1
|
Çınar V, Zhang S, Happel EE, K Dewage NTS, Montemore MM, Sykes ECH. 100% selective cyclotrimerization of acetylene to benzene on Ag(111). Chem Sci 2024; 15:6716-6725. [PMID: 38725512 PMCID: PMC11077525 DOI: 10.1039/d4sc01053a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Accepted: 04/03/2024] [Indexed: 05/12/2024] Open
Abstract
Benzene, a high-volume chemical, is produced from larger molecules by inefficient and environmentally harmful processes. Recent changes in hydrocarbon feedstocks from oil to gas motivate research into small molecule upgrading. For example, the cyclotrimerization of acetylene reaction has been demonstrated on Pd, Pd alloy, and Cu surfaces and catalysts, but they are not 100% selective to benzene. We discovered that acetylene can be converted to benzene with 100% selectivity on the Ag(111) surface. Our temperature programmed desorption experiments reveal a threshold acetylene surface coverage of ∼one monolayer, above which benzene is formed. Furthermore, additional layers of acetylene increase the amount of benzene produced while retaining 100% selectivity. Our scanning tunneling microscopy images show that acetylene prefers square packing on the Ag(111) surface at low coverages, which converts to hexagonal packing when acetylene multilayers are present. Within this denser layer, features consistent with the proposed C4 intermediates of the cyclotrimerization process are observed. Density functional theory calculations demonstrate that the barrier for forming the crucial C4 intermediate generally decreases as acetylene multilayers are formed because the multilayer interacts more strongly with the surface in the transition state than in the initial state. Given that acetylene desorbs from Ag(111) at ∼90 K, the C4 intermediate on the pathway to benzene must be formed below this temperature, implying that if Ag-based heterogeneous catalysts can be run at sufficiently high pressure and low enough temperature, efficient and selective trimerization of acetylene to benzene may be possible.
Collapse
Affiliation(s)
- Volkan Çınar
- Department of Chemistry, Tufts University Medford Massachusetts 02155 USA
| | - Shengjie Zhang
- Department of Chemical and Biomolecular Engineering, Tulane University New Orleans Louisiana 70118 USA
| | - Elizabeth E Happel
- Department of Chemistry, Tufts University Medford Massachusetts 02155 USA
| | - Nipun T S K Dewage
- Department of Chemistry, Tufts University Medford Massachusetts 02155 USA
| | - Matthew M Montemore
- Department of Chemical and Biomolecular Engineering, Tulane University New Orleans Louisiana 70118 USA
| | - E Charles H Sykes
- Department of Chemistry, Tufts University Medford Massachusetts 02155 USA
| |
Collapse
|
2
|
Hannagan RT, Lam HY, Réocreux R, Wang Y, Dunbar A, Lal V, Çınar V, Chen Y, Deshlahra P, Stamatakis M, Eagan NM, Sykes ECH. Investigating Spillover Energy as a Descriptor for Single-Atom Alloy Catalyst Design. J Phys Chem Lett 2023; 14:10561-10569. [PMID: 37976045 DOI: 10.1021/acs.jpclett.3c02551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The identification of thermodynamic descriptors of catalytic performance is essential for the rational design of heterogeneous catalysts. Here, we investigate how spillover energy, a descriptor quantifying whether intermediates are more stable at the dopant or host metal sites, can be used to design single-atom alloys (SAAs) for formic acid dehydrogenation. Using theoretical calculations, we identify NiCu as a SAA with favorable spillover energy and demonstrate that formate intermediates produced after the initial O-H activation are more stable at Ni sites where rate-determining C-H activation occurs. Surface science experiments demonstrated that NiCu(111) SAAs are more reactive than Cu(111) while they still follow the formate reaction pathway. However, reactor studies of silica-supported NiCu SAA nanoparticles showed only a modest improvement over Cu resulting from surface coverage effects. Overall, this study demonstrates the potential of engineering SAAs using spillover energy as a design parameter and highlights the importance of adsorbate-adsorbate interactions under steady-state operation.
Collapse
Affiliation(s)
- Ryan T Hannagan
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Ho Yi Lam
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Romain Réocreux
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K
| | - Yicheng Wang
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Andrew Dunbar
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Vinita Lal
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Volkan Çınar
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Yunfan Chen
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Prashant Deshlahra
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Michail Stamatakis
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K
| | - Nathaniel M Eagan
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - E Charles H Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| |
Collapse
|
3
|
Cramer L, Larson A, Daniels AS, Sykes ECH, Gellman AJ. Molecular Origins of Chiral Amplification on an Achiral Surface: 2D Monolayers of Aspartic Acid on Cu(111). ACS Nano 2023; 17:5799-5807. [PMID: 36877997 PMCID: PMC10062026 DOI: 10.1021/acsnano.2c12312] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 02/27/2023] [Indexed: 06/18/2023]
Abstract
Recent experiments have demonstrated an intriguing phenomenon in which adsorption of a nonracemic mixture of aspartic acid (Asp) enantiomers onto an achiral Cu(111) metal surface leads to autoamplification of surface enantiomeric excess, ees, to values well above those of the impinging gas mixtures, eeg. This is particularly interesting because it demonstrates that a slightly nonracemic mixture of enantiomers can be further purified simply by adsorption onto an achiral surface. In this work, we seek a deeper understanding of this phenomena and apply scanning tunneling microscopy to image the overlayer structures formed by mixed monolayers of d- and l-Asp on Cu(111) over the full range of surface enantiomeric excess; ees = -1 (pure l-Asp) through ees = 0 (racemic dl-Asp) to ees = 1 (pure d-Asp). Both enantiomers of three chiral monolayer structures are observed. One is a conglomerate (enantiomerically pure), another is a racemate (equimolar mixture of d- and l-Asp); however, the third structure accommodates both enantiomers in a 2:1 ratio. Such solid phases of enantiomer mixtures with nonracemic composition are rare in 3D crystals of enantiomers. We argue that, in 2D, the formation of chiral defects in a lattice of one enantiomer is easier than in 3D, simply because the stress associated with the chiral defect in a 2D monolayer of the opposite enantiomer can be dissipated by strain into the space above the surface.
Collapse
Affiliation(s)
- Laura
A. Cramer
- Department
of Chemistry, Tufts University, Medford, Massachusetts 02155-5813, United States
| | - Amanda Larson
- Department
of Chemistry, Tufts University, Medford, Massachusetts 02155-5813, United States
| | - Avery S. Daniels
- Department
of Chemistry, Tufts University, Medford, Massachusetts 02155-5813, United States
| | - E. Charles H. Sykes
- Department
of Chemistry, Tufts University, Medford, Massachusetts 02155-5813, United States
| | - Andrew J. Gellman
- Department of Chemical Engineering and W.E. Scott Institute for Energy Innovation, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| |
Collapse
|
4
|
Patel DA, Giannakakis G, Yan G, Ngan HT, Yu P, Hannagan RT, Kress PL, Shan J, Deshlahra P, Sautet P, Sykes ECH. Mechanistic Insights into Nonoxidative Ethanol Dehydrogenation on NiCu Single-Atom Alloys. ACS Catal 2023. [DOI: 10.1021/acscatal.3c00275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/15/2023]
Affiliation(s)
- Dipna A. Patel
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Georgios Giannakakis
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - George Yan
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
| | - Hio Tong Ngan
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
| | - Peng Yu
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Ryan T. Hannagan
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Paul L. Kress
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Junjun Shan
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Prashant Deshlahra
- Department of Chemical and Biological Engineering, Tufts University, Medford, Massachusetts 02155, United States
| | - Philippe Sautet
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - E. Charles H. Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| |
Collapse
|
5
|
Kress PL, Zhang S, Wang Y, Çınar V, Friend CM, Sykes ECH, Montemore MM. A Priori Design of Dual-Atom Alloy Sites and Experimental Demonstration of Ethanol Dehydrogenation and Dehydration on PtCrAg. J Am Chem Soc 2023; 145. [PMID: 36888984 PMCID: PMC10119928 DOI: 10.1021/jacs.2c13577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Indexed: 03/10/2023]
Abstract
Single-atom catalysts have received significant attention for their ability to enable highly selective reactions. However, many reactions require more than one adjacent site to align reactants or break specific bonds. For example, breaking a C-O or O-H bond may be facilitated by a dual site containing an oxophilic element and a carbophilic or "hydrogenphilic" element that binds each molecular fragment. However, design of stable and well-defined dual-atom sites with desirable reactivity is difficult due to the complexity of multicomponent catalytic surfaces. Here, we describe a new type of dual-atom system, trimetallic dual-atom alloys, which were designed via computation of the alloying energetics. Through a broad computational screening we discovered that Pt-Cr dimers embedded in Ag(111) can be formed by virtue of the negative mixing enthalpy of Pt and Cr in Ag and the favorable interaction between Pt and Cr. These dual-atom alloy sites were then realized experimentally through surface science experiments that enabled the active sites to be imaged and their reactivity related to their atomic-scale structure. Specifically, Pt-Cr sites in Ag(111) can convert ethanol, whereas PtAg and CrAg are unreactive toward ethanol. Calculations show that the oxophilic Cr atom and the hydrogenphilic Pt atom act synergistically to break the O-H bond. Furthermore, ensembles with more than one Cr atom, present at higher dopant loadings, produce ethylene. Our calculations have identified many other thermodynamically favorable dual-atom alloy sites, and hence this work highlights a new class of materials that should offer new and useful chemical reactivity beyond the single-atom paradigm.
