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Luo Z, Shehzad A. Advances in Naked Metal Clusters for Catalysis. Chemphyschem 2024; 25:e202300715. [PMID: 38450926 DOI: 10.1002/cphc.202300715] [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: 09/30/2023] [Revised: 03/06/2024] [Accepted: 03/07/2024] [Indexed: 03/08/2024]
Abstract
The properties of sub-nano metal clusters are governed by quantum confinement and their large surface-to-bulk ratios, atomically precise compositions and geometric/electronic structures. Advances in metal clusters lead to new opportunities in diverse aspects of sciences including chemo-sensing, bio-imaging, photochemistry, and catalysis. Naked metal clusters having synergic multiple active sites and coordinative unsaturation and tunable stability/activity enable researchers to design atomically precise metal catalysts with tailored catalysis for different reactions. Here we summarize the progress of ligand-free naked metal clusters for catalytic applications. It is anticipated that this review helps to better understand the chemistry of small metal clusters and facilitates the design and development of new catalysts for potential applications.
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Affiliation(s)
- Zhixun Luo
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- School of Chemistry, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Aamir Shehzad
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- School of Chemistry, University of Chinese Academy of Sciences, Beijing, 100049, China
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2
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Rötzer MD, Krause M, Hinke T, Bertrang K, Schweinberger FF, Crampton AS, Heiz U. Same size, same support, same spectator? Selective acetylene hydrogenation on supported Pd nanoparticles. Phys Chem Chem Phys 2024; 26:13740-13750. [PMID: 38683102 DOI: 10.1039/d4cp00719k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2024]
Abstract
The selective hydrogenation of acetylene catalyzed by Pd nanoparticles is industrially used to increase the purity of ethylene. Despite the implementation of Pd based catalysts on an industrial scale, little is known about metal-support interactions on a fundamental level due to the complexity of these systems. In this study, the influence of metal-support interactions between Pd nanoparticles and two electronically modified a-SiO2 thin films on acetylene hydrogenation is investigated under ultra-high vacuum (UHV) conditions. The hydrogenation is performed under isothermal reaction conditions using a pulsed molecular beam reactive scattering (pMBRS) technique. Besides the activity and selectivity of clean Pd particles also the impact of dehydrogenated species intentionally introduced a priori is elucidated, whereas the active phase of the catalyst is additionally characterized by CO infrared reflection-absorption spectroscopy (IRRAS) and post-mortem temperature-programmed reaction (TPR). Metal-support interactions are found to influence the catalytic properties of Pd particles by charge-transfer, where positive charging leads to increased activity for acetylene hydrogenation. However, the increased activity is accompanied by formation of undesired byproducts. The active sites for acetylene and ethylene hydrogenation are shown to be different as previously proposed by the A and E model. The availability of the two different active sites on the Pd nanoparticles is determined by dehydrogenated species, whose nature and stability can be tuned by metal-support interactions. Based on these findings an electronic model is proposed how selectivity for acetylene hydrogenation can be steered solely by metal-support interactions leading to blocking of unselective sites in situ.
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Affiliation(s)
- Marian D Rötzer
- Technical University of Munich, TUM School of Natural Sciences, Chair of Physical Chemistry, Catalysis Research Center, Lichtenbergstrasse 4, Garching bei München, Germany.
| | - Maximilian Krause
- Technical University of Munich, TUM School of Natural Sciences, Chair of Physical Chemistry, Catalysis Research Center, Lichtenbergstrasse 4, Garching bei München, Germany.
| | - Tobias Hinke
- Technical University of Munich, TUM School of Natural Sciences, Chair of Physical Chemistry, Catalysis Research Center, Lichtenbergstrasse 4, Garching bei München, Germany.
| | - Kevin Bertrang
- Technical University of Munich, TUM School of Natural Sciences, Chair of Physical Chemistry, Catalysis Research Center, Lichtenbergstrasse 4, Garching bei München, Germany.
| | - Florian F Schweinberger
- Technical University of Munich, TUM School of Natural Sciences, Chair of Physical Chemistry, Catalysis Research Center, Lichtenbergstrasse 4, Garching bei München, Germany.
| | - Andrew S Crampton
- Technical University of Munich, TUM School of Natural Sciences, Chair of Physical Chemistry, Catalysis Research Center, Lichtenbergstrasse 4, Garching bei München, Germany.
| | - Ueli Heiz
- Technical University of Munich, TUM School of Natural Sciences, Chair of Physical Chemistry, Catalysis Research Center, Lichtenbergstrasse 4, Garching bei München, Germany.
