Article
Chemistry, Inorganic & Nuclear
Kaipeng Tu, Ling Liu, Xiuhui Zhang, R. Bruce King
Summary: The density functional theory reveals the low-energy structures of the missing Cp4M4(CO)(4) (M = Mn, Cr) species, showing variations in spin states and metal-metal bond orders along the central M-4 tetrahedra edges. Different structures exist for Cp4Mn4(mu(3)-CO)(4) and Cp4Cr4(mu(3)-CO)(4) with varying types of metal-metal bonds, including single, double, and triple bonds.
INORGANIC CHEMISTRY
(2021)
Article
Astronomy & Astrophysics
Zhi Qin, Peigen Hu, Tianrui Bai, Linhua Liu
Summary: This study calculates the potential energy curves and transition dipole moments of four electronic states of O-2, and estimates the temperature-dependent photodissociation cross sections and rates. The results are important for understanding Earth's atmospheric chemistry and exploring exoplanetary atmospheres.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Chemistry, Physical
Alexey Pelevkin, Boris Loukhovitski, Alexander S. Sharipov
Summary: The kinetics of the reaction between N and electronically excited O-2 has been theoretically studied using multireference second-order perturbation theory. Different energy barriers for reaction pathways in different states have been identified, with molecular oxygen in the b(1)Sigma(+)(g) state found to be less reactive to atomic nitrogen. Thermal rate constants for specified reaction channels have been calculated, and post-transition-state molecular dynamics simulations suggest that the reaction produces vibrationally much colder NO molecules than a counterpart process.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Materials Science, Multidisciplinary
Xi Zhou, Cuihua Zhao, Cuiting Chen, Jianhua Chen, Xing Chen
Summary: The interactions between H2O, O-2, H2O + O-2, and the surface of graphene carbon nitride (g-C3N4) were investigated using a first-principle method. The results showed that N atoms near the bridge sites and vacancies on the g-C3N4 surface are highly active, promoting the dissociation of water molecules and forming hydrogen bonds after adsorption of water and oxygen. Adsorption of only H2O or O-2 molecules on the g-C(3)N(4) surface does not result in dissociation of the H2O and O-2 molecules, but hydrogen bonds are formed after H2O molecule adsorption. After O-2 adsorption, the two oxygen atoms of the O-2 molecule are bonded to carbon and nitrogen atoms on the g-C3N4 surface. There are two stable configurations for H2O + O-2 co-adsorption on the g-C3N4 surface (MA and MC), with adsorption energies of -57.35 kJ/mol and -61.10 kJ/mol, respectively. In the MA configuration, the two oxygen atoms of the O-2 molecule are bonded to C and N atoms of the g-C3N4 surface, respectively, and one hydrogen bond is formed between the H2O and O-2 molecules. In the MC configuration, three hydrogen bonds are formed at the interface of H2O + O-2 and the g-C3N4 surface. The H2O molecule dissociates, and the O-2 molecule transforms into a superoxide radical by gaining electrons. The formation of superoxide radicals contributes to the degradation of organic pollutants by g-C3N4.
DIAMOND AND RELATED MATERIALS
(2022)
Article
Engineering, Chemical
Pengbo Hu, Shujuan Wang, Yuqun Zhuo
Summary: This study investigates the effects of alkaline metal promoters on the adsorption properties of MgO for CO2, and finds that alkaline metals can counteract the negative effects of SO2/O2/H2O and enhance the average adsorption energy of CO2. The research results have important practical applications.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Article
Thermodynamics
Shanshan Ruan, Jiuzheng Yin, Ying Shi, Chunlan Qin, Kangwei Xu, Chenliang He, Xixi Hu, Lidong Zhang
Summary: In this study, the low-temperature oxidation mechanism of carbon-neutral fuel diethoxymethane (DEM) was investigated. The reaction potential energy surfaces (PESs) of three different DEM radicals reacting with O2 were explored. The rate constants of the relevant reactions were calculated and the main reaction channels were discussed. The data obtained were incorporated into the DEM combustion model, showing good agreement with experimental data and providing support for further study.