Collapse
Affiliation(s)
- Paul L. Kress
- Department
of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Shengjie Zhang
- Department
of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, United States
| | - Yicheng Wang
- Department
of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Volkan Çınar
- Department
of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Cynthia M. Friend
- Department
of Chemistry and Chemical Biology, Harvard
University, Cambridge, Massachusetts 02138, United States
| | - E. Charles H. Sykes
- Department
of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Matthew M. Montemore
- Department
of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, United States
| |
Collapse
|
6
|
Zhang S, Sykes ECH, Montemore MM. Tuning reactivity in trimetallic dual-atom alloys: molecular-like electronic states and ensemble effects. Chem Sci 2022; 13:14070-14079. [PMID: 36540824 PMCID: PMC9728513 DOI: 10.1039/d2sc03650a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 11/12/2022] [Indexed: 10/11/2023] Open
Abstract
Single-atom alloys (SAAs) have drawn significant attention in recent years due to their excellent catalytic properties. Controlling the geometry and electronic structure of this type of localized catalytic active site is of fundamental and technological importance. Dual-atom alloys (DAAs) consisting of a heterometallic dimer embedded in the surface layer of a metal host would bring increased tunability and a larger active site, as compared to SAAs. Here, we use computational studies to show that DAAs allow tuning of the active site electronic structure and reactivity. Interestingly, combining two SAAs into a dual-atom site can result in molecular-like hybridization by virtue of the free-atom-like electronic d states exhibited by many SAAs. DAAs can inherit the weak d-d interaction between dopants and hosts from the constituent SAAs, but exhibit new electronic and reactive properties due to dopant-dopant interactions in the DAA. We identify many heterometallic DAAs that we predict to be more stable than either the constituent SAAs or homometallic dual-atom sites of each dopant. We also show how both electronic and ensemble effects can modify the strength of CO adsorption. Because of the molecular-like interactions that can occur, DAAs require a different approach for tuning chemical properties compared to what is used for previous classes of alloys. This work provides insights into the unique catalytic properties of DAAs, and opens up new possibilities for tailoring localized and well-defined catalytic active sites for optimal reaction pathways.
Collapse
Affiliation(s)
- Shengjie Zhang
- Department of Chemical and Biomolecular Engineering, Tulane University New Orleans LA 70118 USA
| | | | - Matthew M Montemore
- Department of Chemical and Biomolecular Engineering, Tulane University New Orleans LA 70118 USA
| |
Collapse
|
7
|
Muramoto E, Patel DA, Chen W, Sautet P, Sykes ECH, Madix RJ. Direct Observation of Solvent–Reaction Intermediate Interactions in Heterogeneously Catalyzed Alcohol Coupling. J Am Chem Soc 2022; 144:17387-17398. [DOI: 10.1021/jacs.2c02199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eri Muramoto
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Dipna A. Patel
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Wei Chen
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Philippe Sautet
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - E. Charles H. Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Robert J. Madix
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, United States
| |
Collapse
|
8
|
Réocreux R, Sykes ECH, Michaelides A, Stamatakis M. Stick or Spill? Scaling Relationships for the Binding Energies of Adsorbates on Single-Atom Alloy Catalysts. J Phys Chem Lett 2022; 13:7314-7319. [PMID: 35917448 PMCID: PMC9376958 DOI: 10.1021/acs.jpclett.2c01519] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 07/28/2022] [Indexed: 05/19/2023]
Abstract
Single-atom alloy catalysts combine catalytically active metal atoms, present as dopants, with the selectivity of coinage metal hosts. Determining whether adsorbates stick at the dopant or spill over onto the host is key to understanding catalytic mechanisms on these materials. Despite a growing body of work, simple descriptors for the prediction of spillover energies (SOEs), i.e., the relative stability of an adsorbate on the dopant versus the host site, are not yet available. Using Density Functional Theory (DFT) calculations on a large set of adsorbates, we identify the dopant charge and the SOE of carbon as suitable descriptors. Combining them into a linear surrogate model, we can reproduce DFT-computed SOEs within 0.06 eV mean absolute error. More importantly, our work provides an intuitive theoretical framework, based on the concepts of electrostatic interactions and covalency, that explains SOE trends and can guide the rational design of future single-atom alloy catalysts.
Collapse
Affiliation(s)
- Romain Réocreux
- Thomas
Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K.
| | - E. Charles H. Sykes
- Department
of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Angelos Michaelides
- Yusuf
Hamied Department of Chemistry, University
of Cambridge, Lensfield Road, Cambridge CB2 1EW , U.K.
| | - Michail Stamatakis
- Thomas
Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K.
| |
Collapse
|
9
|
Wang Y, Schumann J, Happel EE, Çınar V, Sykes ECH, Stamatakis M, Michaelides A, Hannagan RT. Observation and Characterization of Dicarbonyls on a RhCu Single-Atom Alloy. J Phys Chem Lett 2022; 13:6316-6322. [PMID: 35792939 DOI: 10.1021/acs.jpclett.2c01596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Dicarbonyl species are ubiquitous on Rh/oxide catalysts and are known to form on Rh+ centers. However, dicarbonyl species have never been directly observed on single-atom alloys (SAAs) where the active site is metallic. Herein, using surface science and theoretical modeling, we provide evidence of dicarbonyl species at isolated Rh sites on a RhCu(100) SAA. This approach not only enables us to directly visualize dicarbonyl species at Rh sites but also demonstrates that the transition between the mono- and dicarbonyl configuration can be achieved by changing surface temperature and CO pressure. Density functional theory calculations further support the mono- and dicarbonyl assignments and provide evidence that these species should be stable on other SAA combinations. Together, these results provide a picture of the structure and energetics of both the mono- and dicarbonyl configurations on the RhCu(100) SAA surface and should aid with IR assignments on SAA nanoparticle catalysts.
Collapse
Affiliation(s)
- Yicheng Wang
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Julia Schumann
- Department of Chemical Engineering, University College London, London WC1E 7JE, U.K
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K
- Department of Physics and Astronomy, University College London, London WC1E 6BT, U.K
| | - Elizabeth E Happel
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Volkan Çınar
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - E Charles H Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Michail Stamatakis
- Department of Chemical Engineering, University College London, London WC1E 7JE, U.K
| | - Angelos Michaelides
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, U.K
- Department of Physics and Astronomy, University College London, London WC1E 6BT, U.K
| | - Ryan T Hannagan
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| |
Collapse
|
10
|
Giannakakis G, Kress P, Duanmu K, Ngan HT, Yan G, Hoffman AS, Qi Z, Trimpalis A, Annamalai L, Ouyang M, Liu J, Eagan N, Biener J, Sokaras D, Flytzani-Stephanopoulos M, Bare SR, Sautet P, Sykes ECH. Mechanistic and Electronic Insights into a Working NiAu Single-Atom Alloy Ethanol Dehydrogenation Catalyst. J Am Chem Soc 2021; 143:21567-21579. [PMID: 34908398 DOI: 10.1021/jacs.1c09274] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Elucidation of reaction mechanisms and the geometric and electronic structure of the active sites themselves is a challenging, yet essential task in the design of new heterogeneous catalysts. Such investigations are best implemented via a multipronged approach that comprises ambient pressure catalysis, surface science, and theory. Herein, we employ this strategy to understand the workings of NiAu single-atom alloy (SAA) catalysts for the selective nonoxidative dehydrogenation of ethanol to acetaldehyde and hydrogen. The atomic dispersion of Ni is paramount for selective ethanol to acetaldehyde conversion, and we show that even the presence of small Ni ensembles in the Au surface results in the formation of undesirable byproducts via C-C scission. Spectroscopic, kinetic, and theoretical investigations of the reaction mechanism reveal that both C-H and O-H bond cleavage steps are kinetically relevant and single Ni atoms are confirmed as the active sites. X-ray absorption spectroscopy studies allow us to follow the charge of the Ni atoms in the Au host before, under, and after a reaction cycle. Specifically, in the pristine state the Ni atoms carry a partial positive charge that increases upon coordination to the electronegative oxygen in ethanol and decreases upon desorption. This type of oxidation state cycling during reaction is similar to the behavior of single-site homogeneous catalysts. Given the unique electronic structure of many single-site catalysts, such a combined approach in which the atomic-scale catalyst structure and charge state of the single atom dopant can be monitored as a function of its reactive environment is a key step toward developing structure-function relationships that inform the design of new catalysts.
