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Kordatos A, Mohammed K, Vakili R, Manyar H, Goguet A, Gibson E, Carravetta M, Wells P, Skylaris CK. Bridging the size gap between experiment and theory: large-scale DFT calculations on realistic sized Pd particles for acetylene hydrogenation. RSC Adv 2024; 14:27799-27808. [PMID: 39224642 PMCID: PMC11367406 DOI: 10.1039/d4ra03369h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Accepted: 08/18/2024] [Indexed: 09/04/2024] Open
Abstract
Metal nanoparticles, often supported on metal oxide promoters, are a cornerstone of heterogeneous catalysis. Experimentally, size effects are well-established and are manifested through changes to catalyst selectivity, activity and durability. Density Functional Theory (DFT) calculations have provided an attractive way to study these effects and rationalise the change in nanoparticle properties. However such computational studies are typically limited to smaller nanoparticles (approximately up to 50 atoms) due to the large computational cost of DFT. How well can such simulations describe the electronic properties of the much larger nanoparticles that are often used in practice? In this study, we use the ONETEP code, which is able to achieve more favourable computational scaling for metallic nanoparticles, to bridge this size gap. We present DFT calculations on entire Pd and Pd carbide nanoparticles of more than 300 atoms (approximately 2.5 nm diameter), and find major differences in the electronic structure of such large nanoparticles, in comparison to the commonly investigated smaller clusters. These differences are also manifested in the calculated chemical properties such as adsorption energies for C2H2, C2H4 and C2H6 on the pristine Pd and PdC x nanoparticles which are significantly larger (up to twice in value) for the ∼300 atoms structures. Furthermore, the adsorption of C2H2 and C2H4 on PdC x nanoparticles becomes weaker as more C is introduced in the Pd lattice whilst the impact of C concentration is also observed in the calculated reaction energies towards the hydrogenation of C2H2, where the formation of C2H6 is hindered. Our simulations show that PdC x nanoparticles of about 5% C per atom fraction and diameter of 2.5 nm could be potential candidate catalysts of high activity in hydrogenation reactions. The paradigm presented in this study will enable DFT to be applied on similar sized metal catalyst nanoparticles as in experimental investigations, strengthening the synergy between simulation and experiment in catalysis.
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Affiliation(s)
- Apostolos Kordatos
- School of Chemistry and Chemical Engineering, University of Southampton UK
| | - Khaled Mohammed
- School of Chemistry and Chemical Engineering, University of Southampton UK
| | - Reza Vakili
- School of Chemistry and Chemical Engineering, Queen's University Belfast UK
| | - Haresh Manyar
- School of Chemistry and Chemical Engineering, Queen's University Belfast UK
| | - Alexandre Goguet
- School of Chemistry and Chemical Engineering, Queen's University Belfast UK
| | - Emma Gibson
- School of Chemistry, University of Glasgow UK
| | - Marina Carravetta
- School of Chemistry and Chemical Engineering, University of Southampton UK
| | - Peter Wells
- School of Chemistry and Chemical Engineering, University of Southampton UK
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2
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Kordatos A, Mohammed K, Vakili R, Goguet A, Manyar H, Gibson E, Carravetta M, Wells P, Skylaris CK. Atomistic simulations on the carbidisation processes in Pd nanoparticles. RSC Adv 2023; 13:5619-5626. [PMID: 36798744 PMCID: PMC9926891 DOI: 10.1039/d2ra07462a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
The formation of interstitial PdC x nanoparticles (NPs) is investigated through DFT calculations. Insights on the mechanisms of carbidisation are obtained whilst the material's behaviour under conditions of increasing C-concentration is examined. Incorporation of C atoms in the Pd octahedral interstitial sites is occurring through the [111] facet with an activation energy barrier of 19.3-35.7 kJ mol-1 whilst migration through the [100] facet corresponds to higher activation energy barriers of 124.5-127.4 kJ mol-1. Furthermore, interstitial-type diffusion shows that C will preferentially migrate and reside at the octahedral interstitial sites in the subsurface region with limited mobility towards the core of the NP. For low C-concentrations, migration from the surface into the interstitial sites of the NPs is thermodynamically favored, resulting in the formation of interstitial carbide. Carbidisation reaction energies are exothermic up to 11-14% of C-concentration and slightly vary depending on the shape of the structure. The reaction mechanisms turn to endothermic for higher concentration levels showing that C will preferentially reside on the surface making the interstitial carbide formation unfavorable. As experimentally observed, our simulations confirm that there is a maximum concentration of C in Pd carbide NPs opening the way for further computational investigations on the activity of Pd carbides in directed catalysis.
