35 results on '"Lin He"'
Search Results
2. Zinc Storage Performance of Oxygen-Deficient NH 4 V 3 O 8 : Theoretical and Experimental Study.
- Author
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Lin, He, Cai, Xuanxuan, and Zhang, Yu
- Subjects
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DENSITY functional theory , *ELECTRIC conductivity , *ENERGY storage , *DENSITY of states - Abstract
Using density functional theory (DFT), the density of states of NH4V3O8 (NVO) was analyzed pre- and post-oxygen defect (Od) formation. The findings revealed a reduced bandgap in NVO after Od introduction, emphasizing the role of Od in enhancing conductivity of the material, thus improving its electrochemical attributes. Through the water bath method, both NVO and its oxygen-deficient counterpart, (NH4)2V10O25·8H2O (NVOd), were synthesized as potential cathode materials for aqueous zinc-ion batteries (AZIBs). Experimental outcomes resonated with DFT predictions, highlighting the beneficial role of oxygen defects in boosting electrical conductivity. Notably, the refined material displayed a remarkable capacity of 479.3 mAh g−1 at 0.1 A g−1, underscoring its promise for advanced energy storage solutions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. Dinitromethyl, fluorodinitromethyl derivatives of RDX and HMX as high energy density materials: a computational study
- Author
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Lin, He, Zhu, Qing, Huang, Chuan, Yang, Dong-Dong, Lou, Nan, Zhu, Shun-Guan, and Li, Hong-Zhen
- Published
- 2019
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4. Lattice-Matched Metal–Semiconductor Heterointerface in Monolayer Cu2Te
- Author
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Jingqi Feng, Menglei Li, Xin Tan, Peng Xu, Tian Li, Donglin Ma, Lin He, and Huiying Gao
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Materials science ,Condensed matter physics ,business.industry ,General Engineering ,General Physics and Astronomy ,Heterojunction ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Crystal ,Semiconductor ,law ,Phase (matter) ,Monolayer ,General Materials Science ,Density functional theory ,Scanning tunneling microscope ,0210 nano-technology ,business ,Quantum tunnelling - Abstract
The interface between metals and semiconductors plays an essential role in two-dimensional electronic heterostructures, which has provided an alternative opportunity to realize next-generation electronic devices. Lattice-matched two-dimensional heterointerfaces have been achieved in polymorphic 2D transition-metal dichalcogenides MX2 with M = (W, Mo) and X = (Te, Se, S) through phase engineering; yet other transition-metal chalcogenides have been rarely reported. Here we show that a single layer of hexagonal Cu2Te crystal could be synthesized by one-step liquid-solid interface growth and exfoliation. Characterizations of atomically resolved scanning tunneling microscope reveal that the Cu2Te monolayer consists of two lattice-matched distinct phases, similar to the 1T and 1T' phases of MX2. The scanning tunneling spectra identify the coexistence of the metallic 1T and semiconducting 1T' phases within the chemically homogeneous Cu2Te crystals, as confirmed by density functional theory calculations. Moreover, the two phases could form nanoscale lattice-matched metal-semiconductor junctions with atomically sharp interfaces. These results suggest a promising potential for exploiting atomic-scale electronic devices in 2D materials.
- Published
- 2021
5. Tunable magnetism of a single-carbon vacancy in graphene
- Author
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Lin He, Fei Gao, Shiwu Gao, and Yu Zhang
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Physics ,Multidisciplinary ,Condensed matter physics ,Magnetic moment ,Magnetism ,Graphene ,Fermi level ,Electron ,010502 geochemistry & geophysics ,01 natural sciences ,law.invention ,symbols.namesake ,law ,Vacancy defect ,symbols ,Density functional theory ,Quantum tunnelling ,0105 earth and related environmental sciences - Abstract
Creating a single-carbon vacancy introduces (quasi-)localized states for both σ and π electrons in graphene. Theoretically, interactions between the localized σ electrons and quasilocalized π electrons of a single-carbon vacancy in graphene are predicted to control its magnetism. However, experimentally confirming this prediction through manipulating the interactions remains an outstanding challenge. Here we report the manipulation of magnetism in the vicinity of an individual single-carbon vacancy in graphene by using a scanning tunnelling microscopy (STM) tip. Our spin-polarized STM measurements, complemented by density functional theory calculations, indicate that the interactions between the localized σ and quasilocalized π electrons could split the π electrons into two states with opposite spins even when they are well above the Fermi level. Via the STM tip, we successfully manipulate both the magnitude and direction of magnetic moment of the π electrons with respect to that of the σ electrons. Three different magnetic states of the single-carbon vacancy, exhibiting magnetic moments of about 1.6 μB, 0.5 μB, and 0 μB respectively, are realized in our experiment.
- Published
- 2020
6. Theoretical studies on the thermodynamic properties, densities, detonation properties, and pyrolysis mechanisms of trinitromethyl-substituted aminotetrazole compounds
- Author
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Lin, He, Chen, Peng-Yuan, Zhu, Shun-Guan, Zhang, Lin, Peng, Xin-Hua, Li, Kun, and Li, Hong-Zhen
- Published
- 2013
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7. Robust atomic-structure of the 6 × 2 reconstruction surface of Ge(110) protected by the electronically transparent graphene monolayer
- Author
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Chao Yan, Shujing Li, Wenjing Chen, Lin He, Donglin Ma, Xin-Xin Wang, Yu Yang, Rui-Fen Dou, Jia-Cai Nie, and Ping Zhang
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Local density of states ,Materials science ,Graphene ,Scanning tunneling spectroscopy ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Molecular physics ,0104 chemical sciences ,law.invention ,law ,Density functional theory ,Physical and Theoretical Chemistry ,0210 nano-technology ,Spectroscopy ,Surface reconstruction ,Quantum tunnelling ,Surface states - Abstract
Wafer-scale growth of the unidirectional graphene monolayer on Ge surfaces has rejuvenated the intense study of the surfaces and interfaces of semiconductors underneath graphene. Recently, it was reported that the Ge atoms in the Ge(110) surface beneath a graphene monolayer underwent a rearrangement and formed an ordered (6 × 2) reconstruction. However, a plausible atomic model related to this (6 × 2) reconstruction is still lacking. Here, by using scanning tunnelling microscopy/spectroscopy (STM/S) and density functional theory (DFT) calculations, we deeply investigated the structural and electronic properties of the Ge(110) (6 × 2) surface encapsulated by a graphene monolayer. The (6 × 2) surface reconstruction was confirmed for the post-annealing-graphene-covered Ge(110) surface via STM, and was found to be quite air-stable, owing to the protection of the graphene monolayer against surface oxidation. Our study disclosed that the topographic features of the topmost graphene monolayer and the Ge(110) surface could be selectively imaged by utilizing suitable scanning biases. According to the STM results and DFT calculations, a rational ball-and-stick model of the (6 × 2) reconstruction was successfully provided, in which an elemental building block comprising two Ge triangles and two isolated Ge atoms adsorbed on the unreconstructed ideal Ge(110) surface. Local density of states of the graphene/Ge surface was explored via scanning tunneling spectroscopy (STS), presenting four well-defined differential conductance (dI/dV) peaks, protruding at energies of 0.2, 0.4, 0.6 and 0.8 eV, respectively. The four peaks predominantly originated from the surface states of the reconstructing adatoms and were well reproduced by our theoretical simulation. This result means that the Ge surface is very robust after being encapsulated by the epitaxial graphene, which could be advantageous for directly fabricating graphene/Ge-hybrid high-speed electronics and optoelectronics based on conventional microelectronics technology.
