1
|
Sitja G, Henry CR. A molecular beam study of CO oxidation on Pd clusters supported on alumina: the effect of cluster size. Phys Chem Chem Phys 2024; 26:15338-15343. [PMID: 38753220 DOI: 10.1039/d4cp01030b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
The activity in CO oxidation of regular arrays of Pd clusters, in the size range of 5-180 atoms, supported on alumina has been studied by using a molecular beam method. The Pd clusters are grown on a nanostructured ultrathin alumina film on Ni3Al(111) providing a hexagonal array of clusters with a narrow size distribution. The steady state turnover frequency (TOF) is measured as a function of the mean cluster size. On average the TOF increases with size. Below about 20 atoms, the TOF increases rapidly and for larger clusters it grows slowly and reaches a value close to those obtained on bulk single crystals at 180 atoms. The size effect is explained by the smaller activity of Pd atoms in contact with the alumina support.
Collapse
Affiliation(s)
- Georges Sitja
- CNRS, CINaM, Aix-Marseille Univsersité, F-13288 Marseille, France.
| | - Claude R Henry
- CNRS, CINaM, Aix-Marseille Univsersité, F-13288 Marseille, France.
| |
Collapse
|
2
|
Albrahim MA, Shrotri A, Unocic RR, Hoffman AS, Bare SR, Karim AM. Size-Dependent Dispersion of Rhodium Clusters into Isolated Single Atoms at Low Temperature and the Consequences for CO Oxidation Activity. Angew Chem Int Ed Engl 2023; 62:e202308002. [PMID: 37488071 DOI: 10.1002/anie.202308002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 07/21/2023] [Accepted: 07/24/2023] [Indexed: 07/26/2023]
Abstract
Understanding the dynamic structural evolution of supported metal clusters under reaction conditions is crucial to develop structure reactivity relations. Here, we followed the structure of different size Rh clusters supported on Al2 O3 using in situ/operando spectroscopy and ex situ aberration-corrected electron microscopy. We report a dynamic evolution of rhodium clusters into thermally stable isolated single atoms upon exposure to oxygen and during CO oxidation. Rh clusters partially disperse into single atoms at room temperature and the extent of dispersion increases as the Rh size decreases and as the reaction temperature increases. A strong correlation is found between the extent of dispersion and the CO oxidation kinetics. More importantly, dispersing Rh clusters into single atoms increases the activity at room temperature by more than two orders of magnitude due to the much lower activation energy on single atoms (40 vs. 130 kJ/mol). This work demonstrates that the structure and reactivity of small Rh clusters are very sensitive to the reaction environment.
Collapse
Affiliation(s)
- Malik A Albrahim
- Department of Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, 24060, USA
| | - Abhijit Shrotri
- Institute for Catalysis, Hokkaido University Kita ku, Sapporo, Hokkaido, 001-0021, Japan
| | - Raymond R Unocic
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37830, USA
| | - Adam S Hoffman
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California, 94025, USA
| | - Simon R Bare
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California, 94025, USA
| | - Ayman M Karim
- Department of Chemical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, 24060, USA
| |
Collapse
|
3
|
Dachraoui W, Keller D, Henninen TR, Ashton OJ, Erni R. Atomic Mechanisms of Nanocrystallization via Cluster-Clouds in Solution Studied by Liquid-Phase Scanning Transmission Electron Microscopy. NANO LETTERS 2021; 21:2861-2869. [PMID: 33818087 DOI: 10.1021/acs.nanolett.0c04965] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The formation of nanocrystals is at the heart of various scientific disciplines, but the atomic mechanisms underlying the early stages of crystallization from supersaturated solutions are still rather unclear. Here, we used in situ liquid-phase scanning transmission electron microscopy to study at the atomic level the very early stages of gold nanocrystal growth, and the evolution of its crystallinity. We found that the nucleation is initiated by the formation of poorly crystalline nanoparticles. These are transformed into monocrystals via nanocrystallization governed by a complex process of multiple out-and-in exchanges of matter between a crystalline-core and a disordered-shell, referred to as the cluster-cloud. Our observations at the crystal/cluster-cloud interface during growth demonstrate that the initially formed nanocrystals expel the poorly crystallized phases as nanoclusters into the cluster-cloud, then readsorb it by two distinct pathways, namely, by (i) monomer attachments and (ii) nanocluster coalescence. This growth process eventually leads to the formation of monocrystalline nanoparticles.
