new models in comparison to a range of density functional theory methods. By assessing binding curves, distortion energies of N2O5, and interaction energies in clusters of N2O5 and water, we evaluate the importance of two-body and three-body short-range potentials. The results demonstrate that our MB-nrg model has high accuracy with respect to the coupled cluster reference, outperforms current density functional theory models, and thus enables highly accurate simulations of N2O5 in aqueous environments.</p></div></div></div>

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Structures and reaction rates of the gaseous oxidation of SO<sub>2</sub> by an O<sub>3</sub><sup>−</sup>(H<sub>2</sub>O)<sub>0-5</sub> cluster – a density functional theory investigation

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-3639-2012 ◽

2012 ◽

Vol 12 (8) ◽

pp. 3639-3652 ◽

Cited By ~ 23

Author(s):

N. Bork ◽

T. Kurtén ◽

M. B. Enghoff ◽

J. O. P. Pedersen ◽

K. V. Mikkelsen ◽

...

Keyword(s):

Density Functional Theory ◽

Atmospheric Chemistry ◽

Density Functional ◽

Transition States ◽

Density Functional Theory Calculations ◽

Reaction Rates ◽

Water Molecules ◽

Functional Theory ◽

High Entropy ◽

Collision Complexes

Abstract. Based on density functional theory calculations we present a study of the gaseous oxidation of SO2 to SO3 by an anionic O3−(H2O)n cluster, n = 0–5. The configurations of the most relevant reactants, transition states, and products are discussed and compared to previous findings. Two different classes of transition states have been identified. One class is characterised by strong networks of hydrogen bonds, very similar to the reactant complexes. The other class is characterised by sparser structures of hydration water and is stabilised by high entropy. At temperatures relevant for atmospheric chemistry, the most energetically favourable class of transition states vary with the number of water molecules attached. A kinetic model is utilised, taking into account the most likely outcomes of the initial SO2 O3−(H2O)n collision complexes. This model shows that the reaction takes place at collision rates regardless of the number of water molecules involved. A lifetime analysis of the collision complexes supports this conclusion. Hereafter, the thermodynamics of water and O2 condensation and evaporation from the product SO3−O2(H2O)n cluster is considered and the final products are predicted to be O2SO3− and O2SO3−(H2O)1. The low degree of hydration is rationalised through a charge analysis of the relevant complexes. Finally, the thermodynamics of a few relevant reactions of the O2SO3− and O2SO3−(H2O)1 complexes are considered.

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