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Nifant'ev I, Komarov P, Sadrtdinova G, Safronov V, Kolosov N, Ivchenko P. Mechanistic Insights of Ethylene Polymerization on Phillips Chromium Catalysts. Polymers (Basel) 2024; 16:681. [PMID: 38475365 DOI: 10.3390/polym16050681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 02/28/2024] [Accepted: 02/29/2024] [Indexed: 03/14/2024] Open
Abstract
Silica-supported chromium oxide catalysts, also named Phillips chromium catalysts (PCCs), provide more than half of the world's production of high- and medium-density polyethylenes. PCCs are usually prepared in the Cr(VI)/SiO2 form, which is subjected to reductive activation. It has been explicitly proven that CO reduces Cr(VI) to Cr(II) species that initiate ethylene polymerization; ethylene activates Cr(VI) sites as well, but the nature of the catalytic species is complicated by the presence of the ethylene oxidation products. It is widely accepted that the catalytic species are of a Cr(III)-alkyl nature, but this common assumption faces the challenge of "extra" hydrogen: the formation of similar species under the action of even-electron reducing agents requires an additional H atom. Relatively recently, it was found that saturated hydrocarbons can also activate CrOx/SiO2, and alkyl fragments turn out to be bonded with a polyethylene chain. In recent years, there have been numerous experimental and theoretical studies of the structure and chemistry of PCCs at the different stages of preparation and activation. The use of modern spectral methods (such as extended X-ray absorption fine structure (EXAFS), X-ray absorption near-edge structure (XANES), and others); operando IR, UV-vis, EPR, and XAS spectroscopies; and theoretical approaches (DFT modeling, machine learning) clarified many essential aspects of the mechanisms of CrOx/SiO2 activation and catalytic behavior. Overall, the Cosse-Arlman mechanism of polymerization on Cr(III)-alkyl centers is confirmed in many works, but its theoretical support required the development of nontrivial and contentious mechanistic concepts of Cr(VI)/SiO2 or Cr(II)/SiO2 activation. On the other hand, conflicting experimental data continue to be obtained, and certain mechanistic concepts are being developed with the use of outdated models. Strictly speaking, the main question of what type of catalytic species, Cr(II), Cr(III), or Cr(IV), comes into polymerization still has not received an unambiguous answer. The role of the chemical nature of the support-through the prism of the nature, geometry, and distribution of the active sites-is also not clear in depth. In the present review, we endeavored to summarize and discuss the recent studies in the field of the preparation, activation, and action of PCCs, with a focus on existing contradictions in the interpretation of the experimental and theoretical results.
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Affiliation(s)
- Ilya Nifant'ev
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Pr., 119991 Moscow, Russia
- Department of Chemistry, M.V. Lomonosov Moscow University, 1-3 Leninskie Gory, 119991 Moscow, Russia
| | - Pavel Komarov
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Pr., 119991 Moscow, Russia
| | - Guzelia Sadrtdinova
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Pr., 119991 Moscow, Russia
- Faculty of Chemistry, National Research University Higher School of Economics, Myasnitskaya St. 20, 101100 Moscow, Russia
| | | | | | - Pavel Ivchenko
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Pr., 119991 Moscow, Russia
- Department of Chemistry, M.V. Lomonosov Moscow University, 1-3 Leninskie Gory, 119991 Moscow, Russia
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2
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Groppo E, Rojas-Buzo S, Bordiga S. The Role of In Situ/ Operando IR Spectroscopy in Unraveling Adsorbate-Induced Structural Changes in Heterogeneous Catalysis. Chem Rev 2023; 123:12135-12169. [PMID: 37882638 PMCID: PMC10636737 DOI: 10.1021/acs.chemrev.3c00372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Indexed: 10/27/2023]
Abstract
Heterogeneous catalysts undergo thermal- and/or adsorbate-induced dynamic changes under reaction conditions, which consequently modify their catalytic behavior. Hence, it is increasingly crucial to characterize the properties of a catalyst under reaction conditions through the so-called "operando" approach. Operando IR spectroscopy is probably one of the most ubiquitous and versatile characterization methods in the field of heterogeneous catalysis, but its potential in identifying adsorbate- and thermal-induced phenomena is often overlooked in favor of other less accessible methods, such as XAS spectroscopy and high-resolution microscopy. Without detracting from these techniques, and while aware of the enormous value of a multitechnique approach, the purpose of this Review is to show that IR spectroscopy alone can provide relevant information in this field. This is done by discussing a few selected case studies from our own research experience, which belong to the categories of both "single-site"- and nanoparticle-based catalysts.
