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Zhou L, Sun Y, Wu Y, Zhu Y, Xu Y, Jia J, Wang F, Wang R. Controlled Growth of Pd Nanocrystals by Interface Interaction on Monolayer MoS 2: An Atom-Resolved in Situ Study. NANO LETTERS 2023. [PMID: 38010863 DOI: 10.1021/acs.nanolett.3c03960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
The crystal growth kinetics is crucial for the controllable preparation and performance modulation of metal nanocrystals (NCs). However, the study of growth mechanisms is significantly limited by characterization techniques, and it is still challenging to in situ capture the growth process. Real-time and real-space imaging techniques at the atomic scale can promote the understanding of microdynamics for NC growth. Herein, the growth of Pd NCs on monolayer MoS2 under different atmospheres was in situ studied by environmental transmission electron microscopy. Introducing carbon monoxide can modulate the diffusion of Pd monomers, resulting in the epitaxial growth of Pd NCs with a uniform orientation. The electron energy loss spectroscopy and theoretical calculations showed that the CO adsorption assured the specific exposed facets and good uniformity of Pd NCs. The insight into the gas-solid interface interaction and the microscopic growth mechanism of NCs may shed light on the precise synthesis of NCs on two-dimensional (2D) materials.
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Affiliation(s)
- Liang Zhou
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, The State Key Laboratory for Advanced Metals and Materials, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Yinghui Sun
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, The State Key Laboratory for Advanced Metals and Materials, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Yusong Wu
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, The State Key Laboratory for Advanced Metals and Materials, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Yuchen Zhu
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, The State Key Laboratory for Advanced Metals and Materials, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Yingying Xu
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, The State Key Laboratory for Advanced Metals and Materials, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Jianfeng Jia
- Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education, School of Chemistry and Materials Science, Shanxi Normal University, Taiyuan 030032, China
| | - Fang Wang
- Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education, School of Chemistry and Materials Science, Shanxi Normal University, Taiyuan 030032, China
| | - Rongming Wang
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, The State Key Laboratory for Advanced Metals and Materials, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
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2
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Wang G, Ke X, Sui M. Advanced TEM Characterization for Single-atom Catalysts: from Ex-situ Towards In-situ. Chem Res Chin Univ 2022. [DOI: 10.1007/s40242-022-2245-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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3
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Shi X, Lin X, Luo R, Wu S, Li L, Zhao ZJ, Gong J. Dynamics of Heterogeneous Catalytic Processes at Operando Conditions. JACS AU 2021; 1:2100-2120. [PMID: 34977883 PMCID: PMC8715484 DOI: 10.1021/jacsau.1c00355] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Indexed: 05/02/2023]
Abstract
The rational design of high-performance catalysts is hindered by the lack of knowledge of the structures of active sites and the reaction pathways under reaction conditions, which can be ideally addressed by an in situ/operando characterization. Besides the experimental insights, a theoretical investigation that simulates reaction conditions-so-called operando modeling-is necessary for a plausible understanding of a working catalyst system at the atomic scale. However, there is still a huge gap between the current widely used computational model and the concept of operando modeling, which should be achieved through multiscale computational modeling. This Perspective describes various modeling approaches and machine learning techniques that step toward operando modeling, followed by selected experimental examples that present an operando understanding in the thermo- and electrocatalytic processes. At last, the remaining challenges in this area are outlined.
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Affiliation(s)
- Xiangcheng Shi
- Key
Laboratory for Green Chemical Technology of Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative
Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
- Joint
School of National University of Singapore and Tianjin University,
International Campus of Tianjin University, Fuzhou 350207, China
| | - Xiaoyun Lin
- Key
Laboratory for Green Chemical Technology of Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative
Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Ran Luo
- Key
Laboratory for Green Chemical Technology of Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative
Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Shican Wu
- Key
Laboratory for Green Chemical Technology of Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative
Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Lulu Li
- Key
Laboratory for Green Chemical Technology of Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative
Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Zhi-Jian Zhao
- Key
Laboratory for Green Chemical Technology of Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative
Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Jinlong Gong
- Key
Laboratory for Green Chemical Technology of Ministry of Education,
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative
Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
- Joint
School of National University of Singapore and Tianjin University,
International Campus of Tianjin University, Fuzhou 350207, China
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4
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Zhao M, Zhang N, Yang R, Chen D, Zhao Y. Which is Better for Nanomedicines: Nanocatalysts or Single-Atom Catalysts? Adv Healthc Mater 2021; 10:e2001897. [PMID: 33326185 DOI: 10.1002/adhm.202001897] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/30/2020] [Indexed: 12/24/2022]
Abstract
With the rapid advancements in nanotechnology and materials science, numerous nanomaterials have been used as catalysts for nanomedical applications. Their design and modification according to the microenvironment of diseases have been shown to achieve effective treatment. Chemists are in pursuit of nanocatalysts that are more efficient, controllable, and less toxic by developing innovative synthetic technologies and improving existing ones. Recently, single-atom catalysts (SACs) with excellent catalytic activity and high selectivity have attracted increasing attention because of their accurate design as nanomaterials at the atomic level, thereby highlighting their potential for nanomedical applications. In this review, the recent advances in nanocatalysts and SACs are briefly summarized according to their synthesis, characterizations, catalytic mechanisms, and nanomedical applications. The opportunities and future scope for their development and the issues and challenges for their application as nanomedicine are also discussed. As far as it is known, the review is the systematic comparison of nanocatalysts and SACs, especially in the field of nanomedicine, which has promoted the development of nanocatalytic medicine.