- Published
- 2020
8. Local electronic structure and magnetic properties of 3d transition metal doped GaAs
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Lin, He and Duan, HaiMing
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- 2008
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9. Local electronic structure and magnetic properties of (Ga,Cr)N
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Lin He and Duan Haiming
- Published
- 2006
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10. Kinetic and Theoretical Study of the Atmospheric Aqueous-Phase Reactions of OH Radicals with Methoxyphenolic Compounds
- Author
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Tobias Otto, Hartmut Herrmann, Lin He, Ana Kroflič, and Thomas Schaefer
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Arrhenius equation ,010304 chemical physics ,Chemistry ,Radical ,Analytical chemistry ,Activation energy ,010402 general chemistry ,Kinetic energy ,01 natural sciences ,7. Clean energy ,0104 chemical sciences ,symbols.namesake ,Reaction rate constant ,13. Climate action ,Atmospheric chemistry ,0103 physical sciences ,symbols ,Flash photolysis ,Density functional theory ,Physical and Theoretical Chemistry - Abstract
Methoxyphenols, which are emitted through biomass burning, are an important species in atmospheric chemistry. In the present study, temperature-dependent aqueous-phase OH radical reactions of six methoxyphenols and two related phenols have been investigated through laser flash photolysis and the density functional theory. The rate constants obtained were in a range of (1.1-1.9) × 1010 L mol-1 s-1 with k(3-MC) > k(Cre) ≈ k(Syr) ≈ k(MEP) > k(Res) > k(3-MP) > k(2-EP) ≈ k(2-MP). We derived the parameters of these reactions from the obtained T-dependent rate constants and found a mean Arrhenius activation energy of 16.9 kJ mol-1. The diffusion rate constants were calculated for each case and compared to the measured ones. Generally, the rate constants are found to be close to fully diffusion-controlled (kdiff = (1.4-1.5) × 1010 L mol-1 s-1 for all reactions). A structure-function relationship was established through the measurement result, which could be used for predicting unknown rate constants of other phenolic compounds. All of these findings are expected to enhance the predictive capabilities of models, such as the chemical aqueous-phase radical mechanism.
- Published
- 2019
11. First-principles investigation on diffusion mechanism of alloying elements in dilute Zr alloys
- Author
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Xiao-Gang Lu, Dane Morgan, Nan Zou, Hai-Jin Lu, Yan-Lin He, and Henry Wu
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Materials science ,Polymers and Plastics ,Thermodynamics ,FOS: Physical sciences ,02 engineering and technology ,Activation energy ,01 natural sciences ,Thermal expansion ,Metal ,Condensed Matter::Materials Science ,Impurity ,Vacancy defect ,Interstitial defect ,0103 physical sciences ,Irradiation ,010306 general physics ,Condensed Matter - Materials Science ,Metals and Alloys ,Materials Science (cond-mat.mtrl-sci) ,021001 nanoscience & nanotechnology ,Electronic, Optical and Magnetic Materials ,visual_art ,Ceramics and Composites ,visual_art.visual_art_medium ,Density functional theory ,0210 nano-technology - Abstract
Impurity diffusion in Zr is potentially important for many applications of Zr alloys, and in particular for their use of nuclear reactor cladding. However, significant uncertainty presently exists about which elements are vacancy vs. interstitial diffusers, which can inhibit understanding and prediction of their behavior under different temperature, irradiation, and alloying conditions. Therefore, first-principles calculations based on density functional theory (DFT) have been employed to predict the temperature-dependent dilute impurity diffusion coefficients for 14 substitutional alloying elements in hexagonal closed packed (HCP) Zr. Vacancy-mediated diffusion was modeled with the eight-frequency model. Interstitial contributions to diffusion are estimated from interstitial formation and select migration energies. Formation energies for each impurity in nine high-symmetry interstitial sites were determined, including significant effects of thermal expansion. The dominant diffusion mechanism of each solute in HCP Zr was identified in terms of the calculated vacancy-mediated activation energy, lower and upper bounds of interstitial activation energy, and the formation entropy, suggesting a rough relation with the metallic radii of solutes. It is predicted that Cr, Cu, V, Zn, Mo, W, Au, Ag, Al, Nb, Ta and Ti all diffuse predominantly by an interstitial mechanism, while Hf, Zr, and Sn are likely to be predominantly vacancy-mediated diffusers at low temperature and interstitial diffusers at high temperature, although the identification of mechanisms for these elements at high-temperature is quite uncertain., Comment: 27 pages, 6 figures
- Published
- 2018
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12. Structure of aqueous sodium acetate solutions by X-Ray scattering and density functional theory.