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3
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Yang J, Liu Q, Chen S, Ding X, Chen Y, Cai D, Wang X. Single-Atom and Dual-Atom Electrocatalysts: Synthesis and Applications. Chempluschem 2023; 88:e202300407. [PMID: 37666797 DOI: 10.1002/cplu.202300407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/01/2023] [Accepted: 09/04/2023] [Indexed: 09/06/2023]
Abstract
Distinguishing themselves from nanostructured catalysts, single-atom catalysts (SACs) typically consist of positively charged single metal and coordination atoms without any metal-metal bonds. Dual-atom catalysts (DACs) have emerged as extended family members of SACs in recent years. Both SACs and DACs possess characteristics that combine both homogeneous and heterogeneous catalysis, offering advantages such as uniform active sites and adjustable interactions with ligands, while also inheriting the high stability and recyclability associated with heterogeneous catalyst systems. They offer numerous advantages and are extensively utilized in the field of electrocatalysis, so they have emerged as one of the most prominent material research platforms in the direction of electrocatalysis. This review provides a comprehensive review of SACs and DACs in the field of electrocatalysis: encompassing economic production, elucidating electrocatalytic reaction pathways and associated mechanisms, uncovering structure-performance relationships, and addressing major challenges and opportunities within this domain. Our objective is to present novel ideas for developing advanced synthesis strategies, precisely controlling the microstructure of catalytic active sites, establishing accurate structure-activity relationships, unraveling potential mechanisms underlying electrocatalytic reactions, identifying more efficient reaction paths, and enhancing overall performance in electrocatalytic reactions.
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Affiliation(s)
- Jianjian Yang
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, 515031, P. R. China
| | - Qiang Liu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, P. R. China
| | - Shian Chen
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, 515031, P. R. China
| | - Xiangnong Ding
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, 515031, P. R. China
| | - Yuqi Chen
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, 515031, P. R. China
| | - Dongsong Cai
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, 515031, P. R. China
| | - Xi Wang
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, 515031, P. R. China
- Department of Physics, School of Physical Science and Engineering, Beijing Jiaotong University, Beijing, 100044, P. R. China
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4
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Mass spectrometry in materials synthesis. Trends Analyt Chem 2023. [DOI: 10.1016/j.trac.2023.117010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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5
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Brathwaite AD, Marks JH, Webster IJ, Batchelor AG, Ward TD, Duncan MA. Coordination and Spin States in Fe +(C 2H 2) n Complexes Studied with Selected-Ion Infrared Spectroscopy. J Phys Chem A 2022; 126:9680-9690. [PMID: 36517042 DOI: 10.1021/acs.jpca.2c07556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Fe+(acetylene)n ion-molecule complexes are produced in a supersonic molecular beam with pulsed laser vaporization. These ions are mass selected and studied with infrared photodissociation spectroscopy in the C-H stretching region, complemented by computational chemistry calculations. All C-H stretch vibrations are shifted to frequencies lower than the vibrations of isolated acetylene because of the charge transfer that occurs between the metal ion and the molecules. Complexes in the size range of n = 1-4 are found to have structures with individual acetylene molecules bound to the core metal ion via cation-π interactions. The coordination is completed with four ligands in a structure close to a distorted tetrahedron. Larger complexes in the range of n = 5-8 have external acetylene molecules solvating this n = 4 core ion via CH-π bonding to inner-shell ligands. DFT computations predict that quartet spin states are more stable for all complex sizes, but infrared spectra for quartet and doublet spin states are quite similar, precluding definitive determination of the spin states. There is no evidence for any of these complexes having acetylenes coupled into reacted structures. This is consistent with computed thermochemistry, which finds significant activation barriers to such reactions.
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Affiliation(s)
- Antonio D Brathwaite
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Joshua H Marks
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Ian J Webster
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Anna G Batchelor
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Timothy D Ward
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Michael A Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
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6
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Liang X, Fu N, Yao S, Li Z, Li Y. The Progress and Outlook of Metal Single-Atom-Site Catalysis. J Am Chem Soc 2022; 144:18155-18174. [PMID: 36175359 DOI: 10.1021/jacs.1c12642] [Citation(s) in RCA: 67] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Single-atom-site catalysts (SASCs) featuring maximized atom utilization and isolated active sites have progressed tremendously in recent years as a highly prosperous branch of catalysis research. Varieties of SASCs have been developed that show excellent performance in many catalytic applications. The major goal of SASC research is to establish feasible synthetic strategies for the preparation of high-performance catalysts, to achieve an in-depth understanding of the active-site structures and catalytic mechanisms, and to develop practical catalysts with industrial value. This Perspective describes the up-to-date development of SASCs and related catalysts, such as dual-atom-site catalysts (DASCs) and nano-single-atom-site catalysts (NSASCs), analyzes the current challenges encountered by these catalysts for industrial applications, and proposes their possible future development path.
