101
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Isomura N, Wu X, Watanabe Y. Atomic-resolution imaging of size-selected platinum clusters on TiO2(110) surfaces. J Chem Phys 2009; 131:164707. [DOI: 10.1063/1.3251786] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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102
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Ončák M, Cao Y, Höckendorf R, Beyer M, Zahradník R, Schwarz H. Thermal NH Bond Activation on Anionic and Cationic Platinum Clusters: Non-Predetermined Reaction Pathways Indicate Transitions to a Bulk Surface Reactivity. Chemistry 2009; 15:8465-8474. [DOI: 10.1002/chem.200900677] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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103
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Fedi S, Zanello P, Laschi F, Ceriotti A, El Afefey S. A joint electrochemical/spectroelectrochemical inspection (and re-inspection) of high-nuclearity platinum carbonyl clusters. J Solid State Electrochem 2009. [DOI: 10.1007/s10008-009-0880-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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104
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Sebetci A. Does spin–orbit coupling effect favor planar structures for small platinum clusters? Phys Chem Chem Phys 2009; 11:921-5. [DOI: 10.1039/b810837d] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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105
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Parreira RLT, Caramori GF, Galembeck SE, Huguenin F. The Nature of the Interactions between Pt4 Cluster and the Adsorbates ·H, ·OH, and H2O. J Phys Chem A 2008; 112:11731-43. [DOI: 10.1021/jp8033177] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Renato L. T. Parreira
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, 14040-901, Ribeirão Preto, SP, Brazil, and Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes 748, Bl. 05 sup. Sl 555, Butantã, 05508-000, São Paulo, SP, Brazil
| | - Giovanni F. Caramori
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, 14040-901, Ribeirão Preto, SP, Brazil, and Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes 748, Bl. 05 sup. Sl 555, Butantã, 05508-000, São Paulo, SP, Brazil
| | - Sérgio E. Galembeck
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, 14040-901, Ribeirão Preto, SP, Brazil, and Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes 748, Bl. 05 sup. Sl 555, Butantã, 05508-000, São Paulo, SP, Brazil
| | - Fritz Huguenin
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, 14040-901, Ribeirão Preto, SP, Brazil, and Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, Avenida Prof. Lineu Prestes 748, Bl. 05 sup. Sl 555, Butantã, 05508-000, São Paulo, SP, Brazil
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106
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Lepró X, Terrés E, Vega-Cantú Y, Rodríguez-Macías FJ, Muramatsu H, Kim YA, Hayahsi T, Endo M, Torres R. M, Terrones M. Efficient anchorage of Pt clusters on N-doped carbon nanotubes and their catalytic activity. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.08.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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107
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Dhilip Kumar TJ, Zhou C, Cheng H, Forrey RC, Balakrishnan N. Effect of Co doping on catalytic activity of small Pt clusters. J Chem Phys 2008; 128:124704. [DOI: 10.1063/1.2839437] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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108
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Xu Y, Getman RB, Shelton WA, Schneider WF. A first-principles investigation of the effect of Pt cluster size on CO and NO oxidation intermediates and energetics. Phys Chem Chem Phys 2008; 10:6009-18. [DOI: 10.1039/b805179h] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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109
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Sotelo JC, Seminario JM. Biatomic substrates for bulk-molecule interfaces: The PtCo-oxygen interface. J Chem Phys 2007; 127:244706. [DOI: 10.1063/1.2799997] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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110
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Gong XQ, Selloni A, Dulub O, Jacobson P, Diebold U. Small Au and Pt Clusters at the Anatase TiO2(101) Surface: Behavior at Terraces, Steps, and Surface Oxygen Vacancies. J Am Chem Soc 2007; 130:370-81. [DOI: 10.1021/ja0773148] [Citation(s) in RCA: 256] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xue-Qing Gong
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, and Department of Physics, Tulane University, New Orleans, Louisiana 70118
| | - Annabella Selloni
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, and Department of Physics, Tulane University, New Orleans, Louisiana 70118
| | - Olga Dulub
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, and Department of Physics, Tulane University, New Orleans, Louisiana 70118
| | - Peter Jacobson
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, and Department of Physics, Tulane University, New Orleans, Louisiana 70118
| | - Ulrike Diebold
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, and Department of Physics, Tulane University, New Orleans, Louisiana 70118
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111
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Copenhafer JE, Walters RW, Meyer TY. Synthesis and Characterization of Repeating Sequence Copolymers of Fluorene and Methylene Monomers. Macromolecules 2007. [DOI: 10.1021/ma0703711] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- James E. Copenhafer
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Robert W. Walters
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Tara Y. Meyer
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
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112
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Bhattacharyya K, Majumder C. Growth pattern and bonding trends in Pt (n= 2–13) clusters: Theoretical investigation based on first principle calculations. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.08.084] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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113
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Xu Y, Shelton WA, Schneider WF. Effect of particle size on the oxidizability of platinum clusters. J Phys Chem A 2007; 110:5839-46. [PMID: 16640379 DOI: 10.1021/jp0547111] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The catalytic properties of transition metal particles often depend crucially on their chemical environment, but so far, little is known about how the effects of the environment vary with particle size, especially for clusters consisting of only a few atoms. To gain insight into this topic, we have studied the oxygen affinity of free Pt(x) clusters as a function of cluster size (x = 1, 2, 3, 4, 5, and 10) using density functional theory (DFT) calculations (GGA-PW91). DFT-based Nosé-Hoover molecular dynamics has been used to explore the configuration space of the Pt(x)O(x) and Pt(x)O(2x) clusters, leading to the discovery of several novel Pt-oxide structures. The formation of small Pt-oxide clusters by oxidizing the corresponding Pt(x) clusters is found to be significantly more exothermic than the formation of bulk Pt-oxides from Pt metal. The exothermicity generally increases as cluster size decreases but exhibits strongly nonlinear dependence on the cluster size. The nanoclusters are also structurally distinct from the bulk oxides and prefer one- and two-dimensional chain and ringlike shapes. These findings help elucidate the oxidation behavior of Pt nanoclusters and lay the foundation for understanding the reactivity of Pt nanoclusters in oxidizing chemical environments.