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Affiliation(s)
| | | | - Reza Vakili
- School of Chemistry and Chemical Engineering Queen's University BelfastBT7 1NNUK
| | - Alexandre Goguet
- School of Chemistry and Chemical Engineering Queen's University BelfastBT7 1NNUK
| | - Haresh Manyar
- School of Chemistry and Chemical Engineering Queen's University BelfastBT7 1NNUK
| | - Emma Gibson
- School of Chemistry, University of GlasgowG12 8QQUK
| | | | - Peter Wells
- School of Chemistry, University of Southampton SO17 1BJ UK
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3
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Nakaya Y, Furukawa S. Catalysis of Alloys: Classification, Principles, and Design for a Variety of Materials and Reactions. Chem Rev 2022; 123:5859-5947. [PMID: 36170063 DOI: 10.1021/acs.chemrev.2c00356] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alloying has long been used as a promising methodology to improve the catalytic performance of metallic materials. In recent years, the field of alloy catalysis has made remarkable progress with the emergence of a variety of novel alloy materials and their functions. Therefore, a comprehensive disciplinary framework for catalytic chemistry of alloys that provides a cross-sectional understanding of the broad research field is in high demand. In this review, we provide a comprehensive classification of various alloy materials based on metallurgy, thermodynamics, and inorganic chemistry and summarize the roles of alloying in catalysis and its principles with a brief introduction of the historical background of this research field. Furthermore, we explain how each type of alloy can be used as a catalyst material and how to design a functional catalyst for the target reaction by introducing representative case studies. This review includes two approaches, namely, from materials and reactions, to provide a better understanding of the catalytic chemistry of alloys. Our review offers a perspective on this research field and can be used encyclopedically according to the readers' individual interests.
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Affiliation(s)
- Yuki Nakaya
- Institute for Catalysis, Hokkaido University, N-21, W-10, Kita-ku, Sapporo, Hokkaido 001-0021, Japan
| | - Shinya Furukawa
- Institute for Catalysis, Hokkaido University, N-21, W-10, Kita-ku, Sapporo, Hokkaido 001-0021, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Chiyoda, Tokyo 102-0076, Japan
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4
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Bannenberg LJ, Boshuizen B, Ardy Nugroho FA, Schreuders H. Hydrogenation Kinetics of Metal Hydride Catalytic Layers. ACS APPLIED MATERIALS & INTERFACES 2021; 13:52530-52541. [PMID: 34709777 PMCID: PMC8587611 DOI: 10.1021/acsami.1c13240] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
Catalyzing capping layers on metal hydrides are employed to enhance the hydrogenation kinetics of metal hydride-based systems such as hydrogen sensors. Here, we use a novel experimental method to study the hydrogenation kinetics of catalyzing capping layers composed of several alloys of Pd and Au as well as Pt, Ni, and Ru, all with and without an additional PTFE polymer protection layer and under the same set of experimental conditions. In particular, we employ a thin Ta film as an optical indicator to study the kinetics of the catalytic layers deposited on top of it and which allows one to determine the absolute hydrogenation rates. Our results demonstrate that doping Pd with Au results in significantly faster hydrogenation kinetics, with response times up to five times shorter than Pd through enhanced diffusion and a reduction in the activation energy. On the other hand, the kinetics of non-Pd-based materials turn out to be significantly slower and mainly limited by the diffusion through the capping layer itself. Surprisingly, the additional PTFE layer was only found to improve the kinetics of Pd-based capping materials and has no significant effect on the kinetics of Pt, Ni, and Ru. Taken together, the experimental results aid in rationally choosing a suitable capping material for the application of metal hydrides and other materials in a hydrogen economy. In addition, the used method can be applied to simultaneously study the hydrogenation kinetics in thin-film materials for a wide set of experimental conditions.