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Affiliation(s)
- Mengyang Zhao
- State Key Laboratory of Esophageal Cancer Prevention and Treatment Department of Pharmaceutics School of Pharmaceutical Sciences Zhengzhou University No. 100 Kexue Ave Zhengzhou 450001 P. R. China
- School of Materials Science and Engineering Zhengzhou University No. 100 Kexue Ave Zhengzhou 450001 P. R. China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases Zhengzhou University No. 100 Kexue Ave Zhengzhou 450001 P. R. China
| | - Nan Zhang
- State Key Laboratory of Esophageal Cancer Prevention and Treatment Department of Pharmaceutics School of Pharmaceutical Sciences Zhengzhou University No. 100 Kexue Ave Zhengzhou 450001 P. R. China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases Zhengzhou University No. 100 Kexue Ave Zhengzhou 450001 P. R. China
| | - Ruigeng Yang
- State Key Laboratory of Esophageal Cancer Prevention and Treatment Department of Pharmaceutics School of Pharmaceutical Sciences Zhengzhou University No. 100 Kexue Ave Zhengzhou 450001 P. R. China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases Zhengzhou University No. 100 Kexue Ave Zhengzhou 450001 P. R. China
| | - Deliang Chen
- School of Materials Science and Engineering Zhengzhou University No. 100 Kexue Ave Zhengzhou 450001 P. R. China
- School of Materials Science and Engineering Dongguan University of Technology Dongguan 523808 P. R. China
| | - Yongxing Zhao
- State Key Laboratory of Esophageal Cancer Prevention and Treatment Department of Pharmaceutics School of Pharmaceutical Sciences Zhengzhou University No. 100 Kexue Ave Zhengzhou 450001 P. R. China
- Key Laboratory of Targeting Therapy and Diagnosis for Critical Diseases Zhengzhou University No. 100 Kexue Ave Zhengzhou 450001 P. R. China
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5
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Souri Z, Adeli M, Mehdipour E, Yari A, Shams A, Beyranvand S, Sattari S. Covalent Decoration of MoS 2 Platforms by Silver Nanoparticles through the Reversible Addition-Fragmentation Chain Transfer Reaction. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:3382-3390. [PMID: 33691410 DOI: 10.1021/acs.langmuir.0c03518] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Two-dimensional nanomaterials decorated by metal nanoparticles have gained great interest, due to their potential applications in different areas ranging from electrochemical sensing to photothermal therapy. However, metal nanoparticles that are noncovalently immobilized on the surface of two-dimensional nanomaterials can be dissociated from their surface in the complex mediums. This challenge can be overcome by covalent attachment of nanoparticles to the surface of these platforms. In this work, MoS2 sheets are decorated by silver nanoparticles (AgNPs) through a reversible addition-fragmentation chain transfer (RAFT) reaction. Reactive centers were created on the surface of freshly exfoliated MoS2 and a two-dimensional platform with the ability of initiating the RAFT reaction was obtained. Afterwards, silver nanoparticles with acrylamide functionality were synthesized and attached on the surface of MoS2 sheets by the RAFT reaction. MoS2-AgNPs hybrids were characterized by different spectroscopy and microscopy methods as well as thermal and elemental analyses, and then they were used for the electrochemical determination of dipyridamole in aqueous solution. Taking advantage of the straightforward synthesis and the possible MoS2-AgNPs distance adjustment, a variety of hybrid systems with unique physicochemical and optoelectronic properties can be constructed by using this method.