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Affiliation(s)
- Ye Xu
- Computer Science and Mathematics Division, Oak Ridge National Laboratory, Tennessee 37831, USA
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114
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Han Y, Liu CJ, Ge Q. Interaction of Pt clusters with the anatase TiO(2)(101) surface: a first principles study. J Phys Chem B 2007; 110:7463-72. [PMID: 16599526 DOI: 10.1021/jp0608574] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The adsorption of Pt(n)() (n = 1-3) clusters on the defect-free anatase TiO(2)(101) surface has been studied using total energy pseudopotential calculations based on density functional theory. The defect-free anatase TiO(2)(101) surface has a stepped structure with a step width of two O-Ti bond distances in the (100) plane along the [10] direction and the edge of the step is formed by 2-fold-coordinated oxygen atoms along the [010] direction. For a single Pt adatom, three adsorption sites were found to be stable. Energetically, the Pt adatom prefers the bridge site formed by 2 2-fold-coordinated oxygen atoms with an adsorption energy of 2.84 eV. Electronic structure analysis showed that the Pt-O bonds formed upon Pt adsorption are covalent. Among six stable Pt(2) adsorption configurations examined, Pt(2) was found to energetically favor the O-O bridge sites on the step edge along [010] with the Pt-Pt bond axis perpendicular to [010]. In these configurations, one of the Pt atoms occupies the same O-O bridge site as for a single Pt adatom and the other one either binds a different 2-fold-coordinated oxygen atom on the upper step or a 5-fold-coordinated Ti atom on the lower terrace. Three triangular and three open Pt(3) structures were determined as minima for Pt(3) adsorption on the surface. Platinum trimers adsorbed in triangular structures are more stable than in open structures. In the most stable configuration, Pt(3) occupies the edge O-O site with the Pt(3) plane being upright and almost perpendicular to the [001] terrace. The preference of Pt(n)() to the coordinately unsaturated 2-fold-coordinated oxygen sites indicates that these sites may serve as nucleation centers for the growth of metal clusters on the oxide surface. The increase in clustering energy with increasing size of the adsorbed Pt clusters indicates that the growth of Pt on this surface will lead to the formation of three-dimensional particles.
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Affiliation(s)
- You Han
- Key Laboratory of Green Chemical Technology, School of Chemical Engineering, Tianjin University, Tianjin 300072, China
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115
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Yasumatsu H, Hayakawa T, Koizumi S, Kondow T. Unisized two-dimensional platinum clusters on silicon(111)-7x7 surface observed with scanning tunneling microscope. J Chem Phys 2007; 123:124709. [PMID: 16392513 DOI: 10.1063/1.2018639] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Uni-sized platinum clusters (size range of 5-40) on a silicon(111)-7 x 7 surface were prepared by depositing size-selected platinum cluster ions on the silicon surface at the collision energy of 1.5 eV per atom at room temperature. The surface thus prepared was observed by means of a scanning tunneling microscope (STM) at the temperature of 77 K under an ambient pressure less than 5 x 10(-9) Pa. The STM images observed at different cluster sizes revealed that (1) the clusters are flattened and stuck to the surface with a chemical-bond akin to platinum silicide, (2) every platinum atom occupies preferentially the most reactive sites distributed within a diameter of approximately 2 nm on the silicon surface at a cluster size up to 20, and above this size, the diameter of the cluster increases with the size, and (3) the sticking probability of an incoming cluster ion on the surface increases with the cluster size and reaches nearly unity at a size larger than 20.
