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Van Speybroeck V, Bocus M, Cnudde P, Vanduyfhuys L. Operando Modeling of Zeolite-Catalyzed Reactions Using First-Principles Molecular Dynamics Simulations. ACS Catal 2023; 13:11455-11493. [PMID: 37671178 PMCID: PMC10476167 DOI: 10.1021/acscatal.3c01945] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 07/27/2023] [Indexed: 09/07/2023]
Abstract
Within this Perspective, we critically reflect on the role of first-principles molecular dynamics (MD) simulations in unraveling the catalytic function within zeolites under operating conditions. First-principles MD simulations refer to methods where the dynamics of the nuclei is followed in time by integrating the Newtonian equations of motion on a potential energy surface that is determined by solving the quantum-mechanical many-body problem for the electrons. Catalytic solids used in industrial applications show an intriguing high degree of complexity, with phenomena taking place at a broad range of length and time scales. Additionally, the state and function of a catalyst critically depend on the operating conditions, such as temperature, moisture, presence of water, etc. Herein we show by means of a series of exemplary cases how first-principles MD simulations are instrumental to unravel the catalyst complexity at the molecular scale. Examples show how the nature of reactive species at higher catalytic temperatures may drastically change compared to species at lower temperatures and how the nature of active sites may dynamically change upon exposure to water. To simulate rare events, first-principles MD simulations need to be used in combination with enhanced sampling techniques to efficiently sample low-probability regions of phase space. Using these techniques, it is shown how competitive pathways at operating conditions can be discovered and how broad transition state regions can be explored. Interestingly, such simulations can also be used to study hindered diffusion under operating conditions. The cases shown clearly illustrate how first-principles MD simulations reveal insights into the catalytic function at operating conditions, which could not be discovered using static or local approaches where only a few points are considered on the potential energy surface (PES). Despite these advantages, some major hurdles still exist to fully integrate first-principles MD methods in a standard computational catalytic workflow or to use the output of MD simulations as input for multiple length/time scale methods that aim to bridge to the reactor scale. First of all, methods are needed that allow us to evaluate the interatomic forces with quantum-mechanical accuracy, albeit at a much lower computational cost compared to currently used density functional theory (DFT) methods. The use of DFT limits the currently attainable length/time scales to hundreds of picoseconds and a few nanometers, which are much smaller than realistic catalyst particle dimensions and time scales encountered in the catalysis process. One solution could be to construct machine learning potentials (MLPs), where a numerical potential is derived from underlying quantum-mechanical data, which could be used in subsequent MD simulations. As such, much longer length and time scales could be reached; however, quite some research is still necessary to construct MLPs for the complex systems encountered in industrially used catalysts. Second, most currently used enhanced sampling techniques in catalysis make use of collective variables (CVs), which are mostly determined based on chemical intuition. To explore complex reactive networks with MD simulations, methods are needed that allow the automatic discovery of CVs or methods that do not rely on a priori definition of CVs. Recently, various data-driven methods have been proposed, which could be explored for complex catalytic systems. Lastly, first-principles MD methods are currently mostly used to investigate local reactive events. We hope that with the rise of data-driven methods and more efficient methods to describe the PES, first-principles MD methods will in the future also be able to describe longer length/time scale processes in catalysis. This might lead to a consistent dynamic description of all steps-diffusion, adsorption, and reaction-as they take place at the catalyst particle level.
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Affiliation(s)
| | - Massimo Bocus
- Center for Molecular Modeling, Ghent University, Technologiepark 46, 9052 Zwijnaarde, Belgium
| | - Pieter Cnudde
- Center for Molecular Modeling, Ghent University, Technologiepark 46, 9052 Zwijnaarde, Belgium
| | - Louis Vanduyfhuys
- Center for Molecular Modeling, Ghent University, Technologiepark 46, 9052 Zwijnaarde, Belgium
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Van Speybroeck V. Challenges in modelling dynamic processes in realistic nanostructured materials at operating conditions. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2023; 381:20220239. [PMID: 37211031 DOI: 10.1098/rsta.2022.0239] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/23/2023] [Indexed: 05/23/2023]
Abstract
The question is addressed in how far current modelling strategies are capable of modelling dynamic phenomena in realistic nanostructured materials at operating conditions. Nanostructured materials used in applications are far from perfect; they possess a broad range of heterogeneities in space and time extending over several orders of magnitude. Spatial heterogeneities from the subnanometre to the micrometre scale in crystal particles with a finite size and specific morphology, impact the material's dynamics. Furthermore, the material's functional behaviour is largely determined by the operating conditions. Currently, there exists a huge length-time scale gap between attainable theoretical length-time scales and experimentally relevant scales. Within this perspective, three key challenges are highlighted within the molecular modelling chain to bridge this length-time scale gap. Methods are needed that enable (i) building structural models for realistic crystal particles having mesoscale dimensions with isolated defects, correlated nanoregions, mesoporosity, internal and external surfaces; (ii) the evaluation of interatomic forces with quantum mechanical accuracy albeit at much lower computational cost than the currently used density functional theory methods and (iii) derivation of the kinetics of phenomena taking place in a multi-length-time scale window to obtain an overall view of the dynamics of the process. This article is part of a discussion meeting issue 'Supercomputing simulations of advanced materials'.