Collapse
Affiliation(s)
- Georgios Giannakakis
- Department of Chemical and Biological Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Paul Kress
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Kaining Duanmu
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
| | - Hio Tong Ngan
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
| | - George Yan
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States
| | - Adam S Hoffman
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Zhen Qi
- Nanoscale Synthesis and Characterization Laboratory, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Antonios Trimpalis
- Department of Chemical and Biological Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Leelavathi Annamalai
- Department of Chemical and Biological Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Mengyao Ouyang
- Department of Chemical and Biological Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Jilei Liu
- Department of Chemical and Biological Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Nathaniel Eagan
- Department of Chemical and Biological Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Juergen Biener
- Nanoscale Synthesis and Characterization Laboratory, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Maria Flytzani-Stephanopoulos
- Department of Chemical and Biological Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Simon R Bare
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Philippe Sautet
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, United States.,Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - E Charles H Sykes
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| |
Collapse
|
11
|
Affiliation(s)
- E Charles H Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Phillip Christopher
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, USA
| | - Jun Li
- Department of Chemistry, Tsinghua University, Beijing 100084, China and Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| |
Collapse
|
12
|
Schumann J, Bao Y, Hannagan RT, Sykes ECH, Stamatakis M, Michaelides A. Periodic Trends in Adsorption Energies around Single-Atom Alloy Active Sites. J Phys Chem Lett 2021; 12:10060-10067. [PMID: 34632767 DOI: 10.1021/acs.jpclett.1c02497] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Single-atom alloys (SAAs) make up a special class of alloy surface catalysts that offer well-defined, isolated active sites in a more inert metal host. The dopant sites are generally assumed to have little or no influence on the properties of the host metal, and transport of chemical reactants and products to and from the dopant sites is generally assumed to be facile. Here, by performing density functional theory calculations and surface science experiments, we identify a new physical effect on SAA surfaces, whereby adsorption is destabilized by ≤300 meV on host sites within the perimeter of the reactive dopant site. We identify periodic trends for this behavior and demonstrate a zone of exclusion around the reactive sites for a range of adsorbates and combinations of host and dopant metals. Experiments confirm an increased barrier for diffusion of CO toward the dopant on a RhCu SAA. This effect offers new possibilities for understanding and designing active sites with tunable energetic landscapes surrounding them.
Collapse
Affiliation(s)
- Julia Schumann
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, U.K
- Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Yutian Bao
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, U.K
| | - Ryan T Hannagan
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - E Charles H Sykes
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Michail Stamatakis
- Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, U.K
| | - Angelos Michaelides
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, U.K
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| |
Collapse
|
13
|
Hannagan RT, Giannakakis G, Réocreux R, Schumann J, Finzel J, Wang Y, Michaelides A, Deshlahra P, Christopher P, Flytzani-Stephanopoulos M, Stamatakis M, Sykes ECH. First-principles design of a single-atom–alloy propane dehydrogenation catalyst. Science 2021. [DOI: 10.1126/science.abg8389] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Rhodium atoms for alkane dehydrogenation
Nanoparticles of rhodium dispersed on metal oxides are generally poor catalysts for alkane dehydrogenation because the reactants bind too strongly to the metal. Hannagan
et al.
performed first-principle calculations indicating that single rhodium atoms in a copper surface should be stable and selective for conversion of propane to propene and hydrogen. Model studies of single rhodium atoms embedded in a copper (111) surface revealed a very high selectivity to propene and high resistance to the formation of surface carbon that would deactivate the catalyst.
Science
, abg8389, this issue p.
1444
Collapse
Affiliation(s)
- Ryan T. Hannagan
- Department of Chemistry, Tufts University, Medford, MA 02155, USA
| | - Georgios Giannakakis
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA 02155, USA
| | - Romain Réocreux
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, UK
| | - Julia Schumann
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, UK
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, UK
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
| | - Jordan Finzel
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Yicheng Wang
- Department of Chemistry, Tufts University, Medford, MA 02155, USA
| | - Angelos Michaelides
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW Cambridge, UK
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
| | - Prashant Deshlahra
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA 02155, USA
| | - Phillip Christopher
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
| | | | - Michail Stamatakis
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, UK
| | | |
Collapse
|
14
|
Hannagan RT, Onyango I, Larson A, McEwen JS, Sykes ECH. Microscopic insights into long-range 1D ordering in a dense semi-disordered molecular overlayer. Chem Commun (Camb) 2021; 57:5937-5940. [PMID: 34014236 DOI: 10.1039/d1cc01574e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The formation of a two-phase surface molecular overlayer that transitions from isolated propene molecules to a highly ordered 1D chain structure on Cu(111) is elucidated through combined high-resolution STM imaging and DFT-based calculations. These models reveal how disordered molecules present in-between the 1D chains stabilizes the system as a whole.
Collapse
Affiliation(s)
- Ryan T Hannagan
- Department of Chemistry, Tufts University, Medford, MA 02155, USA.
| | - Isaac Onyango
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164, USA.
| | - Amanda Larson
- Department of Chemistry, Tufts University, Medford, MA 02155, USA.
| | - Jean-Sabin McEwen
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164, USA. and Department of Chemistry, Washington State University, Pullman, WA 99164, USA and Department of Physics, Washington State University, Pullman, WA 99164, USA and Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164, USA and Institute of Integrated Catalysis, Pacific Northwest National Laboratory, Richland, WA 99354, USA
| | | |
Collapse
|
15
|
Kress P, Réocreux R, Hannagan R, Thuening T, Boscoboinik JA, Stamatakis M, Sykes ECH. Mechanistic insights into carbon-carbon coupling on NiAu and PdAu single-atom alloys. J Chem Phys 2021; 154:204701. [PMID: 34241183 DOI: 10.1063/5.0048977] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Carbon-carbon coupling is an important step in many catalytic reactions, and performing sp3-sp3 carbon-carbon coupling heterogeneously is particularly challenging. It has been reported that PdAu single-atom alloy (SAA) model catalytic surfaces are able to selectively couple methyl groups, producing ethane from methyl iodide. Herein, we extend this study to NiAu SAAs and find that Ni atoms in Au are active for C-I cleavage and selective sp3-sp3 carbon-carbon coupling to produce ethane. Furthermore, we perform ab initio kinetic Monte Carlo simulations that include the effect of the iodine atom, which was previously considered a bystander species. We find that model NiAu surfaces exhibit a similar chemistry to PdAu, but the reason for the similarity is due to the role the iodine atoms play in terms of blocking the Ni atom active sites. Specifically, on NiAu SAAs, the iodine atoms outcompete the methyl groups for occupancy of the Ni sites leaving the Me groups on Au, while on PdAu SAAs, the binding strengths of methyl groups and iodine atoms at the Pd atom active site are more similar. These simulations shed light on the mechanism of this important sp3-sp3 carbon-carbon coupling chemistry on SAAs. Furthermore, we discuss the effect of the iodine atoms on the reaction energetics and make an analogy between the effect of iodine as an active site blocker on this model heterogeneous catalyst and homogeneous catalysts in which ligands must detach in order for the active site to be accessed by the reactants.
Collapse
Affiliation(s)
- Paul Kress
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Romain Réocreux
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, United Kingdom
| | - Ryan Hannagan
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Theodore Thuening
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - J Anibal Boscoboinik
- Brookhaven National Laboratory, Center for Functional Nanomaterials, Upton, New York 11973, USA
| | - Michail Stamatakis
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, United Kingdom
| | - E Charles H Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| |
Collapse
|
16
|
Ouyang M, Papanikolaou KG, Boubnov A, Hoffman AS, Giannakakis G, Bare SR, Stamatakis M, Flytzani-Stephanopoulos M, Sykes ECH. Directing reaction pathways via in situ control of active site geometries in PdAu single-atom alloy catalysts. Nat Commun 2021; 12:1549. [PMID: 33750788 PMCID: PMC7943817 DOI: 10.1038/s41467-021-21555-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 01/28/2021] [Indexed: 01/31/2023] Open
Abstract
The atomic scale structure of the active sites in heterogeneous catalysts is central to their reactivity and selectivity. Therefore, understanding active site stability and evolution under different reaction conditions is key to the design of efficient and robust catalysts. Herein we describe theoretical calculations which predict that carbon monoxide can be used to stabilize different active site geometries in bimetallic alloys and then demonstrate experimentally that the same PdAu bimetallic catalyst can be transitioned between a single-atom alloy and a Pd cluster phase. Each state of the catalyst exhibits distinct selectivity for the dehydrogenation of ethanol reaction with the single-atom alloy phase exhibiting high selectivity to acetaldehyde and hydrogen versus a range of products from Pd clusters. First-principles based Monte Carlo calculations explain the origin of this active site ensemble size tuning effect, and this work serves as a demonstration of what should be a general phenomenon that enables in situ control over catalyst selectivity.