- Author
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Wang, Guangguo, Zhou, Yongquan, Lin, He, Jing, Zhuanfang, Liu, Hongyan, and Zhu, Fayan
- Subjects
SODIUM acetate ,DENSITY functional theory ,SMALL-angle X-ray scattering ,ION pairs ,X-ray scattering ,HYDRATION - Abstract
The structure of aq. sodium acetate solution (CH
3 COONa, NaOAc) was studied by X-ray scattering and density function theory (DFT). For the first hydrated layer of Na+ , coordination number (CN) between Na+ and O(W, I) decreases from 5.02 ± 0.85 at 0.976 mol/L to 3.62 ± 1.21 at 4.453 mol/L. The hydration of carbonyl oxygen (OC) and hydroxyl oxygen (OOC) of CH3 COO− were investigated separately and the OC shows a stronger hydration bonds comparing with OOC. With concentrations increasing, the hydration shell structures of CH3 COO− are not affected by the presence of large number of ions, each CH3 COO− group binds about 6.23 ± 2.01 to 7.35 ± 1.73 water molecules, which indicates a relatively strong interaction between CH3 COO− and water molecules. The larger uncertainty of the CN of Na+ and OC(OOC) reflects the relative looseness of Na-OC and Na-OOC ion pairs in aq. NaOAc solutions, even at the highest concentration (4.453 mol/L), suggesting the lack of contact ion pair (CIP) formation. In aq. NaOAc solutions, the so called "structure breaking" property of Na+ and CH3 COO− become effective only for the second hydration sphere of bulk water. The DFT calculations of CH3 COONa (H2 O)n=5–7 clusters suggest that the solvent-shared ion pair (SIP) structures appear at n = 6 and become dominant at n = 7, which is well consistent with the result from X-ray scattering. [ABSTRACT FROM AUTHOR]- Published
- 2020
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13. OH-initiated transformation and hydrolysis of aspirin in AOPs system: DFT and experimental studies
- Author
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Fan-ping Zhu, Xiaomin Sun, Lin He, Shaojie Ren, and Shu-Guang Wang
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Environmental Engineering ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Hydrolysis ,Transition state theory ,Reaction rate constant ,Computational chemistry ,Environmental Chemistry ,Organic chemistry ,Benzene ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Aspirin ,Hydroxyl Radical ,Hydrogen Peroxide ,021001 nanoscience & nanotechnology ,Pollution ,Bond-dissociation energy ,Kinetics ,chemistry ,Potential energy surface ,Degradation (geology) ,Density functional theory ,0210 nano-technology ,Oxidation-Reduction - Abstract
Advanced oxidation processes (AOPs) are widely used in wastewater treatment of pharmaceutical and personal care products (PPCPs). In this work, the OH-initiated transformation as well as the hydrolysis of a typical PPCPs, aspirin, was investigated using density functional theory (DFT) calculations and laboratory experiments. For DFT calculations, the frontier electron densities and bond dissociation energies were analyzed. Profiles of the potential energy surface were constructed, and all the possible pathways were discussed. Additionally, rate constants for each pathway were calculated with transition state theory (TST) method. UV/H2O2 experiments of aspirin were performed and degradation intermediates were identified by UPLC-MS-MS analysis. Different findings from previous experimental works were reported that the H-abstraction pathways at methyl position were dominated and OH-addition pathways on benzene ring were also favored. Meantime, hydroxyl ASA was confirmed as the main stable intermediate. Moreover, it was the first time to use DFT method to investigate the hydrolysis mechanisms of organic ester compound.
- Published
- 2017
14. Electronic-property dependent interactions between tetracycline and graphene nanomaterials in aqueous solution
- Author
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Mengyao Zhao, Zhen Qi, Fei-fei Liu, Jingcheng Hao, Yanhui Li, Muhammad Zaheer Afzal, Xue-Fei Sun, Shu-Guang Wang, Lin He, and Xiaomin Sun
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Environmental Engineering ,Inorganic chemistry ,Oxide ,02 engineering and technology ,Carbon nanotube ,010501 environmental sciences ,01 natural sciences ,Nanomaterials ,law.invention ,Physical Phenomena ,chemistry.chemical_compound ,Adsorption ,law ,Environmental Chemistry ,Graphite ,0105 earth and related environmental sciences ,General Environmental Science ,Aqueous solution ,Chemistry ,Graphene ,General Medicine ,Tetracycline ,021001 nanoscience & nanotechnology ,Nanostructures ,Models, Chemical ,Density functional theory ,0210 nano-technology ,Water Pollutants, Chemical - Abstract
Understanding the interactions between graphene nanomaterials (GNMs) and antibiotics in aqueous solution is critical to both the engineering applications of GNMs and the assessment of their potential impact on the fate and transport of antibiotics in the aquatic environment. In this study, adsorption of one common antibiotic, tetracycline, by graphene oxide (GO) and reduced graphene oxide (RGO) was examined with multi-walled carbon nanotubes (MWCNTs) and graphite as comparison. The results showed that the tetracycline adsorption capacity by the four selected carbonaceous materials on the unit mass basis followed an order of GO>RGO>MWCNTs>graphite. Upon normalization by surface area, graphite, RGO and MWCNTs had almost the same high tetracycline adsorption affinity while GO exhibited the lowest. We proposed π-electron-property dependent interaction mechanisms to explain the observed different adsorption behaviors. Density functional theory (DFT) calculations suggested that the oxygen-containing functional groups on GO surface reduced its π-electron-donating ability, and thus decreased the π-based interactions between tetracycline and GO surface. Comparison of adsorption efficiency at different pH indicated that electrostatic interaction also played an important role in tetracycline-GO interactions. Site energy analysis confirmed a highly heterogeneous distribution of the binding sites and strong tetracycline binding affinity of GO surface.
- Published
- 2016
15. Computational design of high energy density materials with zero oxygen balance: A combination of furazan and piperazine rings.
- Author
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Lin, He, Yang, Dong-Dong, Lou, Nan, Zhu, Shun-Guan, and Li, Hong-Zhen
- Subjects
FURAZANS ,PIPERAZINE ,DENSITY functionals ,THERMAL stability ,DETONATION waves - Abstract
The development of novel high energy density materials (HEDMs) with balanced detonation performance and sensitivity is a long-term goal in the energetic material field. In this work, by means of density functional theory, we systematically investigated physicochemical and energetic properties of three novel HEDMs constructed from furazan and piperazine frameworks with zero oxygen balance. Our results show that all these compounds have high densities (2.01–2.06 g·cm −3 ), positive heats of formation (94.48–1132.95 kJ·mol −1 ), excellent detonation performance (detonation velocity 9.24–9.85 km·s −1 ; detonation pressure 40.33–46.47 GPa) and acceptable impact sensitivity ( H 50 26–44 cm). However, based on bond dissociation energy (BDE) calculations, it is found that only compound 1 is thermally stable. Given these properties, it could be expected compound 1 is the most promising HEDM with acceptable sensitivity. Meanwhile, in this work, it is also demonstrated that the introduction of coupled heterocyclic backbone and zero oxygen balance is an effective strategy to achieve a good balance between detonation performance and sensitivity. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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16. Hexagonal close-packed nickel or Ni3C?