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Berger F, Rybicki M, Sauer J. Molecular Dynamics with Chemical Accuracy─Alkane Adsorption in Acidic Zeolites. ACS Catal 2023. [DOI: 10.1021/acscatal.2c05493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Fabian Berger
- Institut für Chemie, Humboldt-Universität zu Berlin, D-10099Berlin, Germany
| | - Marcin Rybicki
- Institut für Chemie, Humboldt-Universität zu Berlin, D-10099Berlin, Germany
| | - Joachim Sauer
- Institut für Chemie, Humboldt-Universität zu Berlin, D-10099Berlin, Germany
- Department of Physical and Macromolecular Chemistry & Charles University Center of Advanced Materials, Charles University, Hlavova 8, 128 43Prague 2, Czech Republic
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4
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Montalvo-Castro H, DeLuca M, Kilburn L, Hibbitts D. Mechanisms and Kinetics of the Dehydrogenation of C 6–C 8 Cycloalkanes, Cycloalkenes, and Cyclodienes to Aromatics in H-MFI Zeolite Framework. ACS Catal 2022. [DOI: 10.1021/acscatal.2c03360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Hansel Montalvo-Castro
- Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611, United States
| | - Mykela DeLuca
- Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611, United States
| | - Lauren Kilburn
- Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611, United States
| | - David Hibbitts
- Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611, United States
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5
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Gong X, Ye Y, Chowdhury AD. Evaluating the Role of Descriptor- and Spectator-Type Reaction Intermediates During the Early Phases of Zeolite Catalysis. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Xuan Gong
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei People’s Republic of China
| | - Yiru Ye
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei People’s Republic of China
| | - Abhishek Dutta Chowdhury
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei People’s Republic of China
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Bocus M, Vanduyfhuys L, De Proft F, Weckhuysen BM, Van Speybroeck V. Mechanistic Characterization of Zeolite-Catalyzed Aromatic Electrophilic Substitution at Realistic Operating Conditions. JACS AU 2022; 2:502-514. [PMID: 35252999 PMCID: PMC8889610 DOI: 10.1021/jacsau.1c00544] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Indexed: 05/11/2023]
Abstract
Zeolite-catalyzed benzene ethylation is an important industrial reaction, as it is the first step in the production of styrene for polymer manufacturing. Furthermore, it is a prototypical example of aromatic electrophilic substitution, a key reaction in the synthesis of many bulk and fine chemicals. Despite extensive research, the reaction mechanism and the nature of elusive intermediates at realistic operating conditions is not properly understood. More in detail, the existence of the elusive arenium ion (better known as Wheland complex) formed upon electrophilic attack on the aromatic ring is still a matter of debate. Temperature effects and the presence of protic guest molecules such as water are expected to impact the reaction mechanism and lifetime of the reaction intermediates. Herein, we used enhanced sampling ab initio molecular dynamics simulations to investigate the complete mechanism of benzene ethylation with ethene and ethanol in the H-ZSM-5 zeolite. We show that both the stepwise and concerted mechanisms are active at reaction conditions and that the Wheland intermediate spontaneously appears as a shallow minimum in the free energy surface after the electrophilic attack on the benzene ring. Addition of water enhances the protonation kinetics by about 1 order of magnitude at coverages of one water molecule per Brønsted acidic site. In the fully solvated regime, an overstabilization of the BAS as hydronium ion occurs and the rate enhancement disappears. The obtained results give critical atomistic insights in the role of water to selectively tune the kinetics of protonation reactions in zeolites.