Collapse
Affiliation(s)
- Walid Dachraoui
- Electron Microscopy Center, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland
| | - Debora Keller
- Electron Microscopy Center, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland
| | - Trond R Henninen
- Electron Microscopy Center, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland
| | - Olivia J Ashton
- Electron Microscopy Center, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland
| | - Rolf Erni
- Electron Microscopy Center, Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600, Dübendorf, Switzerland
| |
Collapse
|
4
|
Hartl T, Will M, Čapeta D, Singh R, Scheinecker D, Boix de la Cruz V, Dellmann S, Lacovig P, Lizzit S, Senkovskiy BV, Grüneis A, Kralj M, Knudsen J, Kotakoski J, Michely T, Bampoulis P. Cluster Superlattice Membranes. ACS NANO 2020; 14:13629-13637. [PMID: 32910634 DOI: 10.1021/acsnano.0c05740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cluster superlattice membranes consist of a two-dimensional hexagonal lattice of similar-sized nanoclusters sandwiched between single-crystal graphene and an amorphous carbon matrix. The fabrication process involves three main steps, the templated self-organization of a metal cluster superlattice on epitaxial graphene on Ir(111), conformal embedding in an amorphous carbon matrix, and subsequent lift-off from the Ir(111) substrate. The mechanical stability provided by the carbon-graphene matrix makes the membrane stable as a free-standing material and enables transfer to other substrates. The fabrication procedure can be applied to a wide variety of cluster materials and cluster sizes from the single-atom limit to clusters of a few hundred atoms, as well as other two-dimensional layer/host matrix combinations. The versatility of the membrane composition, its mechanical stability, and the simplicity of the transfer procedure make cluster superlattice membranes a promising material in catalysis, magnetism, energy conversion, and optoelectronics.
Collapse
Affiliation(s)
- Tobias Hartl
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Moritz Will
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Davor Čapeta
- Institute of Physics, Bijenička cesta 46, 10000, Zagreb, Croatia
| | - Rajendra Singh
- Faculty of Physics, Vienna University, Boltzmanngasse 5, 1090, Vienna, Austria
| | - Daniel Scheinecker
- Faculty of Physics, Vienna University, Boltzmanngasse 5, 1090, Vienna, Austria
| | - Virginia Boix de la Cruz
- MAX IV Laboratory and Division of Synchrotron Radiation Research, Lund University, Box 118, 22100 Lund, Sweden
| | - Sophia Dellmann
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Paolo Lacovig
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14 Km 163.5, I-34149 Trieste, Italy
| | - Silvano Lizzit
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14 Km 163.5, I-34149 Trieste, Italy
| | - Boris V Senkovskiy
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Alexander Grüneis
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Marko Kralj
- Institute of Physics, Bijenička cesta 46, 10000, Zagreb, Croatia
| | - Jan Knudsen
- MAX IV Laboratory and Division of Synchrotron Radiation Research, Lund University, Box 118, 22100 Lund, Sweden
| | - Jani Kotakoski
- Faculty of Physics, Vienna University, Boltzmanngasse 5, 1090, Vienna, Austria
| | - Thomas Michely
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| | - Pantelis Bampoulis
- II. Physikalisches Institut, Universität zu Köln, Cologne, D-50937, Germany
| |
Collapse
|
5
|
Kohaut S, Rapps T, Fink K, Schooss D. Structural Evolution of Palladium Clusters Pd55––Pd147–: Transition to the Bulk. J Phys Chem A 2019; 123:10940-10946. [DOI: 10.1021/acs.jpca.9b09369] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stephan Kohaut
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Thomas Rapps
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Karin Fink
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Detlef Schooss
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| |
Collapse
|
6
|
