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Fernandes GFS, Machado FBC, Ferrão LFA. Electronic Structure of Small Isolated and Supported Manganese Oxide Clusters. J Phys Chem A 2023; 127:8773-8781. [PMID: 37839039 DOI: 10.1021/acs.jpca.3c01644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
In the present work, possible molecular models of the isolated manganese oxides and supported Mn3Ox/Al2O3 structures were built based on small clusters of passivated MnOx. The support was represented as a simplified model of the alumina tetramer cluster based on small fragments of AlOxHy. Combinations of MnOxHy and AlOxHy clusters were made to form both the isolated and supported manganese oxides clusters. The electronic structure of these systems was characterized by ab initio methods (DFT and CASPT2). It was observed that the vertical excitation energy of the isolated and supported Mn3OxHy clusters is significantly lower than that of the alumina cluster model, while both the isolated and supported Mn3OxHy wave function characters are qualitatively similar with respect to the ground state and electronic transition processes, suggesting that the alumina cluster behaves as an inert support, since there is little contribution of this component in the description of the low-lying electronic states. The present study also reports for the first time the spectroscopic parameters of several clusters containing the manganese transition metal atom.
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Affiliation(s)
- Gabriel F S Fernandes
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos,SP 12228-900, Brasil
| | - Francisco B C Machado
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos,SP 12228-900, Brasil
| | - Luiz F A Ferrão
- Departamento de Química, Instituto Tecnológico de Aeronáutica, São José dos Campos,SP 12228-900, Brasil
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2
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Influence of the metal − support and metal − metal interactions on Pd nucleation and NO adsorption in a Pd4/γ-Al2O3 (110D) model. J Mol Model 2022; 28:394. [DOI: 10.1007/s00894-022-05374-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 11/01/2022] [Indexed: 11/22/2022]
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3
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Weber NH, Delva CS, Stockenhuber SP, Grimison CC, Lucas JA, Mackie JC, Stockenhuber M, Kennedy EM. Modeling and Experimental Study on the Thermal Decomposition of Perfluorooctanesulfonic Acid (PFOS) in an α-Alumina Reactor. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c00339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nathan H. Weber
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Cameron S. Delva
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Sebastian P. Stockenhuber
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | | | - John A. Lucas
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - John C. Mackie
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Michael Stockenhuber
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - Eric M. Kennedy
- Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, New South Wales 2308, Australia
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5
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Escatllar AM, Lazaukas T, Woodley SM, Bromley ST. Structure and Properties of Nanosilicates with Olivine (Mg 2SiO 4) N and Pyroxene (MgSiO 3) N Compositions. ACS EARTH & SPACE CHEMISTRY 2019; 3:2390-2403. [PMID: 32055761 PMCID: PMC7009040 DOI: 10.1021/acsearthspacechem.9b00139] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/25/2019] [Accepted: 07/18/2019] [Indexed: 05/26/2023]
Abstract
Magnesium-rich silicates are ubiquitous both terrestrially and astronomically, where they are often present as small particles. Nanosized Mg-rich silicate particles are likely to be particularly important for understanding the formation, processing, and properties of cosmic dust grains. Although astronomical observations and laboratory studies have revealed much about such silicate dust, our knowledge of this hugely important class of nanosolids largely rests on top-down comparisons with the properties of bulk silicates. Herein, we provide a foundational bottom-up study of the structure and properties of Mg-rich nanosilicates based on carefully procured atomistic models. Specifically, we employ state-of-the-art global optimization methods to search for the most stable structures of silicate nanoclusters with olivine (Mg2SiO4) N and pyroxene (MgSiO3) N compositions with N = 1-10. To ensure the reliability of our searches, we develop a new interatomic potential that has been especially tuned for nanosilicates. Subsequently, we refine these searches and calculate a range of physicochemical properties of the most stable nanoclusters using accurate density functional theory based electronic structure calculations. We report a detailed analysis of structural and energy properties, charge distributions, and infrared vibrational spectra, where in all cases we compare our finding for nanosilicates with those of the corresponding bulk silicate crystals. For most properties considered, we find large differences with respect to the bulk limit, underlining the limitations of a top-down approach for describing these species. Overall, our work provides a new platform for an accurate and detailed understanding of nanoscale silicates.