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Affiliation(s)
- Xiao Liang
- Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
| | - Ninghua Fu
- Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
| | - Shuangchao Yao
- Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China
| | - Zhi Li
- Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.,College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Yadong Li
- Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.,College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China.,Key Laboratory of Functional Molecular Solids, Ministry of Education, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241002, P. R. China
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7
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Gan W, Geng L, Yin B, Zhang H, Luo Z, Hansen K. Cyclotrimerization of Acetylene on Clusters Co n+/Fe n+/Ni n+( n = 1-16). J Phys Chem A 2021; 125:10392-10400. [PMID: 34846886 DOI: 10.1021/acs.jpca.1c09015] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cyclotrimerization of acetylene to benzene has attracted significant interest, but the role of geometric and electronic effects on catalytic chemistry remains unclear. To fully elucidate the mechanism of catalytic acetylene-to-benzene conversion, we have performed a gas-phase reaction study of the Fen+, Con+, and Nin+ (n = 1-16) clusters with acetylene utilizing a customized mass spectrometer. It is found that their reactions with acetylene are initiated by C2H2 molecular adsorption and allow for dominant dehydrogenation with the relatively low partial pressure of the acetylene gas. However, at high acetylene concentrations, the cyclotrimerization in Mn+ + 3C2H2 (M = Fe, Co, Ni) becomes the dominant reaction channel. We demonstrate theoretically the favorable thermodynamics and reaction dynamics leading to the formation of the M+(C6H6) products. The results are discussed in terms of a cluster-catalyzed multimolecule synergistic effect and the cation-π interactions.
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Affiliation(s)
- Wen Gan
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lijun Geng
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Baoqi Yin
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hanyu Zhang
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhixun Luo
- Beijing National Laboratory for Molecular Science, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Klavs Hansen
- Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, 92 Weijin Road, Tianjin 300072, China
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8
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Rodygin KS, Ledovskaya MS, Voronin VV, Lotsman KA, Ananikov VP. Calcium Carbide: Versatile Synthetic Applications, Green Methodology and Sustainability. European J Org Chem 2020. [DOI: 10.1002/ejoc.202001098] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Konstantin S. Rodygin
- Institute of Chemistry Saint Petersburg State University Universitetskiy pr. 26 198504 Saint Petersburg Russia
- N. D. Zelinsky Institute of Organic Chemistry Russian Academy of Sciences Leninsky pr. 47 119991 Moscow Russia
| | - Maria S. Ledovskaya
- Institute of Chemistry Saint Petersburg State University Universitetskiy pr. 26 198504 Saint Petersburg Russia
| | - Vladimir V. Voronin
- Institute of Chemistry Saint Petersburg State University Universitetskiy pr. 26 198504 Saint Petersburg Russia
| | - Kristina A. Lotsman
- Institute of Chemistry Saint Petersburg State University Universitetskiy pr. 26 198504 Saint Petersburg Russia
| | - Valentine P. Ananikov
- Institute of Chemistry Saint Petersburg State University Universitetskiy pr. 26 198504 Saint Petersburg Russia
- N. D. Zelinsky Institute of Organic Chemistry Russian Academy of Sciences Leninsky pr. 47 119991 Moscow Russia
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9
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Marks JH, Ward TB, Brathwaite AD, Duncan MA. Infrared Spectroscopy of Zn(Acetylene)n+ Complexes: Ligand Activation and Nascent Polymerization. J Phys Chem A 2020; 124:4764-4776. [DOI: 10.1021/acs.jpca.0c03358] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joshua H. Marks
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Timothy B. Ward
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | | | - Michael A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
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10
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Li Z, Ji S, Liu Y, Cao X, Tian S, Chen Y, Niu Z, Li Y. Well-Defined Materials for Heterogeneous Catalysis: From Nanoparticles to Isolated Single-Atom Sites. Chem Rev 2019; 120:623-682. [PMID: 31868347 DOI: 10.1021/acs.chemrev.9b00311] [Citation(s) in RCA: 448] [Impact Index Per Article: 89.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The use of well-defined materials in heterogeneous catalysis will open up numerous new opportunities for the development of advanced catalysts to address the global challenges in energy and the environment. This review surveys the roles of nanoparticles and isolated single atom sites in catalytic reactions. In the second section, the effects of size, shape, and metal-support interactions are discussed for nanostructured catalysts. Case studies are summarized to illustrate the dynamics of structure evolution of well-defined nanoparticles under certain reaction conditions. In the third section, we review the syntheses and catalytic applications of isolated single atomic sites anchored on different types of supports. In the final part, we conclude by highlighting the challenges and opportunities of well-defined materials for catalyst development and gaining a fundamental understanding of their active sites.