Sitja G, Tissot H, Henry CR. Particle size effect on the Langmuir-Hinshelwood barrier for CO oxidation on regular arrays of Pd clusters supported on ultrathin alumina films. J Chem Phys 2019; 151:174703. [PMID: 31703513 DOI: 10.1063/1.5125572] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The Langmuir-Hinshelwood barrier (ELH) and the pre-exponential factor (νLH) for CO oxidation have been measured at high temperatures on hexagonal arrays of Pd clusters supported on an ultrathin alumina film on Ni3Al (111). The Pd clusters have a sharp size distribution, and the mean sizes are 174 ± 13, 360 ± 19, and 768 ± 28 atoms. ELH and νLH are determined from the initial reaction rate of a CO molecular beam with a saturation layer of adsorbed oxygen on the Pd clusters measured at different temperatures [493 ≤ T(K) ≤ 613]. The largest particles (3.5 nm) give values of ELH and νLH similar to those measured on Pd (111) [T. Engel and G. Ertl, J. Chem. Phys. 69, 1267 (1978)]. However, smaller particles (2.7 and 2.1 nm) show very different behaviors. The origin of this size effect is discussed in terms of variation of the electronic structure and of the atomic structure of the Pd clusters.
Collapse
Affiliation(s)
- Georges Sitja
- Aix-Marseille Université, CNRS, CINaM, F-13000 Marseille, France
| | - Héloïse Tissot
- Aix-Marseille Université, CNRS, CINaM, F-13000 Marseille, France
| | - Claude R Henry
- Aix-Marseille Université, CNRS, CINaM, F-13000 Marseille, France
| |
Collapse
|
7
|
Will M, Bampoulis P, Hartl T, Valerius P, Michely T. Conformal Embedding of Cluster Superlattices with Carbon. ACS APPLIED MATERIALS & INTERFACES 2019; 11:40524-40532. [PMID: 31588723 DOI: 10.1021/acsami.9b14616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Iridium cluster superlattices on the graphene moiré with Ir(111) are embedded with elemental carbon through vapor-phase deposition. Using scanning tunneling microscopy and spectroscopy, we find that carbon embedding is conformal and does not deteriorate the excellent order of the iridium clusters. The thermal and mechanical stability of the embedded clusters is greatly enhanced. Smoluchowski ripening as well as cluster pick-up by the scanning tunneling microscopy tip are both suppressed. The only cluster decay path left takes place at an elevated temperature of around 1050 K. The cluster material penetrates through the graphene sheet, whereby it becomes bound to the underlying metal. It is argued that conformal carbon embedding is an important step towards the formation of a new type of sintering-resistant cluster lattice material for nanocatalysis and nanomagnetism.
Collapse
Affiliation(s)
- Moritz Will
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Pantelis Bampoulis
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Tobias Hartl
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Philipp Valerius
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Thomas Michely
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| |
Collapse
|
8
|
Alyabyeva N, Ouvrard A, Zakaria AM, Bourguignon B. Probing Nanoparticle Geometry down to Subnanometer Size: The Benefits of Vibrational Spectroscopy. J Phys Chem Lett 2019; 10:624-629. [PMID: 30673284 DOI: 10.1021/acs.jpclett.8b03830] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Understanding the role of nanoparticle size and shape in the binding of molecules is very relevant for heterogeneous catalysis and molecular electronics. The geometry of Pd nanoparticles (NPs) has been studied from very small clusters containing 4 atoms up to large (>500 atoms), well-faceted NPs. Their geometry was retrieved by combining scanning tunneling microscopy and vibrational sum frequency generation (SFG) spectroscopy of adsorbed CO. SFG has been revealed to be highly sensitive to the geometry of NPs smaller than 100 atoms by identifying the nature of CO adsorption sites. NP growth could be followed layer by layer in the critical size range corresponding to the transition from a nonmetallic to a metallic state and to oscillations of CO adsorption energy. NP height remained at two Pd planes up to 30 atoms, and adsorption energy minima correspond to the completion of successive layers.