- Author
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Lin He
- Subjects
Materials science ,Condensed matter physics ,Condensed Matter::Other ,Hexagonal crystal system ,Close-packing of equal spheres ,chemistry.chemical_element ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Materials Science ,Nickel ,chemistry ,Lattice (order) ,Physics::Atomic and Molecular Clusters ,Density functional theory - Abstract
I compare the lattice spacings, synthesis conditions, and magnetic properties of hexagonal close-packed (hcp) Ni with Ni3C reported recently in the literature. The reported lattice spacings and synthesis conditions of hcp Ni and Ni3C are almost indiscernible. In addition, the magnetic properties of hcp Ni and Ni3C show similar characteristics. Based on my experimental investigations on Ni3C and the reported density functional theory calculations on the magnetic properties of hcp Ni, I present an explanation for understanding the discrepancies in the experimental results regarding hcp Ni reported in the literature.
- Published
- 2010
17. Structural, electronic, and optical properties of wurtzite and rocksalt InN under pressure
- Author
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Kostya Ostrikov, Lin He, Ming Xu, Ming-yao Xu, Shuyan Xu, and Man-Yi Duan
- Subjects
Indium nitride ,Materials science ,Condensed matter physics ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Materials Science ,chemistry.chemical_compound ,Lattice constant ,chemistry ,Structural stability ,High pressure ,Structural transition ,Density functional theory ,Electronic band structure ,Wurtzite crystal structure - Abstract
Structural stability, electronic, and optical properties of InN under high pressure are studied using the first-principles calculations. The lattice constants and electronic band structure are found consistent with the available experimental and theoretical values. The pressure of the wurtzite-to-rocksalt structural transition is 13.4 GPa, which is in an excellent agreement with the most recent experimental values. The optical characteristics reproduce the experimental data thus justifying the feasibility of our theoretical predictions of the optical properties of InN at high pressures.
- Published
- 2010
18. Magnetic properties of undoped Cu2O fine powders with magnetic impurities and/or cation vacancies
- Author
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Lin Guo, Hua Zhang, Chinping Chen, Yadong Li, Jing Lu, Lin He, and Lin Lai
- Subjects
Condensed Matter - Materials Science ,Materials science ,Magnetic moment ,Condensed matter physics ,Magnetism ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,Condensed Matter Physics ,Magnetic susceptibility ,Paramagnetism ,Condensed Matter::Materials Science ,Ferromagnetism ,Octahedron ,Diamagnetism ,General Materials Science ,Density functional theory - Abstract
Fine powders of micron- and submicron-sized particles of undoped Cu2O semiconductor, with three different sizes and morphologies have been synthesized by different chemical processes. These samples include nanospheres 200 nm in diameter, octahedra of size 1 micron, and polyhedra of size 800 nm. They exhibit a wide spectrum of magnetic properties. At low temperature, T = 5 K, the octahedron sample is diamagnetic. The nanosphere is paramagnetic. The other two polyhedron samples synthesized in different runs by the same process are found to show different magnetic properties. One of them exhibits weak ferromagnetism with T_C = 455 K and saturation magnetization, M_S = 0.19 emu/g at T = 5 K, while the other is paramagnetic. The total magnetic moment estimated from the detected impurity concentration of Fe, Co, and Ni, is too small to account for the observed magnetism by one to two orders of magnitude. Calculations by the density functional theory (DFT) reveal that cation vacancies in the Cu2O lattice are one of the possible causes of induced magnetic moments. The results further predict that the defect-induced magnetic moments favour a ferromagnetically coupled ground state if the local concentration of cation vacancies, n_C, exceeds 12.5%. This offers a possible scenario to explain the observed magnetic properties. The limitations of the investigations in the present work, in particular in the theoretical calculations, are discussed and possible areas for further study are suggested., Comment: 20 pages, 5 figures 2 tables, submitted to J Phys Condense Matter
- Published
- 2008
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19. A DFT-D Study on Structural, Electronic, Thermodynamic, and Mechanical Properties of HMX/MPNO Cocrystal under High Pressure.
- Author
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Lin, He, Chen, Jian-Fu, Cui, Yu-Ming, Zhang, Zhen-Jiang, Yang, Dong-Dong, Zhu, Shun-Guan, and Li, Hong-Zhen
- Subjects
- *
DENSITY functional theory , *THERMODYNAMICS , *MECHANICAL behavior of materials , *ELECTRIC properties of materials , *HIGH pressure (Technology) - Abstract
An investigation on the structural, electronic, thermodynamic, and mechanical properties of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)/2-methylpyridine-N-oxide (MPNO) cocrystal was carried out from 0 to 100 GPa by using a dispersion-corrected density functional theory (DFT-D) method. Our calculated crystal structure is in excellent agreement with experimental results at ambient pressure. Based on the analysis of lattice parameters, lattice angles, bond lengths, bond angles, and dihedral angles under high pressure, we observe that HMX molecules in the cocrystal bulk are seriously distorted but MPNO molecules remain relatively unchanged. Hydrogen bond lengths are greatly shortened under high pressure. In addition, with the increase in pressure, the bandgap decreases gradually. However, it increases suddenly at 70 GPa. Some important hydrogen bonds between HMX and MPNO are also observed in the density of states spectrum. According to the thermodynamic analysis, this cocrystal is more easily prepared under low pressure. Finally, we characterized its mechanical properties and the results show that this cocrystal is malleable in nature. We expect that this research can provide a fundamental basis for further HMX cocrystal design and preparation. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
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20. Synthesis, Characterization, Detonation Performance, and DFT Calculation of HMX/PNO Cocrystal Explosive.