COMBUSTION AND FLAME
(2023)
Article
Chemistry, Physical
Shuanghui Xi, Jie Xue, Fan Wang, Xiangyuan Li
Summary: The study investigated the reactions of alpha-hydroxyethyl and alpha-hydroxypropyl radicals with oxygen, determining pressure-dependent rate constants and elucidating reaction pathways. Results showed significant differences in rate constants between the two reaction systems, which are helpful for developing combustion mechanisms for ethanol and propanol.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Thermodynamics
Shangkun Zhou, Wenjun Yang, Shijie Zheng, Shilin Yu, Houzhang Tan, Baochong Cui, Jinhua Wang, Shuanghui Deng, Xuebin Wang
Summary: The oxidation of neat NH3 and co-oxidation of NH3 with H2/CO/CH4 were investigated experimentally and numerically. Results showed that H2 can promote NH3 reactivity below 950 K, while CO/CH4 can promote it below 1175 K. HO2 radical was found to be an important intermediate for NH3 oxidation. As temperature increased, the oxidation of NH3 was dominated by independent interactions between fuels and H/OH/O radicals. In stoichiometric conditions, NO formation mainly depended on NH radicals, while in lean conditions, it depended on the conversion of NH2 to NO through HNO intermediate.
COMBUSTION AND FLAME
(2023)
Article
Chemistry, Physical
Katherine J. Catani, Nastasia I. Bartlett, Michael S. Scholz, Giel Muller, Peter R. Taylor, Evan J. Bieske
Summary: Electronic transitions are observed for the O-2(+)-Ar and O-2(+)-N-2 complexes, indicating charge transfer transitions. The onsets of the band systems occur at 3.68 and 3.62 eV, originating from intramolecular charge transfer transitions. The dominant vibronic progressions have similar values as the neutral O-2 molecule, indicating their correlation.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Mahmoud A. A. Ibrahim, Yasmeen A. M. Mohamed, Hassan A. A. Abuelliel, Al-shimaa S. M. Rady, Mahmoud E. S. Soliman, Muhammad Naeem Ahmed, Lamiaa A. Mohamed, Nayra A. M. Moussa
Summary: The study focused on sigma-hole interactions of group IV-VIII element-containing molecules in tetrahedral geometry with Lewis bases. Results showed that electrostatic energy was the primary force governing the interactions, and the strength of interactions could be modulated by external electric fields.
Article
Biochemistry & Molecular Biology
Jun Luo, Hongjing Dai, Chenglu Zeng, Dawang Wu, Maoqi Cao
Summary: This study investigates the structural characteristics and interaction energies of the halogen bond between heteronuclear halogens (ClF, BrCl, IBr, ICl, BrF, and IF) and benzene using density functional theory. The results show that the interaction energies increase with the polarity between the atoms and are proportional to the angles between the Z axis and the covalent bond of the heteronuclear halogen. The electron density and Laplacian values indicate that the interaction is a long-range weak interaction similar to a hydrogen bond. The main interaction in the complexes varies depending on the halogen species, with van der Waals forces dominating in some and electrostatic interactions dominating in others.
Article
Chemistry, Multidisciplinary
Philipp Dabringhaus, Silja Zedlitz, Luisa Giarrana, David Scheschkewitz, Ingo Krossing
Summary: Schnockel's [(AlCp*)(4)] and Jutzi's [SiCp*][B(C6F5)(4)] are important in modern main-group chemistry with various applications in synthesis and catalysis. However, the reactivity between AlCp* and [SiCp*](+) has not been explored. In this study, their reaction was investigated and complex salts [Cp*Si(AlCp*)(3)][WCA] were obtained. The tetrahedral [SiAl3](+) core not only represents a rare example of a low-valent silicon-doped aluminium-cluster, but also provides a convenient preparative entry towards low-valent Si-Al clusters.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Environmental Sciences
Mohanapriya Subramani, Vinnarasi Saravanan, Jayaraman Theerthagiri, Vijayakumar Subramaniam, Thangavelu Pazhanivel, Shankar Ramasamy, Sivakumar Manickam
Summary: In this study, the oxidation of camphene by OH radicals in the atmosphere was investigated using quantum chemical methods. The results showed that the addition of OH radicals to the C10 position of camphene is more stable and dominant compared to the C7 position.