Collapse
Affiliation(s)
- Natalia Alyabyeva
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS , Université Paris-Saclay , F-91405 Orsay , France
| | - Aimeric Ouvrard
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS , Université Paris-Saclay , F-91405 Orsay , France
| | - Abdoul-Mouize Zakaria
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS , Université Paris-Saclay , F-91405 Orsay , France
| | - Bernard Bourguignon
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS , Université Paris-Saclay , F-91405 Orsay , France
| |
Collapse
|
9
|
Barcaro G, Fortunelli A. 2D oxides on metal materials: concepts, status, and perspectives. Phys Chem Chem Phys 2019; 21:11510-11536. [DOI: 10.1039/c9cp00972h] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two-dimensional oxide-on-metal materials: concepts, methods, and link to technological applications, with 5 subtopics: structural motifs, robustness, catalysis, ternaries, and nanopatterning.
Collapse
|
10
|
Ghalgaoui A, Horchani R, Wang J, Ouvrard A, Carrez S, Bourguignon B. Identification of Active Sites in Oxidation Reaction from Real-Time Probing of Adsorbate Motion over Pd Nanoparticles. J Phys Chem Lett 2018; 9:5202-5206. [PMID: 30111106 DOI: 10.1021/acs.jpclett.8b02215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Obtaining insight into the type of surface sites involved in a reaction is essential to understand catalytic mechanisms at the atomic level and a key for understanding selectivity in surface-catalyzed reactions. Here we use ultrafast broad-band vibrational spectroscopy to follow in real-time diffusion of CO molecules over a palladium nanoparticle surface toward an active site. Site-to-site hopping is triggered by laser excitation of electrons and followed in real-time from subpicosecond changes in the vibrational spectra. CO photoexcitation occurs in 400 fs and hopping from NP facets to edges follows within ∼1 ps. Kinetic modeling allows to quantify the contribution of different facet sites to the catalytic reaction. These results provide useful insights for understanding the mechanism of chemical reactions catalyzed by metal NPs.
Collapse
Affiliation(s)
- Ahmed Ghalgaoui
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay , France
- Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , Max-Born-Strasse 2 a , 12489 Berlin , Germany
| | - Ridha Horchani
- College of Arts and Applied Science , Dhofar University , 211 Salalah , Oman
| | - Jijin Wang
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay , France
| | - Aimeric Ouvrard
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay , France
| | - Serge Carrez
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay , France
| | - Bernard Bourguignon
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay , France
| |
Collapse
|
11
|
Will M, Atodiresei N, Caciuc V, Valerius P, Herbig C, Michely T. A Monolayer of Hexagonal Boron Nitride on Ir(111) as a Template for Cluster Superlattices. ACS NANO 2018; 12:6871-6880. [PMID: 29920200 DOI: 10.1021/acsnano.8b02127] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The moiré of a monolayer of hexagonal boron nitride on Ir(111) is found to be a template for Ir, C, and Au cluster superlattices. Using scanning tunneling microscopy, the cluster structure and epitaxial relation to the substrate, the cluster binding site, the role of defects, as well as the thermal stability of the cluster lattice are investigated. The Ir and C cluster superlattices display a high thermal stability, before they decay by intercalation and Smoluchowski ripening. Ab initio calculations explain the extraordinarily strong Ir cluster binding through selective sp3 rehybridization of boron nitride involving B-Ir cluster bonds and a strengthening of the nitrogen bonds to the Ir substrate in a specific, initially only chemisorbed valley area within the moiré.