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Affiliation(s)
- Antoni Macià Escatllar
- Departament
de Ciència de Materials i Química Física &
Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, E-08028 Barcelona, Spain
| | - Tomas Lazaukas
- Department
of Chemistry, University College, London WC1H 0AJ, U.K.
| | - Scott M. Woodley
- Department
of Chemistry, University College, London WC1H 0AJ, U.K.
| | - Stefan T. Bromley
- Departament
de Ciència de Materials i Química Física &
Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, E-08028 Barcelona, Spain
- Institució
Catalana de Recerca i Estudis Avançats (ICREA), E-08010 Barcelona, Spain
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Wang G, Xiao Y, Song Y, Zhou H, Tian Q, Li F. A density functional study on the aggregation of alumina clusters. RESEARCH ON CHEMICAL INTERMEDIATES 2017. [DOI: 10.1007/s11164-016-2708-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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8
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Assaf NW, Altarawneh M, Radny MW, Al-Nu'airat J, Dlugogorski BZ. Formation of environmentally-persistent free radicals (EPFR) on α-Al2O3 clusters. RSC Adv 2017. [DOI: 10.1039/c7ra09527a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
This study explores the role of alumina clusters assume an important role in catalyzing formation of notorious environmental persistent free radicals (EPFRs).
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Affiliation(s)
- Niveen W. Assaf
- School of Engineering and Information Technology
- Murdoch University
- Perth
- Australia
| | | | - Marian W. Radny
- School of Mathematical and Physical Sciences
- The University of Newcastle
- Australia
| | - Jomana Al-Nu'airat
- School of Engineering and Information Technology
- Murdoch University
- Perth
- Australia
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9
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Álvarez-Barcia S, Flores JR. Can alumina particles be formed from Al hydroxide in the circumstellar media? A first-principles chemical study. Phys Chem Chem Phys 2016; 18:6103-12. [PMID: 26846699 DOI: 10.1039/c5cp06676j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
AlOH has been detected in the circumstellar envelope of an oxygen-rich supergiant star (VY CMa) and is an abundant Al-containing system. Water molecules have also been detected, even in a vibrationally excited state. The coalescence of AlOH units and other processes involving AlOH could be the source of alumina-type particles. The results indicate that the formation of (AlOH)2 dimers is barrier-free but (HAlO)2 systems are far more stable. The (AlOH)2 → (HAlO)2 transformation is hindered by substantial energy barriers but is probably moderately fast at very high temperatures. Water catalysis by relay (or Grotthuss-like) mechanisms substantially reduces those barriers to the point that, in the (AlOH)2·(H2O)2 system, the critical transition states lie clearly below 2AlOH + 2H2O. A surface or nucleation environment may favor the (AlOH)2 → (HAlO)2 conversion as to be kinetically competitive with water elimination ((AlOH)2·(H2O)n → (AlOH)2 + nH2O) in the hydrated systems. The hydrated (HAlO)2 structures can easily produce very stable hydrogenated Al2O3 and Al2O4 frames, which, to the same extent, can eliminate molecular hydrogen by exothermic processes. The remaining hydrogen atoms are exterior to the frames and perhaps could be removed by reaction with atomic hydrogen. The possible role of the coalescence of the undetected HAl(OH)2 and Al(OH)2 or AlO2H molecules is discussed. Al(OH)2 can easily be formed by reaction of AlO with a water molecule in exothermic barrier-free processes.
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Affiliation(s)
- Sonia Álvarez-Barcia
- Departamento de Química Física, Facultad de Química, Universidade de Vigo, E-36310-Vigo, Pontevedra, Spain
| | - Jesús R Flores
- Departamento de Química Física, Facultad de Química, Universidade de Vigo, E-36310-Vigo, Pontevedra, Spain
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Li YJ, Brndiar J, Naitoh Y, Sugawara Y, Štich I. Atomic force microscopy identification of Al-sites on ultrathin aluminum oxide film on NiAl(110). NANOTECHNOLOGY 2015; 26:505704. [PMID: 26588437 DOI: 10.1088/0957-4484/26/50/505704] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Ultrathin alumina film formed by oxidation of NiAl(110) was studied by non-contact atomic force microscopy in an ultra high vacuum at room temperature with the quest to provide the ultimate understanding of structure and bonding of this complicated interface. Using a very stiff Si cantilever with significantly improved resolution, we have obtained images of this system with unprecedented resolution, surpassing all the previous results. In particular, we were able to unambiguously resolve all the differently coordinated aluminum atoms. This is of importance as the previous images provide very different image patterns, which cannot easily be reconciled with the existing structural models. Experiments are supported by extensive density functional theory modeling. We find that the system is strongly ionic and the atomic force microscopy images can reliably be understood from the electrostatic potential which provides an image model in excellent agreement with the experiments. However, in order to resolve the finer contrast features we have proposed a more sophisticated model based on more realistic approximants to the incommensurable alumina interface.