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Affiliation(s)
- Massimo Bocus
- Center
for Molecular Modeling, Ghent University, Technologiepark 46, 9052 Zwijnaarde, Belgium
| | - Louis Vanduyfhuys
- Center
for Molecular Modeling, Ghent University, Technologiepark 46, 9052 Zwijnaarde, Belgium
| | - Frank De Proft
- Eenheid
Algemene Chemie (ALGC), Vrije Universiteit
Brussel, Pleinlaan 2, 1050 Brussels, Belgium
| | - Bert M. Weckhuysen
- Inorganic
Chemistry and Catalysis Group, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
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Ma H, Liao J, Wei Z, Tian X, Li J, Chen YY, Wang S, Wang H, Dong M, Qin Z, Wang J, Fan W. Trimethyloxonium ion – a zeolite confined mobile and efficient methyl carrier at low temperatures: a DFT study coupled with microkinetic analysis. Catal Sci Technol 2022. [DOI: 10.1039/d2cy00207h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction network of ethene methylation over H-ZSM-5, including methanol dehydration, ethene methylation, and C3H7+ conversion, is investigated by employing a multiscale approach combining DFT calculations and microkinetic modeling.
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Affiliation(s)
- Hong Ma
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
- Engineering Research Center of Ministry of Education for Fine Chemicals, Shanxi University, Taiyuan 030006, China
| | - Jian Liao
- School of Computer & Information Technology, Shanxi University, Taiyuan 030006, China
| | - Zhihong Wei
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
| | - Xinxin Tian
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
| | - Junfen Li
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
| | - Yan-Yan Chen
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
| | - Sen Wang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
| | - Hao Wang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
- Engineering Research Center of Ministry of Education for Fine Chemicals, Shanxi University, Taiyuan 030006, China
| | - Mei Dong
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
| | - Zhangfeng Qin
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
| | - Jianguo Wang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
| | - Weibin Fan
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
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Piccini G, Lee MS, Yuk SF, Zhang D, Collinge G, Kollias L, Nguyen MT, Glezakou VA, Rousseau R. Ab initio molecular dynamics with enhanced sampling in heterogeneous catalysis. Catal Sci Technol 2022. [DOI: 10.1039/d1cy01329g] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Enhanced sampling ab initio simulations enable to study chemical phenomena in catalytic systems including thermal effects & anharmonicity, & collective dynamics describing enthalpic & entropic contributions, which can significantly impact on reaction free energy landscapes.
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Affiliation(s)
- GiovanniMaria Piccini
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
- Istituto Eulero, Università della Svizzera italiana, Via Giuseppe Buffi 13, Lugano, Ticino, Switzerland
| | - Mal-Soon Lee
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Simuck F. Yuk
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY 10996, USA
| | - Difan Zhang
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Greg Collinge
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Loukas Kollias
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Manh-Thuong Nguyen
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Vassiliki-Alexandra Glezakou
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
| | - Roger Rousseau
- Basic & Applied Molecular Foundations, Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352, USA
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9
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Nastase SAF, Logsdail AJ, Catlow CRA. QM/MM study of the reactivity of zeolite bound methoxy and carbene groups. Phys Chem Chem Phys 2021; 23:17634-17644. [PMID: 34369957 DOI: 10.1039/d1cp02535j] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The conversion of methanol-to-hydrocarbons (MTH) is known to occur via an autocatalytic process in zeolites, where framework-bound methoxy species play a pivotal role, especially during catalyst induction. Recent NMR and FT-IR experimental studies suggest that methoxylated zeolites are able to produce hydrocarbons by a mechanism involving carbene migration and association. In order to understand these observations, we have performed QM/MM computational investigations on a range of reaction mechanisms for the reaction of zeolite bound methoxy and carbene groups, which are proposed to initiate hydrocarbon formation in the MTH process. Our simulations demonstrate that it is kinetically unfavourable for methyl species to form on the framework away from the zeolite acid site, and both kinetically and thermodynamically unfavourable for methyl groups to migrate through the framework and aggregate around an acid site. Formation of carbene moieties was considered as an alternative pathway to the formation of C-C bonds; however, the reaction energy for conversion of a methyl to a carbene is unfavourable. Metadynamics simulations help confirm further that methyl species at the framework acid sites would be more reactive towards formed C2+ species, rather than inter-framework migration, and that the role of carbenes in the formation of the first C-C bond will be via a concerted type of mechanism rather than stepwise.