Collapse
Affiliation(s)
- Moritz Will
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Nicolae Atodiresei
- Peter Grünberg Institut (PGI-1) and Institute for Advanced Simulation (IAS-1) , Forschungszentrum Jülich and JARA , Jülich D-52425 , Germany
| | - Vasile Caciuc
- Peter Grünberg Institut (PGI-1) and Institute for Advanced Simulation (IAS-1) , Forschungszentrum Jülich and JARA , Jülich D-52425 , Germany
| | - Philipp Valerius
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Charlotte Herbig
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| | - Thomas Michely
- II. Physikalisches Institut , Universität zu Köln , Cologne D-50937 , Germany
| |
Collapse
|
12
|
Liu L, Corma A. Metal Catalysts for Heterogeneous Catalysis: From Single Atoms to Nanoclusters and Nanoparticles. Chem Rev 2018; 118:4981-5079. [PMID: 29658707 PMCID: PMC6061779 DOI: 10.1021/acs.chemrev.7b00776] [Citation(s) in RCA: 1801] [Impact Index Per Article: 300.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
![]()
Metal species with
different size (single atoms, nanoclusters,
and nanoparticles) show different catalytic behavior for various heterogeneous
catalytic reactions. It has been shown in the literature that many
factors including the particle size, shape, chemical composition,
metal–support interaction, and metal–reactant/solvent
interaction can have significant influences on the catalytic properties
of metal catalysts. The recent developments of well-controlled synthesis
methodologies and advanced characterization tools allow one to correlate
the relationships at the molecular level. In this Review, the electronic
and geometric structures of single atoms, nanoclusters, and nanoparticles
will be discussed. Furthermore, we will summarize the catalytic applications
of single atoms, nanoclusters, and nanoparticles for different types
of reactions, including CO oxidation, selective oxidation, selective
hydrogenation, organic reactions, electrocatalytic, and photocatalytic
reactions. We will compare the results obtained from different systems
and try to give a picture on how different types of metal species
work in different reactions and give perspectives on the future directions
toward better understanding of the catalytic behavior of different
metal entities (single atoms, nanoclusters, and nanoparticles) in
a unifying manner.
Collapse
Affiliation(s)
- Lichen Liu
- Instituto de Tecnología Química , Universitat Politécnica de València-Consejo Superior de Investigaciones Científicas (UPV-CSIC) , Avenida de los Naranjos s/n , 46022 Valencia , España
| | - Avelino Corma
- Instituto de Tecnología Química , Universitat Politécnica de València-Consejo Superior de Investigaciones Científicas (UPV-CSIC) , Avenida de los Naranjos s/n , 46022 Valencia , España
| |
Collapse
|
13
|
Campbell CT, Mao Z. Chemical Potential of Metal Atoms in Supported Nanoparticles: Dependence upon Particle Size and Support. ACS Catal 2017. [DOI: 10.1021/acscatal.7b03090] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Charles T. Campbell
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
| | - Zhongtian Mao
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
| |
Collapse
|
14
|
Ghalgaoui A, Ouvrard A, Wang J, Carrez S, Zheng W, Bourguignon B. Electron to Adsorbate Energy Transfer in Nanoparticles: Adsorption Site, Size, and Support Matter. J Phys Chem Lett 2017; 8:2666-2671. [PMID: 28558245 DOI: 10.1021/acs.jpclett.7b00698] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Confinement of hot electrons in metal nanoparticles (NPs) is expected to lead to increased reactivity in heterogeneous catalysis. NP size as well as support may influence molecule-NP coupling. Here, we use ultrafast nonlinear vibrational spectroscopy to follow energy transfer from hot electrons generated in Pd NP/MgO/Ag(100) to chemisorbed CO. Photoexcitation and photodesorption occur on an ultrashort time scale and are selective according to adsorption site. When the MgO layer is thick enough, it becomes NP size-dependent. Hot electron confinement within NPs is unfavorable for photodesorption, presumably because its dominant effect is to increase relaxation to phonons. An avenue of research is open where NP size and support thickness, photon energy, and molecular electronic structure will be tuned to obtain either molecular stability or reactivity in response to photon excitation.