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Affiliation(s)
- Elena Groppo
- Department of Chemistry,
NIS Centre and INSTM, University of Torino, via Giuria 7, 10125 Turin, Italy
| | - Sergio Rojas-Buzo
- Department of Chemistry,
NIS Centre and INSTM, University of Torino, via Giuria 7, 10125 Turin, Italy
| | - Silvia Bordiga
- Department of Chemistry,
NIS Centre and INSTM, University of Torino, via Giuria 7, 10125 Turin, Italy
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Shayesteh Zadeh A, Khan SA, Vandervelden C, Peters B. Site-Averaged Ab Initio Kinetics: Importance Learning for Multistep Reactions on Amorphous Supports. J Chem Theory Comput 2023; 19:2873-2886. [PMID: 37093705 DOI: 10.1021/acs.jctc.3c00160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Single-atom centers on amorphous supports include catalysts for polymerization, partial oxidation, metathesis, hydrogenolysis, and more. The disordered environment makes each site different, and the kinetics exponentially magnifies these differences to make ab initio site-averaged kinetics calculations extremely difficult. This work extends the importance learning algorithm for efficient and precise site-averaged kinetics estimates to ab initio calculations and multistep reaction mechanisms. Specifically, we calculate site-averaged proton transfer relaxation rates on an ensemble of cluster models representing Brønsted acid sites on silica-alumina. We include direct and water-assisted proton transfer pathways and simultaneously estimate the water adsorption and activation enthalpies for forward and backward proton transfers. We use density functional theory (DFT) to obtain a site-averaged rate, somewhat like a turnover frequency, for the proton transfer relaxation rate. Finally, we show that importance learning can provide orders-of-magnitude acceleration over standard sampling methods for site-averaged rate calculations in cases where the rate is dominated by a few highly active sites.
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Affiliation(s)
- Armin Shayesteh Zadeh
- Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Salman A Khan
- Delaware Energy Institute (DEI), University of Delaware, Newark, Delaware 19711, United States
| | | | - Baron Peters
- Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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4
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Huang C, Liu Z, Liu B, Terano M, Jin Y. Computational Insights into the Multisite Nature of the Phillips CrO x/SiO 2 Catalyst for Ethylene Polymerization: The Perspective of Chromasiloxane Ring Size and F Modification. ACS Catal 2022. [DOI: 10.1021/acscatal.1c04998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Cuimin Huang
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou 510630, People’s Republic of China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510630, People’s Republic of China
| | - Zhen Liu
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, People’s Republic of China
| | - Boping Liu
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou 510630, People’s Republic of China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510630, People’s Republic of China
| | - Minoru Terano
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Yulong Jin
- Key Laboratory for Biobased Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou 510630, People’s Republic of China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510630, People’s Republic of China
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5
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Wang D, Zhou S, Liu Y, Kang X, Liu S, Li Z, Braunstein P. Controlling Polyethylene Molecular Weights and Distributions Using Chromium Complexes Supported by SNN-Tridentate Ligands. Macromolecules 2022. [DOI: 10.1021/acs.macromol.1c02351] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dongqi Wang
- Key Laboratory of Biobased Polymer Materials, College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Shengmei Zhou
- Key Laboratory of Biobased Polymer Materials, College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Yongxin Liu
- Key Laboratory of Biobased Polymer Materials, College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Xiaohui Kang
- College of Pharmacy, Dalian Medical University, Dalian 116044, China
| | - Shaofeng Liu
- Key Laboratory of Biobased Polymer Materials, College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Zhibo Li
- Key Laboratory of Biobased Polymer Materials, College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
- College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
| | - Pierre Braunstein