Article
Chemistry, Physical
Di Mu, Quan-Song Li
Summary: Organic borylenes are highly reactive species, and their photochemical generation mechanisms from phenyldiazidoborane were investigated in this study. The results showed that the reactions involved stepwise extrusion of dinitrogen and azido region rearrangement, and were kinetically feasible. Conical intersections between the singlet states were found to participate and facilitate the studied photochemical processes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
M. Patanen, A. R. Abid, S. T. Pratt, A. Kivimaki, A. B. Trofimov, A. D. Skitnevskaya, E. K. Grigoricheva, E. V. Gromov, I. Powis, D. M. P. Holland
Summary: Linearly polarized synchrotron radiation was used to record polarization dependent valence shell photoelectron spectra of imidazole in the photon energy range of 21-100 eV. Experimental and theoretical data were used to characterize the photoelectron angular distributions and electronic state intensity branching ratios. The structure in the experimental photoelectron spectra was guided by various theoretical methods incorporating electron correlation and orbital relaxation.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
David Mahlberg, Sung Sakong, Axel Gross
Summary: This study investigates the meta-stability of surface alloy systems through kinetic Monte Carlo simulations based on density functional theory calculation. The analysis reveals the factors underlying the stability and structure of bimetallic surface alloys, offering new insights for tuning catalytic activity.
Article
Materials Science, Coatings & Films
Florian Buchner, Katrin Forster-Tonigold, Tim Bolter, Alexander Rampf, Jens Klein, Axel Gross, R. Juergen Behm
Summary: This study investigates the interaction between a battery-relevant ionic liquid and a Mg thin film model electrode through a combined experimental and computational model study. The aim is to gain a fundamental understanding of the solid electrolyte interphase formation at the electrode-electrolyte interface in postlithium batteries. The results reveal the formation of a contact layer on the Mg thin film, which is created by the reactive decomposition of the ionic liquid. Various inorganic surface compounds were identified, along with molecularly adsorbed ionic liquid on the contact layer.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Multidisciplinary Sciences
Matthias Scheffler, Martin Aeschlimann, Martin Albrecht, Tristan Bereau, Hans-Joachim Bungartz, Claudia Felser, Mark Greiner, Axel Gross, Christoph T. Koch, Kurt Kremer, Wolfgang E. Nagel, Markus Scheidgen, Christof Woell, Claudia Draxl
Summary: Achievements in condensed matter physics, chemistry, and materials science greatly influence the prosperity and lifestyle of our society, as new materials are crucial for various sectors. However, the value of the enormous amount of research data produced in these fields can only be realized through the establishment of a FAIR data infrastructure, allowing for comprehensive characterization and sharing of the data to advance science.
Article
Chemistry, Physical
Axel Gross
Summary: In interfacial electrochemistry, it is commonly believed that the stability of adsorbate phases containing only hydrogen atoms is independent of the pH of the electrolyte, while the stability of adsorbate phases without hydrogen is independent of the pH on the scale of the standard hydrogen electrode. This Perspective argues that such Nernstian behavior can only occur if the free energy of the adsorbate phase is not affected by the electrochemical control parameters, which is generally not true. However, certain structural and chemical factors may lead to Nernstian behavior. The analysis also provides guidance for the validity of grand-canonical simulations using the computational hydrogen electrode concept.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Mengru Li, Axel Gross, R. Juergen Behm
Summary: In this study, the effect of increasing oxygen vacancies at the Ru-ZrO2 interface on CO adsorption properties was investigated. Density functional theory calculations revealed trends in O-vacancy formation energy, charge transfer, local density of states, CO adsorption energy, and C-O vibrational frequencies as a function of oxygen vacancies. The findings have implications for our understanding of electronic metal-support interactions in heterogeneous catalysis and the catalytic performance of catalysts supported on reducible oxides.
