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Liu L, Corma A. Bimetallic Sites for Catalysis: From Binuclear Metal Sites to Bimetallic Nanoclusters and Nanoparticles. Chem Rev 2023; 123:4855-4933. [PMID: 36971499 PMCID: PMC10141355 DOI: 10.1021/acs.chemrev.2c00733] [Citation(s) in RCA: 37] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Indexed: 03/29/2023]
Abstract
Heterogeneous bimetallic catalysts have broad applications in industrial processes, but achieving a fundamental understanding on the nature of the active sites in bimetallic catalysts at the atomic and molecular level is very challenging due to the structural complexity of the bimetallic catalysts. Comparing the structural features and the catalytic performances of different bimetallic entities will favor the formation of a unified understanding of the structure-reactivity relationships in heterogeneous bimetallic catalysts and thereby facilitate the upgrading of the current bimetallic catalysts. In this review, we will discuss the geometric and electronic structures of three representative types of bimetallic catalysts (bimetallic binuclear sites, bimetallic nanoclusters, and nanoparticles) and then summarize the synthesis methodologies and characterization techniques for different bimetallic entities, with emphasis on the recent progress made in the past decade. The catalytic applications of supported bimetallic binuclear sites, bimetallic nanoclusters, and nanoparticles for a series of important reactions are discussed. Finally, we will discuss the future research directions of catalysis based on supported bimetallic catalysts and, more generally, the prospective developments of heterogeneous catalysis in both fundamental research and practical applications.
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Affiliation(s)
- Lichen Liu
- Department
of Chemistry, Tsinghua University, Beijing 100084, China
| | - Avelino Corma
- Instituto
de Tecnología Química, Universitat
Politècnica de València−Consejo Superior de Investigaciones
Científicas (UPV-CSIC), Avenida de los Naranjos s/n, Valencia 46022, Spain
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2
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Takazawa S, Kang J, Abe M, Uematsu H, Ishiguro N, Takahashi Y. Demonstration of single-frame coherent X-ray diffraction imaging using triangular aperture: Towards dynamic nanoimaging of extended objects. OPTICS EXPRESS 2021; 29:14394-14402. [PMID: 33985163 DOI: 10.1364/oe.419998] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 04/16/2021] [Indexed: 06/12/2023]
Abstract
Coherent diffraction imaging (CDI) is a powerful method for visualizing the structure of an object with a high spatial resolution that exceeds the performance limits of the lens. Single-frame CDI in the X-ray region has potential use for probing dynamic phenomena with a high spatiotemporal resolution. Here, we experimentally demonstrate a general method for single-frame X-ray CDI using a triangular aperture and a Fresnel zone plate. Using 5 keV synchrotron radiation X-rays, we reconstructed the object image of the locally illuminated area with a spatial resolution of higher than 50 nm and an exposure time of more than 0.1 s without prior information about the sample. After a 10 s exposure, a resolution of 17 nm was achieved. The present method opens new frontiers in the study of dynamics at the nanoscale by using next-generation synchrotron radiation X-rays/free-electron lasers as light sources.
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3
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Bikondoa O, Carbone D. On Compton scattering as a source of background in coherent diffraction imaging experiments. JOURNAL OF SYNCHROTRON RADIATION 2021; 28:538-549. [PMID: 33650567 PMCID: PMC7941292 DOI: 10.1107/s1600577521000722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 01/21/2021] [Indexed: 06/12/2023]
Abstract
Compton scattering is generally neglected in diffraction experiments because the incoherent radiation it generates does not give rise to interference effects and therefore is negligible at Bragg peaks. However, as the scattering volume is reduced, the difference between the Rayleigh (coherent) and Compton (incoherent) contributions at Bragg peaks diminishes and the incoherent part may become substantial. The consequences can be significant for coherent diffraction imaging at high scattering angles: the incoherent radiation produces background that smears out the secondary interference fringes, affecting thus the achievable resolution of the technique. Here, a criterion that relates the object shape and the resolution is introduced. The Compton contribution for several object shapes is quantified, and it is shown that the maximum achievable resolution along different directions has a strong dependence on the crystal shape and size.