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Affiliation(s)
- Zhi Li
- Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Shufang Ji
- Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Yiwei Liu
- Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Xing Cao
- Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Shubo Tian
- Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Yuanjun Chen
- Department of Chemistry , Tsinghua University , Beijing 100084 , China
| | - Zhiqiang Niu
- Department of Chemical Engineering , Tsinghua University , Beijing 100084 , China
| | - Yadong Li
- Department of Chemistry , Tsinghua University , Beijing 100084 , China
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11
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Marks JH, Ward TB, Brathwaite AD, Ferguson S, Duncan MA. Cyclotrimerization of Acetylene in Gas Phase V+(C2H2)n Complexes: Detection of Intermediates and Products with Infrared Spectroscopy. J Phys Chem A 2019; 123:6733-6743. [DOI: 10.1021/acs.jpca.9b04962] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joshua H. Marks
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Timothy B. Ward
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | | | - Sojourna Ferguson
- College of Science and Mathematics, University of the Virgin Islands, St. Thomas, United States Virgin Islands 00802
| | - Michael A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
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12
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13
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Ruiz Puigdollers A, Schlexer P, Tosoni S, Pacchioni G. Increasing Oxide Reducibility: The Role of Metal/Oxide Interfaces in the Formation of Oxygen Vacancies. ACS Catal 2017. [DOI: 10.1021/acscatal.7b01913] [Citation(s) in RCA: 423] [Impact Index Per Article: 60.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Antonio Ruiz Puigdollers
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, via R. Cozzi, 55 I-20125 Milano, Italy
| | - Philomena Schlexer
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, via R. Cozzi, 55 I-20125 Milano, Italy
| | - Sergio Tosoni
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, via R. Cozzi, 55 I-20125 Milano, Italy
| | - Gianfranco Pacchioni
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, via R. Cozzi, 55 I-20125 Milano, Italy
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14
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Johnson GE, Gunaratne D, Laskin J. Soft- and reactive landing of ions onto surfaces: Concepts and applications. MASS SPECTROMETRY REVIEWS 2016; 35:439-479. [PMID: 25880894 DOI: 10.1002/mas.21451] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 10/31/2014] [Indexed: 06/04/2023]
Abstract
Soft- and reactive landing of mass-selected ions is gaining attention as a promising approach for the precisely-controlled preparation of materials on surfaces that are not amenable to deposition using conventional methods. A broad range of ionization sources and mass filters are available that make ion soft-landing a versatile tool for surface modification using beams of hyperthermal (<100 eV) ions. The ability to select the mass-to-charge ratio of the ion, its kinetic energy and charge state, along with precise control of the size, shape, and position of the ion beam on the deposition target distinguishes ion soft landing from other surface modification techniques. Soft- and reactive landing have been used to prepare interfaces for practical applications as well as precisely-defined model surfaces for fundamental investigations in chemistry, physics, and materials science. For instance, soft- and reactive landing have been applied to study the surface chemistry of ions isolated in the gas-phase, prepare arrays of proteins for high-throughput biological screening, produce novel carbon-based and polymer materials, enrich the secondary structure of peptides and the chirality of organic molecules, immobilize electrochemically-active proteins and organometallics on electrodes, create thin films of complex molecules, and immobilize catalytically active organometallics as well as ligated metal clusters. In addition, soft landing has enabled investigation of the size-dependent behavior of bare metal clusters in the critical subnanometer size regime where chemical and physical properties do not scale predictably with size. The morphology, aggregation, and immobilization of larger bare metal nanoparticles, which are directly relevant to the design of catalysts as well as improved memory and electronic devices, have also been studied using ion soft landing. This review article begins in section 1 with a brief introduction to the existing applications of ion soft- and reactive landing. Section 2 provides an overview of the ionization sources and mass filters that have been used to date for soft landing of mass-selected ions. A discussion of the competing processes that occur during ion deposition as well as the types of ions and surfaces that have been investigated follows in section 3. Section 4 discusses the physical phenomena that occur during and after ion soft landing, including retention and reduction of ionic charge along with factors that impact the efficiency of ion deposition. The influence of soft landing on the secondary structure and biological activity of complex ions is addressed in section 5. Lastly, an overview of the structure and mobility as well as the catalytic, optical, magnetic, and redox properties of bare ionic clusters and nanoparticles deposited onto surfaces is presented in section 6.
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Affiliation(s)
- Grant E Johnson
- Physical Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, MSIN K8-88, Richland, WA, 99352
| | - Don Gunaratne
- Physical Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, MSIN K8-88, Richland, WA, 99352
| | - Julia Laskin
- Physical Sciences Division, Pacific Northwest National Laboratory, P.O. Box 999, MSIN K8-88, Richland, WA, 99352
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15
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Ma Z, Xiong X, Song C, Hu B, Zhang W. Electronic metal–support interactions enhance the ammonia synthesis activity over ruthenium supported on Zr-modified CeO2 catalysts. RSC Adv 2016. [DOI: 10.1039/c6ra10540h] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Doping Zr4+ alters the electronic properties of the support. The electronic metal–support interaction produces the upshift of d-band center of Ru nanoparticles, which further influences the catalytic activity of ammonia synthesis.