Article
Chemistry, Physical
Mohsen Sotoudeh, Axel Gross
Summary: The article calculated the electrochemical stability of magnesium spinel compounds using first-principles calculations, providing guidelines for the selection of solid materials for Mg batteries with improved properties.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Physical
Mohsen Sotoudeh, Manuel Dillenz, Johannes Doehn, Julian Hansen, Sonia Dsoke, Axel Gross
Summary: Through theoretical and experimental research, we have identified cathode materials with improved Mg-ion mobility, which is significant for the utilization of Mg-metal batteries.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Physical
Jun Huang, Yufan Zhang, Mengru Li, Axel Gross, Sung Sakong
Summary: The theoretical modeling of metal/water interfaces focuses on the configuration of the electric double layer (EDL) under grand canonical conditions. Ab initio molecular dynamics (AIMD) simulations are ideal for treating water-metal interactions but are limited by small ensembles and short simulation times. Semiclassical approaches can efficiently handle the EDL model by averaging microscopic details. By combining AIMD and semiclassical methods, an improved description of the EDL can be obtained. Comparing these approaches using the Pt(111)/water interface, we analyze the differences in electric field, water configuration, and double-layer capacitance, and discuss their contributions to EDL theory.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Tao Zhang, Mohsen Sotoudeh, Axel Gross, Robert M. McMeeking, Marc Kamlah
Summary: The cathode material NaxFePO4 of sodium-ion batteries exhibits complex phase segregation thermodynamics and large volume change during (dis)charging. A virtual multiscale modeling chain is established to construct a 3D anisotropic electro-chemo-mechanical phase-field model based on first-principles calculations for NaxFePO4, which considers various factors such as phase changes, electrochemical reactions, anisotropic diffusion, anisotropic misfit strain, and anisotropic elasticity. The study investigates the influence of surface reaction kinetics and crystal anisotropy on the microstructure evolution of NaxFePO4 particles and provides insights into engineering desired phase behavior with better mechanical stability.
JOURNAL OF POWER SOURCES
(2023)
Article
Electrochemistry
Daniel Stottmeister, Axel Gross
Summary: The transition from lithium-based energy storage to post lithium systems is crucial for achieving environmentally sustainable energy infrastructure. Sodium and potassium batteries are prime candidates for replacing lithium. However, the formation process of the solid electrolyte interphase (SEI) for Na and K batteries is not well-understood compared to lithium systems. In this study, ab initio molecular dynamics simulations are used to investigate the initial steps of SEI formation on lithium, sodium, and potassium metal anodes. The results show that carbon monoxide and alkali-carbonate are the dominant products during the early SEI formation of cyclical carbonates on alkali metal anodes.
BATTERIES & SUPERCAPS
(2023)
Article
Chemistry, Multidisciplinary
Daniel Stottmeister, Leonie Wildersinn, Julia Maibach, Andreas Hofmann, Fabian Jeschull, Axel Gross
Summary: The increasing demand for electrochemical energy storage has led to the development of post-lithium battery systems. Sodium-based batteries are among the most promising new battery types. However, similar to lithium batteries, sodium batteries face issues such as parasitic side reactions and an unstable solid electrolyte interface (SEI). This study investigates the formation of SEI on sodium metal and reveals the crucial role of a sodium chloride layer in the formation of propylene oxide.
Article
Chemistry, Physical
Majid Rezaei, Sung Sakong, Axel Gross
Summary: Accurate modeling of highly concentrated aqueous solutions, such as WiS electrolytes, requires proper consideration of polarization contributions. This study analyzes different approaches to include polarization effects in MD simulations and identifies an efficient combination of force fields for Na-OTF solution: a Drude polarizable force field for salt ions and non-polarizable models for water. This cost-effective combination ensures simulation stability and reproduces a broad range of electrolyte properties.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Electrochemistry
Katrin Forster-Tonigold, Florian Buchner, Axel Gross, R. Juergen Behm
Summary: By utilizing surface chemistry experiments and DFT calculations, this study investigates the initial stages of SEI formation in Na ion or Na metal batteries. The results reveal the interactions and reactions between a Na surface and the ionic liquid, leading to the formation of larger TFSI-based fragments and atomic adsorbates at the Na surface.
BATTERIES & SUPERCAPS
(2023)
Review
Chemistry, Physical
Mohsen Sotoudeh, Sebastian Baumgart, Manuel Dillenz, Johannes Doehn, Katrin Forster-Tonigold, Katharina Helmbrecht, Daniel Stottmeister, Axel Gross
Summary: Ion mobility is a critical performance parameter in electrochemical devices. This review discusses the chemical trends in ion mobility in crystalline materials and the nature of the migrating species.
ADVANCED ENERGY MATERIALS
(2023)
Article
Chemistry, Applied
Behnaz Rahmani Didar, Axel Gross
Summary: Density functional theory calculations and ab initio molecular dynamics simulations were employed to investigate the solvation, diffusion, and transformation of Li+ and LiO2 in three organic electrolytes during O2 reduction in Li-air batteries. The study revealed a significant impact of the electrolytes on these reactions.
CHINESE JOURNAL OF CATALYSIS
(2022)