- Laboratoire de Chimie de Coordination, CNRS, CHIMIE UMR 7177, Université de Strasbourg, 4 rue Blaise Pascal, 67081 Cedex Strasbourg, France
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Piovano A, Groppo E. Flexible ligands in heterogeneous catalysts for olefin polymerization: Insights from spectroscopy. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214258] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Liu K, Liu Z, Cheng R, He X, Liu B. Mechanistic study of vanadium-modified and sulfation-modified Phillips catalyst. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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8
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Trummer D, Searles K, Algasov A, Guda SA, Soldatov AV, Ramanantoanina H, Safonova OV, Guda AA, Copéret C. Deciphering the Phillips Catalyst by Orbital Analysis and Supervised Machine Learning from Cr Pre-edge XANES of Molecular Libraries. J Am Chem Soc 2021; 143:7326-7341. [PMID: 33974429 DOI: 10.1021/jacs.0c10791] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Unveiling the nature and the distribution of surface sites in heterogeneous catalysts, and for the Phillips catalyst (CrO3/SiO2) in particular, is still a grand challenge despite more than 60 years of research. Commonly used references in Cr K-edge XANES spectral analysis rely on bulk materials (Cr-foil, Cr2O3) or molecules (CrCl3) that significantly differ from actual surface sites. In this work, we built a library of Cr K-edge XANES spectra for a series of tailored molecular Cr complexes, varying in oxidation state, local coordination environment, and ligand strength. Quantitative analysis of the pre-edge region revealed the origin of the pre-edge shape and intensity distribution. In particular, the characteristic pre-edge splitting observed for Cr(III) and Cr(IV) molecular complexes is directly related to the electronic exchange interactions in the frontier orbitals (spin-up and -down transitions). The series of experimental references was extended by theoretical spectra for potential active site structures and used for training the Extra Trees machine learning algorithm. The most informative features of the spectra (descriptors) were selected for the prediction of Cr oxidation states, mean interatomic distances in the first coordination sphere, and type of ligands. This set of descriptors was applied to uncover the site distribution in the Phillips catalyst at three different stages of the process. The freshly calcined catalyst consists of mainly Cr(VI) sites. The CO-exposed catalyst contains mainly Cr(II) silicates with a minor fraction of Cr(III) sites. The Phillips catalyst exposed to ethylene contains mainly highly coordinated Cr(III) silicates along with unreduced Cr(VI) sites.
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Affiliation(s)
- David Trummer
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Keith Searles
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Alexander Algasov
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, Rostov-on-Don, Russia, 344090.,Institute of Mathematics, Mechanics and Computer Science, Southern Federal University, Milchakova 8a, Rostov-on-Don, Russia, 344090
| | - Sergey A Guda
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, Rostov-on-Don, Russia, 344090.,Institute of Mathematics, Mechanics and Computer Science, Southern Federal University, Milchakova 8a, Rostov-on-Don, Russia, 344090
| | - Alexander V Soldatov
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, Rostov-on-Don, Russia, 344090
| | | | | | - Alexander A Guda
- The Smart Materials Research Institute, Southern Federal University, Sladkova 178/24, Rostov-on-Don, Russia, 344090
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
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Liang P, Li W, Chen Y, Dong C, Zhou Q, Feng Y, Chen M, Dai J, Ren C, Jiang B, Wang J, Yang Y. Revealing the Dynamic Behaviors of Tetrahydrofuran for Tailoring the Active Species of Ziegler–Natta Catalysts. ACS Catal 2021. [DOI: 10.1021/acscatal.0c05301] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peng Liang
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China
- Ningbo Key Laboratory of Specialty Polymers, School of Material Science and Chemical Engineering, Ningbo University, Ningbo 315211, P.R. China
| | - Wei Li
- Ningbo Key Laboratory of Specialty Polymers, School of Material Science and Chemical Engineering, Ningbo University, Ningbo 315211, P.R. China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, P. R. China
| | - Yuming Chen
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, P. R. China
| | - Chuanding Dong
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China
