Nucleation and Growth of Nanoparticles in the Atmosphere Renyi Zhang,* Alexei Khalizov, Lin Wang, Min Hu, and Wen Xu Department of Atmospheric Sciences andDepartment of Chemistry, Center for Atmospheric Chemistry and Environment, Texas A&M University, College Station, Texas 77843, United States Department of Environmental Science & Engineering and Institute of Global Environment Change Research, Fudan University, Shanghai 200433, China State Key Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China

Nucleation and Growth of Nanoparticles in the Atmosphere

The chemistry of the atmosphere encompasses a vast number of reactions acting on a plethora of intermediates. These reactions, occurring sequentially and in parallel, give rise to intertwined and irreducible mechanisms describing the complex chemical transformations of organic and inorganic compounds in the atmosphere. The complexity of this system is that it requires combined experimental, theoretical, and modeling approaches to elucidate the characteristics of the individual reactions, and their mutual interaction. In this review, we describe recent results from quantum chemical and theoretical kinetic studies of relevance to atmospheric chemistry. The review first summarizes the most commonly used theoretical methodologies. It then examines the VOC oxidation initiation channels by OH, O(3), NO(3) and Cl, followed by the reactions of the alkyl, alkoxy, alkylperoxy and Criegee intermediates active in the subsequent oxidation steps. Specific systems such as the oxidation of aromatics and the current state of knowledge on OH-regeneration in VOC oxidation are also discussed, as well as some inorganic reactions.

Theoretical studies of atmospheric reaction mechanisms in the troposphere

This work assesses different computational strategies for predicting structures and Gibb’s free energies of reaction of atmospheric prenucleation clusters. The performance of 22 Density Functional Theory functionals in predicting equilibrium structures of molecules and water prenucleation clusters of atmospheric relevance is evaluated against experimental data using a test set of eight molecules and prenucleation clusters: SO2, H2SO4, CO2·H2O, CS2·H2O, OCS·H2O, SO2·H2O, SO3·H2O, and H2SO4·H2O. Furthermore, the functionals are tested and compared for their ability to predict the free energy of reaction for the formation of five benchmark atmospheric prenucleation clusters: H2SO4·H2O, H2SO4·(H2O)2, H2SO4·NH3, HSO4–·H2O, and HSO4–·(H2O)2. The performance is evaluated against experimental data, coupled cluster, and complete basis set extrapolation procedure methods. Our investigation shows that the utilization of the M06-2X functional with the 6-311++G(3df,3pd) basis set represents an improved approach compar...

Assessment of Density Functional Theory in Predicting Structures and Free Energies of Reaction of Atmospheric Prenucleation Clusters

This work assesses the binding energies of atmospherically relevant clusters containing H2SO4, H2O, NH3 and (CH3)2NH using density functional theory. The performance of seven DFT functionals (B3LYP, CAM-B3LYP, M06-2X, PW91, LC-PW91, PBE0 and ωB97X-D) is evaluated against high level explicitly correlated coupled cluster methods using a test set of 107 atmospherically relevant clusters. Our studies show that all the tested functionals correlate well with the coupled cluster results, but with highly varying mean absolute errors. The PBE0, CAM-B3LYP, PW91 and M06-2X functionals are found to perform similarly with errors in the range of 2.53–3.46 kcal mol−1, while the B3LYP and LC-PW91 functionals yield higher errors of 6.95 kcal mol−1 and 10.66 kcal mol−1, respectively. The ωB97X-D functional gives the best estimate of the binding energies with a mean absolute error as low as 2.12 kcal mol−1 over the large test set of clusters.

Assessment of binding energies of atmospherically relevant clusters.

Dicarboxylic acids are important products from photooxidation of volatile organic compounds and are believed to play an important role in the formation and growth of atmospheric secondary organic a...

Theoretical Investigation of Interaction of Dicarboxylic Acids with Common Aerosol Nucleation Precursors

Nucleation in the Earth’s atmosphere plays a vital role in the aerosol radiative forcing associated directly with the production of ultrafine particles responsible for adverse public health impacts and global climate changes. In the present work, the interaction of the common organic oxalic acid with the atmospheric nucleation precursors and trace ionic species has been investigated using the Density Functional Theory (DFT). A comprehensive study of the hydrogen-bonded complexes of oxalic acid with neutral monomers and ionic clusters of the sulfuric acid, water and ammonia, the key atmospheric nucleation precursors, has been carried out. We found that the bonding of the oxalic acid with the above-mentioned neutrals is moderately weak, and thus, the oxalic acid cannot stabilize the binary sulfuric acid–water and ternary sulfuric acid–ammonia clusters. The interaction of the oxalic acid with positive ionic species is, in contrast, strong and significantly enhances stability of the clusters formed over the ions. The hydration of positively charged (C2H2O4)(H3O+), ( C 2 H 2 O 4 ) ( NH 4 + ) and (C2H2O4)(H3O+)(H2SO4) clusters is also strong and close to that of the sulfuric acid, the key atmospheric nucleation precursor. These considerations lead us to a logical conclusion that the oxalic acid can catalyse the production of positively charged pre-nucleation clusters and, thus, its role in nucleation of positive ions in the Earth’s troposphere should be studied in further details.

Formation and properties of hydrogen-bonded complexes of common organic oxalic acid with atmospheric nucleation precursors

The reaction of the O3 addition to double bonds of the limonene in the gas phase has been investigated using ab initio methods. Four different possibilities for the O3 addition to the double bonds, which correspond to the two C–C double bonds (endocyclic or exocyclic), and two different orientations of each C–C double bonds, have been considered. The corresponding rate constants have been calculated using the transition-state theory (TST) at the CCSD(T)/6-31G(d) + CF//B3LYP/6-311+G(d,p) level of theory. The high-pressure limit of the overall rate constant at 298 K is found to be ∼2.92 × 10−16 cm3 molecule−1 s−1 that is in a good agreement with the experimental data, and the rate constants of the four individual reaction channels turn out to be 2.1 × 10−16 cm3 molecule−1 s−1, 1.2 × 10−17 cm3 molecule−1 s−1, 6.5 × 10−17 cm3 molecule−1 s−1 and 5.1 × 10−18 cm3 molecule−1 s−1 for 1-endo, 2-endo, 1-exo and 2-exo, respectively.

Ab initio investigation of O3 addition to double bonds of limonene

The addition reactions of NO3 to limonene have been investigated using ab initio methods. Six different possibilities for NO3 addition to the double bonds, which correspond to the two C–C double bonds (endocyclic or exocyclic) have been considered. The negative activation energies for the addition of NO3 to limonene are calculated and the energies of NO3-limonene radical adducts are found to be 14.55 to 20.17 kcal mol-1 more stable than the separated NO3 and limonene at the CCSD(T)/6–31G(d) + CF level. The results also indicate that the endocyclic addition reaction is more energetically favorable than the exocyclic one.

https://www.mdpi.com/1422-0067/10/9/3743/pdf

Lei Jiang

Papers

Formation and properties of hydrogen-bonded complexes of common organic oxalic acid with atmospheric nucleation precursors

Ab initio investigation of O3 addition to double bonds of limonene

Theoretical Investigation of the NO3 Radical Addition to Double Bonds of Limonene