- Author
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Lin, He, Chen, Jian-Fu, Zhu, Shun-Guan, Li, Hong-Zhen, and Huang, Yong
- Subjects
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DETONATION waves , *DENSITY functional theory , *PYRIDINE oxide , *X-ray diffraction , *SPACE groups - Abstract
A novel 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX)/pyridine-N-oxide (PNO) cocrystal at 1:1 molar ratio was synthesized by a solvent evaporation method, and its crystal structure was determined using X-ray diffraction (XRD). It crystallizes in the orthorhombic system with thePbcn space group and cell parametersa = 12.712(3)Å,b = 9.315(3)Å,c = 12.909(3)Å. In addition, detonation performance of this cocrystal was estimated. The predicted detonation velocity and detonation pressure of this cocrystal are 7.47 km/s and 23.20 GPa, respectively, suggesting that it is less powerful than β-HMX. Finally, density functional theory, involving binding energy, atoms in molecule (AIM) theory, natural bond orbital (NBO) analysis, band structure, and density of states, was adopted to characterize the driving forces for the formation of this cocrystal. The results show that driving forces are dominated by the interactions between O atoms of PNO and methylene groups of HMX. It is expected that this research provides some bases for further HMX cocrystal design and preparation. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
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21. Formation of the first aromatic ring through the self-recombination of but-1-ene-3-yne with H-assistance in combustion.
- Author
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Lin, He, Liu, Peng, He, Zhenwu, Zhang, Yiran, Guan, Bin, and Huang, Zhen
- Subjects
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DEHYDROGENATION , *ENYNES , *TRANSITION state theory (Chemistry) , *AROMATIC compounds , *COMBUSTION , *DENSITY functional theory , *POTENTIAL energy surfaces - Abstract
The free H atom existing in flame plays vital role in combustion chemistry. As a continuation of our previous study, the possibility of forming the first aromatic ring via the self-recombination reaction of but-1-ene-3-yne (C 4 H 4 ) with H-assistance was investigated in the present study. The potential energy surfaces were calculated with density functional theory and indicate that the C 4 H 4 + C 4 H 4 (+H) reaction can generate 6-membered ring, ring-opening and 5-membered ring structures. The zero point energies of the investigated molecules were obtained at CBS-QB3 level, and the reliability of energy calculation was checked with T1 diagnostic. The rate coefficients were calculated using conventional transition state theory (TST) and Rice-Ramsperger-Kassel-Marcus (RRKM) theory with solving master equation. By comparing the rate coefficients and branching ratio of product, we found that the CS10 + H, CS16, CS19 and CS38 are the dominant product of C 4 H 4 + C 4 H 4 (+H) reaction in the temperature range of 500–2500 K, and the formation of other products can be ignored. The self-dehydrogenation reaction is the essential step in the formation of the main product CS10 + H. Similar to H-transfer reactions, the self-dehydrogenation reactions are found to be sensitive to the molecular structure in terms of the energy barrier. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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22. The mechanism and kinetic analysis of C4H4 + C4H4 (but-1-ene-3-yne) reaction with features of H-transfer in combustion.
- Author
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Liu, Peng, Lin, He, He, Zhenwu, Zhang, Yiran, Guan, Bin, and Huang, Zhen
- Subjects
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CARBON isotopes , *BIOMASS burning , *HYDROGEN production , *CHEMICAL reactions , *DENSITY functional theory , *STYRENE - Abstract
Detailed mechanisms of C 4 H 4 + C 4 H 4 reaction were investigated by accurate ab initio density functional theory B3LYP/6-311 + G(d,p) calculations, as well as CBS-QB3 calculations. It was found that styrene, phenylacetylene and 5-membered ring structure can be formed in C 4 H 4 + C 4 H 4 reaction through five parallel and competing pathways. Three pathways are featured with H-transfer and dehydrogenation reactions, and the other two pathways are characterized with the forming and breaking of C–C bond. The H-transfer reactions play a vital role in stabilizing intermediates. It was found that the H-transfer reaction is significantly dependent on the relative position of two C atoms, the degree of saturation of the second C atom, and the electronic environment of molecule. Generally, an ortho-position unsaturated C atom with relative small positive atomic charge is preferable in H-transfer reaction. The yield of products and reaction rate coefficients were evaluated by using Rice−Ramsperger−Kassel−Marcus theory with solving master equation at different combustion temperatures and pressures ( T = 800–2500 K, P = 0.1–10 atm). The kinetic results indicate that styrene is the dominant product and the formation of other two products can be ignored when temperature is lower than 1600 K. The formations of phenylacetylene and 5-membered ring structure are only facilitated at higher temperature, but dependent on the combustion pressure. Specifically, phenylacetylene is favored by higher pressure and higher temperature, while 5-membered ring structure is favored by lower pressure and higher temperature. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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23. Investigatingthe Role of CH2Radicals in the HACA Mechanism.
- Author
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Liu, Peng, Lin, He, Yang, Yang, Shao, Can, Guan, Bin, and Huang, Zhen
- Subjects
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RADICALS (Chemistry) , *METHYLENE blue , *DENSITY functional theory , *APPROXIMATION theory , *INTRAMOLECULAR catalysis - Abstract
Detailedmechanisms of PAH growth involving methylene (CH2) werestudied using accurate ab initio density functional theory B3LYP/6-311+G(d,p)calculations, as well as approximate QCISD(T,full)/6-311++G(3df,2pd)calculations. The PAH growth can be divided into five essential reactionsteps, namely, addition C2H2→ intramolecularhydrogen migration → addition CH2→ cyclization→ H-elimination. The aliphatic species of indene and 1H-phenaleneare found in the pathways of PAH growth, which is in accord with theexperimental results that reveal the formation of aliphatic speciesin flames. It was found that the simultaneous removal of two H atomsin one reaction step is feasible in PAH evolution, and this can reasonablyinterpret the absence of a H atom in the post-flame region. The correspondingrate coefficients at 1 atm were evaluated by using TST and RRKM theoryby solving the master equations in the temperature range of 500–2500K. The calculated branching ratios suggest that the pathways involvingCH2are competitive in PAH growth. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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24. New Insightsinto Thermal Decomposition of PolycyclicAromatic Hydrocarbon Oxyradicals.