- Ningbo Key Laboratory of Specialty Polymers, School of Material Science and Chemical Engineering, Ningbo University, Ningbo 315211, P.R. China
| | - Qi Zhou
- School of Materials and Chemical Engineering, Ningbo University of Technology, Ningbo 315016, P.R. China
| | - Yirong Feng
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China
| | - Mei Chen
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China
- Ningbo Key Laboratory of Specialty Polymers, School of Material Science and Chemical Engineering, Ningbo University, Ningbo 315211, P.R. China
| | - Jincheng Dai
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China
| | - Congjing Ren
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, P. R. China
| | - Binbo Jiang
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China
| | - Jingdai Wang
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, P. R. China
| | - Yongrong Yang
- Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China
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10
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De S, Ould-Chikh S, Aguilar A, Hazemann JL, Zitolo A, Ramirez A, Telalovic S, Gascon J. Stable Cr-MFI Catalysts for the Nonoxidative Dehydrogenation of Ethane: Catalytic Performance and Nature of the Active Sites. ACS Catal 2021. [DOI: 10.1021/acscatal.0c05170] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Sudipta De
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia
| | - Samy Ould-Chikh
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia
| | - Antonio Aguilar
- Institut Neel, UPR 2940 CNRS − Université Grenoble Alpes, F-38000 Grenoble, France
| | - Jean-Louis Hazemann
- Institut Neel, UPR 2940 CNRS − Université Grenoble Alpes, F-38000 Grenoble, France
| | - Andrea Zitolo
- Synchrotron SOLEIL, L’orme des Merisiers, BP 48 Saint Aubin, 91192 Gif-sur-Yvette, France
| | - Adrian Ramirez
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia
| | - Selvedin Telalovic
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia
| | - Jorge Gascon
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia
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11
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Monwar M, Cruz C, Barr J, McDaniel M. Ethylene polymerization by hydrocarbon-reduced Cr/silica catalyst. J Catal 2021. [DOI: 10.1016/j.jcat.2020.10.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Cr[CH(SiMe3)2]3/SiO2 catalysts for ethene polymerization: The correlation at a molecular level between the chromium loading and the microstructure of the produced polymer. J Catal 2021. [DOI: 10.1016/j.jcat.2020.12.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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13
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Jongkind MK, Meirer F, Bossers KW, ten Have IC, Ohldag H, Watts B, van Kessel T, Friederichs N, Weckhuysen BM. Influence of Metal-Alkyls on Early-Stage Ethylene Polymerization over a Cr/SiO 2 Phillips Catalyst: A Bulk Characterization and X-ray Chemical Imaging Study. Chemistry 2021; 27:1688-1699. [PMID: 32729972 PMCID: PMC7898848 DOI: 10.1002/chem.202002632] [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: 05/30/2020] [Revised: 07/22/2020] [Indexed: 12/03/2022]
Abstract
The Cr/SiO2 Phillips catalyst has taken a central role in ethylene polymerization since its invention in 1953. The uniqueness of this catalyst is related to its ability to produce broad molecular weight distribution (MWD) PE materials as well as that no co-catalysts are required to attain activity. Nonetheless, co-catalysts in the form of metal-alkyls can be added for scavenging poisons, enhancing catalyst activity, reducing the induction period, and tailoring polymer characteristics. The activation mechanism and related polymerization mechanism remain elusive, despite extensive industrial and academic research. Here, we show that by varying the type and amount of metal-alkyl co-catalyst, we can tailor polymer properties around a single Cr/SiO2 Phillips catalyst formulation. Furthermore, we show that these different polymer properties exist in the early stages of polymerization. We have used conventional polymer characterization techniques, such as size exclusion chromatography (SEC) and 13 C NMR, for studying the metal-alkyl co-catalyst effect on short-chain branching (SCB), long-chain branching (LCB) and molecular weight distribution (MWD) at the bulk scale. In addition, scanning transmission X-ray microscopy (STXM) was used as a synchrotron technique to study the PE formation in the early stages: allowing us to investigate the produced type of early-stage PE within one particle cross-section with high energy resolution and nanometer scale spatial resolution.