Collapse
Affiliation(s)
- Mengyao Ouyang
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA, USA
| | | | - Alexey Boubnov
- Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Adam S Hoffman
- Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Georgios Giannakakis
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA, USA
| | - Simon R Bare
- Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Michail Stamatakis
- Thomas Young Centre and Department of Chemical Engineering, University College London, London, UK
| | | | | |
Collapse
|
17
|
Wang Y, Papanikolaou KG, Hannagan RT, Patel DA, Balema TA, Cramer LA, Kress PL, Stamatakis M, Sykes ECH. Surface facet dependence of competing alloying mechanisms. J Chem Phys 2020; 153:244702. [DOI: 10.1063/5.0034520] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Affiliation(s)
- Yicheng Wang
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| | - Konstantinos G. Papanikolaou
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, United Kingdom
| | - Ryan T. Hannagan
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| | - Dipna A. Patel
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| | - Tedros A. Balema
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| | - Laura A. Cramer
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| | - Paul L. Kress
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| | - Michail Stamatakis
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, United Kingdom
| | - E. Charles H. Sykes
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| |
Collapse
|
18
|
Larson AM, Balema TA, Zahl P, Schilling AC, Stacchiola DJ, Sykes ECH. Hypothetical Efficiency of Electrical to Mechanical Energy Transfer during Individual Stochastic Molecular Switching Events. ACS Nano 2020; 14:16558-16564. [PMID: 32946215 DOI: 10.1021/acsnano.0c04082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
There are now many examples of single molecule rotors, motors, and switches in the literature that, when driven by photons, electrons, or chemical reactions, exhibit well-defined motions. As a step toward using these single molecule devices to perform useful functions, one must understand how they interact with their environment and quantify their ability to perform work on it. Using a single molecule rotary switch, we examine the transfer of electrical energy, delivered via electron tunneling, to mechanical motion and measure the forces the switch experiences with a noncontact q-plus atomic force microscope. Action spectra reveal that the molecular switch has two stable states and can be excited resonantly between them at a bias of 100 mV via a one-electron inelastic tunneling process which corresponds to an energy input of 16 zJ. While the electrically induced switching events are stochastic and no net work is done on the cantilever, by measuring the forces between the molecular switch and the AFM cantilever, we can derive the maximum hypothetical work the switch could perform during a single switching event, which is ∼55 meV, equal to 8.9 zJ, which translates to a hypothetical efficiency of ∼55% per individual inelastic tunneling electron-induced switching event. When considering the total electrical energy input, this drops to 1 × 10-7% due to elastic tunneling events that dominate the tunneling current. However, this approach constitutes a general method for quantifying and comparing the energy input and output of molecular-mechanical devices.
Collapse
Affiliation(s)
- Amanda M Larson
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Tedros A Balema
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Percy Zahl
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Alex C Schilling
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Dario J Stacchiola
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - E Charles H Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| |
Collapse
|
19
|
Réocreux R, Kress PL, Hannagan RT, Çınar V, Stamatakis M, Sykes ECH. Controlling Hydrocarbon (De)Hydrogenation Pathways with Bifunctional PtCu Single-Atom Alloys. J Phys Chem Lett 2020; 11:8751-8757. [PMID: 32940467 DOI: 10.1021/acs.jpclett.0c02455] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The conversions of surface-bound alkyl groups to alkanes and alkenes are important steps in many heterogeneously catalyzed reactions. On the one hand, while Pt is ubiquitous in industry because of its high activity toward C-H activation, many Pt-based catalysts tend to overbind reactive intermediates, which leads to deactivation by carbon deposition and coke formation. On the other hand, Cu binds intermediates more weakly than Pt, but activation barriers tend to be higher on Cu. We examine the reactivity of ethyl, the simplest alkyl group that can undergo hydrogenation and dehydrogenation via β-elimination, and show that isolated Pt atoms in Cu enable low-temperature hydrogenation of ethyl, unseen on Cu, while avoiding the decomposition pathways on pure Pt that lead to coking. Furthermore, we confirm the predictions of our theoretical model and experimentally demonstrate that the selectivity of ethyl (de)hydrogenation can be controlled by changing the surface coverage of hydrogen.
Collapse
Affiliation(s)
- Romain Réocreux
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, United Kingdom
| | - Paul L Kress
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford 02155, Massachusetts, United States
| | - Ryan T Hannagan
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford 02155, Massachusetts, United States
| | - Volkan Çınar
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford 02155, Massachusetts, United States
| | - Michail Stamatakis
- Thomas Young Centre and Department of Chemical Engineering, University College London, Roberts Building, Torrington Place, London WC1E 7JE, United Kingdom
| | - E Charles H Sykes
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford 02155, Massachusetts, United States
| |
Collapse
|
20
|
Luneau M, Lim JS, Patel DA, Sykes ECH, Friend CM, Sautet P. Guidelines to Achieving High Selectivity for the Hydrogenation of α,β-Unsaturated Aldehydes with Bimetallic and Dilute Alloy Catalysts: A Review. Chem Rev 2020; 120:12834-12872. [DOI: 10.1021/acs.chemrev.0c00582] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Mathilde Luneau
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Jin Soo Lim
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Dipna A. Patel
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - E. Charles H. Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Cynthia M. Friend
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Philippe Sautet
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| |
Collapse
|
21
|
Abstract
Recent studies have shown that the addition of Cu to Ag catalysts improves their epoxidation performance by increasing the overall selectivity of the bimetallic catalyst. We have prepared AgCu near-surface alloys and used scanning tunneling microscopy to gain an atomistic picture of O2 dissociation on the bimetallic system. These data reveal a higher dissociative sticking probability for O2 on AgCu than on Ag(111), and density functional theory (DFT) confirms that the O2 dissociation barrier is 0.17 eV lower on the alloy. Surprisingly, we find that, after a slow initial uptake of O2, the sticking probability increases exponentially. Further DFT calculations indicate that surface oxygen reverses the segregation energy for AgCu, stabilizing Cu atoms in the Ag layer. These single Cu atoms in the Ag surface are found to significantly lower the O2 dissociation barrier. Together, these results explain nonlinear effects in the activation of O2 on this catalytically relevant surface alloy.
Collapse
|
22
|
|
23
|
Cao S, Zhao Y, Lee S, Yang S, Liu J, Giannakakis G, Li M, Ouyang M, Wang D, Sykes ECH, Flytzani-Stephanopoulos M. High-loading single Pt atom sites [Pt-O(OH) x ] catalyze the CO PROX reaction with high activity and selectivity at mild conditions. Sci Adv 2020; 6:eaba3809. [PMID: 32596455 PMCID: PMC7299615 DOI: 10.1126/sciadv.aba3809] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 05/05/2020] [Indexed: 06/11/2023]
Abstract
The preferential oxidation of CO (PROX) in hydrogen-rich fuel gas streams is an attractive option to remove CO while effectively conserving energy and H2. However, high CO conversion with concomitant high selectivity to CO2 but not H2O is challenging. Here, we report the synthesis of high-loading single Pt atom (2.0 weight %) catalysts with oxygen-bonded alkaline ions that stabilize the cationic Pt. The synthesis is performed in aqueous solution and achieves high Pt atom loadings in a single-step incipient wetness impregnation of alumina or silica. Promisingly, these catalysts have high CO PROX selectivity even at high CO conversion (~99.8% conversion, 70% selectivity at 110°C) and good stability under reaction conditions. These findings pave the way for the design of highly efficient single-atom catalysts, elucidate the role of ─OH species in CO oxidation, and confirm the absence of a support effect for our case.
Collapse
Affiliation(s)
- Sufeng Cao
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA 02155, USA
| | - Yanyan Zhao
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
| | - Sungsik Lee
- X-ray Science Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Shize Yang
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jilei Liu
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA 02155, USA
| | - Georgios Giannakakis
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA 02155, USA
| | - Mengwei Li
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA 02155, USA
| | - Mengyao Ouyang
- Department of Chemical and Biological Engineering, Tufts University, Medford, MA 02155, USA
| | - Dunwei Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA
| | - E. Charles H. Sykes
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, MA 02155, USA
| | | |
Collapse
|
24
|
Abstract
Studies of radioactive isotopes at the liquid-solid or gas-solid interface are enabling a detailed mechanistic understanding of the effects of radioactive decay on physical, biological, and chemical systems. In recent years, there has been a burgeoning interest in using radioactive isotopes for both imaging and therapeutic purposes by attaching them to the surface of colloidal nanoparticles. By merging the field of nanomedicine with the more mature field of internal radiation therapy, researchers are discovering new ways to diagnose and treat cancer. In this Perspective, we discuss state-of-the-art radioactive thin films as applied to both well-defined surfaces and more complex nanoparticles. We highlight the design considerations that are unique to radioactive films, which originate from the damaging and potentially self-destructive emissions produced during radioactive decay, and highlight future opportunities in the largely underexplored area between radioisotope chemistry and nanoscience.