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Affiliation(s)
- Stefan A F Nastase
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University, CF10 3AT, UK.
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10
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Identifying the key steps determining the selectivity of toluene methylation with methanol over HZSM-5. Nat Commun 2021; 12:3725. [PMID: 34140511 PMCID: PMC8211704 DOI: 10.1038/s41467-021-24098-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 06/02/2021] [Indexed: 11/09/2022] Open
Abstract
Methylation of toluene with methanol to produce p-xylene has been investigated for decades, but the origin of selectivity is still under debate. Here we report computational studies based on ab initio molecular dynamics simulations and free energy sampling methods to identify the key steps determining the selectivity. The steps of toluene methylation to protonated-xylene, deprotonation of protonated-xylenes, and diffusion of xylene in HZSM-5 channels are compared. We find the pathways of formation for protonated p-/m-xylenes have similar free energy barriers. Meanwhile, the methylation is found rate-determining, thus the probability to generate p-/m-xylenes at the active site are similar. We then find that the diffusion for m-xylene along the zigzag channel is more difficult than its isomerization to p-xylene, which in turn further promotes the selectivity of p-xylene formation. These insights obtained at the molecular level are crucial for further development of high-performance zeolite catalysts for toluene methylation. The selectivity of zeolite catalyzed toluene methylation is still under debate. Here the authors report a comprehensive theoretical investigation based on ab-initio molecular dynamics to identify the key-steps of methylation of toluene with methanol over a zeolite to produce p-xylene.
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11
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Bailleul S, Dedecker K, Cnudde P, Vanduyfhuys L, Waroquier M, Van Speybroeck V. Ab initio enhanced sampling kinetic study on MTO ethene methylation reaction. J Catal 2020. [DOI: 10.1016/j.jcat.2020.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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12
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Potter ME. Down the Microporous Rabbit Hole of Silicoaluminophosphates: Recent Developments on Synthesis, Characterization, and Catalytic Applications. ACS Catal 2020. [DOI: 10.1021/acscatal.0c02278] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Matthew E. Potter
- Department of Chemistry, University of Southampton, Southampton, Hampshire SO17 1BJ, United Kingdom
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13
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Redekop EA, Lazzarini A, Bordiga S, Olsbye U. A temporal analysis of products (TAP) study of C2-C4 alkene reactions with a well-defined pool of methylating species on ZSM-22 zeolite. J Catal 2020. [DOI: 10.1016/j.jcat.2020.03.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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14
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Chizallet C. Toward the Atomic Scale Simulation of Intricate Acidic Aluminosilicate Catalysts. ACS Catal 2020. [DOI: 10.1021/acscatal.0c01136] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Céline Chizallet
- IFP Energies nouvelles Solaize, Rond-Point de l’Echangeur de Solaize, BP 3, 69360 Solaize, France
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15
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Bailleul S, Yarulina I, Hoffman AEJ, Dokania A, Abou-Hamad E, Chowdhury AD, Pieters G, Hajek J, De Wispelaere K, Waroquier M, Gascon J, Van Speybroeck V. A Supramolecular View on the Cooperative Role of Brønsted and Lewis Acid Sites in Zeolites for Methanol Conversion. J Am Chem Soc 2019; 141:14823-14842. [PMID: 31464134 PMCID: PMC6753656 DOI: 10.1021/jacs.9b07484] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A systematic molecular level and spectroscopic investigation is presented to show the cooperative role of Brønsted acid and Lewis acid sites in zeolites for the conversion of methanol. Extra-framework alkaline-earth metal containing species and aluminum species decrease the number of Brønsted acid sites, as protonated metal clusters are formed. A combined experimental and theoretical effort shows that postsynthetically modified ZSM-5 zeolites, by incorporation of extra-framework alkaline-earth metals or by demetalation with dealuminating agents, contain both mononuclear [MOH]+ and double protonated binuclear metal clusters [M(μ-OH)2M]2+ (M = Mg, Ca, Sr, Ba, and HOAl). The metal in the extra-framework clusters has a Lewis acid character, which is confirmed experimentally and theoretically by IR spectra of adsorbed pyridine. The strength of the Lewis acid sites (Mg > Ca > Sr > Ba) was characterized by a blue shift of characteristic IR peaks, thus offering a tool to sample Lewis acidity experimentally. The incorporation of extra-framework Lewis acid sites has a substantial influence on the reactivity of propene and benzene methylations. Alkaline-earth Lewis acid sites yield increased benzene methylation barriers and destabilization of typical aromatic intermediates, whereas propene methylation routes are less affected. The effect on the catalytic function is especially induced by the double protonated binuclear species. Overall, the extra-framework metal clusters have a dual effect on the catalytic function. By reducing the number of Brønsted acid sites and suppressing typical catalytic reactions in which aromatics are involved, an optimal propene selectivity and increased lifetime for methanol conversion over zeolites is obtained. The combined experimental and theoretical approach gives a unique insight into the nature of the supramolecular zeolite catalyst for methanol conversion which can be meticulously tuned by subtle interplay of Brønsted and Lewis acid sites.