- Author
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Liu, Peng, Lin, He, Yang, Yang, Shao, Can, Gu, Chen, and Huang, Zhen
- Subjects
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POLYCYCLIC aromatic hydrocarbons , *THERMAL analysis , *CHEMICAL decomposition , *RADICALS (Chemistry) , *DENSITY functional theory , *TEMPERATURE effect - Abstract
Thermaldecompositions of polycyclic aromatic hydrocarbon (PAH)oxyradicals on various surface sites including five-membered ring,free-edge, zigzag, and armchair have been systematically investigatedby using ab initio density functional theory B3LYP/6-311+G(d,p) basisset. The calculation based on Hückel theory indicates thatPAHs (3H-cydopenta[a]anthracene oxyradical) withoxyradicals on a five-membered ring site have high chemical reactivity.The rate coefficients of PAH oxyradical decomposition were evaluatedby using Rice–Ramsperger–Kassel–Marcus theoryand solving the master equations in the temperature range of 1500–2500K and the pressure range of 0.1–10 atm. The kinetic calculationsrevealed that the rate coefficients of PAH oxyradical decompositionare temperature-, pressure-, and surface site-dependent, and the oxyradicalon a five-membered ring is easier to decompose than that on a six-memberedring. Four-membered rings were found in decomposition of the five-memberedring, and a new reaction channel of PAH evolution involving four-memberedrings is recommended. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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25. Theoretical Investigation of Pyridine Derivatives as High Energy Materials.
- Author
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Lin, He, Chen, Peng-Yuan, Zhu, Shun-Guan, Li, Kun, Li, Hong-Zhen, and Peng, Xin-Hua
- Subjects
- *
PYRIDINE derivatives , *GAS phase reactions , *RING formation (Chemistry) , *NUMERICAL calculations , *HEAT of formation , *THERMAL stability , *ENERGY density - Abstract
In this work, properties of polynitro-bridged pyridine derivatives were systemically studied at the B3LYP/6-31G(d) level. Gas-phase heats of formation (HOFs) for the designed compounds were calculated using isodesmic reactions, and their solid-phase HOFs were estimated using the Politzer approach. All designed compounds possess large solid-phase HOFs, larger than 700 kJ/mol. Based on the predicted crystal densities, solid-phase HOFs, and chemical energies, detonation properties were evaluated by means of Kamlet-Jacobs empirical equations. The results show that detonation velocities and pressures of all of the designed compounds are above 9.30 km/s and 40.00 GPa, respectively. In addition, bond dissociation energy (BDE) was employed to investigate their thermal stability. Considering solid-phase HOFs, detonation performance, and thermal stability, most of the designed compounds meet the requirements of high energy density materials (HEDMs). [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
26. Structure and detonation performance of a novel HMX/LLM-105 cocrystal explosive.
- Author
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Lin, He, Zhu, Shun ‐ Guan, Li, Hong ‐ Zhen, and Peng, Xin ‐ Hua
- Subjects
- *
CRYSTAL structure , *DENSITY functional theory , *CHEMICAL bonds , *INTERMOLECULAR interactions , *THERMODYNAMICS , *DISSOCIATION (Chemistry) - Abstract
interactions and properties of octahydro-1,3,5,7-tetranitro-1,3,5,7- tetrazocine (HMX) / 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) cocrystal were studied by using the dispersion-corrected density functionals (ωB97XD, B97D) and meta-hybrid functional (M062x) methods. Binding energies, heats of formation, thermodynamic properties, atoms in molecules, and natural bond orbital analysis were performed to investigate HMX/LLM-105 complexes. Results show that the main interactions between HMX and LLM-105 are CH...O, NH...O, N...O, and O...O interactions. In addition, Monte Carlo simulation was employed to predict the crystal structure of HMX/LLM-105 cocrystal. The HMX/LLM-105 cocrystal is most likely to crystallize in C2/c space group, and its corresponding cell parameters are Z = 8, a = 41.63 Å, b = 6.77 Å, c = 45.63 Å, ß = 164.55°, and ρ = 1.99 g/cm3. Detonation velocity and pressure of HMX/LLM-105 cocrystal are 8.95 km/s, 37.69GPa, a little lower than those of HMX (9.10 km/s, 37.76GPa). However, according to the net charges of nitro group, HMX/LLM-105 cocrystal exhibits less sensitive than HMX. Finally, bond dissociation energy calculation shows that HMX/LLM-105 complexes are thermally stable. Considering , sensitivity, and detonation performance, HMX/LLM-105 cocrystal meets the requirements of insensitive high energy density materials. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
27. Synthesis, characterization, AIM and NBO analysis of HMX/DMI cocrystal explosive.
- Author
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Lin, He, Zhu, Shun-Guan, Li, Hong-Zhen, and Peng, Xin-Hua
- Subjects
- *
CRYSTAL structure , *BINDING energy , *X-ray diffraction , *HYDROGEN bonding , *METHYLENE group , *HOST-guest chemistry - Abstract
Highlights: [•] HMX/DMI cocrystal explosive was synthesized and characterized by using X-ray single crystal diffraction. [•] Binding energies, atoms in molecules (AIM), natural bond orbital (NBO), band structure and density of states were employed to investigate host–guest interactions. [•] Results show that the main driving forces is hydrogen bondings between methylene group of HMX and O atoms of DMI. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
28. Computational study of pyrazine-based derivatives and their N-oxides as high energy materials.
- Author
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Lin, He, Chen, Peng ‐ Yuan, Zhu, Shun ‐ Guan, Zhang, Lin, Peng, Xin ‐ Hua, and Li, Hong ‐ Zhen
- Subjects
- *
COMPUTATIONAL chemistry , *PYRAZINES , *HEAT of formation , *ELECTRONIC structure , *THERMAL stability , *HETEROCYCLIC compounds , *DISSOCIATION (Chemistry) - Abstract
Gas-phase heats of formation (HOF), solid-phase HOF, detonation properties, electronic structure and thermal stability for a series of polynitro pyrazine derivatives containing three heterocycles have been investigated using density functional theory. It is found that the nitro group is an efficient tool to improve HOF of pyrazine derivatives. Furthermore, detonation velocities and detonation pressures of these compounds are evaluated using empirical Kamlet-Jacobs equations. As a result, it indicates that the nitro group is useful to enhance detonation properties. Detonation velocities of five compounds are 9.67, 9.20, 9.74, 9.76 and 9.87 km/s, respectively, which are significantly larger than that of HMX (9.10 km/s). Bond dissociation energy is also performed to investigate their thermal stability, showing that thermal stability of these compounds is little affected by nitro groups or the position of substituent groups. Considering solid-phase HOF, detonation properties and thermal stability, some of pyrazine derivatives can be potential high energy density materials. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