Collapse
Affiliation(s)
- Benjamin P Coughlin
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Charles R Mace
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - E Charles H Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| |
Collapse
|
25
|
Schilling AC, Therrien AJ, Hannagan RT, Marcinkowski MD, Kress PL, Patel DA, Balema TA, Larson AM, Lucci FR, Coughlin BP, Zhang R, Thuening T, Çınar V, McEwen JS, Gellman AJ, Sykes ECH. Templated Growth of a Homochiral Thin Film Oxide. ACS Nano 2020; 14:4682-4688. [PMID: 32186852 DOI: 10.1021/acsnano.0c00398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Chiral surfaces are of growing interest for enantioselective adsorption and reactions. While metal surfaces can be prepared with a wide range of chiral surface orientations, chiral oxide surface preparation is more challenging. We demonstrate the chirality of a metal surface can be used to direct the homochiral growth of a thin film chiral oxide. Specifically, we study the chiral "29" copper oxide, formed by oxidizing a Cu(111) single crystal at 650 K. Surface structure spread single crystals, which expose a continuous distribution of surface orientations as a function of position on the crystal, enable us to systematically investigate the mechanism of chirality transfer between the metal and the surface oxide with high-resolution scanning tunneling microscopy. We discover that the local underlying metal facet directs the orientation and chirality of the oxide overlayer. Importantly, single homochiral domains of the "29" oxide were found in areas where the Cu step edges that templated growth were ≤20 nm apart. We use this information to select a Cu(239 241 246) oriented single crystal and demonstrate that a "29" oxide surface can be grown in homochiral domains by templating from the subtle chirality of the underlying metal crystal. This work demonstrates how a small degree of chirality induced by slight misorientation of a metal surface (∼1 sites/20 nm2) can be amplified by oxidation to yield a homochiral oxide with a regular array of chiral oxide pores (∼75 sites/20 nm2). This offers a general approach for making chiral oxide surfaces via oxidation of an appropriately "miscut" metal surface.
Collapse
Affiliation(s)
- Alex C Schilling
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Andrew J Therrien
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Ryan T Hannagan
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | | | - Paul L Kress
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Dipna A Patel
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Tedros A Balema
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Amanda M Larson
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Felicia R Lucci
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Benjamin P Coughlin
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Renqin Zhang
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, United States
| | - Theodore Thuening
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Volkan Çınar
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Jean-Sabin McEwen
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, United States
- Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164, United States
- Department of Chemistry, Washington State University, Pullman, Washington 99164, United States
- Department of Biological Systems Engineering, Washington State University, Pullman, Washington 99164, United States
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Andrew J Gellman
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- W.E. Scott Institute for Energy Innovation, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - E Charles H Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| |
Collapse
|
26
|
Schilling AC, Groden K, Simonovis JP, Hunt A, Hannagan RT, Çınar V, McEwen JS, Sykes ECH, Waluyo I. Accelerated Cu2O Reduction by Single Pt Atoms at the Metal-Oxide Interface. ACS Catal 2020. [DOI: 10.1021/acscatal.9b05270] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alex C. Schilling
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Kyle Groden
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, United States
| | - Juan Pablo Simonovis
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Adrian Hunt
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Ryan T. Hannagan
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Volkan Çınar
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Jean-Sabin McEwen
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, United States
- Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164, United States
- Department of Chemistry, Washington State University, Pullman, Washington 99164, United States
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
- Department of Biological Systems Engineering, Washington State University, Pullman, Washington 99164, United States
| | - E. Charles H. Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Iradwikanari Waluyo
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, United States
| |
Collapse
|
27
|
Hannagan RT, Patel DA, Cramer LA, Schilling AC, Ryan PTP, Larson AM, Çınar V, Wang Y, Balema TA, Sykes ECH. Combining STM, RAIRS and TPD to Decipher the Dispersion and Interactions Between Active Sites in RhCu Single‐Atom Alloys. ChemCatChem 2019. [DOI: 10.1002/cctc.201901488] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Dipna A. Patel
- Department of Chemistry Tufts University Medford MA-02155 USA
| | - Laura A. Cramer
- Department of Chemistry Tufts University Medford MA-02155 USA
| | | | - Paul T. P. Ryan
- Diamond Light Source Harwell Science and Innovation Campus Didcot Oxfordshire OX11 0DE UK
- Department of Materials Imperial College South Kensington London SW7 2AZ UK
| | | | - Volkan Çınar
- Department of Chemistry Tufts University Medford MA-02155 USA
| | - Yicheng Wang
- Department of Chemistry Tufts University Medford MA-02155 USA
| | | | | |
Collapse
|
28
|
Patel DA, Kress PL, Cramer LA, Larson AM, Sykes ECH. Elucidating the composition of PtAg surface alloys with atomic-scale imaging and spectroscopy. J Chem Phys 2019; 151:164705. [DOI: 10.1063/1.5124687] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Dipna A. Patel
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| | - Paul L. Kress
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| | - Laura A. Cramer
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| | - Amanda M. Larson
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| | - E. Charles H. Sykes
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, USA
| |
Collapse
|
29
|
Liu J, Uhlman MB, Montemore MM, Trimpalis A, Giannakakis G, Shan J, Cao S, Hannagan RT, Sykes ECH, Flytzani-Stephanopoulos M. Integrated Catalysis-Surface Science-Theory Approach to Understand Selectivity in the Hydrogenation of 1-Hexyne to 1-Hexene on PdAu Single-Atom Alloy Catalysts. ACS Catal 2019. [DOI: 10.1021/acscatal.9b00491] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
| | | | - Matthew M. Montemore
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | | | | | | | | | | | | | | |
Collapse
|
30
|
|
31
|
Larson AM, Groden K, Hannagan RT, McEwen JS, Sykes ECH. Understanding Enantioselective Interactions by Pulling Apart Molecular Rotor Complexes. ACS Nano 2019; 13:5939-5946. [PMID: 31070888 DOI: 10.1021/acsnano.9b01781] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Enantioselective interactions underpin many important phenomena from biological mechanisms to chemical catalysis. In this regard, there is great interest in understanding these effects at the molecular level. Surfaces provide a platform for these studies and aid in the long-term goal of designing heterogeneous enantiospecific interfaces. Herein we report a model system consisting of molecular rotors, one intrinsically chiral (propylene oxide) and one that becomes chiral when adsorbed on a surface (propene). Scanning tunneling microscopy (STM) measurements enable the chirality of each individual molecule to be directly visualized, and density functional theory based calculations are performed to rationalize the chiral time-averaged appearance of the molecular rotors. While there are no attractive intermolecular interactions between the molecular species themselves, when mixed together there is a strong preference for the formation of 1:1 heteromolecular pairs. We demonstrate that STM tip-induced molecular manipulations can be used to assemble these complexes, examine the chirality of each species, and thereby interrogate if their interactions are enantioselective. A statistical analysis of this data reveals that intrinsically chiral propylene oxide preferentially binds one of the enantiomers of propene with a 3:2 ratio, thereby demonstrating that the surface chirality of small nonchiral molecules can be directed with a chiral modifier. As such, this investigation sheds light onto previously reported ensemble studies in which chirally seeded layers of molecules that are achiral in the gas phase can lead to an amplification of enantioselective adsorption.