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Affiliation(s)
- Oier Bikondoa
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
- XMaS – The UK Materials Science Facility, ESRF – The European Synchrotron, CS40220, F-38043 Grenoble Cedex 09, France
| | - Dina Carbone
- MAX IV Laboratory, Fotongatan 2, 225 94 Lund, Sweden
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Shen Z, Teo CZW, Ayyer K, Loh ND. An encryption-decryption framework to validating single-particle imaging. Sci Rep 2021; 11:971. [PMID: 33441629 PMCID: PMC7806625 DOI: 10.1038/s41598-020-79589-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/17/2020] [Indexed: 11/11/2022] Open
Abstract
We propose an encryption-decryption framework for validating diffraction intensity volumes reconstructed using single-particle imaging (SPI) with X-ray free-electron lasers (XFELs) when the ground truth volume is absent. This conceptual framework exploits each reconstructed volumes' ability to decipher latent variables (e.g. orientations) of unseen sentinel diffraction patterns. Using this framework, we quantify novel measures of orientation disconcurrence, inconsistency, and disagreement between the decryptions by two independently reconstructed volumes. We also study how these measures can be used to define data sufficiency and its relation to spatial resolution, and the practical consequences of focusing XFEL pulses to smaller foci. This conceptual framework overcomes critical ambiguities in using Fourier Shell Correlation (FSC) as a validation measure for SPI. Finally, we show how this encryption-decryption framework naturally leads to an information-theoretic reformulation of the resolving power of XFEL-SPI, which we hope will lead to principled frameworks for experiment and instrument design.
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Affiliation(s)
- Zhou Shen
- Centre for Bio-imaging Sciences, National University of Singapore, 14 Science Drive 4, 117557, Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551, Singapore, Singapore
| | - Colin Zhi Wei Teo
- Centre for Bio-imaging Sciences, National University of Singapore, 14 Science Drive 4, 117557, Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551, Singapore, Singapore
| | - Kartik Ayyer
- Max Planck Institute for the Structure and Dynamics of Matter, Luruper Chaussee 149, 22761, Hamburg, Germany
- Center for Free-Electron Laser Science, Luruper Chaussee 149, 22761, Hamburg, Germany
| | - N Duane Loh
- Centre for Bio-imaging Sciences, National University of Singapore, 14 Science Drive 4, 117557, Singapore, Singapore.
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551, Singapore, Singapore.
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117557, Singapore, Singapore.
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Zhao J, Chen B, Wang F. Shedding Light on the Role of Misfit Strain in Controlling Core-Shell Nanocrystals. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2004142. [PMID: 33051904 DOI: 10.1002/adma.202004142] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/21/2020] [Indexed: 05/17/2023]
Abstract
Heteroepitaxial modification of nanomaterials has become a powerful means to create novel functionalities for various applications. One of the most elementary factors in heteroepitaxial nanostructures is the misfit strain arising from mismatched lattices of the constituent parts. Misfit strain not only dictates epitaxy kinetics for diversifying nanocrystal morphologies but also provides rational control over materials properties. In recent years, advances in chemical synthesis along with the rapid development of electron microscopy and X-ray diffraction techniques have enabled a substantial understanding of strain-related processes, which offers theoretical foundation and experimental guidance for researchers to refine heteroepitaxial nanostructures and their properties. Herein, recent investigations on heterogeneous core-shell nanocrystals containing misfit strains are summarized, with a focus on the mechanistic understanding of strain and strain-induced effects such as tuning the epitaxial habit, modulating the optical emission, and enhancing the catalytic activity and magnetic coercivity.