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Affiliation(s)
- Lars J. Bannenberg
- Faculty
of Applied Sciences, Delft University of
Technology, Mekelweg
15, Delft 2629 JB, The Netherlands
| | - Bart Boshuizen
- Faculty
of Applied Sciences, Delft University of
Technology, Mekelweg
15, Delft 2629 JB, The Netherlands
| | - Ferry Anggoro Ardy Nugroho
- Department
of Physics and Astronomy, Vrije Universiteit
Amsterdam, De Boelelaan
1081, Amsterdam 1081 HV, The Netherlands
| | - Herman Schreuders
- Faculty
of Applied Sciences, Delft University of
Technology, Mekelweg
15, Delft 2629 JB, The Netherlands
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5
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6
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Schuster R, Bertram M, Runge H, Geile S, Chung S, Vonk V, Noei H, Poulain A, Lykhach Y, Stierle A, Libuda J. Metastability of palladium carbide nanoparticles during hydrogen release from liquid organic hydrogen carriers. Phys Chem Chem Phys 2021; 23:1371-1380. [PMID: 33393575 DOI: 10.1039/d0cp05606e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Efficient hydrogen release from liquid organic hydrogen carriers (LOHCs) requires a high level of control over the catalytic properties of supported noble metal nanoparticles. Here, the formation of carbon-containing phases under operation conditions has a direct influence on the activity and selectivity of the catalyst. We studied the formation and stability of carbide phases using well-defined Pd/α-Al2O3(0001) model catalysts during dehydrogenation of a model LOHC, methylcyclohexane, in a flow reactor by in situ high-energy grazing incidence X-ray diffraction. The phase composition of supported Pd nanoparticles was investigated as a function of particle size and reaction conditions. Under operating conditions, we detected the formation of a PdxC phase followed by its conversion to Pd6C. The dynamic stability of the Pd6C phase results from the balance between uptake and release of carbon by the supported Pd nanoparticles in combination with the thermodynamically favorable growth of carbon deposits in the form of graphene. For small Pd nanoparticles (6 nm), the Pd6C phase is dynamically stable under low flow rate of reactants. At the high reactant flow, the Pd6C phase decomposes shortly after its formation due to the growth of graphene. Structural analysis of larger Pd nanoparticles (15 nm) reveals the formation and simultaneous presence of two types of carbides, PdxC and Pd6C. Formation and decomposition of Pd6C proceeds via a PdxC phase. After an incubation period, growth of graphene triggers the decomposition of carbides. The process is accompanied by segregation of carbon from the bulk of the nanoparticles to the graphene phase. Notably, nucleation of graphene is more favorable on bigger Pd nanoparticles. Our studies demonstrate that metastability of palladium carbides associated with dynamic formation and decomposition of the Pd6C and PdxC phases is an intrinsic phenomenon in LOHC dehydrogenation on Pd-based catalysts and strongly depends on particle size and reaction conditions.
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Affiliation(s)
- Ralf Schuster
- Interface Research and Catalysis, ECRC, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany.
| | - Manon Bertram
- Interface Research and Catalysis, ECRC, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany.
| | - Henning Runge
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany and Fachbereich Physik, Universität Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany
| | - Simon Geile
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Simon Chung
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Vedran Vonk
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Heshmat Noei
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Agnieszka Poulain
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Yaroslava Lykhach
- Interface Research and Catalysis, ECRC, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany.
| | - Andreas Stierle
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany and Fachbereich Physik, Universität Hamburg, Jungiusstrasse 11, 20355 Hamburg, Germany
| | - Jörg Libuda
- Interface Research and Catalysis, ECRC, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen, Germany.
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7
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Fedoseev IV, Shevelkov AV, Vasekin VV, Poyarkov KB, Rovinskaya NV. Formation and Destruction of Palladium Carbonyl Nanoclusters in the Pd(II)–Cl––H+–H2O–CO Systems. RUSS J INORG CHEM+ 2020. [DOI: 10.1134/s0036023620020035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Evolution of surface and bulk carbon species derived from propylene and their influence on the interaction of hydrogen with palladium. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2019.117738] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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9
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Carro P, Salvarezza RC. Gold adatoms modulate sulfur adsorption on gold. NANOSCALE 2019; 11:19341-19351. [PMID: 31435624 DOI: 10.1039/c9nr05709a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Sulfur adsorption on Au(111) at high coverage has been studied by density functional calculations. In this case S species organize into rectangular structures containing 8 S atoms irrespective of the S source, which have been alternatively assigned to adsorbed monomeric S, adsorbed S2, adsorbed monomeric plus S2 species, and gold sulfide. We found that monomeric S at the high coverage organizes into S2 species that are stabilized into the 8-S structures by Au adatoms, forming gold disulfide complexes (Au-(S2)4). The Au atoms could be provided by decomposition of more diluted AuS3 containing phases, as recently proposed, and direct removal from terraces and step edges, both explaining the surface coverage of vacancy islands coexisting with the 8-S structures. The gold-disulfide complexes capture the disorder shown in the experimental STM images, explain the intrigued features of XPS, and also, give a smooth pathway to gold sulfide formation at higher temperatures. More importantly, the gold-disulfide complexes allow a unified picture of the gold-sulfur surface chemistry at high coverage for thiols and adsorbed sulfur species where the surface chemistry remains under discussion.