Collapse
Affiliation(s)
- Ahmed Ghalgaoui
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay, France
| | - Aimeric Ouvrard
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay, France
| | - Jijin Wang
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay, France
| | - Serge Carrez
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay, France
| | - Wanquan Zheng
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay, France
| | - Bernard Bourguignon
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay, France
| |
Collapse
|
15
|
Zhang MQ, Zhao YX, Liu QY, Li XN, He SG. Does Each Atom Count in the Reactivity of Vanadia Nanoclusters? J Am Chem Soc 2016; 139:342-347. [DOI: 10.1021/jacs.6b10839] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mei-Qi Zhang
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, Institute of
Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Yan-Xia Zhao
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, Institute of
Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
| | - Qing-Yu Liu
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, Institute of
Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Xiao-Na Li
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, Institute of
Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
| | - Sheng-Gui He
- Beijing
National Laboratory for Molecular Sciences, State Key Laboratory for
Structural Chemistry of Unstable and Stable Species, Institute of
Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
| |
Collapse
|
16
|
Freund HJ. The Surface Science of Catalysis and More, Using Ultrathin Oxide Films as Templates: A Perspective. J Am Chem Soc 2016; 138:8985-96. [PMID: 27380426 DOI: 10.1021/jacs.6b05565] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Surface science has had a major influence on the understanding of processes at surfaces relevant to catalysis. Real catalysts are complex materials, and in order to approach an understanding at the atomic level, it is necessary in a first step to drastically reduce complexity and then systematically increase it again in order to capture the various structural and electronic factors important for the function of the real catalytic material. The use of thin oxide films as templates to mimic three-dimensional supports as such or for metal particles as well as to model charge barriers turns out to be appropriate to approach an understanding of metal-support interactions. Thin oxide films also exhibit properties in their own right that turn out to be relevant in catalysis. Thin oxide film formation may also be used to create unique two-dimensional materials. The present perspective introduces the subject using case studies and indicates possible routes to further apply this approach successfully.
Collapse
Affiliation(s)
- Hans-Joachim Freund
- Fritz-Haber-Institut der Max-Planck Gesellschaft , Department of Chemical Physics, Faradayweg 4-6, 14195 Berlin, Germany
| |
Collapse
|
17
|
The CO oxidation mechanism on small Pd clusters. A theoretical study. J Mol Model 2015; 21:279. [PMID: 26438446 DOI: 10.1007/s00894-015-2828-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 09/22/2015] [Indexed: 10/23/2022]
Abstract
CO is a pollutant that is removed by oxidation using Pd, Pt or Rh as catalysts in the exhaust pipes of vehicles. Here, a quantum chemistry study on the CO + O2 reaction catalyzed by small Pdn clusters (n ≤ 5) using the PBE/TZ2P/ZORA method is performed. The limiting step in this reaction at low temperature and coverage is the O2 dissociation. Pdn clusters catalyze the O=O bond breaking, reducing the energy barrier from 119 kcal mol(-1) without catalyst to ∼35 kcal mol(-1). The charge transfer from Pd to the O2,ad antibonding orbital weakens, and finally breaks the O─O bond. The CO oxidation takes place by the Eley-Rideal (ER) mechanism or the Langmuir-Hinshelwood (LH) mechanism. The ER mechanism presents an energy barrier of 4.10-7.05 kcal mol(-1) and the formed CO2 is released after the reaction. The LH mechanism also shows barrier energies to produce CO2 (7-15 kcal mol(-1)) but it remains adsorbed on Pd clusters. An additional energy (7-25 kcal mol(-1)) is necessary to desorb CO2 and release the metal site. The triplet multiplicity is the ground states of studied Pdn clusters, with the following order of stability: triplet > singlet > quintet state. Graphical Abstract CO oxidation mechanism on small Pd clusters.