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Affiliation(s)
- Zhanwei Ma
- State Key Laboratory for Oxo Synthesis and Selective Oxidation
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
- China
| | - Xumao Xiong
- State Key Laboratory for Oxo Synthesis and Selective Oxidation
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
- China
| | - Chengli Song
- State Key Laboratory for Oxo Synthesis and Selective Oxidation
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
- China
| | - Bin Hu
- State Key Laboratory for Oxo Synthesis and Selective Oxidation
- Lanzhou Institute of Chemical Physics
- Chinese Academy of Sciences
- Lanzhou 730000
- China
| | - Weiqiang Zhang
- Changchun Zhongke Haorong New Material Research Co., Ltd
- Changchun 130000
- China
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16
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Affiliation(s)
- Stefan Vajda
- Materials
Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Nanoscience
and Technology Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Institute
for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Department
of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520, United States
| | - Michael G. White
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
- Department
of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
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17
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Tyo EC, Vajda S. Catalysis by clusters with precise numbers of atoms. NATURE NANOTECHNOLOGY 2015; 10:577-88. [PMID: 26139144 DOI: 10.1038/nnano.2015.140] [Citation(s) in RCA: 378] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 06/05/2015] [Indexed: 05/26/2023]
Abstract
Clusters that contain only a small number of atoms can exhibit unique and often unexpected properties. The clusters are of particular interest in catalysis because they can act as individual active sites, and minor changes in size and composition--such as the addition or removal of a single atom--can have a substantial influence on the activity and selectivity of a reaction. Here, we review recent progress in the synthesis and characterization of well-defined subnanometre clusters, and the understanding and exploitation of their catalytic properties. We examine work on size-selected supported clusters in ultrahigh-vacuum environments and under realistic reaction conditions, and explore the use of computational methods to provide a mechanistic understanding of their catalytic properties. We also highlight the potential of size-selected clusters to provide insights into important catalytic processes and their use in the development of novel catalytic systems.
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Affiliation(s)
- Eric C Tyo
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Stefan Vajda
- 1] Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA [2] Nanoscience and Technology Division, Argonne National Laboratory, Argonne, Illinois 60439, USA [3] Department of Chemical and Environmental Engineering, School of Engineering, Yale University, New Haven, Connecticut 06520, USA [4] Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, USA
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18
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Watanabe Y. Atomically precise cluster catalysis towards quantum controlled catalysts. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2014; 15:063501. [PMID: 27877723 PMCID: PMC5090382 DOI: 10.1088/1468-6996/15/6/063501] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 10/29/2014] [Accepted: 10/14/2014] [Indexed: 05/30/2023]
Abstract
Catalysis of atomically precise clusters supported on a substrate is reviewed in relation to the type of reactions. The catalytic activity of supported clusters has generally been discussed in terms of electronic structure. Several lines of evidence have indicated that the electronic structure of clusters and the geometry of clusters on a support, including the accompanying cluster-support interaction, are strongly correlated with catalytic activity. The electronic states of small clusters would be easily affected by cluster-support interactions. Several studies have suggested that it is possible to tune the electronic structure through atomic control of the cluster size. It is promising to tune not only the number of cluster atoms, but also the hybridization between the electronic states of the adsorbed reactant molecules and clusters in order to realize a quantum-controlled catalyst.
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19
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Roberts FS, Kane MD, Baxter ET, Anderson SL. Oxygen activation and CO oxidation over size-selected Ptn/alumina/Re(0001) model catalysts: correlations with valence electronic structure, physical structure, and binding sites. Phys Chem Chem Phys 2014; 16:26443-57. [DOI: 10.1039/c4cp02083a] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Trotuş IT, Zimmermann T, Schüth F. Catalytic Reactions of Acetylene: A Feedstock for the Chemical Industry Revisited. Chem Rev 2013; 114:1761-82. [DOI: 10.1021/cr400357r] [Citation(s) in RCA: 254] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Ioan-Teodor Trotuş
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, D-45470 Mülheim, Germany
| | - Tobias Zimmermann
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, D-45470 Mülheim, Germany
| | - Ferdi Schüth
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz
1, D-45470 Mülheim, Germany
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Gross E, Sorek E, Murugadoss A, Asscher M. Reduced oxide sites and surface corrugation affecting the reactivity, thermal stability, and selectivity of supported Au-Pd bimetallic clusters on SiO2/Si(100). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:6025-6031. [PMID: 23659535 DOI: 10.1021/la400005d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The morphology and surface elemental composition of Au-Pd bimetallic nanoclusters are reported to be sensitive to and affected by reduced silicon defect sites and structural corrugation on SiO2/Si(100), generated by argon ion sputtering under ultrahigh vacuum (UHV) conditions. Metastable structures of the bimetallic clusters, where Au atoms are depleted from the top surface upon annealing, are stabilized by the interaction with the reduced silica sites, as indicated from CO temperature programmed desorption (TPD) titration measurements. Acetylene conversion to ethylene and benzene has been studied as a probe reaction, revealing the modification of selectivity and reactivity enhancement in addition to improved thermal stability on substrates rich in reduced-silica sites. These observations suggest that these unique sites play an important role in anchoring thermodynamically metastable conformations of supported Au-Pd bimetallic catalysts and dictate their high-temperature activity.