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Affiliation(s)
- Jianxiong Zhao
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong SAR, China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, 518057, China
| | - Bing Chen
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong SAR, China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, 518057, China
| | - Feng Wang
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong SAR, China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, 518057, China
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Goldberger D, Barolak J, Durfee CG, Adams DE. Three-dimensional single-shot ptychography. OPTICS EXPRESS 2020; 28:18887-18898. [PMID: 32672178 DOI: 10.1364/oe.395205] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/03/2020] [Indexed: 06/11/2023]
Abstract
Here we introduce three-dimensional single-shot ptychography (3DSSP). 3DSSP leverages an additional constraint unique to the single-shot geometry to deconvolve multiple 2D planes of a 3D object. Numeric simulations and analytic calculations demonstrate that 3DSSP reconstructs multiple planes in an extended 3D object with a minimum separation consistent with the depth of field for a conventional microscope. We experimentally demonstrate 3DSSP by reconstructing orthogonal hair strands axially separated by 5 mm. 3DSSP provides a pathway towards volumetric imaging of dynamically evolving systems on ultrafast timescales.
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Mukherjee D, Gamler JTL, Skrabalak SE, Unocic RR. Lattice Strain Measurement of Core@Shell Electrocatalysts with 4D Scanning Transmission Electron Microscopy Nanobeam Electron Diffraction. ACS Catal 2020. [DOI: 10.1021/acscatal.0c00224] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Debangshu Mukherjee
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jocelyn T. L. Gamler
- Department of Chemistry, Indiana University—Bloomington, Bloomington, Indiana 47405, United States
| | - Sara E. Skrabalak
- Department of Chemistry, Indiana University—Bloomington, Bloomington, Indiana 47405, United States
| | - Raymond R. Unocic
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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Nathanson M, Kanhaiya K, Pryor A, Miao J, Heinz H. Atomic-Scale Structure and Stress Release Mechanism in Core-Shell Nanoparticles. ACS NANO 2018; 12:12296-12304. [PMID: 30457827 DOI: 10.1021/acsnano.8b06118] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Core-shell nanoparticles find applications in catalysts, sensors, and theranostics. The full internal 3D atomic structure, however, cannot be resolved by current imaging and diffraction techniques. We analyzed the atomic positions and stress-release mechanism in a cubic Au-Pd core-shell nanoparticle in approximately 1000 times higher resolution than current experimental techniques using large-scale molecular dynamics simulation to overcome these limitations. The core-shell nanocube of 73 nm size was modeled similarly to solution synthesis by random epitaxial deposition of a 4 nm thick shell of Pd atoms onto a Au core of 65 nm side length using reliable interatomic potentials. The internal structure reveals specific deformations and stress relaxation mechanisms that are caused by the +4.8% lattice mismatch of gold relative to palladium and differential confinement of extended particle facets, edges, and corners by one, two, or three Au-Pd interfaces, respectively. The three-dimensional lattice strain causes long-range, arc-like bending of atomic rows along the faces and edges of the particle, especially near the Au-Pd interface, a bulging deformation of the Pd shell, and stacking faults in the Pd shell at the corners of the particle. The strain pattern and mechanism of stress release were further characterized by profiles of the atomic layer spacing in the principal crystallographic directions. Accordingly, strain in the Pd shell is several times larger in the extended facets than near the edges and corners of the nanoparticle, which likely affects adsorption, optical, and electrochemical properties. The findings are consistent with available experimental data, including 3D reconstructions of the same cubic nanoparticle by coherent diffractive imaging (CDI) and may be verified by more powerful experimental techniques in the future. The stress release mechanisms are representative for cubic core-shell nanoparticles with fcc structure and can be explored for different shapes by the same methods.
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Affiliation(s)
- Michael Nathanson
- Department of Chemical and Biological Engineering , University of Colorado at Boulder , Boulder , Colorado 80309 , United States
| | - Krishan Kanhaiya
- Department of Chemical and Biological Engineering , University of Colorado at Boulder , Boulder , Colorado 80309 , United States
| | - Alan Pryor
- Department of Physics & Astronomy and California NanoSystems Institute , University of California , Los Angeles , California 90095 , United States
| | - Jianwei Miao
- Department of Physics & Astronomy and California NanoSystems Institute , University of California , Los Angeles , California 90095 , United States
| | - Hendrik Heinz
- Department of Chemical and Biological Engineering , University of Colorado at Boulder , Boulder , Colorado 80309 , United States
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