Collapse
Affiliation(s)
- Amanda M Larson
- Department of Chemistry , Tufts University , Medford , Massachusetts 02155 , United States
| | - Kyle Groden
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering , Washington State University , Pullman , Washington 99164 , United States
| | - Ryan T Hannagan
- Department of Chemistry , Tufts University , Medford , Massachusetts 02155 , United States
| | - Jean-Sabin McEwen
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering , Washington State University , Pullman , Washington 99164 , United States
- Department of Chemistry , Washington State University , Pullman , Washington 99164 , United States
- Department of Physics , Washington State University , Pullman , Washington 99164 , United States
- Department of Biological Systems Engineering , Washington State University , Pullman , Washington 99164 , United States
- Institute of Integrated Catalysis , Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
| | - E Charles H Sykes
- Department of Chemistry , Tufts University , Medford , Massachusetts 02155 , United States
| |
Collapse
|
32
|
Giannakakis G, Flytzani-Stephanopoulos M, Sykes ECH. Single-Atom Alloys as a Reductionist Approach to the Rational Design of Heterogeneous Catalysts. Acc Chem Res 2019; 52:237-247. [PMID: 30540456 DOI: 10.1021/acs.accounts.8b00490] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Heterogeneous catalysts are workhorses in the industrial production of most commodity and specialty chemicals, and have widespread energy and environmental applications, with the annual market value of the catalysts themselves reaching almost $20 billion in 2018. These catalysts are complex, comprising multicomponent materials and multiple structures, making their rational design challenging, if not impossible. Furthermore, typical active metals like Pt, Pd, and Rh are expensive and can be susceptible to poisoning by CO, coking, and they are not always 100% selective. Efforts to use these elements sparingly and improve their selectivity has led to recent identification of single-atom heterogeneous catalysts in which individual transition metal atoms anchored on oxide or carbon-based supports are excellent catalysts for reactions like the CO oxidation, water-gas shift, alcohol dehydrogenation, and steam reforming. In this Account, we describe a new class of single-atom heterogeneous catalysts, namely, Single-Atom Alloys (SAAs) that comprise catalytically active elements like Pt, Pd, and Ni alloyed in more inert host metals at the single-atom limit. These materials evolved by complementary surface science and scanning probe studies using single crystals, and catalytic evaluation of the corresponding alloy nanoparticles with compositions informed by the surface science findings. The well-defined nature of the active sites in SAAs makes accurate modeling with theory relatively easy, enabling the rational design of SAA catalysts via a complementary three-prong approach, encompassing surface science model catalysts, theory, and real catalyst synthesis and testing under industrially relevant conditions. SAAs constitute one of just a few examples of when heterogeneous catalyst design has been guided by an understanding of fundamental surface processes. The Account starts by describing scanning tunneling microscopy studies of highly dilute alloys formed by doping small amounts of a catalytically active element into a more inert host metal. We first discuss hydrogenation reactions in which dissociation of H2 is often rate limiting. Results indicate how the SAA geometry allows the transition state and the binding site of the reaction intermediates to be decoupled, which enables both facile dissociation of reactants and weak binding of intermediates, two key factors for efficient and selective catalysis. These results were exploited to design the first PtCu SAA hydrogenation catalysts which showed high selectivity, stability and resistance to poisoning in industrially relevant hydrogenation reactions, such as the selective conversion of butadiene to butenes. Model studies also revealed spillover of hydrogen atoms from the Pt site where dissociation of H2 occurs to Cu sites where selective hydrogenation is facilitated in a bifunctional manner. We then discuss selective dehydrogenations on SAAs demonstrating that they enable efficient C-H activation, while being resistant to coking that plagues typical Pt catalysts. SAA PtCu nanoparticle catalysts showed excellent stability in butane dehydrogenation for days-on-stream at 400 °C. Another advantage of SAA catalysts is that on many alloy combinations CO, a common catalyst poison, binds more weakly to the alloy than the pure metal. We conclude by discussing recent theory results that predict the energetics of many key reaction steps on a wide range of SAAs and the exciting possibilities this reductionist approach to heterogeneous catalysis offers for the rational design of new catalysts.
Collapse
Affiliation(s)
- Georgios Giannakakis
- Department of Chemical and Biological Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155 United States
| | - Maria Flytzani-Stephanopoulos
- Department of Chemical and Biological Engineering, Tufts University, 4 Colby Street, Medford, Massachusetts 02155 United States
| | - E. Charles H. Sykes
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155 United States
| |
Collapse
|
33
|
Réocreux R, Uhlman M, Thuening T, Kress P, Hannagan R, Stamatakis M, Sykes ECH. Efficient and selective carbon–carbon coupling on coke-resistant PdAu single-atom alloys. Chem Commun (Camb) 2019; 55:15085-15088. [DOI: 10.1039/c9cc07932g] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We demonstrate that PdAu single-atom alloy model catalysts offer a heterogeneous route to selective Würtz-type C–C coupling.
Collapse
Affiliation(s)
- Romain Réocreux
- Thomas Young Centre and Department of Chemical Engineering
- University College London
- Roberts Building
- London WC1E 7JE
- UK
| | | | | | - Paul Kress
- Department of Chemistry
- Tufts University
- Medford
- USA
| | | | - Michail Stamatakis
- Thomas Young Centre and Department of Chemical Engineering
- University College London
- Roberts Building
- London WC1E 7JE
- UK
| | | |
Collapse
|
34
|
Darby MT, Stamatakis M, Michaelides A, Sykes ECH. Lonely Atoms with Special Gifts: Breaking Linear Scaling Relationships in Heterogeneous Catalysis with Single-Atom Alloys. J Phys Chem Lett 2018; 9:5636-5646. [PMID: 30188735 DOI: 10.1021/acs.jpclett.8b01888] [Citation(s) in RCA: 129] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We discuss a simple yet effective strategy for escaping traditional linear scaling relations in heterogeneous catalysis with highly dilute bimetallic alloys known as single-atom alloys (SAAs). These systems, in which a reactive metal is atomically dispersed in a less reactive host, were first demonstrated with the techniques of surface science to be active and selective for hydrogenation reactions. Informed by these early results, PdCu and PtCu SAA nanoparticle hydrogenation catalysts were shown to work under industrially relevant conditions. To efficiently survey the many potential metal combinations and reactions, simulation is crucial for making predictions about reactivity and guiding experimental focus on the most promising candidate materials. This recent work reveals that the high surface chemical heterogeneity of SAAs can result in significant deviations from Brønsted-Evans-Polanyi scaling relationships for many key reaction steps. These recent insights into SAAs and their ability to break linear scaling relations motivate discovery of novel alloy catalysts.
Collapse
Affiliation(s)
- Matthew T Darby
- Department of Chemical Engineering , University College London , 203 Roberts Building, Torrington Place , London WC1E 7JE , United Kingdom
| | - Michail Stamatakis
- Department of Chemical Engineering , University College London , 203 Roberts Building, Torrington Place , London WC1E 7JE , United Kingdom
| | - Angelos Michaelides
- Thomas Young Centre, London Centre for Nanotechnology and Department of Physics and Astronomy , University College London , Gower Street , London WC1E 6BT , United Kingdom
| | - E Charles H Sykes
- Department of Chemistry , Tufts University , 62 Talbot Avenue , Medford , Massachusetts 02155 , United States
| |
Collapse
|
35
|
Therrien AJ, Groden K, Hensley AJ, Schilling AC, Hannagan RT, Marcinkowski MD, Pronschinske A, Lucci FR, Sykes ECH, McEwen JS. Water activation by single Pt atoms supported on a Cu2O thin film. J Catal 2018. [DOI: 10.1016/j.jcat.2018.04.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
36
|
Liriano ML, Larson AM, Gattinoni C, Carrasco J, Baber AE, Lewis EA, Murphy CJ, Lawton TJ, Marcinkowski MD, Therrien AJ, Michaelides A, Sykes ECH. Chirality at two-dimensional surfaces: A perspective from small molecule alcohol assembly on Au(111). J Chem Phys 2018; 149:034703. [PMID: 30037261 DOI: 10.1063/1.5035500] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The delicate balance between hydrogen bonding and van der Waals interactions determines the stability, structure, and chirality of many molecular and supramolecular aggregates weakly adsorbed on solid surfaces. Yet the inherent complexity of these systems makes their experimental study at the molecular level very challenging. In this quest, small alcohols adsorbed on metal surfaces have become a useful model system to gain fundamental insight into the interplay of such molecule-surface and molecule-molecule interactions. Here, through a combination of scanning tunneling microscopy and density functional theory, we compare and contrast the adsorption and self-assembly of a range of small alcohols from methanol to butanol on Au(111). We find that longer chained alcohols prefer to form zigzag chains held together by extended hydrogen bonded networks between adjacent molecules. When alcohols bind to a metal surface datively via one of the two lone electron pairs of the oxygen atom, they become chiral. Therefore, the chain structures are formed by a hydrogen-bonded network between adjacent molecules with alternating adsorbed chirality. These chain structures accommodate longer alkyl tails through larger unit cells, while the position of the hydroxyl group within the alcohol molecule can produce denser unit cells that maximize intermolecular interactions. Interestingly, when intrinsic chirality is introduced into the molecule as in the case of 2-butanol, the assembly changes completely and square packing structures with chiral pockets are observed. This is rationalized by the fact that the intrinsic chirality of the molecule directs the chirality of the adsorbed hydroxyl group meaning that heterochiral chain structures cannot form. Overall this study provides a general framework for understanding the effect of simple alcohol molecular adstructures on hydrogen bonded aggregates and paves the way for rationalizing 2D chiral supramolecular assembly.
Collapse
Affiliation(s)
- Melissa L Liriano
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Amanda M Larson
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Chiara Gattinoni
- Thomas Young Centre, London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - Javier Carrasco
- CIC Energigune, Albert Einstein 48, 01510 Miñano, Álava, Spain
| | - Ashleigh E Baber
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Emily A Lewis
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Colin J Murphy
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Timothy J Lawton
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | | | - Andrew J Therrien
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Angelos Michaelides
- Thomas Young Centre, London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - E Charles H Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| |
Collapse
|
37
|
Therrien AJ, Hensley AJR, Marcinkowski MD, Zhang R, Lucci FR, Coughlin B, Schilling AC, McEwen JS, Sykes ECH. An atomic-scale view of single-site Pt catalysis for low-temperature CO oxidation. Nat Catal 2018. [DOI: 10.1038/s41929-018-0028-2] [Citation(s) in RCA: 232] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
38
|
Lewis EA, Marcinkowski MD, Murphy CJ, Liriano ML, Therrien AJ, Pronschinske A, Sykes ECH. Controlling selectivity in the Ullmann reaction on Cu(111). Chem Commun (Camb) 2018; 53:7816-7819. [PMID: 28653058 DOI: 10.1039/c7cc02901b] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Using a surface science approach, the selectivity in the Ullmann cross-coupling of aryl halides on Cu(111) has been understood and controlled. The binding strength of the reactants and repulsion between them dictates which organometallic intermediates form, and hence the product distribution. Cross coupling can be maximized at low reactant concentrations.