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Affiliation(s)
- Elad Gross
- Department of Chemistry, University of California-Berkeley , Berkeley, California 94720, United States
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Berr MJ, Schweinberger FF, Döblinger M, Sanwald KE, Wolff C, Breimeier J, Crampton AS, Ridge CJ, Tschurl M, Heiz U, Jäckel F, Feldmann J. Size-selected subnanometer cluster catalysts on semiconductor nanocrystal films for atomic scale insight into photocatalysis. NANO LETTERS 2012; 12:5903-6. [PMID: 23043642 DOI: 10.1021/nl3033069] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We introduce size-selected subnanometer cluster catalysts deposited on thin films of colloidal semiconductor nanocrystals as a novel platform to obtain atomic scale insight into photocatalytic generation of solar fuels. Using Pt-cluster-decorated CdS nanorod films for photocatalytic hydrogen generation as an example, we determine the minimum amount of catalyst necessary to obtain maximum quantum efficiency of hydrogen generation. Further, we provide evidence for tuning photocatalytic activities by precisely controlling the cluster catalyst size.
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Affiliation(s)
- Maximilian J Berr
- Photonics and Optoelectronics Group, Department of Physics and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität München, Amalienstrasse 54, 80799 München, Germany
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Harding C, Habibpour V, Kunz S, Farnbacher ANS, Heiz U, Yoon B, Landman U. Control and Manipulation of Gold Nanocatalysis: Effects of Metal Oxide Support Thickness and Composition. J Am Chem Soc 2008; 131:538-48. [DOI: 10.1021/ja804893b] [Citation(s) in RCA: 183] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chris Harding
- Lehrstuhl für Physikalische Chemie, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany, and School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430
| | - Vahideh Habibpour
- Lehrstuhl für Physikalische Chemie, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany, and School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430
| | - Sebastian Kunz
- Lehrstuhl für Physikalische Chemie, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany, and School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430
| | - Adrian Nam-Su Farnbacher
- Lehrstuhl für Physikalische Chemie, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany, and School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430
| | - Ueli Heiz
- Lehrstuhl für Physikalische Chemie, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany, and School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430
| | - Bokwon Yoon
- Lehrstuhl für Physikalische Chemie, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany, and School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430
| | - Uzi Landman
- Lehrstuhl für Physikalische Chemie, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany, and School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430
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Pacchioni G. Modeling doped and defective oxides in catalysis with density functional theory methods: room for improvements. J Chem Phys 2008; 128:182505. [PMID: 18532790 DOI: 10.1063/1.2819245] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Due to the well-known problem of the self-interaction, standard density functional theory (DFT) methods tend to produce delocalized holes and electrons in defective oxide materials even when there is ample experimental evidence of a strong localization. For late transition metal compounds or rare earth oxides, this results in the incorrect description of the electronic structure of the system (e.g., magnetic insulators are predicted to be metallic). Practical ways to correct this deficiency are based on the use of hybrid functionals or of the DFT+U approach. In this way, most of the limitations related to the self-interaction are removed, and the electronic structure is properly described. What is less clear is to what extent hybrid functionals, DFT+U approaches, or standard DFT functionals can properly describe the strength of the chemical bonds at the surface of an oxide. This is a crucial question if one is interested in the catalytic properties of oxide surfaces. Oxidation reactions often involve oxygen detachment from the surface and incorporation into an organic substrate. Oxides are doped with heteroatoms to create defects and facilitate oxygen removal from the surface, with formation of oxygen vacancies. Do standard DFT calculations provide a good binding energy of the missing oxygen despite the failure in giving the right electronic structure? Can hybrid functionals or the DFT+U approach provide a simple yet reliable way to get accurate reaction enthalpies and energy barriers? In this essay, we discuss these problems by analyzing some case histories and the relatively scarce data existing in the literature. The conclusion is that while modern electronic structure methods accurately reproduce and predict a wide range of electronic, optical, and magnetic properties of oxides, the description of the strength of chemical bonds still needs considerable improvements.
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Affiliation(s)
- Gianfranco Pacchioni
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via R. Cozzi 53, Milan, Italy.