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Affiliation(s)
- Yan Jun Li
- Department of Applied Physics, Osaka University, Japan
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11
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Lam J, Amans D, Dujardin C, Ledoux G, Allouche AR. Atomistic Mechanisms for the Nucleation of Aluminum Oxide Nanoparticles. J Phys Chem A 2015. [DOI: 10.1021/acs.jpca.5b05829] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Julien Lam
- Université Lyon 1, F-69622 Villeurbanne, France, UMR5306 CNRS,
Institut Lumiere Matiere, PRES-Université de Lyon, F-69361 Lyon, France
| | - David Amans
- Université Lyon 1, F-69622 Villeurbanne, France, UMR5306 CNRS,
Institut Lumiere Matiere, PRES-Université de Lyon, F-69361 Lyon, France
| | - Christophe Dujardin
- Université Lyon 1, F-69622 Villeurbanne, France, UMR5306 CNRS,
Institut Lumiere Matiere, PRES-Université de Lyon, F-69361 Lyon, France
| | - Gilles Ledoux
- Université Lyon 1, F-69622 Villeurbanne, France, UMR5306 CNRS,
Institut Lumiere Matiere, PRES-Université de Lyon, F-69361 Lyon, France
| | - Abdul-Rahman Allouche
- Université Lyon 1, F-69622 Villeurbanne, France, UMR5306 CNRS,
Institut Lumiere Matiere, PRES-Université de Lyon, F-69361 Lyon, France
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12
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Neogi SG, Chaudhury P. Structure, electronic properties and vibrational spectra of (MgF2)nclusters through a combination of genetic algorithm and DFT-based approach. Mol Phys 2015. [DOI: 10.1080/00268976.2015.1059508] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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13
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Structures, stabilities and properties of hollow (Al2O3)n clusters (n=10, 12, 16, 18, 24 and 33): Studied with density functional theory. COMPUT THEOR CHEM 2015. [DOI: 10.1016/j.comptc.2015.03.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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14
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Cheng H, Cheng L. Secondary bonding networks in small (HgS)n clusters: A theoretical investigation. COMPUT THEOR CHEM 2015. [DOI: 10.1016/j.comptc.2015.02.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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15
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Feng Y, Cheng L. Structural evolution of (Au2S)n (n = 1–8) clusters from first principles global optimization. RSC Adv 2015. [DOI: 10.1039/c5ra06137g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
First principles global optimization reveals the structural evolution and novel geometries of (Au2S)n nanoclusters at n = 1–8.
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Affiliation(s)
- Yiqun Feng
- Department of Chemistry
- Anhui University
- Hefei
- China
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16
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Moniz SJA, Shevlin SA, An X, Guo ZX, Tang J. Fe2O3-TiO2Nanocomposites for Enhanced Charge Separation and Photocatalytic Activity. Chemistry 2014; 20:15571-9. [DOI: 10.1002/chem.201403489] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Indexed: 11/10/2022]
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17
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Yuan HK, Chen H, Tian CL, Kuang AL, Wang JZ. Density functional calculations for structural, electronic, and magnetic properties of gadolinium-oxide clusters. J Chem Phys 2014. [DOI: 10.1063/1.4871410] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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18
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Alnemrat S, Hooper JP. Oxidation of ligand-protected aluminum clusters: an ab initio molecular dynamics study. J Chem Phys 2014; 140:104313. [PMID: 24628175 DOI: 10.1063/1.4867467] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report Car-Parrinello molecular dynamics simulations of the oxidation of ligand-protected aluminum clusters that form a prototypical cluster-assembled material. These clusters contain a small aluminum core surrounded by a monolayer of organic ligand. The aromatic cyclopentadienyl ligands form a strong bond with surface Al atoms, giving rise to an organometallic cluster that crystallizes into a low-symmetry solid and is briefly stable in air before oxidizing. Our calculations of isolated aluminum/cyclopentadienyl clusters reacting with oxygen show minimal reaction between the ligand and O2 molecules at simulation temperatures of 500 and 1000 K. In all cases, the reaction pathway involves O2 diffusing through the ligand barrier, splitting into atomic oxygen upon contact with the aluminum, and forming an oxide cluster with aluminum/ligand bonds still largely intact. Loss of individual aluminum-ligand units, as expected from unimolecular decomposition calculations, is not observed except following significant oxidation. These calculations highlight the role of the ligand in providing a steric barrier against oxidizers and in maintaining the large aluminum surface area of the solid-state cluster material.
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Affiliation(s)
- Sufian Alnemrat
- Department of Physics, Naval Postgraduate School, Monterey, California 93943, USA
| | - Joseph P Hooper
- Department of Physics, Naval Postgraduate School, Monterey, California 93943, USA
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Benzene analogues of (quasi-)planar M@BnHn compounds (M = V−, Cr, Mn+): A theoretical investigation. J Chem Phys 2013; 139:174310. [DOI: 10.1063/1.4827517] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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First principle structural determination of (B2O3)n (n = 1–6) clusters: From planar to cage. J Chem Phys 2013; 138:094312. [DOI: 10.1063/1.4793707] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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