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Affiliation(s)
- Zeinab Souri
- Department of Organic Chemistry, Faculty of Chemistry, Lorestan University, Khorramabad 68137-17133, Iran
| | - Mohsen Adeli
- Department of Organic Chemistry, Faculty of Chemistry, Lorestan University, Khorramabad 68137-17133, Iran
| | - Ebrahim Mehdipour
- Department of Organic Chemistry, Faculty of Chemistry, Lorestan University, Khorramabad 68137-17133, Iran
| | - Abdolah Yari
- Department of Analytical Chemistry, Faculty of Chemistry, Lorestan University, Khorramabad 68137-17133, Iran
| | - Azim Shams
- Department of Analytical Chemistry, Faculty of Chemistry, Lorestan University, Khorramabad 68137-17133, Iran
| | - Siamak Beyranvand
- Department of Organic Chemistry, Faculty of Chemistry, Lorestan University, Khorramabad 68137-17133, Iran
| | - Shabnam Sattari
- Department of Organic Chemistry, Faculty of Chemistry, Lorestan University, Khorramabad 68137-17133, Iran
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6
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Song B, Yang Y, Yang TT, He K, Hu X, Yuan Y, Dravid VP, Zachariah MR, Saidi WA, Liu Y, Shahbazian-Yassar R. Revealing High-Temperature Reduction Dynamics of High-Entropy Alloy Nanoparticles via In Situ Transmission Electron Microscopy. NANO LETTERS 2021; 21:1742-1748. [PMID: 33570961 DOI: 10.1021/acs.nanolett.0c04572] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Understanding the behavior of high-entropy alloy (HEA) materials under hydrogen (H2) environment is of utmost importance for their promising applications in structural materials, catalysis, and energy-related reactions. Herein, the reduction behavior of oxidized FeCoNiCuPt HEA nanoparticles (NPs) in atmospheric pressure H2 environment was investigated by in situ gas-cell transmission electron microscopy (TEM). The reduction reaction front was maintained at the external surface of the oxide. During reduction, the oxide layer expanded and transformed into porous structures where oxidized Cu was fully reduced to Cu NPs while Fe, Co, and Ni remained in the oxidized form. In situ chemical analysis showed that the expansion of the oxide layer resulted from the outward diffusion flux of all transition metals (Fe, Co, Ni, Cu). Revealing the H2 reduction behavior of HEA NPs facilitates the development of advanced multicomponent alloys for applications targeting H2 formation and storage, catalytic hydrogenation, and corrosion removal.
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Affiliation(s)
- Boao Song
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Yong Yang
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States
- Department of Chemical Engineering and Materials Science, University of California Riverside, Riverside, California 92521, United States
| | - Timothy T Yang
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Kun He
- Department of Materials Science and Engineering, International Institute for Nanotechnology (IIN), Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Xiaobing Hu
- Department of Materials Science and Engineering, International Institute for Nanotechnology (IIN), Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Yifei Yuan
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Vinayak P Dravid
- Department of Materials Science and Engineering, International Institute for Nanotechnology (IIN), Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Michael R Zachariah
- Department of Chemical Engineering and Materials Science, University of California Riverside, Riverside, California 92521, United States
| | - Wissam A Saidi
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Yuzi Liu
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Reza Shahbazian-Yassar
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, United States
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7
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Lansford JL, Vlachos DG. Spectroscopic Probe Molecule Selection Using Quantum Theory, First-Principles Calculations, and Machine Learning. ACS NANO 2020; 14:17295-17307. [PMID: 33196162 DOI: 10.1021/acsnano.0c07408] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Probe molecule vibrational spectra have a long history of being used to characterize materials including metals, oxides, metal-organic frameworks, and even human proteins. Furthermore, recent advances in machine learning have enabled computationally generated spectra to aid in detailed characterization of complex surfaces with probe molecules. Despite widespread use of probe molecules, the science of probe molecule selection is underdeveloped. Here, we develop physical concepts, including orbital interaction energy and the energy overlap integral, to explain and predict the ability of probe molecules to discriminate structural descriptors. We resolve the crystal orbital overlap population (COOP) to specific molecular orbitals and quantify their bonding character, which directly influences vibrational frequencies. Using only a single adsorbate calculation from density function theory (DFT), we compute the interaction energy of individual adsorbate molecular orbitals with adsorption site atomic orbitals across many different sites. Combining the molecular orbital resolved COOP and changes in orbital interaction energy enables probe molecule selection for improved discrimination of various sites. We demonstrate these concepts by comparing the predicted effectiveness of carbon monoxide (CO), nitric oxide (NO), and ethylene (C2H4) to probe Pt adsorption sites. Finally, using a previously developed machine learning framework, we show that models trained on hundreds of thousands of C2H4 spectra, computed from DFT, which regress surface binding-type and generalized coordination number, outperform those trained using CO and NO spectra. A python package, pDOS_overlap, for implementing the electron density-based analysis on any combination of adsorbates and materials, is also made available.