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Affiliation(s)
- Maarten K. Jongkind
- Inorganic Chemistry and CatalysisDebye Institute for Nanomaterial ScienceUtrecht UniversityUniversiteitsweg 993584 CGUtrechtThe Netherlands
| | - Florian Meirer
- Inorganic Chemistry and CatalysisDebye Institute for Nanomaterial ScienceUtrecht UniversityUniversiteitsweg 993584 CGUtrechtThe Netherlands
| | - Koen W. Bossers
- Inorganic Chemistry and CatalysisDebye Institute for Nanomaterial ScienceUtrecht UniversityUniversiteitsweg 993584 CGUtrechtThe Netherlands
| | - Iris C. ten Have
- Inorganic Chemistry and CatalysisDebye Institute for Nanomaterial ScienceUtrecht UniversityUniversiteitsweg 993584 CGUtrechtThe Netherlands
| | - Hendrik Ohldag
- Advanced Light Source, MicroscopyLawrence Berkeley National Laboratory1 Cyclotron RoadBerkeleyCA94720USA
- Department of Materials Science and EngineeringStanford University450 Serra MallStanfordCA943505USA
- Department of PhysicsUniversity of California Santa Cruz1156 High StreetSanta CruzCA95064USA
| | - Benjamin Watts
- Laboratory for Synchotron Radiation—Condensed Matter (LSC)Paul Scherrer Institute (PSI)Forschungsstrasse 1115232VilligenSwitzerland
| | - Theo van Kessel
- Technology and Innovation DepartmentSABICUrmonderbaan 226167 RDGeleenThe Netherlands
| | - Nic. Friederichs
- Technology and Innovation DepartmentSABICUrmonderbaan 226167 RDGeleenThe Netherlands
| | - Bert M. Weckhuysen
- Inorganic Chemistry and CatalysisDebye Institute for Nanomaterial ScienceUtrecht UniversityUniversiteitsweg 993584 CGUtrechtThe Netherlands
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14
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Guda A, Guda S, Martini A, Bugaev A, Soldatov M, Soldatov A, Lamberti C. Machine learning approaches to XANES spectra for quantitative 3D structural determination: The case of CO2 adsorption on CPO-27-Ni MOF. Radiat Phys Chem Oxf Engl 1993 2020. [DOI: 10.1016/j.radphyschem.2019.108430] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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15
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Tielens F, Gierada M, Handzlik J, Calatayud M. Characterization of amorphous silica based catalysts using DFT computational methods. Catal Today 2020. [DOI: 10.1016/j.cattod.2019.03.062] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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16
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Jongkind MK, van Kessel T, Velthoen MEZ, Friederichs N, Weckhuysen BM. Tuning the Redox Chemistry of a Cr/SiO 2 Phillips Catalyst for Controlling Activity, Induction Period and Polymer Properties. Chemphyschem 2020; 21:1665-1674. [PMID: 32539171 PMCID: PMC7496818 DOI: 10.1002/cphc.202000488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 06/12/2020] [Indexed: 11/06/2022]
Abstract
The Cr/SiO2 Phillips catalyst has taken a central role in ethylene polymerization ever since its discovery in 1953. This catalyst is unique compared to other ethylene polymerization catalysts, since it is active without the addition of a metal-alkyl co-catalyst. However, metal-alkyls can be added for scavenging poisons, enhancing the catalyst activity, reducing the induction period and altering polymer characteristics. Despite extensive research into the working state of the catalyst, still no consensus has been reached. Here, we show that by varying the type of metal-alkyl co-catalyst and its amount, the Cr redox chemistry can be tailored, resulting in distinct catalyst activities, induction periods, and polymer characteristics. We have used in-situ UV-Vis-NIR diffuse reflectance spectroscopy (DRS) for studying the Cr oxidation state during the reduction by tri-ethyl borane (TEB) or tri-ethyl aluminum (TEAl) and during subsequent ethylene polymerization. The results show that TEB primarily acts as a reductant and reduces Cr6+ with subsequent ethylene polymerization resulting in rapid polyethylene formation. TEAl generated two types of Cr2+ sites, inaccessible Cr3+ sites and active Cr4+ sites. Subsequent addition of ethylene also revealed an increased reducibility of residual Cr6+ sites and resulted in rapid polyethylene formation. Our results demonstrate the possibility of controlling the reduction chemistry by adding the proper amount and type of metal-alkyl for obtaining desired catalyst activities and tailored polyethylene characteristics.
