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Álvarez-Zapatero P, Lebon A, Aguilera Del Toro RH, Aguado A, Vega A. Why are Zn-rich Zn-Mg nanoalloys optimal protective coatings against corrosion? A first-principles study of the initial stages of the oxidation process. Phys Chem Chem Phys 2021; 23:24685-24698. [PMID: 34708842 DOI: 10.1039/d1cp03447b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
ZnMg alloys of certain compositions in the Zn-rich side of the phase diagram are particularly efficient, and widely used, as anticorrosive coatings, but a sound understanding of the physico-chemical properties behind such quality is still far from being achieved. The present work focuses on the first stage of the corrosion process, namely the initial growth of a sacrificial surface oxide layer, whose characteristics will condition the next stages of the corrosion. A comprehensive ab initio study, based on density functional theory, is carried out on ZnMg nanoalloys with 20 atoms and different compositions, which serve as model systems to simulate the complex processes that occur in extended granular surfaces. The structural and electronic properties, when progressive oxidation of the nanoalloys takes place, are analyzed in detail with the help of structural descriptors, energetic descriptors such as the oxygen adsorption energies and excess adsorption energies, as well as with electronic ones based on the topological analysis of the electron density and the electron localization function, from which a detailed analysis of the bonding patterns is extracted. We explain why small amounts of Mg create a very positive synergy between Zn and Mg that increases the reactivity to oxygen while reducing, at the same time, the stress induced on the cluster substrate, both facts working in favor of promoting the growth of the oxide crust whilst protecting the core. Moreover, we also show that stoichiometries close to the Mg2Zn11 and MgZn2 compositions are the best candidates to optimize the protection against corrosion in Zn-Mg alloys, in agreement with the experimental observations.
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Affiliation(s)
- P Álvarez-Zapatero
- Departamento de Física Teórica, Atómica, y Óptica. Universidad de Valladolid, E-47011 Valladolid, Spain.
| | - A Lebon
- Laboratoire de Chimie Électrochimie Moléculaire et Chimie Analytique, UEB/UBO, UMR CNRS 6521, 29238 Brest Cedex, France.
| | - R H Aguilera Del Toro
- Departamento de Física Teórica, Atómica, y Óptica. Universidad de Valladolid, E-47011 Valladolid, Spain.
| | - A Aguado
- Departamento de Física Teórica, Atómica, y Óptica. Universidad de Valladolid, E-47011 Valladolid, Spain.
| | - A Vega
- Departamento de Física Teórica, Atómica, y Óptica. Universidad de Valladolid, E-47011 Valladolid, Spain.
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Nakano M, Ishimura Y, Hotta R, Hebiguchi D, Nagata T, Misaizu F. Structures of stoichiometric sodium oxide cluster cations studied by ion mobility mass spectrometry. CHINESE J CHEM PHYS 2019. [DOI: 10.1063/1674-0068/cjcp1812295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Motoyoshi Nakano
- Institute for Excellence in Higher Education, Tohoku University, 41 Kawauchi, Aoba-ku, Sendai, 980-8576, Japan
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
| | - Yudai Ishimura
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
| | - Riki Hotta
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
| | - Daiki Hebiguchi
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
| | - Toshiaki Nagata
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
| | - Fuminori Misaizu
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
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Majer K, Issendorff BV. Photoelectron spectroscopy of silicon doped gold and silver cluster anions. Phys Chem Chem Phys 2012; 14:9371-6. [PMID: 22362061 DOI: 10.1039/c2cp24095e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photoelectron spectra of low temperature silicon doped gold cluster anions Au(n)Si(-) with n = 2-56 and silver cluster anions Ag(n)Si(-) with n = 5-82 have been measured. Comparing the spectra as well as the general size dependence of the electron detachment energies to the results on undoped clusters shows that the silicon atom changes the apparent free electron count in the clusters. In the case of larger gold clusters (with more than about 30 gold atoms) the silicon atom seems to consistently delocalize all of its four valence electrons, while in the case of the silver clusters a less uniform behavior is observed. Here the silicon atoms act partly as electron donors, partly as electron acceptors, without following an obvious simple principle. Additionally some structural information can be obtained from the measured spectra: while Ag(54)Si(-) seems to adopt an icosahedral structural motif, Au(54)Si(-) seems to take on a low symmetry structure, much like the corresponding pure 55 atom clusters. This indicates that for such larger clusters the incorporation of a single silicon atom does not change the ground state geometry significantly.
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Affiliation(s)
- Kiran Majer
- Physikalisches Institut, Universität Freiburg, 79104 Freiburg, Germany
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Aguado A, Largo A, Vega A, Balbás LC. On the electric dipole moments of small sodium clusters from different theoretical approaches. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2011.07.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Aguado A, Kostko O. First-principles determination of the structure of NaN and NaN− clusters with up to 80 atoms. J Chem Phys 2011; 134:164304. [DOI: 10.1063/1.3582911] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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Aguado A, López JM. Structure determination in 55-atom Li–Na and Na–K nanoalloys. J Chem Phys 2010; 133:094302. [DOI: 10.1063/1.3479396] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Andrés Aguado
- Departamento de Física Teórica, Atómica y Optica, Universidad de Valladolid, Valladolid 47071, Spain.
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Cao B, Starace AK, Judd OH, Bhattacharyya I, Jarrold MF, López JM, Aguado A. Activation of Dinitrogen by Solid and Liquid Aluminum Nanoclusters: A Combined Experimental and Theoretical Study. J Am Chem Soc 2010; 132:12906-18. [DOI: 10.1021/ja103356r] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Baopeng Cao
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, and Departamento de Física Teórica, Universidad de Valladolid, Valladolid 47011, Spain
| | - Anne K. Starace
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, and Departamento de Física Teórica, Universidad de Valladolid, Valladolid 47011, Spain
| | - Oscar H. Judd
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, and Departamento de Física Teórica, Universidad de Valladolid, Valladolid 47011, Spain
| | - Indrani Bhattacharyya
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, and Departamento de Física Teórica, Universidad de Valladolid, Valladolid 47011, Spain
| | - Martin F. Jarrold
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, and Departamento de Física Teórica, Universidad de Valladolid, Valladolid 47011, Spain
| | - José M. López
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, and Departamento de Física Teórica, Universidad de Valladolid, Valladolid 47011, Spain
| | - Andrés Aguado
- Chemistry Department, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, and Departamento de Física Teórica, Universidad de Valladolid, Valladolid 47011, Spain
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