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Affiliation(s)
- Simon Bailleul
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 46 , B-9052 Zwijnaarde , Belgium
| | - Irina Yarulina
- King Abdullah University of Science and Technology , KAUST Catalysis Center, Advanced Catalytic Materials , Thuwal 23955-6900 , Saudi Arabia
| | - Alexander E J Hoffman
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 46 , B-9052 Zwijnaarde , Belgium
| | - Abhay Dokania
- King Abdullah University of Science and Technology , KAUST Catalysis Center, Advanced Catalytic Materials , Thuwal 23955-6900 , Saudi Arabia
| | - Edy Abou-Hamad
- King Abdullah University of Science and Technology (KAUST) , Core Laboratories , Thuwal , Saudi Arabia
| | - Abhishek Dutta Chowdhury
- King Abdullah University of Science and Technology , KAUST Catalysis Center, Advanced Catalytic Materials , Thuwal 23955-6900 , Saudi Arabia
| | - Giovanni Pieters
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 46 , B-9052 Zwijnaarde , Belgium
| | - Julianna Hajek
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 46 , B-9052 Zwijnaarde , Belgium
| | - Kristof De Wispelaere
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 46 , B-9052 Zwijnaarde , Belgium
| | - Michel Waroquier
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 46 , B-9052 Zwijnaarde , Belgium
| | - Jorge Gascon
- King Abdullah University of Science and Technology , KAUST Catalysis Center, Advanced Catalytic Materials , Thuwal 23955-6900 , Saudi Arabia
| | - Veronique Van Speybroeck
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 46 , B-9052 Zwijnaarde , Belgium
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16
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Bailleul S, Rogge SMJ, Vanduyfhuys L, Van Speybroeck V. Insight into the Role of Water on the Methylation of Hexamethylbenzene in H‐SAPO‐34 from First Principle Molecular Dynamics Simulations. ChemCatChem 2019. [DOI: 10.1002/cctc.201900618] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Simon Bailleul
- Center for Molecular Modeling (CMM)Ghent University Technologiepark 46 Zwijnaarde B-9052 Belgium
| | - Sven M. J. Rogge
- Center for Molecular Modeling (CMM)Ghent University Technologiepark 46 Zwijnaarde B-9052 Belgium
| | - Louis Vanduyfhuys
- Center for Molecular Modeling (CMM)Ghent University Technologiepark 46 Zwijnaarde B-9052 Belgium
| | - Veronique Van Speybroeck
- Center for Molecular Modeling (CMM)Ghent University Technologiepark 46 Zwijnaarde B-9052 Belgium
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17
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Wang D, Wang CM, Yang G, Du YJ, Yang WM. First-principles kinetic study on benzene alkylation with ethanol vs. ethylene in H-ZSM-5. J Catal 2019. [DOI: 10.1016/j.jcat.2019.04.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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18
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Grajciar L, Heard CJ, Bondarenko AA, Polynski MV, Meeprasert J, Pidko EA, Nachtigall P. Towards operando computational modeling in heterogeneous catalysis. Chem Soc Rev 2018; 47:8307-8348. [PMID: 30204184 PMCID: PMC6240816 DOI: 10.1039/c8cs00398j] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Indexed: 12/19/2022]
Abstract
An increased synergy between experimental and theoretical investigations in heterogeneous catalysis has become apparent during the last decade. Experimental work has extended from ultra-high vacuum and low temperature towards operando conditions. These developments have motivated the computational community to move from standard descriptive computational models, based on inspection of the potential energy surface at 0 K and low reactant concentrations (0 K/UHV model), to more realistic conditions. The transition from 0 K/UHV to operando models has been backed by significant developments in computer hardware and software over the past few decades. New methodological developments, designed to overcome part of the gap between 0 K/UHV and operando conditions, include (i) global optimization techniques, (ii) ab initio constrained thermodynamics, (iii) biased molecular dynamics, (iv) microkinetic models of reaction networks and (v) machine learning approaches. The importance of the transition is highlighted by discussing how the molecular level picture of catalytic sites and the associated reaction mechanisms changes when the chemical environment, pressure and temperature effects are correctly accounted for in molecular simulations. It is the purpose of this review to discuss each method on an equal footing, and to draw connections between methods, particularly where they may be applied in combination.