Collapse
|
18
|
Smerieri M, Pal J, Savio L, Vattuone L, Ferrando R, Tosoni S, Giordano L, Pacchioni G, Rocca M. Spontaneous Oxidation of Ni Nanoclusters on MgO Monolayers Induced by Segregation of Interfacial Oxygen. J Phys Chem Lett 2015; 6:3104-3109. [PMID: 26267209 DOI: 10.1021/acs.jpclett.5b01362] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report the study of Ni nanoclusters deposited on MgO/Ag(100) ultrathin films (one monolayer) at T = 200 K. We show by STM analysis and DFT calculations that in the limit of low Ni coverage the formation of nanoclusters of four to six atoms occurs and that these aggregates are flat rather than 3D, as expected for Ni tetramers, pentamers, or hexamers. Both the shape of the clusters and the interatomic distance between neighboring Ni atoms are indicative that the nanoparticles do not consist of pure metal atoms but that a NiyOx structure has formed thanks to the availability of atomic oxygen accumulated at the MgO/Ag interface, with Ni clusters acting as oxygen pumps. Besides being of relevance in view of the use of metal nanoclusters in catalysis and other applications, this finding gives a further proof of the peculiar behavior of ultrathin oxide films.
Collapse
Affiliation(s)
- M Smerieri
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - J Pal
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
- ‡Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - L Savio
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - L Vattuone
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
- ‡Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| | - R Ferrando
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
- §Dipartimento di Chimica e Chimica Industriale, Università di Genova, Via Dodecaneso 31, 16146 Genova, Italy
| | - S Tosoni
- ∥Dipartimento di Scienza dei Materiali, Università Milano Bicocca, via R. Cozzi 55, 20125 Milano, Italy
| | - L Giordano
- ∥Dipartimento di Scienza dei Materiali, Università Milano Bicocca, via R. Cozzi 55, 20125 Milano, Italy
| | - G Pacchioni
- ∥Dipartimento di Scienza dei Materiali, Università Milano Bicocca, via R. Cozzi 55, 20125 Milano, Italy
| | - M Rocca
- †IMEM-CNR, U.O.S. Genova, Via Dodecaneso 33, 16146 Genova, Italy
- ‡Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova, Italy
| |
Collapse
|
19
|
Lang SM, Fleischer I, Bernhardt TM, Barnett RN, Landman U. Low-Temperature CO Oxidation Catalyzed by Free Palladium Clusters: Similarities and Differences to Pd Surfaces and Supported Particles. ACS Catal 2015. [DOI: 10.1021/cs5016222] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Sandra M. Lang
- Institute
of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee
47, 89069 Ulm, Germany
| | - Irene Fleischer
- Institute
of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee
47, 89069 Ulm, Germany
| | - Thorsten M. Bernhardt
- Institute
of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee
47, 89069 Ulm, Germany
| | - Robert N. Barnett
- School
of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, United States
| | - Uzi Landman
- School
of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430, United States
| |
Collapse
|
20
|
|
21
|
Heard CJ, Heiles S, Vajda S, Johnston RL. Pd(n)Ag(4-n) and Pd(n)Pt(4-n) clusters on MgO (100): a density functional surface genetic algorithm investigation. NANOSCALE 2014; 6:11777-11788. [PMID: 25158024 DOI: 10.1039/c4nr03363a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The novel surface mode of the Birmingham Cluster Genetic Algorithm (S-BCGA) is employed for the global optimisation of noble metal tetramers upon an MgO (100) substrate at the GGA-DFT level of theory. The effect of element identity and alloying in surface-bound neutral subnanometre clusters is determined by energetic comparison between all compositions of PdnAg(4-n) and PdnPt(4-n). While the binding strengths to the surface increase in the order Pt > Pd > Ag, the excess energy profiles suggest a preference for mixed clusters for both cases. The binding of CO is also modelled, showing that the adsorption site can be predicted solely by electrophilicity. Comparison to CO binding on a single metal atom shows a reversal of the 5σ-d activation process for clusters, weakening the cluster-surface interaction on CO adsorption. Charge localisation determines homotop, CO binding and surface site preferences. The electronic behaviour, which is intermediate between molecular and metallic particles allows for tunable features in the subnanometre size range.