29. Theoretical design of pyrazine-based high energy materials.
- Author
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Lin, He, Chen, Peng-Yuan, Zhu, Shun-Guan, Zhang, Lin, Peng, Xin-Hua, Li, Kun, and Li, Hong-Zhen
- Subjects
PYRAZINE derivatives ,CHEMICAL structure ,PERFORMANCE evaluation ,THERMAL stability ,NITROGEN dioxide ,COMPUTATIONAL chemistry - Abstract
Highlights: [•] The pyrazine based compounds designed to estimate structure–performance relationship. [•] Pyrazine derivatives exhibit better detonation performance. [•] Bond dissociation energies of weakest N–NO
2 bonds calculated to predict thermal stability. [ABSTRACT FROM AUTHOR]- Published
- 2013
- Full Text
- View/download PDF
30. Theoretical study on molecular structures, intramolecular proton transfer reaction, and solvent effects of 1-phenyl-3-methyl-4-(6-hydro-4-amino-5-sulfo-2,3-pyrazine)-pyrazole-5-one
- Author
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Lin, He, Wu, Dong-ling, Liu, Lang, and Jia, Dian-zeng
- Subjects
- *
CHEMICAL reactions , *MOLECULAR structure , *HYDROGEN , *MAGNETIC dipoles - Abstract
Abstract: The molecular structures and intramolecular proton transfer reaction of 1-phenyl-3-methyl-4-(6-hydro-4-amino-5-sulfo-2,3-pyrazine)-pyrazole-5-one have been investigated with both ab initio method and the density functional theory. The solvent effects are simulated using the self-consistent reaction field (SCRF) method within the framework of the polarizable continuum model (PCM). The results show that the computed geometrical parameters at the B3LYP levels are in better agreement with experimental values than those at the RHF levels, and the choice of functional in DFT plays an important role in describing the title compound. It is found that strong hydrogen bonds (O–H···N and O···H–N) exist in the title compound, and in the proton transfer process, the O–H bond is broken while the N–H bond is formed. In addition, the order of stability of the isomers remains the same in different solvents, while the barrier height of the proton transfer reaction and dipole moments for the title compound grow with the increase of the solvent polarity. Eventually, the NBO analysis shows that the strength of the hydrogen bond reduces with the increase of the solvent polarity. [Copyright &y& Elsevier]
- Published
- 2008
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31. One‐Step Controllable Synthesis of Catalytic Ni4Mo/MoOx/Cu Nanointerfaces for Highly Efficient Water Reduction.
- Author
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An, Yiming, Long, Xia, Ma, Ming, Hu, Jue, Lin, He, Zhou, Dan, Xing, Zheng, Huang, Bolong, and Yang, Shihe
- Subjects
HYDROGEN evolution reactions ,OXYGEN evolution reactions ,CHARGE exchange ,ELECTRON configuration ,DENSITY functional theory ,METAL catalysts ,CHARGE transfer - Abstract
Currently, in addition to the electroactive non‐noble metal water‐splitting electrocatalysts, a scalable synthetic route and simple activity enhancement strategy is also urgently needed. In particular, the well‐controlled synthesis of the well‐recognized metal–metal nanointer face in a single step remains a key challenge. Here, the synthesis of Cu‐supported Ni4Mo nanodots on MoOx nanosheets (Ni4Mo/MoOx) with controllable Ni4Mo particle size and d‐band structure is reported via a facile one‐step electrodeposition process. Density functional theory (DFT) calculations reveal that the active open‐shell effect from Ni‐3d‐band optimizes the electronic configuration. The Cu‐substrate enables the surface Ni–Mo alloy dots to be more electron‐rich, forming a local connected electron‐rich network, which boosts the charge transfer for effective binding of O‐related species and proton–electron charge exchange in the hydrogen evolution reaction. The Cu‐supported Ni4Mo/MoOx shows an ultralow overpotential of 16 mV at a current density of 10 mA cm−2 in 1 m KOH, demonstrating the smallest overpotential, at loadings as low as 0.27 mg cm−2, among all non‐noble metal catalysts reported to date. Moreover, an overpotential of 105 mV allows it to achieve a current density of 250 mA cm−2 in 70 °C 30% KOH, a remarkable performance for alkaline hydrogen evolution with competitive potential for applications. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
32. Entrapment of polysulfides by Al2O3 modified separator for high energy Li–S redox flow batteries.
- Author
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Yan, Dengxin, Huang, Yudai, Fan, Chengwei, Wang, Xingchao, Yan, Junfeng, Lin, He, Jia, Dianzeng, Zong, Jun, Wang, Wei, and Wu, Guangming
- Subjects
- *
POLYSULFIDES , *ALUMINUM oxide , *MAGNETIC separators , *OXIDATION-reduction reaction , *DENSITY functional theory , *FLOW batteries - Abstract
Abstract Although the lithium–sulfur redox flow batteries (Li–S RFBs) are promising candidates for large-scale energy storage application because of outstanding solubility of long-chain polysulfides and low cost of sulfur. Their implementation has been impeded by multiple challenges, especially the dissolution of intermediate lithium polysulfide (Li 2 S X) species into the electrolyte. Here, Al 2 O 3 particles decorated polypropylene separator (PP-Al 2 O 3) was investigated. The results show that the thermal stability and the electrolyte wettability of the PP-Al 2 O 3 separator are improved obviously. When the PP-Al 2 O 3 separator is used for Li–S RFB, the cyclic stability and rate capability of the battery are enhanced. The PP-Al 2 O 3 separators are effective in improving the initial discharge capacity of Li–S RFBs from 27.5 to 91.5 mAh g−1 at 6.25 mA cm−2. The reason could be ascribed to that the polar Al 2 O 3 coating not only alleviates the shuttle effect by chemical interaction and physical barrier, but also facilitates Li-ion migration by favorable electrolyte wettability. In addition, theoretical calculations reveal that chemical bonds are formed between Al 2 O 3 and Li 2 S X. This work provides the rational design strategy for functional separators at cell scale to effective utilizing of active sulfur and retarding of polysulfides, which offers the possibility of high energy density Li–S RFBs with long cycling life. Highlights • Al 2 O 3 layer can enhance the thermal stability and the electrolyte wettability. • PP-Al 2 O 3 separator is used as a shuttle inhibitor for Li–S RFBs. • Li–S RFBs using PP-Al 2 O 3 separator show excellent electrochemical performance. • The results of XPS show that the Li–O is formed between the Li 2 S X and the Al 2 O 3. • DFT calculations reveal the interaction between Li 2 S X and Al 2 O 3. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
33. Degenerating effect of transformation and loss of active sites on NH3-SCR activity during the hydrothermal aging process for Cu-SSZ-13 molecular sieve catalyst.