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Affiliation(s)
- Pilar Carro
- Área de Química Física, Departamento de Química, Facultad de Ciencias, Universidad de La Laguna, Instituto de Materiales y Nanotecnología, Avda. Francisco Sánchez, s/n 38200-La Laguna, Tenerife, Spain
| | - Roberto C Salvarezza
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CONICET, La Plata 1900, Argentina.
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10
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Jørgensen M, Grönbeck H. First-Principles Microkinetic Modeling of Methane Oxidation over Pd(100) and Pd(111). ACS Catal 2016. [DOI: 10.1021/acscatal.6b01752] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mikkel Jørgensen
- Department of Physics
and
Competence Centre for Catalysis, Chalmers University of Technology, 412 58 Göteborg, Sweden
| | - Henrik Grönbeck
- Department of Physics
and
Competence Centre for Catalysis, Chalmers University of Technology, 412 58 Göteborg, Sweden
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11
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Chemisorption–XRD particle size discrepancy of carbon supported palladium: Carbon decoration of Pd? Catal Today 2015. [DOI: 10.1016/j.cattod.2014.07.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Westenfelder B, Biskupek J, Meyer JC, Kurasch S, Lin X, Scholz F, Gross A, Kaiser U. Bottom-up formation of robust gold carbide. Sci Rep 2015; 5:8891. [PMID: 25772348 PMCID: PMC5390915 DOI: 10.1038/srep08891] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 02/10/2015] [Indexed: 02/06/2023] Open
Abstract
A new phenomenon of structural reorganization is discovered and characterized
for a gold-carbon system by in-situ atomic-resolution imaging at temperatures
up to 1300 K. Here, a graphene sheet serves in three ways, as a quasi
transparent substrate for aberration-corrected high-resolution transmission
electron microscopy, as an in-situ heater, and as carbon supplier. The sheet
has been decorated with gold nanoislands beforehand. During electron irradiation
at 80 kV and at elevated temperatures, the accumulation of gold atoms
has been observed on defective graphene sites or edges as well as at the facets
of gold nanocrystals. Both resulted in clustering, forming unusual crystalline
structures. Their lattice parameters and surface termination differ significantly
from standard gold nanocrystals. The experimental data, supported by electron
energy loss spectroscopy and density-functional theory calculations, suggests
that isolated gold and carbon atoms form – under conditions of heat
and electron irradiation – a novel type of compound crystal, Au-C in
zincblende structure. The novel material is metastable, but surprisingly robust,
even under annealing condition.
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Affiliation(s)
| | - Johannes Biskupek
- Central Facility of Electron Microscopy, Ulm University, 89081 Ulm, Germany
| | - Jannik C Meyer
- Department of Physics, University of Vienna, 1090 Vienna, Austria
| | - Simon Kurasch
- Central Facility of Electron Microscopy, Ulm University, 89081 Ulm, Germany
| | - Xiaohang Lin
- Institute of Theoretical Chemistry, Ulm University, 89081 Ulm, Germany
| | - Ferdinand Scholz
- Institute of Optoelectronics, Ulm University, 89081 Ulm, Germany
| | - Axel Gross
- Institute of Theoretical Chemistry, Ulm University, 89081 Ulm, Germany
| | - Ute Kaiser
- Central Facility of Electron Microscopy, Ulm University, 89081 Ulm, Germany
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13
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Ngene P, Westerwaal RJ, Sachdeva S, Haije W, de Smet LCPM, Dam B. Polymer-Induced Surface Modifications of Pd-based Thin Films Leading to Improved Kinetics in Hydrogen Sensing and Energy Storage Applications. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201406911] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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14
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Ngene P, Westerwaal RJ, Sachdeva S, Haije W, de Smet LCPM, Dam B. Polymer-Induced Surface Modifications of Pd-based Thin Films Leading to Improved Kinetics in Hydrogen Sensing and Energy Storage Applications. Angew Chem Int Ed Engl 2014; 53:12081-5. [DOI: 10.1002/anie.201406911] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 08/08/2014] [Indexed: 11/12/2022]
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15
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Zhao Z, Meng C, Li P, Zhu W, Wang Q, Ma Y, Shen G, Bai L, He H, He D, Yu D, He J, Xu B, Tian Y. Carbon coated face-centered cubic Ru-C nanoalloys. NANOSCALE 2014; 6:10370-10376. [PMID: 25074821 DOI: 10.1039/c4nr02632b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Carbon-encapsulated ruthenium-carbon (Ru-C) nanoalloys were synthesized by dynamic shocks. The Ru-C alloy shows a new fcc structure different from the original hcp structure of metal Ru. This fcc phase is assigned to a Ru32C4 solid solution with a lattice parameter of 3.868(2) Å and a bulk modulus KT0 of 272(12) GPa. The small amount of carbon in the solid solution enhances the thermodynamic and chemical stabilities with respect to pure Ru, as well as induces changes in the electronic properties, which have direct applications in improving the material's catalytic activity and selectivity.