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Affiliation(s)
- Maarten K. Jongkind
- Inorganic Chemistry and CatalysisDebye Institute for Nanomaterial ScienceUtrecht UniversityUniversiteitsweg 993584 CGUtrechtThe Netherlands
| | - Theo van Kessel
- SABICTechnology and Innovation DepartmentUrmonderbaan 226167RD GeleenThe Netherlands
| | - Marjolein E. Z. Velthoen
- Inorganic Chemistry and CatalysisDebye Institute for Nanomaterial ScienceUtrecht UniversityUniversiteitsweg 993584 CGUtrechtThe Netherlands
| | - Nic. Friederichs
- SABICTechnology and Innovation DepartmentUrmonderbaan 226167RD GeleenThe Netherlands
| | - Bert M. Weckhuysen
- Inorganic Chemistry and CatalysisDebye Institute for Nanomaterial ScienceUtrecht UniversityUniversiteitsweg 993584 CGUtrechtThe Netherlands
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17
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Spectral Decomposition of X-ray Absorption Spectroscopy Datasets: Methods and Applications. CRYSTALS 2020. [DOI: 10.3390/cryst10080664] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
X-ray absorption spectroscopy (XAS) today represents a widespread and powerful technique, able to monitor complex systems under in situ and operando conditions, while external variables, such us sampling time, sample temperature or even beam position over the analysed sample, are varied. X-ray absorption spectroscopy is an element-selective but bulk-averaging technique. Each measured XAS spectrum can be seen as an average signal arising from all the absorber-containing species/configurations present in the sample under study. The acquired XAS data are thus represented by a spectroscopic mixture composed of superimposed spectral profiles associated to well-defined components, characterised by concentration values evolving in the course of the experiment. The decomposition of an experimental XAS dataset in a set of pure spectral and concentration values is a typical example of an inverse problem and it goes, usually, under the name of multivariate curve resolution (MCR). In the present work, we present an overview on the major techniques developed to realize the MCR decomposition together with a selection of related results, with an emphasis on applications in catalysis. Therein, we will highlight the great potential of these methods which are imposing as an essential tool for quantitative analysis of large XAS datasets as well as the directions for further development in synergy with the continuous instrumental progresses at synchrotron sources.
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Martino GA, Piovano A, Barzan C, Rabeah J, Agostini G, Bruekner A, Leone G, Zanchin G, Monoi T, Groppo E. Rationalizing the Effect of Triethylaluminum on the Cr/SiO 2 Phillips Catalysts. ACS Catal 2020. [DOI: 10.1021/acscatal.9b04726] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Giorgia A. Martino
- Department of Chemistry, NIS Centre and INSTM, University of Torino, via G. Quarello 15A, 10135 Torino, Italy
| | - Alessandro Piovano
- Department of Chemistry, NIS Centre and INSTM, University of Torino, via G. Quarello 15A, 10135 Torino, Italy
| | - Caterina Barzan
- Department of Chemistry, NIS Centre and INSTM, University of Torino, via G. Quarello 15A, 10135 Torino, Italy
| | - Jabor Rabeah
- Leibniz Institute for Catalysis at the University of Rostock (LIKAT), Albert-Einstein-Str. 29, D-18059 Rostock, Germany
| | - Giovanni Agostini
- Leibniz Institute for Catalysis at the University of Rostock (LIKAT), Albert-Einstein-Str. 29, D-18059 Rostock, Germany
| | - Angelika Bruekner
- Leibniz Institute for Catalysis at the University of Rostock (LIKAT), Albert-Einstein-Str. 29, D-18059 Rostock, Germany
| | - Giuseppe Leone
- CNR, Istituto di Scienze e Tecnologie Chimiche “Giulio Natta” (SCITEC), via A. corti 12, I-20133 Milano, Italy
| | - Giorgia Zanchin
- CNR, Istituto di Scienze e Tecnologie Chimiche “Giulio Natta” (SCITEC), via A. corti 12, I-20133 Milano, Italy
| | - Takashi Monoi
- R&D Division, Japan Polychem Corporation, 1-1 Marunouchi 1-chome, Chiyoda-ku, 100-8251 Tokyo, Japan
| | - Elena Groppo
- Department of Chemistry, NIS Centre and INSTM, University of Torino, via G. Quarello 15A, 10135 Torino, Italy