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Affiliation(s)
- Hisato Yasumatsu
- Toyota Technological Institute, East Tokyo Laboratory, Genesis Research Institute, Inc., 717-86 Futamata, Ichikawa, Chiba 272-0001, Japan
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116
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Xiao L, Wang L. Methane Activation on Pt and Pt4: A Density Functional Theory Study. J Phys Chem B 2007; 111:1657-63. [PMID: 17266353 DOI: 10.1021/jp065288e] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The activation mechanisms of a methane molecule on a Pt atom (CH4-Pt) and on a Pt tetramer (CH4-Pt4) were investigated using density functional theory (B3LYP and PW91) calculations. The results from these two functionals are different mostly in predicting the reaction barrier, in particular for the CH4-Pt system. A new lower energy pathway was identified for the CH4 dehydrogenation on a Pt atom. In the new pathway, the PtCH2 + H2 products were formed via a transition state, in which the Pt atom forms a complex with carbene and both dissociated hydrogen atoms. We report here the first theoretical study of methane activation on a Pt4 cluster. Among the five single steps toward dehydrogenation, our results show that the rate-limiting step is the third step, that is, breaking the second C-H bond, which requires overcoming an energy barrier of 28 kcal/mol. On the other hand, the cleavage of the first C-H bond, that is, the first reaction step, requires overcoming an energy barrier of 4 kcal/mol.
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Affiliation(s)
- Li Xiao
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA
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117
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Yan JC, Cheng X, Zhou QL, Pei J. Chiral Polyfluorene Derivatives: Synthesis, Chiroptical Properties, and Investigation of the Structure−Property Relationships. Macromolecules 2007. [DOI: 10.1021/ma062691a] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ji-Chao Yan
- The Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, and the State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Xu Cheng
- The Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, and the State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Qi-Lin Zhou
- The Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, and the State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Jian Pei
- The Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, and the State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
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118
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Pawluk T, Xiao L, Yukna J, Wang L. Impact of PES on MD Results of the Coalescence of M2 + M with M = Ir, Pt, Au, Ag. J Chem Theory Comput 2007; 3:328-35. [DOI: 10.1021/ct600257p] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Tiffany Pawluk
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901
| | - Li Xiao
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901
| | - Jennifer Yukna
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901
| | - Lichang Wang
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901
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119
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Binding energy, vapor pressure, and melting point of semiconductor nanoparticles. ACTA ACUST UNITED AC 2007. [DOI: 10.1116/1.2748415] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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120
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Sadek MM, Wang L. Effect of Adsorption Site, Size, and Composition of Pt/Au Bimetallic Clusters on the CO Frequency: A Density Functional Theory Study. J Phys Chem A 2006; 110:14036-42. [PMID: 17181366 DOI: 10.1021/jp065286u] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Density functional theory (DFT) calculations were performed to investigate the C-O stretching frequency changes when a CO molecule was adsorbed to Pt/Au clusters of 2-4 atoms. Our calculations show that the adsorption site is the most sensitive quantity to the C-O stretching frequency shifts. All the bridge site adsorptions yield a CO frequency band of 1737-1927 cm-1 with the CO bond distance of 1.167-1.204 A regardless of cluster composition and size, and all the atop site adsorptions yield a CO frequency band of 2000-2091 cm-1 with the CO bond distance of 1.151-1.167 A. More detailed analysis of the two frequency bands shows that each band may consist of two emerging subbands with the lower frequencies corresponding to the CO adsorption to Pt atoms and the higher frequencies to the CO adsorption to Au atoms. The insensitivity of the CO frequency shift to the cluster size indicates that the trend discussed here for small clusters may be used to interpret the experimental observations for nanoparticles. Our results also illustrated that the Fourier transform infrared spectroscopy measurement may be used as a sensitive tool to identify adsorption sites of the Pt/Au nanoparticles using CO adsorption as the probe.