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Affiliation(s)
- Zhisheng Zhao
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China.
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16
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Conversion of ethanol into hydrocarbon components of fuels in the presence of Pd-Zn-containing catalysts. Russ Chem Bull 2014. [DOI: 10.1007/s11172-014-0399-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Crespo-Quesada M, Yoon S, Jin M, Xia Y, Weidenkaff A, Kiwi-Minsker L. Size and Shape-controlled Pd Nanocrystals on ZnO and SiO2: When the Nature of the Support Determines the Active Phase. ChemCatChem 2014. [DOI: 10.1002/cctc.201301043] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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18
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Gong C, McDonnell S, Qin X, Azcatl A, Dong H, Chabal YJ, Cho K, Wallace RM. Realistic metal-graphene contact structures. ACS NANO 2014; 8:642-649. [PMID: 24261695 DOI: 10.1021/nn405249n] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The contact resistance of metal-graphene junctions has been actively explored and exhibited inconsistencies in reported values. The interpretation of these electrical data has been based exclusively on a side-contact model, that is, metal slabs sitting on a pristine graphene sheet. Using in situ X-ray photoelectron spectroscopy to study the wetting of metals on as-synthesized graphene on copper foil, we show that side-contact is sometimes a misleading picture. For instance, metals like Pd and Ti readily react with graphitic carbons, resulting in Pd- and Ti-carbides. Carbide formation is associated with C-C bond breaking in graphene, leading to an end-contact geometry between the metals and the periphery of the remaining graphene patches. This work validates the spontaneous formation of the metal-graphene end-contact during the metal deposition process as a result of the metal-graphene reaction instead of a simple carbon diffusion process.
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Affiliation(s)
- Cheng Gong
- Department of Materials Science and Engineering, The University of Texas at Dallas , Richardson, Texas 75080, United States
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19
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Affiliation(s)
- Rafael Chinchilla
- Departamento de Química Orgánica,
Facultad
de Ciencias, and Instituto de Síntesis Orgánica (ISO), Universidad de Alicante, Apartado 99, 03080 Alicante,
Spain
| | - Carmen Nájera
- Departamento de Química Orgánica,
Facultad
de Ciencias, and Instituto de Síntesis Orgánica (ISO), Universidad de Alicante, Apartado 99, 03080 Alicante,
Spain
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20
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Gatla S, Madaan N, Radnik J, Kalevaru V, Pohl MM, Lücke B, Martin A, Bentrup U, Brückner A. Rutile – A superior support for highly selective and stable Pd-based catalysts in the gas-phase acetoxylation of toluene. J Catal 2013. [DOI: 10.1016/j.jcat.2012.10.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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21
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Armbrüster M, Behrens M, Cinquini F, Föttinger K, Grin Y, Haghofer A, Klötzer B, Knop-Gericke A, Lorenz H, Ota A, Penner S, Prinz J, Rameshan C, Révay Z, Rosenthal D, Rupprechter G, Sautet P, Schlögl R, Shao L, Szentmiklósi L, Teschner D, Torres D, Wagner R, Widmer R, Wowsnick G. How to Control the Selectivity of Palladium-based Catalysts in Hydrogenation Reactions: The Role of Subsurface Chemistry. ChemCatChem 2012. [DOI: 10.1002/cctc.201200100] [Citation(s) in RCA: 196] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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22