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Affiliation(s)
- Lukáš Grajciar
- Department of Physical and Macromolecular Chemistry
, Faculty of Science
, Charles University in Prague
,
128 43 Prague 2
, Czech Republic
.
;
;
| | - Christopher J. Heard
- Department of Physical and Macromolecular Chemistry
, Faculty of Science
, Charles University in Prague
,
128 43 Prague 2
, Czech Republic
.
;
;
| | - Anton A. Bondarenko
- TheoMAT group
, ITMO University
,
Lomonosova 9
, St. Petersburg
, 191002
, Russia
| | - Mikhail V. Polynski
- TheoMAT group
, ITMO University
,
Lomonosova 9
, St. Petersburg
, 191002
, Russia
| | - Jittima Meeprasert
- Inorganic Systems Engineering group
, Department of Chemical Engineering
, Faculty of Applied Sciences
, Delft University of Technology
,
Van der Maasweg 9
, 2629 HZ Delft
, The Netherlands
.
| | - Evgeny A. Pidko
- TheoMAT group
, ITMO University
,
Lomonosova 9
, St. Petersburg
, 191002
, Russia
- Inorganic Systems Engineering group
, Department of Chemical Engineering
, Faculty of Applied Sciences
, Delft University of Technology
,
Van der Maasweg 9
, 2629 HZ Delft
, The Netherlands
.
| | - Petr Nachtigall
- Department of Physical and Macromolecular Chemistry
, Faculty of Science
, Charles University in Prague
,
128 43 Prague 2
, Czech Republic
.
;
;
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19
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Cnudde P, De Wispelaere K, Vanduyfhuys L, Demuynck R, Van der Mynsbrugge J, Waroquier M, Van Speybroeck V. How Chain Length and Branching Influence the Alkene Cracking Reactivity on H-ZSM-5. ACS Catal 2018; 8:9579-9595. [PMID: 30319885 PMCID: PMC6179455 DOI: 10.1021/acscatal.8b01779] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/09/2018] [Indexed: 12/22/2022]
Abstract
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Catalytic alkene
cracking on H-ZSM-5 involves a complex reaction
network with many possible reaction routes and often elusive intermediates.
Herein, advanced molecular dynamics simulations at 773 K, a typical
cracking temperature, are performed to clarify the nature of the intermediates
and to elucidate dominant cracking pathways at operating conditions.
A series of C4–C8 alkene intermediates
are investigated to evaluate the influence of chain length and degree
of branching on their stability. Our simulations reveal that linear,
secondary carbenium ions are relatively unstable, although their lifetime
increases with carbon number. Tertiary carbenium ions, on the other
hand, are shown to be very stable, irrespective of the chain length.
Highly branched carbenium ions, though, tend to rapidly rearrange
into more stable cationic species, either via cracking or isomerization
reactions. Dominant cracking pathways were determined by combining
these insights on carbenium ion stability with intrinsic free energy
barriers for various octene β-scission reactions, determined
via umbrella sampling simulations at operating temperature (773 K).
Cracking modes A (3° → 3°) and B2 (3°
→ 2°) are expected to be dominant at operating conditions,
whereas modes B1 (2° → 3°), C (2°
→ 2°), D2 (2° → 1°), and E2 (3° → 1°) are expected to be less important.
All β-scission modes in which a transition state with primary
carbocation character is involved have high intrinsic free energy
barriers. Reactions starting from secondary carbenium ions will contribute
less as these intermediates are short living at the high cracking
temperature. Our results show the importance of simulations at operating
conditions to properly evaluate the carbenium ion stability for β-scission
reactions and to assess the mobility of all species in the pores of
the zeolite.