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Affiliation(s)
- Mark M Sadek
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
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121
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122
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123
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Tian WQ, Ge M, Gu F, Yamada T, Aoki Y. Binary Clusters AuPt and Au6Pt: Structure and Reactivity within Density Functional Theory. J Phys Chem A 2006; 110:6285-93. [PMID: 16686464 DOI: 10.1021/jp055506o] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Within density functional theory with the general gradient approximation for the exchange and correlation, the bimetallic clusters AuPt and Au(6)Pt have been studied for their structure and reactivity. The bond strength of AuPt lies between those of Au(2) and Pt(2), and it is closer to that of Au(2). The Pt atom is the reactive center in both AuPt and AuPt(+) according to electronic structure analysis. AuPt(+) is more stable than AuPt. Au(6)Pt prefers electronic states with low multiplicity. The most stable conformation of Au(6)Pt is a singlet and has quasi-planar hexagonal frame with Pt lying at the hexagonal center. The doping of Pt in Au cluster enhances the chemical regioselectivity of the Au cluster. The Pt atom essentially serves as electron donor and the Au atoms bonded to the Pt atom acts as electron acceptor in Au(6)Pt. The lowest triplet of edge-capped rhombus Au(6)Pt clusters is readily accessible with very small singlet-triplet energy gap (0.32 eV). O(2) prefers to adsorb on Au and CO prefers to adsorb on Pt. O(2) and CO have stronger adsorption on AuPt than they do on Au(6)Pt. CO has a much stronger adsorption on AuPt bimetallic cluster than O(2) does. The adsorption of CO on Pt modifies the geometry of AuPt bimetallic clusters.
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Affiliation(s)
- Wei Quan Tian
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China.
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124
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Abstract
Density functional theory (DFT) calculations were carried out to study gold clusters of up to 55 atoms. Between the linear and zigzag monoatomic Au nanowires, the zigzag nanowires were found to be more stable. Furthermore, the linear Au nanowires of up to 2 nm are formed by slightly stretched Au dimers. These suggest that a substantial Peierls distortion exists in those structures. Planar geometries of Au clusters were found to be the global minima till the cluster size of 13. A quantitative correlation is provided between various properties of Au clusters and the structure and size. The relative stability of selected clusters was also estimated by the Sutton-Chen potential, and the result disagrees with that obtained from the DFT calculations. This suggests that a modification of the Sutton-Chen potential has to be made, such as obtaining new parameters, in order to use it to search the global minima for bigger Au clusters.
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Affiliation(s)
- Li Xiao
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA.
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125
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Song C, Ge Q, Wang L. DFT Studies of Pt/Au Bimetallic Clusters and Their Interactions with the CO Molecule. J Phys Chem B 2005; 109:22341-50. [PMID: 16853910 DOI: 10.1021/jp0546709] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Density functional theory (DFT) calculations were performed to study Pt/Au clusters of different size, structure, and composition as well as their interactions with a CO molecule. Among the Pt/Au isomers studied here, the planar structure is the most stable structure in many Pt compositions, although three-dimensional structures become more stable with increasing Pt composition. Furthermore, structures with the Pt atoms surrounded by Au atoms are more stable among homotops. However, these conclusions will be altered if ligands are attached to the Pt/Au bimetallic clusters, as evidenced from the results of CO adsorption. When both Au and Pt sites are exposed, CO adsorption at the Pt site is stronger. If only a Au site is available for CO adsorption, the strongest adsorption occurs at approximately 25% Pt composition, which may correlate with the experimentally observed reactivity of the core-shell structured Pt/Au nanoparticles.
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Affiliation(s)
- Chunrong Song
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA
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126
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Pawluk T, Hirata Y, Wang L. Studies of Iridium Nanoparticles Using Density Functional Theory Calculations. J Phys Chem B 2005; 109:20817-23. [PMID: 16853698 DOI: 10.1021/jp053563b] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The energetics and the electronic and magnetic properties of iridium nanoparticles in the range of 2-64 atoms were investigated using density functional theory calculations. A variety of different geometric configurations were studied, including planar, three-dimensional, nanowire, and single-walled nanotube. The binding energy per atom increases with size and dimensionality from 2.53 eV/atom for the iridium dimer to 6.09 eV/atom for the 64-atom cluster. The most stable geometry is planar until four atoms are reached and three-dimensional thereafter. The simple cubic structure is the most stable geometric building block until a strikingly large 48-atom cluster, when the most stable geometry transitions to face-centered cubic, as found in the bulk metal. The strong preference for cubic structure among small clusters demonstrates their rigidity. This result indicates that iridium nanoparticles intrinsically do not favor the coalescence process. Nanowires formed from linear atomic chains of up to 4-atom rings were studied, and the wires formed from 4-atom rings were extremely stable. Single-walled nanotubes were also studied. These nanotubes were formed by stacking 5- and 6-atom rings to form a tube. The ring stacking with each atom directly above the previous atom is more stable than if the alternate rings are rotated.
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Affiliation(s)
- Tiffany Pawluk
- Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, IL 62901, USA
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127
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Tong Y, Zelakiewicz BS, Dy BM, Pogozelski AR. Local quantum size effect as seen by room-temperature 195Pt NMR in octanethiol-protected Pt nanoparticles. Chem Phys Lett 2005. [DOI: 10.1016/j.cplett.2005.02.085] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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128
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Theoretical and experimental study of hydrodechlorination reactions on Pt- and Pd-containing zeolites. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s0167-2991(05)80541-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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