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Jacobson P, Stöger B, Garhofer A, Parkinson GS, Schmid M, Caudillo R, Mittendorfer F, Redinger J, Diebold U. Nickel carbide as a source of grain rotation in epitaxial graphene. ACS NANO 2012; 6:3564-72. [PMID: 22414295 DOI: 10.1021/nn300625y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Graphene has a close lattice match to the Ni(111) surface, resulting in a preference for 1 × 1 configurations. We have investigated graphene grown by chemical vapor deposition (CVD) on the nickel carbide (Ni(2)C) reconstruction of Ni(111) with scanning tunneling microscopy (STM). The presence of excess carbon, in the form of Ni(2)C, prevents graphene from adopting the preferred 1 × 1 configuration and leads to grain rotation. STM measurements show that residual Ni(2)C domains are present under rotated graphene. Nickel vacancy islands are observed at the periphery of rotated grains and indicate Ni(2)C dissolution after graphene growth. Density functional theory (DFT) calculations predict a very weak (van der Waals type) interaction of graphene with the underlying Ni(2)C, which should facilitate a phase separation of the carbide into metal-supported graphene. These results demonstrate that surface phases such as Ni(2)C can play a major role in the quality of epitaxial graphene.
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Affiliation(s)
- Peter Jacobson
- Department of Physics, Tulane University, New Orleans, Louisiana 70118, United States.
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23
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Park DS, Kwak BK, Kim ND, Park JR, Cho JH, Oh S, Yi J. Capturing Coke Precursors in a Pd Lattice: A Carbon-Supported Heteropoly Acid Catalyst for the Dehydration of Glycerol into Acrolein. ChemCatChem 2012. [DOI: 10.1002/cctc.201100473] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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24
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Ding K, Derk AR, Zhang A, Hu Z, Stoimenov P, Stucky GD, Metiu H, McFarland EW. Hydrodebromination and Oligomerization of Dibromomethane. ACS Catal 2012. [DOI: 10.1021/cs2006058] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Aihua Zhang
- Gas Reaction Technologies, Inc., 861 Ward Drive, Santa Barbara, California 93111, United States
| | | | - Peter Stoimenov
- Gas Reaction Technologies, Inc., 861 Ward Drive, Santa Barbara, California 93111, United States
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Balmes O, Resta A, Wermeille D, Felici R, Messing ME, Deppert K, Liu Z, Grass ME, Bluhm H, van Rijn R, Frenken JWM, Westerström R, Blomberg S, Gustafson J, Andersen JN, Lundgren E. Reversible formation of a PdC(x) phase in Pd nanoparticles upon CO and O2 exposure. Phys Chem Chem Phys 2012; 14:4796-801. [PMID: 22361687 DOI: 10.1039/c2cp22873d] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The structure and chemical composition of Pd nanoparticles exposed to pure CO and mixtures of CO and O(2) at elevated temperatures have been studied in situ by a combination of X-ray Diffraction and X-ray Photoelectron Spectroscopy in pressures ranging from ultra high vacuum to 10 mbar and from room temperature to a few hundred degrees celsius. Our investigation shows that under CO exposure, above a certain temperature, carbon dissolves into the Pd particles forming a carbide phase. Upon exposure to CO and O(2) mixtures, the carbide phase forms and disappears reversibly, switching at the stoichiometric ratio for CO oxidation. This finding opens new scenarios for the understanding of catalytic oxidation of C-based molecules.
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Matczak P. Theoretical study of the interaction of simple molecules such as H2, C2H2, and C2H4 with Pd–Pb catalysts. REACTION KINETICS MECHANISMS AND CATALYSIS 2011. [DOI: 10.1007/s11144-011-0384-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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27
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Tew MW, Janousch M, Huthwelker T, van Bokhoven JA. The roles of carbide and hydride in oxide-supported palladium nanoparticles for alkyne hydrogenation. J Catal 2011. [DOI: 10.1016/j.jcat.2011.06.025] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Bisti F, Stroppa A, Picozzi S, Ottaviano L. Fingerprints of the hydrogen bond in the photoemission spectra of croconic acid condensed phase: An x-ray photoelectron spectroscopy and ab-initio study. J Chem Phys 2011; 134:174505. [DOI: 10.1063/1.3586813] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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