Collapse
Affiliation(s)
- Christopher J Heard
- Department of Applied Physics, Chalmers University of Technology, SE 412-96 Gothenburg, Sweden
| | | | | | | |
Collapse
|
22
|
Hu KJ, Plant SR, Ellis PR, Brown CM, Bishop PT, Palmer RE. The effects of 1-pentyne hydrogenation on the atomic structures of size-selected AuNand PdN(N = 923 and 2057) nanoclusters. Phys Chem Chem Phys 2014; 16:26631-7. [DOI: 10.1039/c4cp02686a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
23
|
Yuan Z, Hanf M, Stephan R, Dulot F, Denys E, Florentin A, Harbich W, Wetzel P. Growth of palladium nanoparticles on nanostructured highly ordered pyrolytic graphite. SURF INTERFACE ANAL 2014. [DOI: 10.1002/sia.5674] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Z. Yuan
- CNRS-UHA; IS2M UMR CNRS 7361-UHA; Mulhouse 68057 France
| | - M.C. Hanf
- CNRS-UHA; IS2M UMR CNRS 7361-UHA; Mulhouse 68057 France
| | - R. Stephan
- CNRS-UHA; IS2M UMR CNRS 7361-UHA; Mulhouse 68057 France
| | - F. Dulot
- CNRS-UHA; IS2M UMR CNRS 7361-UHA; Mulhouse 68057 France
| | - E. Denys
- CNRS-UHA; IS2M UMR CNRS 7361-UHA; Mulhouse 68057 France
| | - A. Florentin
- CNRS-UHA; IS2M UMR CNRS 7361-UHA; Mulhouse 68057 France
| | | | - P. Wetzel
- CNRS-UHA; IS2M UMR CNRS 7361-UHA; Mulhouse 68057 France
| |
Collapse
|
24
|
Bonanni S, Aït-Mansour K, Harbich W, Brune H. Reaction-induced cluster ripening and initial size-dependent reaction rates for CO oxidation on Pt(n)/TiO2(110)-(1×1). J Am Chem Soc 2014; 136:8702-7. [PMID: 24870394 DOI: 10.1021/ja502867r] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We determined the CO oxidation rates for size-selected Ptn (n ∈ {3,7,10}) clusters deposited onto TiO2(110). In addition, we investigated the cluster morphologies and their mean sizes before and after the reaction. While the clusters are fairly stable upon annealing in ultrahigh vacuum up to 600 K, increasing the temperature while adsorbing either one of the two reactants leads to ripening already from 430 K on. This coarsening is even more pronounced when both reactants are dosed simultaneously, i.e., running the CO oxidation reaction. Since the ripening depends on the size initially deposited, there is nevertheless a size effect; the catalytic activity decreases monotonically with increasing initial cluster size.
Collapse
Affiliation(s)
- Simon Bonanni
- Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | | | | | | |
Collapse
|
25
|
Marsault M, Sitja G, Henry CR. Regular arrays of Pd and PdAu clusters on ultrathin alumina films for reactivity studies. Phys Chem Chem Phys 2014; 16:26458-66. [DOI: 10.1039/c4cp02200a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Regular arrays of Pd and PdAu clusters with tunable size and composition supported on nanostructured alumina usable as model catalysts.
Collapse
Affiliation(s)
- M. Marsault
- Centre Interdisciplinaire de Nanoscience de Marseille
- Aix-Marseille Université/CNRS
- UMR 7325
- F-13288 Marseille cedex 09, France
| | - G. Sitja
- Centre Interdisciplinaire de Nanoscience de Marseille
- Aix-Marseille Université/CNRS
- UMR 7325
- F-13288 Marseille cedex 09, France
| | - C. R. Henry
- Centre Interdisciplinaire de Nanoscience de Marseille
- Aix-Marseille Université/CNRS
- UMR 7325
- F-13288 Marseille cedex 09, France
| |
Collapse
|