- Author
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Guan, Bin, Zhou, Jiefei, Liu, Ziqian, Wu, Xingze, Wei, Yanfei, Guo, Jiangfeng, Jiang, Han, Lin, He, and Huang, Zhen
- Subjects
- *
MOLECULAR sieves , *CATALYSTS , *ION-permeable membranes , *COPPER , *ION exchange (Chemistry) - Abstract
• Exploring the effects of Si/Al ratio and Cu/Al ratio on catalyst activity. • Researching the sensitivity of catalyst to aging time and aging temperature. • Explaining the reasons for the degradation of catalyst performance caused by hydrothermal aging. • Using in-situ DRIFTS experiments and DFT molecular simulation calculations to explore the mechanism. • Completing the hydrothermal aging mechanism of Cu-SSZ-13 small pore molecular sieve catalyst. A series of Cu-SSZ-13 small-pore molecular sieve catalysts are prepared by the ion-exchange method, analyzed, and tested by changing the synthesis ratio, and performing hydrothermal aging treatment under various aging conditions to explain the degree of influence. The investigations are carried out to reveal that when the Si/Al ratio is 10, the catalyst has the best comprehensive performance and ZCuOH sites are more prone to transformation and loss than Z 2 Cu sites during the hydrothermal aging process. In-situ DRIFTS experiments and DFT molecular simulation calculations are used to explain the reasons for the degradation of catalytic performance caused by the hydrothermal aging, which completes the study of the hydrothermal aging mechanism for Cu-SSZ-13 molecular sieve catalysts. The result shows that Z 2 Cu active sites exhibit better hydrothermal aging resistance than ZCuOH, the catalyst is more sensitive to aging temperatures than durations, and its limit of the aging temperature is about 850 ℃. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
34. Ion-exchange-induced high-performance of inverse spinel Mg2VO4 for aqueous zinc-ion batteries.
- Author
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Zhang, Yu, Xu, Jing, Liu, Chenfan, Cheng, Huanhuan, Cai, Xuanxuan, Jia, Dianzeng, and Lin, He
- Subjects
- *
ACTIVATION energy , *SPINEL , *DIFFUSION kinetics , *MOLECULAR dynamics , *DENSITY functional theory , *ELECTROSTATIC interaction , *ION exchange (Chemistry) - Abstract
Aqueous zinc-ion batteries (ZIBs) stand out among the next generation of large-scale energy storage devices owing to their overwhelming advantages of high safety, low-cost and environmental benefit. However, this promising technology is still plagued by lack of superior cathode materials due to the inherent slow diffusion kinetics. Herein, with theoretical calculations as a guide, we proposed a new strategy to promote Zn2+ migration based on ion-exchange. Specifically, we first find the tendency of Mg2+ and Zn2+ exchange in inverse-spinel Mg 2 VO 4 by molecular dynamics simulations. Density functional theory (DFT) calculations reveal that this ion exchange can moderate the electrostatic interaction between Zn2+ and host material, and reduce the diffusion energy barrier of Zn2+. Meanwhile, the Mg2+ of host leaves vacancies when it is detached, and both contribute to the improvement of Zn2+ diffusion kinetics. Based on theoretical calculations, we for the first time used a simple sol-gel method to synthesize inverse-spinel Mg 2 VO 4 as an aqueous ZIBs cathode. As predicted in theoretical calculations, after optimization of Zn2+ and Mg2+ exchange, the Mg 2 VO 4 /Zn system demonstrates rewarding cyclic stability. This work provides a new insight into the development of cathode materials for high-performance ZIBs. • Theoretical calculations guide experiments. • An ion exchange mechanism is proposed. • The ion exchange mechanism is favorable for zinc ion diffusion. • Mg 2 VO 4 is evaluated as a cathode for zinc-ion batteries for the first time. • The ion-exchange optimized Mg 2 VO 4 shows excellent performance and applicability. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. Density functional theory researches for atomic structure, properties prediction, and rational design of selective catalytic reduction catalysts: Current progresses and future perspectives.
- Author
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Guan, Bin, Jiang, Han, Wei, Yanfei, Liu, Ziqian, Wu, Xingze, Lin, He, and Huang, Zhen
- Subjects
- *
DENSITY functional theory , *MOLECULAR dynamics , *ATOMIC structure , *CATALYTIC reduction , *QUANTUM chemistry - Abstract
• Using DFT to explore the adsorption of gas molecules on catalysts surface. • Investigating the characteristics of catalytic active sites and reaction mechanisms through DFT. • Explaining the catalysts poisoning process through DFT. • Illustrating the catalysts hydrothermal aging process through DFT. • Catalysts modification and design based on DFT. In recent years, molecular simulation methods, especially density functional theory (DFT), have attracted much attention and been widely used to study the SCR reaction theoretically and microscopically. This review discusses the application of DFT in SCR research from the aspects of surface adsorption, active site characteristics, reaction mechanism, poisoning mechanism, and hydrothermal aging mechanism to illustrate the status of quantum chemical computing in this field. The gas adsorption includes the adsorption of nitrogen oxides, ammonia, and their co-adsorption. The site and mechanism include the properties of different active sites, intermediate species analysis, and reaction mechanism research. The poisoning includes related research on sulfur poisoning and alkali metal poisoning. The hydrothermal aging includes research on dealumination and loss of active sites. It is demonstrated that the catalysts can be improved and rationally designed based on quantum chemistry calculations. Finally, the application of DFT in this field is evaluated, hoping to provide good suggestions for DFT calculations to further understand the more complicated reaction mechanisms and optimally design the SCR catalysts. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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