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Affiliation(s)
- Joshua L Lansford
- Department of Chemical and Biomolecular Engineering, University of Delaware, 150 Academy Street, Newark, Delaware 19716, United States
| | - Dionisios G Vlachos
- Department of Chemical and Biomolecular Engineering, University of Delaware, 150 Academy Street, Newark, Delaware 19716, United States
- Catalysis Center for Energy Innovation, University of Delaware, 221 Academy Street, Newark, Delaware 19716, United States
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8
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Song B, Yang Y, Rabbani M, Yang TT, He K, Hu X, Yuan Y, Ghildiyal P, Dravid VP, Zachariah MR, Saidi WA, Liu Y, Shahbazian-Yassar R. In Situ Oxidation Studies of High-Entropy Alloy Nanoparticles. ACS NANO 2020; 14:15131-15143. [PMID: 33079522 DOI: 10.1021/acsnano.0c05250] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Although high-entropy alloys (HEAs) have shown tremendous potential for elevated temperature, anticorrosion, and catalysis applications, little is known on how HEA materials behave under complex service environments. Herein, we studied the high-temperature oxidation behavior of Fe0.28Co0.21Ni0.20Cu0.08Pt0.23HEA nanoparticles (NPs) in an atmospheric pressure dry air environment by in situ gas-cell transmission electron microscopy. It is found that the oxidation of HEA NPs is governed by Kirkendall effects with logarithmic oxidation rates rather than parabolic as predicted by Wagner's theory. Further, the HEA NPs are found to oxidize at a significantly slower rate compared to monometallic NPs. The outward diffusion of transition metals and formation of disordered oxide layer are observed in real time and confirmed through analytical energy dispersive spectroscopy, and electron energy loss spectroscopy characterizations. Localized ordered lattices are identified in the oxide, suggesting the formation of Fe2O3, CoO, NiO, and CuO crystallites in an overall disordered matrix. Hybrid Monte Carlo and molecular dynamics simulations based on first-principles energies and forces support these findings and show that the oxidation drives surface segregation of Fe, Co, Ni, and Cu, while Pt stays in the core region. The present work offers key insights into how HEA NPs behave under high-temperature oxidizing environment and sheds light on future design of highly stable alloys under complex service conditions.
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Affiliation(s)
- Boao Song
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Yong Yang
- Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States
- Department of Chemical Engineering and Materials Science, University of California Riverside, Riverside, California 92521, United States
| | - Muztoba Rabbani
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Timothy T Yang
- Department of Mechanical Engineering and Materials Science and Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Kun He
- Department of Materials Science and Engineering, International Institute for Nanotechnology (IIN), Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Xiaobing Hu
- Department of Materials Science and Engineering, International Institute for Nanotechnology (IIN), Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Yifei Yuan
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, United States
| | - Pankaj Ghildiyal
- Department of Chemical Engineering and Materials Science, University of California Riverside, Riverside, California 92521, United States
| | - Vinayak P Dravid
- Department of Materials Science and Engineering, International Institute for Nanotechnology (IIN), Northwestern University Atomic and Nanoscale Characterization Experimental (NUANCE) Center, Northwestern University, Evanston, Illinois 60208, United States
| | - Michael R Zachariah
- Department of Chemical Engineering and Materials Science, University of California Riverside, Riverside, California 92521, United States
| | - Wissam A Saidi
- Department of Mechanical Engineering and Materials Science and Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Yuzi Liu
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Reza Shahbazian-Yassar
- Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, Illinois 60607, United States
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Boniface M, Plodinec M, Schlögl R, Lunkenbein T. Quo Vadis Micro-Electro-Mechanical Systems for the Study of Heterogeneous Catalysts Inside the Electron Microscope? Top Catal 2020. [DOI: 10.1007/s11244-020-01398-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
AbstractDuring the last decade, modern micro-electro-mechanical systems (MEMS) technology has been used to create cells that can act as catalytic nanoreactors and fit into the sample holders of transmission electron microscopes. These nanoreactors can maintain atmospheric or higher pressures inside the cells as they seal gases or liquids from the vacuum of the TEM column and can reach temperatures exceeding 1000 °C. This has led to a paradigm shift in electron microscopy, which facilitates the local characterization of structural and morphological changes of solid catalysts under working conditions. In this review, we outline the development of state-of-the-art nanoreactor setups that are commercially available and are currently applied to study catalytic reactions in situ or operando in gaseous or liquid environments. We also discuss challenges that are associated with the use of environmental cells. In catalysis studies, one of the major challenge is the interpretation of the results while considering the discrepancies in kinetics between MEMS based gas cells and fixed bed reactors, the interactions of the electron beam with the sample, as well as support effects. Finally, we critically analyze the general role of MEMS based nanoreactors in electron microscopy and catalysis communities and present possible future directions.
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