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The role of quantum chemistry in the elucidation of the elementary mechanisms of catalytic processes: from atoms, to surfaces, to enzymes. Theor Chem Acc 2007. [DOI: 10.1007/s00214-006-0199-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Martinez M, del Carmen Michelini M, Rivalta I, Russo N, Sicilia E. Acetylene Cyclotrimerization by Early Second-Row Transition Metals in the Gas Phase. A Theoretical Study. Inorg Chem 2005; 44:9807-16. [PMID: 16363850 DOI: 10.1021/ic051281k] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The acetylene cyclotrimerization reaction mediated by the left-hand-side bare transition metal atoms Y, Zr, Nb, and Mo has been studied theoretically, employing DFT in its B3LYP formulation. The complete reaction mechanism has been analyzed, identifying intermediates and transition states. Both the ground spin state and at least one low-lying excited state have been considered to establish whether possible spin crossings between surfaces of different multiplicity can occur. Our results show that the overall reaction is highly favorable from a thermodynamic point of view and ground state transition states lie always below the energy limit represented by ground state reactants. After the activation of two acetylene molecules and formation of a bis-ligated complex, the reaction proceeds to give a metallacycle intermediate, as the alternative formation of a cyclobutadiene complex is energetically disfavored. All the examined reaction paths involve formation of a metallacycloheptatriene intermediate that in turn generates a metal-benzene adduct from which finally benzene is released. Similarities and differences in the behaviors of the considered four metal atoms have been examined.
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Affiliation(s)
- Mayra Martinez
- Dipartimento di Chimica and Centro di Calcolo ad Alte Prestazioni per Elaborazioni Parallele e Distribuite-Centro d'Eccellenza MURST, Università della Calabria, I-87030 Arcavacata di Rende, Italy
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Schneider H, Boese AD, Weber JM. Unusual hydrogen bonding behavior in binary complexes of coinage metal anions with water. J Chem Phys 2005; 123:084307. [PMID: 16164291 DOI: 10.1063/1.2006092] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have studied the interaction of atomic coinage metal anions with water molecules by infrared photodissociation spectroscopy of M-.H2O.Ar(n) clusters (M=Cu, Ag, Au; n=1, 2). We compare our observations with calculations on density-functional and coupled cluster levels of theory. The gold anion is bound to the water molecule by a single ionic hydrogen bond, similar to the halide-water complexes. In contrast, zero-point motion in the silver and copper complexes leads to a deviation from this motif.
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Affiliation(s)
- Holger Schneider
- Institut für Physikalische Chemie, Universität Karlsruhe, D-76128 Karlsruhe, Germany
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Chou J, Zhang S, Sun S, McFarland EW. Benzene Formation at 70 °C by Coupling of Propylene on Supported Pd Nanoclusters. Angew Chem Int Ed Engl 2005; 44:4735-9. [PMID: 15984040 DOI: 10.1002/anie.200500022] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ju Chou
- Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, LA 70402, USA
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Chou J, Zhang S, Sun S, McFarland EW. Benzene Formation at 70 °C by Coupling of Propylene on Supported Pd Nanoclusters. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200500022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Neyman KM, Illas F. Theoretical aspects of heterogeneous catalysis: Applications of density functional methods. Catal Today 2005. [DOI: 10.1016/j.cattod.2005.04.006] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Antonietti JM, Michalski M, Heiz U, Jones H, Lim KH, Rösch N, Vitto AD, Pacchioni G. Optical absorption spectrum of gold atoms deposited on SiO(2) from cavity ringdown spectroscopy. PHYSICAL REVIEW LETTERS 2005; 94:213402. [PMID: 16090321 DOI: 10.1103/physrevlett.94.213402] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Indexed: 05/03/2023]
Abstract
The optical properties of gold atoms supported on amorphous silica (alpha-SiO2) were studied experimentally and theoretically in the visible range. Samples were prepared in situ by depositing Au atoms at low coverages (5 x 10(12) cm(-2)) in UHV, and the optical absorption spectra were recorded by cavity ringdown spectroscopy. The atomic absorption bands can be attributed to gold atoms trapped at [triple bond] Si-O(.-) and [triple bond]Si-O(-) defect sites. The absence of optical transitions typical for Au(2) shows that the atoms are efficiently anchored at these defect sites, preventing diffusion and aggregation. Furthermore, these experimental results reveal that it is now possible to study optical properties of well-defined nanostructures at surface coverages as low as 5 x 10(11) cm(-2).
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Affiliation(s)
- Jean-Marie Antonietti
- Lehrstuhl für Physikalische Chemie 1, Technische Universität München, D-85747 Garching, Germany.