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Affiliation(s)
- Pieter Cnudde
- Center for Molecular Modeling, Ghent University, Technologiepark 903, B-9052, Zwijnaarde, Belgium
| | - Kristof De Wispelaere
- Center for Molecular Modeling, Ghent University, Technologiepark 903, B-9052, Zwijnaarde, Belgium
| | - Louis Vanduyfhuys
- Center for Molecular Modeling, Ghent University, Technologiepark 903, B-9052, Zwijnaarde, Belgium
| | - Ruben Demuynck
- Center for Molecular Modeling, Ghent University, Technologiepark 903, B-9052, Zwijnaarde, Belgium
| | | | - Michel Waroquier
- Center for Molecular Modeling, Ghent University, Technologiepark 903, B-9052, Zwijnaarde, Belgium
| | - Veronique Van Speybroeck
- Center for Molecular Modeling, Ghent University, Technologiepark 903, B-9052, Zwijnaarde, Belgium
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20
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De Wispelaere K, Martínez-Espín JS, Hoffmann MJ, Svelle S, Olsbye U, Bligaard T. Understanding zeolite-catalyzed benzene methylation reactions by methanol and dimethyl ether at operating conditions from first principle microkinetic modeling and experiments. Catal Today 2018. [DOI: 10.1016/j.cattod.2018.02.042] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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21
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Structure–performance descriptors and the role of Lewis acidity in the methanol-to-propylene process. Nat Chem 2018; 10:804-812. [DOI: 10.1038/s41557-018-0081-0] [Citation(s) in RCA: 164] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 05/14/2018] [Indexed: 11/08/2022]
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22
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Rogge SMJ, Bavykina A, Hajek J, Garcia H, Olivos-Suarez AI, Sepúlveda-Escribano A, Vimont A, Clet G, Bazin P, Kapteijn F, Daturi M, Ramos-Fernandez EV, Llabrés I Xamena FX, Van Speybroeck V, Gascon J. Metal-organic and covalent organic frameworks as single-site catalysts. Chem Soc Rev 2018; 46:3134-3184. [PMID: 28338128 PMCID: PMC5708534 DOI: 10.1039/c7cs00033b] [Citation(s) in RCA: 602] [Impact Index Per Article: 100.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Heterogeneous single-site catalysts consist of isolated, well-defined, active sites that are spatially separated in a given solid and, ideally, structurally identical. In this review, the potential of metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) as platforms for the development of heterogeneous single-site catalysts is reviewed thoroughly. In the first part of this article, synthetic strategies and progress in the implementation of such sites in these two classes of materials are discussed. Because these solids are excellent playgrounds to allow a better understanding of catalytic functions, we highlight the most important recent advances in the modelling and spectroscopic characterization of single-site catalysts based on these materials. Finally, we discuss the potential of MOFs as materials in which several single-site catalytic functions can be combined within one framework along with their potential as powerful enzyme-mimicking materials. The review is wrapped up with our personal vision on future research directions.
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Affiliation(s)
- S M J Rogge
- Center for Molecular Modeling, Ghent University, Technologiepark 903, 9052 Zwijnaarde, Belgium.
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23
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Hajek J, Caratelli C, Demuynck R, De Wispelaere K, Vanduyfhuys L, Waroquier M, Van Speybroeck V. On the intrinsic dynamic nature of the rigid UiO-66 metal-organic framework. Chem Sci 2018; 9:2723-2732. [PMID: 29732056 PMCID: PMC5911970 DOI: 10.1039/c7sc04947a] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 01/26/2018] [Indexed: 11/21/2022] Open
Abstract
Enhanced molecular dynamics simulations of UiO-66 reveal a highly intrinsic dynamic behavior during activation and easy changes in the coordination number.
UiO-66 is a showcase example of an extremely stable metal–organic framework, which maintains its structural integrity during activation processes such as linker exchange and dehydration. The framework can even accommodate a substantial number of defects without compromising its stability. These observations point to an intrinsic dynamic flexibility of the framework, related to changes in the coordination number of the zirconium atoms. Herein we follow the dynamics of the framework in situ, by means of enhanced sampling molecular dynamics simulations such as umbrella sampling, during an activation process, where the coordination number of the bridging hydroxyl groups capped in the inorganic Zr6(μ3-O)4(μ3-OH)4 brick is reduced from three to one. Such a reduction in the coordination number occurs during the dehydration process and in other processes where defects are formed. We observe a remarkable fast response of the system upon structural changes of the hydroxyl group. Internal deformation modes are detected, which point to linker decoordination and recoordination. Detached linkers may be stabilized by hydrogen bonds with hydroxyl groups of the inorganic brick, which gives evidence for an intrinsic dynamic acidity even in the absence of protic guest molecules. Our observations yield a major step forward in the understanding on the molecular level of activation processes realized experimentally but that is hard to track on a purely experimental basis.