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19
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Guda AA, Guda SA, Lomachenko KA, Soldatov MA, Pankin IA, Soldatov AV, Braglia L, Bugaev AL, Martini A, Signorile M, Groppo E, Piovano A, Borfecchia E, Lamberti C. Quantitative structural determination of active sites from in situ and operando XANES spectra: From standard ab initio simulations to chemometric and machine learning approaches. Catal Today 2019. [DOI: 10.1016/j.cattod.2018.10.071] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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20
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Timoshenko J, Frenkel AI. “Inverting” X-ray Absorption Spectra of Catalysts by Machine Learning in Search for Activity Descriptors. ACS Catal 2019. [DOI: 10.1021/acscatal.9b03599] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Janis Timoshenko
- Department of Interface Science, Fritz-Haber-Institute of the Max Planck Society, 14195 Berlin, Germany
| | - Anatoly I. Frenkel
- Department of Materials Science and Chemical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
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21
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22
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Barzan C, Piovano A, Botavina M, Martino GA, Agostini G, Martra G, Groppo E. Exploring the benefits beyond the pre-reduction in methane of the Cr/SiO2 Phillips catalyst: The molecular structure of the Cr sites and their role in the catalytic performance. J Catal 2019. [DOI: 10.1016/j.jcat.2019.03.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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23
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Bucinsky L, Breza M, Malček M, Powers DC, Hwang SJ, Krzystek J, Nocera DG, Telser J. High-Frequency and -Field EPR (HFEPR) Investigation of a Pseudotetrahedral CrIV Siloxide Complex and Computational Studies of Related CrIVL4 Systems. Inorg Chem 2019; 58:4907-4920. [DOI: 10.1021/acs.inorgchem.8b03512] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Lukas Bucinsky
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-81237 Bratislava, Slovakia
| | - Martin Breza
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-81237 Bratislava, Slovakia
| | - Michal Malček
- Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-81237 Bratislava, Slovakia
| | - David C. Powers
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Seung Jun Hwang
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - J. Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310, United States
| | - Daniel G. Nocera
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Joshua Telser
- Department of Biological, Physical and Health Sciences, Roosevelt University, Chicago, Illinois 60605, United States
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24
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Yuan N, Majeed MH, Bajnóczi ÉG, Persson AR, Wallenberg LR, Inge AK, Heidenreich N, Stock N, Zou X, Wendt OF, Persson I. In situ XAS study of the local structure and oxidation state evolution of palladium in a reduced graphene oxide supported Pd(ii) carbene complex during an undirected C–H acetoxylation reaction. Catal Sci Technol 2019. [DOI: 10.1039/c8cy02430h] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In situ XAS is used to reveal the evolution of palladium species during an undirected C–H acetoxylation reaction.
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25
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Borfecchia E, Negri C, Lomachenko KA, Lamberti C, Janssens TVW, Berlier G. Temperature-dependent dynamics of NH3-derived Cu species in the Cu-CHA SCR catalyst. REACT CHEM ENG 2019. [DOI: 10.1039/c8re00322j] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In situ XAS and UV-vis–NIR spectroscopy shed light on Cu-speciation during NH3 temperature-programmed desorption and surface reaction (TPSR) over a commercial Cu-chabazite deNOx catalyst, expanding the fundamental knowledge required to unravel the NH3-SCR mechanism across the whole operation-relevant temperature range.