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Judai K, Wörz AS, Abbet S, Antonietti JM, Heiz U, Del Vitto A, Giordano L, Pacchioni G. Acetylene trimerization on Ag, Pd and Rh atoms deposited on MgO thin films. Phys Chem Chem Phys 2005; 7:955-62. [DOI: 10.1039/b414399j] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Neyman KM, Vayssilov GN, Rösch N. Transition metal clusters and supported species with metal–carbon bonds from first-principles quantum chemistry. J Organomet Chem 2004. [DOI: 10.1016/j.jorganchem.2004.06.042] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Chemistry on single atoms: key factors for the acetylene trimerization on MgO-supported Rh, Pd, and Ag atoms. Chem Phys Lett 2004. [DOI: 10.1016/j.cplett.2004.10.027] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Judai K, Abbet S, Wörz AS, Heiz U, Henry CR. Low-temperature cluster catalysis. J Am Chem Soc 2004; 126:2732-7. [PMID: 14995189 DOI: 10.1021/ja039037k] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Free and supported metal clusters reveal unique chemical and physical properties, which vary as a function of size as each cluster possesses a characteristic electron confinement. Several previous experimental results showed that the outcome of a given chemical reaction can be controlled by tuning the cluster size. However, none of the examples indicate that clusters prepared in the gas phase and then deposited on a support material are indeed catalytically active over several reaction cycles nor that their catalytic properties remain constant during such a catalytic process. In this work we report turn-over frequencies (TOF) for Pd(n) (n = 4, 8, 30) clusters using pulsed molecular beam experiments. The obtained results illustrate that the catalytic reactivity for the NO reduction by CO (CO + NO --> 1/2N(2) + CO(2)) is indeed a function of cluster size and that the measured TOF remain constant at a given temperature. More interestingly, the temperature of maximal reactivity is at least 100 K lower than observed for palladium nanoparticles or single crystals. One reason for this surprising observation is the character of the binding sites of these small clusters: N(2) forms already at relatively low temperatures (400 and 450 K) and therefore poisoning by adsorbed nitrogen adatoms is prevented. Thus, small clusters not only open the possibility of tuning a catalytic process by changing cluster size, but also of catalyzing chemical reactions at low temperatures.
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Affiliation(s)
- Ken Judai
- University of Ulm, Institute of Surface Chemistry and Catalysis, Albert-Einstein-Allee 47, D-89069 Ulm, Germany
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Supported metal species and adsorption complexes on metal oxides and in zeolites: Density functional cluster model studies. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/s1380-7323(04)80025-6] [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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Affiliation(s)
- Gianfranco Pacchioni
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Istituto Nazionale per la Fisica della Materia via R. Cozzi, 53, 20125 Milano, Italy.
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Abstract
Recent experimental advances have uncovered many of the diverse reaction pathways following an energetic collision between a molecular ion and a solid surface. Hyperthermal translational energies (5-500 eV) are sufficient to activate a number of chemical transformations in the near-surface region, including charge transfer, dissociation, abstraction, and deposition. State-of-the-art scattering studies probe the consumption and disposal of energy and the effects of approach geometry and surface electronic structure on the operative reaction mechanisms. These fundamental investigations provide insight relevant to the fabrication of microelectronics devices, the interaction of space vehicles with the earth's atmosphere, and the development of analytical techniques in mass spectrometry.
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Affiliation(s)
- Dennis C Jacobs
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
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Ferrari AM, Giordano L, Pacchioni G, Abbet S, Heiz U. Selectivity of Surface Defects for the Activation of Supported Metal Atoms: Acetylene Cyclotrimerization on Pd1/MgO. J Phys Chem B 2002. [DOI: 10.1021/jp013766+] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Massen C, Mortimer-Jones TV, Johnston RL. Geometries and segregation properties of platinum–palladium nanoalloy clusters. ACTA ACUST UNITED AC 2002. [DOI: 10.1039/b207847c] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abbet S, Riedo E, Brune H, Heiz U, Ferrari AM, Giordano L, Pacchioni G. Identification of defect sites on MgO(100) thin films by decoration with Pd atoms and studying CO adsorption properties. J Am Chem Soc 2001; 123:6172-8. [PMID: 11414852 DOI: 10.1021/ja0157651] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
CO adsorption on Pd atoms deposited on MgO(100) thin films has been studied by means of thermal desorption (TDS) and Fourier transform infrared (FTIR) spectroscopies. CO desorbs from the adsorbed Pd atoms at a temperature of about 250 K, which corresponds to a binding energy, E(b), of about 0.7 +/- 0.1 eV. FTIR spectra suggest that at saturation two different sites for CO adsorption exist on a single Pd atom. The vibrational frequency of the most stable, singly adsorbed CO molecule is 2055 cm(-)(1). Density functional cluster model calculations have been used to model possible defect sites at the MgO surface where the Pd atoms are likely to be adsorbed. CO/Pd complexes located at regular or low-coordinated O anions of the surface exhibit considerably stronger binding energies, E(b) = 2-2.5 eV, and larger vibrational shifts than were observed in the experiment. CO/Pd complexes located at oxygen vacancies (F or F(+) centers) are characterized by much smaller binding energies, E(b) = 0.5 +/- 0.2 or 0.7 +/- 0.2 eV, which are in agreement with the experimental value. CO/Pd complexes located at the paramagnetic F(+) centers show vibrational frequencies in closest agreement with the experimental data. These comparisons therefore suggest that the Pd atoms are mainly adsorbed at oxygen vacancies.
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Affiliation(s)
- S Abbet
- Institut de Physique de la Matière Condensée, Université de Lausanne, CH-1015 Lausanne, Switzerland
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