Collapse
Affiliation(s)
- E A Lewis
- Department of Chemistry, Tufts University, 62 Talbot Ave., Medford, MA 02155, USA.
| | | | | | | | | | | | | |
Collapse
|
39
|
Therrien AJ, Hensley AJR, Zhang R, Pronschinske A, Marcinkowski MD, McEwen JS, Sykes ECH. Characterizing the geometric and electronic structure of defects in the “29” copper surface oxide. J Chem Phys 2017; 147:224706. [DOI: 10.1063/1.4996729] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Andrew J. Therrien
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Alyssa J. R. Hensley
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, USA
| | - Renqin Zhang
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, USA
| | - Alex Pronschinske
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | | | - Jean-Sabin McEwen
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington 99164, USA
- Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164, USA
- Department of Chemistry, Washington State University, Pullman, Washington 99164, USA
- Institute for Integrated Catalysis, Pacific Northwest National Laboratory, Richland, Washington 99352, USA
| | - E. Charles H. Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| |
Collapse
|
40
|
Liriano ML, Gattinoni C, Lewis EA, Murphy CJ, Sykes ECH, Michaelides A. Water-Ice Analogues of Polycyclic Aromatic Hydrocarbons: Water Nanoclusters on Cu(111). J Am Chem Soc 2017; 139:6403-6410. [PMID: 28418246 PMCID: PMC5432957 DOI: 10.1021/jacs.7b01883] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
![]()
Water has an incredible ability to
form a rich variety of structures,
with 16 bulk ice phases identified, for example, as well as numerous
distinct structures for water at interfaces or under confinement.
Many of these structures are built from hexagonal motifs of water
molecules, and indeed, for water on metal surfaces, individual hexamers
of just six water molecules have been observed. Here, we report the
results of low-temperature scanning tunneling microscopy experiments
and density functional theory calculations which reveal a host of
new structures for water–ice nanoclusters when adsorbed on
an atomically flat Cu surface. The H-bonding networks within the nanoclusters
resemble the resonance structures of polycyclic aromatic hydrocarbons,
and water–ice analogues of inene, naphthalene, phenalene, anthracene,
phenanthrene, and triphenylene have been observed. The specific structures
identified and the H-bonding patterns within them reveal new insight
about water on metals that allows us to refine the so-called “2D
ice rules”, which have so far proved useful in understanding
water–ice structures at solid surfaces.
Collapse
Affiliation(s)
- Melissa L Liriano
- Department of Chemistry, Tufts University , Medford, Massachusetts 02155, United States
| | - Chiara Gattinoni
- Thomas Young Centre, Department of Physics and Astronomy, London Centre for Nanotechnology, University College London , Gower Street, London WC1E 6BT, U.K
| | - Emily A Lewis
- Department of Chemistry, Tufts University , Medford, Massachusetts 02155, United States
| | - Colin J Murphy
- Department of Chemistry, Tufts University , Medford, Massachusetts 02155, United States.,Competence Centre for Catalysis, Chalmers University of Technology , SE-412 96 Gothenburg, Sweden
| | - E Charles H Sykes
- Department of Chemistry, Tufts University , Medford, Massachusetts 02155, United States
| | - Angelos Michaelides
- Thomas Young Centre, Department of Physics and Astronomy, London Centre for Nanotechnology, University College London , Gower Street, London WC1E 6BT, U.K
| |
Collapse
|
41
|
Beniwal S, Hooper J, Miller DP, Costa PS, Chen G, Liu SY, Dowben PA, Sykes ECH, Zurek E, Enders A. Graphene-like Boron-Carbon-Nitrogen Monolayers. ACS Nano 2017; 11:2486-2493. [PMID: 28165713 DOI: 10.1021/acsnano.6b08136] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A strategy to synthesize a 2D graphenic but ternary monolayer containing atoms of carbon, nitrogen, and boron, h-BCN, is presented. The synthesis utilizes bis-BN cyclohexane, B2N2C2H12, as a precursor molecule and relies on thermally induced dehydrogenation of the precursor molecules and the formation of an epitaxial monolayer on Ir(111) through covalent bond formation. The lattice mismatch between the film and substrate causes a strain-driven periodic buckling of the film. The structure of the film and its corrugated morphology is discussed based on comprehensive data from molecular-resolved scanning tunneling microscopy imaging, X-ray photoelectron spectroscopy, low-energy electron diffraction, and density functional theory. First-principles calculations further predict a direct electronic band gap that is intermediate between gapless graphene and insulating h-BN.
Collapse
Affiliation(s)
- Sumit Beniwal
- Department of Physics & Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States
| | - James Hooper
- Department of Theoretical Chemistry, Faculty of Chemistry, Jagiellonian University , Krakow, Poland 30-060
| | - Daniel P Miller
- Department of Chemistry, State University of New York at Buffalo , Buffalo, New York 14260-3000, United States
| | - Paulo S Costa
- Department of Physics & Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States
| | - Gang Chen
- Department of Chemistry, Boston College , Chestnut Hill, Massachusetts 02467-3860, United States
| | - Shih-Yuan Liu
- Department of Chemistry, Boston College , Chestnut Hill, Massachusetts 02467-3860, United States
| | - Peter A Dowben
- Department of Physics & Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States
| | - E Charles H Sykes
- Department of Chemistry, Tufts University , Medford, Massachusetts 02155, United States
| | - Eva Zurek
- Department of Chemistry, State University of New York at Buffalo , Buffalo, New York 14260-3000, United States
| | - Axel Enders
- Department of Physics & Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States
- Physikalisches Institut, Universität Bayreuth , 95440 Bayreuth, Germany
| |
Collapse
|
42
|
Liu J, Shan J, Lucci FR, Cao S, Sykes ECH, Flytzani-Stephanopoulos M. Palladium–gold single atom alloy catalysts for liquid phase selective hydrogenation of 1-hexyne. Catal Sci Technol 2017. [DOI: 10.1039/c7cy00794a] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Silica supported and unsupported PdAu single atom alloys (SAAs) were investigated for the selective hydrogenation of 1-hexyne to hexenes under mild conditions.
Collapse
Affiliation(s)
- Jilei Liu
- Department of Chemical and Biological Engineering
- Tufts University
- Medford
- USA
| | - Junjun Shan
- Department of Chemical and Biological Engineering
- Tufts University
- Medford
- USA
| | | | - Sufeng Cao
- Department of Chemical and Biological Engineering
- Tufts University
- Medford
- USA
| | | | | |
Collapse
|
43
|
Marcinkowski MD, Liu J, Murphy CJ, Liriano ML, Wasio NA, Lucci FR, Flytzani-Stephanopoulos M, Sykes ECH. Selective Formic Acid Dehydrogenation on Pt-Cu Single-Atom Alloys. ACS Catal 2016. [DOI: 10.1021/acscatal.6b02772] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthew D. Marcinkowski
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Jilei Liu
- Department
of Chemical and Biological Engineering, Tufts University, 4
Colby Street, Medford, Massachusetts 02155, United States
| | - Colin J. Murphy
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Melissa L. Liriano
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Natalie A. Wasio
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Felicia R. Lucci
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Maria Flytzani-Stephanopoulos
- Department
of Chemical and Biological Engineering, Tufts University, 4
Colby Street, Medford, Massachusetts 02155, United States
| | - E. Charles H. Sykes
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| |
Collapse
|
44
|
Liu J, Lucci FR, Yang M, Lee S, Marcinkowski MD, Therrien AJ, Williams CT, Sykes ECH, Flytzani-Stephanopoulos M. Tackling CO Poisoning with Single-Atom Alloy Catalysts. J Am Chem Soc 2016; 138:6396-9. [DOI: 10.1021/jacs.6b03339] [Citation(s) in RCA: 296] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Jilei Liu
- Department
of Chemical and Biological Engineering, Tufts University, 4
Colby Street, Medford, Massachusetts 02155, United States
| | - Felicia R. Lucci
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Ming Yang
- Department
of Chemical and Biological Engineering, Tufts University, 4
Colby Street, Medford, Massachusetts 02155, United States
| | - Sungsik Lee
- X-ray
Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Matthew D. Marcinkowski
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Andrew J. Therrien
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Christopher T. Williams
- Department
of Chemical Engineering, University of South Carolina, 301 Main Street, Columbia, South Carolina 29208, United States
| | - E. Charles H. Sykes
- Department
of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Maria Flytzani-Stephanopoulos
- Department
of Chemical and Biological Engineering, Tufts University, 4
Colby Street, Medford, Massachusetts 02155, United States
| |
Collapse
|
45
|
Murphy CJ, Smith ZC, Pronschinski A, Lewis EA, Liriano ML, Wong C, Ivimey CJ, Duffy M, Musial W, Therrien AJ, Thomas SW, Sykes ECH. Ullmann coupling mediated assembly of an electrically driven altitudinal molecular rotor. Phys Chem Chem Phys 2016; 17:31931-7. [PMID: 26567846 DOI: 10.1039/c5cp05294g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Surface-bound molecular rotation can occur with the rotational axis either perpendicular (azimuthal) or parallel (altitudinal) to the surface. The majority of molecular rotor studies involve azimuthal rotors, whereas very few altitudinal rotors have been reported. In this work, altitudinal rotors are formed by means of coupling aryl halides through a surface-mediated Ullmann coupling reaction, producing a reaction state-dependent altitudinal molecular rotor/stator. All steps in the reaction on a Cu(111) surface are visualized by low-temperature scanning tunneling microscopy. The intermediate stage of the coupling reaction is a metal-organic complex consisting of two aryl groups attached to a single copper atom with the aryl rings angled away from the surface. This conformation leads to nearly unhindered rotational motion of ethyl groups at the para positions of the aryl rings. Rotational events of the ethyl group are both induced and quantified by electron tunneling current versus time measurements and are only observed for the intermediate structure of the Ullmann coupling reaction, not the starting material or finished product in which the ethyl groups are static. We perform an extensive set of inelastic electron tunneling driven rotation experiments that reveal that torsional motion around the ethyl group is stimulated by tunneling electrons in a one-electron process with an excitation energy threshold of 45 meV. This chemically tunable system offers an ideal platform for examining many fundamental aspects of the dynamics of chemically tunable molecular rotor and motors.