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Affiliation(s)
- Julianna Hajek
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 903 , B-9052 Zwijnaarde , Belgium .
| | - Chiara Caratelli
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 903 , B-9052 Zwijnaarde , Belgium .
| | - Ruben Demuynck
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 903 , B-9052 Zwijnaarde , Belgium .
| | - Kristof De Wispelaere
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 903 , B-9052 Zwijnaarde , Belgium .
| | - Louis Vanduyfhuys
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 903 , B-9052 Zwijnaarde , Belgium .
| | - Michel Waroquier
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 903 , B-9052 Zwijnaarde , Belgium .
| | - Veronique Van Speybroeck
- Center for Molecular Modeling (CMM) , Ghent University , Technologiepark 903 , B-9052 Zwijnaarde , Belgium .
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24
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Abstract
New insights and successful use of computational catalysis is highlighted.
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Affiliation(s)
- Rutger A. van Santen
- Institute for Complex Molecular Systems
- Eindhoven University of Technology
- 5612AZ Eindhoven
- The Netherlands
- Laboratory of Inorganic Materials Chemistry
| | - Aditya Sengar
- Multi-Phase Flows Group
- Department of Chemistry and Chemical Engineering
- Eindhoven University of Technology
- 5612AZ Eindhoven
- The Netherlands
| | - Erik Steur
- Delft Center for Systems and Control
- Delft Technical University
- The Netherlands
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25
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Martínez-Espín JS, De Wispelaere K, Janssens TVW, Svelle S, Lillerud KP, Beato P, Van Speybroeck V, Olsbye U. Hydrogen Transfer versus Methylation: On the Genesis of Aromatics Formation in the Methanol-To-Hydrocarbons Reaction over H-ZSM-5. ACS Catal 2017. [DOI: 10.1021/acscatal.7b01643] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Juan S. Martínez-Espín
- Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, P.O.
Box 1033, Blindern, N-0315 Oslo, Norway
- Haldor Topsøe A/S, Haldor Topsøes Allé 1, DK-2800 Kongens Lyngby, Denmark
| | - Kristof De Wispelaere
- Center for Molecular Modeling, Ghent University, Technologiepark 903, B-9052 Zwijnaarde, Belgium
| | - Ton V. W. Janssens
- Haldor Topsøe A/S, Haldor Topsøes Allé 1, DK-2800 Kongens Lyngby, Denmark
| | - Stian Svelle
- Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, P.O.
Box 1033, Blindern, N-0315 Oslo, Norway
| | - Karl Petter Lillerud
- Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, P.O.
Box 1033, Blindern, N-0315 Oslo, Norway
| | - Pablo Beato
- Haldor Topsøe A/S, Haldor Topsøes Allé 1, DK-2800 Kongens Lyngby, Denmark
| | - Veronique Van Speybroeck
- Center for Molecular Modeling, Ghent University, Technologiepark 903, B-9052 Zwijnaarde, Belgium
| | - Unni Olsbye
- Centre for Materials Science and Nanotechnology, Department of Chemistry, University of Oslo, P.O.
Box 1033, Blindern, N-0315 Oslo, Norway
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26
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Martinez-Espin JS, De Wispelaere K, Westgård Erichsen M, Svelle S, Janssens TV, Van Speybroeck V, Beato P, Olsbye U. Benzene co-reaction with methanol and dimethyl ether over zeolite and zeotype catalysts: Evidence of parallel reaction paths to toluene and diphenylmethane. J Catal 2017. [DOI: 10.1016/j.jcat.2017.03.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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27
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Cnudde P, De Wispelaere K, Van der Mynsbrugge J, Waroquier M, Van Speybroeck V. Effect of temperature and branching on the nature and stability of alkene cracking intermediates in H-ZSM-5. J Catal 2017. [DOI: 10.1016/j.jcat.2016.11.010] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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