Collapse
Affiliation(s)
- Colin J Murphy
- Department of Chemistry, Tufts University, Medford, MA 02155, USA.
| | - Zachary C Smith
- Department of Chemistry, Tufts University, Medford, MA 02155, USA.
| | | | - Emily A Lewis
- Department of Chemistry, Tufts University, Medford, MA 02155, USA.
| | | | - Chloe Wong
- Department of Chemistry, Tufts University, Medford, MA 02155, USA.
| | | | - Mitchell Duffy
- Department of Chemistry, Tufts University, Medford, MA 02155, USA.
| | - Wojciech Musial
- Department of Chemistry, Tufts University, Medford, MA 02155, USA.
| | | | - Samuel W Thomas
- Department of Chemistry, Tufts University, Medford, MA 02155, USA.
| | | |
Collapse
|
46
|
Liriano ML, Carrasco J, Lewis EA, Murphy CJ, Lawton TJ, Marcinkowski MD, Therrien AJ, Michaelides A, Sykes ECH. The interplay of covalency, hydrogen bonding, and dispersion leads to a long range chiral network: The example of 2-butanol. J Chem Phys 2016; 144:094703. [DOI: 10.1063/1.4941560] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Melissa L. Liriano
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Javier Carrasco
- CIC Energigune, Albert Einstein 48, 01510 Miñano, Álava, Spain
| | - Emily A. Lewis
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Colin J. Murphy
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Timothy J. Lawton
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | | | - Andrew J. Therrien
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| | - Angelos Michaelides
- Thomas Young Centre, London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom
| | - E. Charles H. Sykes
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
| |
Collapse
|
47
|
Pronschinske A, Pedevilla P, Coughlin B, Murphy CJ, Lucci FR, Payne MA, Gellman AJ, Michaelides A, Sykes ECH. Atomic-Scale Picture of the Composition, Decay, and Oxidation of Two-Dimensional Radioactive Films. ACS Nano 2016; 10:2152-2158. [PMID: 26735687 DOI: 10.1021/acsnano.5b06640] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Two-dimensional radioactive (125)I monolayers are a recent development that combines the fields of radiochemistry and nanoscience. These Au-supported monolayers show great promise for understanding the local interaction of radiation with 2D molecular layers, offer different directions for surface patterning, and enhance the emission of chemically and biologically relevant low-energy electrons. However, the elemental composition of these monolayers is in constant flux due to the nuclear transmutation of (125)I to (125)Te, and their precise composition and stability under ambient conditions has yet to be elucidated. Unlike I, which is stable and unreactive when bound to Au, the newly formed Te atoms would be expected to be more reactive. We have used electron emission and X-ray photoelectron spectroscopy (XPS) to quantify the emitted electron energies and to track the film composition in vacuum and the effect of exposure to ambient conditions. Our results reveal that the Auger electrons emitted during the ultrafast radioactive decay process have a kinetic energy corresponding to neutral Te. By combining XPS and scanning tunneling microscopy experiments with density functional theory, we are able to identify the reaction of newly formed Te to TeO2 and its subsequent dimerization. The fact that the Te2O4 units stay intact during major lateral rearrangement of the monolayer illustrates their stability. These results provide an atomic-scale picture of the composition and mobility of surface species in a radioactive monolayer as well as an understanding of the stability of the films under ambient conditions, which is a critical aspect in their future applications.
Collapse
Affiliation(s)
- Alex Pronschinske
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Philipp Pedevilla
- Thomas Young Centre, London Centre for Nanotechnology and Department of Chemistry, University College London , London WC1E 6BT, United Kingdom
| | - Benjamin Coughlin
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Colin J Murphy
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Felicia R Lucci
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Matthew A Payne
- Department of Chemical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Andrew J Gellman
- Department of Chemical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States
| | - Angelos Michaelides
- Thomas Young Centre, London Centre for Nanotechnology and Department of Chemistry, University College London , London WC1E 6BT, United Kingdom
| | - E Charles H Sykes
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| |
Collapse
|
48
|
Lucci FR, Darby MT, Mattera MFG, Ivimey CJ, Therrien AJ, Michaelides A, Stamatakis M, Sykes ECH. Controlling Hydrogen Activation, Spillover, and Desorption with Pd-Au Single-Atom Alloys. J Phys Chem Lett 2016; 7:480-5. [PMID: 26747698 DOI: 10.1021/acs.jpclett.5b02400] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Key descriptors in hydrogenation catalysis are the nature of the active sites for H2 activation and the adsorption strength of H atoms to the surface. Using atomically resolved model systems of dilute Pd-Au surface alloys and density functional theory calculations, we determine key aspects of H2 activation, diffusion, and desorption. Pd monomers in a Au(111) surface catalyze the dissociative adsorption of H2 at temperatures as low as 85 K, a process previously expected to require contiguous Pd sites. H atoms preside at the Pd sites and desorb at temperatures significantly lower than those from pure Pd (175 versus 310 K). This facile H2 activation and weak adsorption of H atom intermediates are key requirements for active and selective hydrogenations. We also demonstrate weak adsorption of CO, a common catalyst poison, which is sufficient to force H atoms to spill over from Pd to Au sites, as evidenced by low-temperature H2 desorption.
Collapse
Affiliation(s)
- Felicia R Lucci
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Matthew T Darby
- Thomas Young Centre and Department of Chemical Engineering, University College London , Roberts Building, Torrington Place, London WC1E 7JE, United Kingdom
| | - Michael F G Mattera
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Christopher J Ivimey
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Andrew J Therrien
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| | - Angelos Michaelides
- Thomas Young Centre, London Centre for Nanotechnology and Department of Physics and Astronomy, University College London , 17-19 Gordon Street, London WC1H 0AH, United Kingdom
| | - Michail Stamatakis
- Thomas Young Centre and Department of Chemical Engineering, University College London , Roberts Building, Torrington Place, London WC1E 7JE, United Kingdom
| | - E Charles H Sykes
- Department of Chemistry, Tufts University , 62 Talbot Avenue, Medford, Massachusetts 02155, United States
| |
Collapse
|
49
|
Marcinkowski MD, Murphy CJ, Liriano ML, Wasio NA, Lucci FR, Sykes ECH. Microscopic View of the Active Sites for Selective Dehydrogenation of Formic Acid on Cu(111). ACS Catal 2015. [DOI: 10.1021/acscatal.5b01994] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Matthew D. Marcinkowski
- Department of Chemistry, Tufts University, 62 Talbot
Avenue, Medford, Massachusetts 02155, United States
| | - Colin J. Murphy
- Department of Chemistry, Tufts University, 62 Talbot
Avenue, Medford, Massachusetts 02155, United States
| | - Melissa L. Liriano
- Department of Chemistry, Tufts University, 62 Talbot
Avenue, Medford, Massachusetts 02155, United States
| | - Natalie A. Wasio
- Department of Chemistry, Tufts University, 62 Talbot
Avenue, Medford, Massachusetts 02155, United States
| | - Felicia R. Lucci
- Department of Chemistry, Tufts University, 62 Talbot
Avenue, Medford, Massachusetts 02155, United States
| | - E. Charles H. Sykes
- Department of Chemistry, Tufts University, 62 Talbot
Avenue, Medford, Massachusetts 02155, United States
| |
Collapse
|
50
|
Sykes ECH, Steinrück HP. Taking a Nanoscale "Look" at Chemical Reactions on Surfaces. Acc Chem Res 2015; 48:2661. [PMID: 26481329 DOI: 10.1021/acs.accounts.5b00432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|