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Affiliation(s)
- Elisa Borfecchia
- Department of Chemistry
- NIS Centre and INSTM Reference Center
- University of Turin
- Turin
- 10125 Italy
| | - Chiara Negri
- Department of Chemistry
- NIS Centre and INSTM Reference Center
- University of Turin
- Turin
- 10125 Italy
| | | | - Carlo Lamberti
- International Research Institute “Smart Materials”
- Southern Federal University
- Rostov-on-Don
- 344090 Russia
- Department of Physics
| | | | - Gloria Berlier
- Department of Chemistry
- NIS Centre and INSTM Reference Center
- University of Turin
- Turin
- 10125 Italy
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26
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Leone G, Groppo E, Zanchin G, Martino GA, Piovano A, Bertini F, Martí-Rujas J, Parisini E, Ricci G. Concerted Electron Transfer in Iminopyridine Chromium Complexes: Ligand Effects on the Polymerization of Various (Di)olefins. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00812] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Giuseppe Leone
- CNR-Istituto per lo Studio delle Macromolecole (ISMAC), via A. Corti 12, I-20133 Milano, Italy
| | - Elena Groppo
- Dipartimento di Chimica, NIS Interdepartmental Research Center and INSTM Reference Center, Università degli Studi di Torino, Via G. Quarello 15A, I-10135 Torino, Italy
| | - Giorgia Zanchin
- CNR-Istituto per lo Studio delle Macromolecole (ISMAC), via A. Corti 12, I-20133 Milano, Italy
| | - Giorgia A. Martino
- Dipartimento di Chimica, NIS Interdepartmental Research Center and INSTM Reference Center, Università degli Studi di Torino, Via G. Quarello 15A, I-10135 Torino, Italy
| | - Alessandro Piovano
- Dipartimento di Chimica, NIS Interdepartmental Research Center and INSTM Reference Center, Università degli Studi di Torino, Via G. Quarello 15A, I-10135 Torino, Italy
| | - Fabio Bertini
- CNR-Istituto per lo Studio delle Macromolecole (ISMAC), via A. Corti 12, I-20133 Milano, Italy
| | - Javier Martí-Rujas
- Center for Nano Science and Technology at Polimi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, I-20133 Milano, Italy
| | - Emilio Parisini
- Center for Nano Science and Technology at Polimi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, I-20133 Milano, Italy
| | - Giovanni Ricci
- CNR-Istituto per lo Studio delle Macromolecole (ISMAC), via A. Corti 12, I-20133 Milano, Italy
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27
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Soldatov MA, Martini A, Bugaev AL, Pankin I, Medvedev PV, Guda AA, Aboraia AM, Podkovyrina YS, Budnyk AP, Soldatov AA, Lamberti C. The insights from X-ray absorption spectroscopy into the local atomic structure and chemical bonding of Metal–organic frameworks. Polyhedron 2018. [DOI: 10.1016/j.poly.2018.08.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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28
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Groppo E, Martino GA, Piovano A, Barzan C. The Active Sites in the Phillips Catalysts: Origins of a Lively Debate and a Vision for the Future. ACS Catal 2018. [DOI: 10.1021/acscatal.8b02521] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Elena Groppo
- Department of Chemistry, NIS Centre and INSTM, University of Torino, Via Quarello 15/A, 10125 Torino, Italy
| | - Giorgia Antonina Martino
- Department of Chemistry, NIS Centre and INSTM, University of Torino, Via Quarello 15/A, 10125 Torino, Italy
| | - Alessandro Piovano
- Department of Chemistry, NIS Centre and INSTM, University of Torino, Via Quarello 15/A, 10125 Torino, Italy
| | - Caterina Barzan
- Department of Chemistry, NIS Centre and INSTM, University of Torino, Via Quarello 15/A, 10125 Torino, Italy
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29
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The Effect of Al-Alkyls on the Phillips Catalyst for Ethylene Polymerization: The Case of Diethylaluminum Ethoxide (DEALE). Top Catal 2018. [DOI: 10.1007/s11244-018-1041-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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30
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Piovano A, Pletcher P, Velthoen MEZ, Zanoni S, Chung SH, Bossers K, Jongkind MK, Fiore G, Groppo E, Weckhuysen BM. Genesis of MgCl2
-based Ziegler-Natta Catalysts as Probed with Operando Spectroscopy. Chemphyschem 2018; 19:2662-2671. [DOI: 10.1002/cphc.201800592] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Alessandro Piovano
- Department of Chemistry, INSTM and NIS Centre; University of Torino; Via Quarello 15A 10135 Torino Italy
| | - Paul Pletcher
- Inorganic Chemistry and Catalysis Group; Debye Institute for Nanomaterials Science; Utrecht University; Universiteitsweg 99 3584 CG Utrecht The Netherlands
| | - Marjolein E. Z. Velthoen
- Inorganic Chemistry and Catalysis Group; Debye Institute for Nanomaterials Science; Utrecht University; Universiteitsweg 99 3584 CG Utrecht The Netherlands
| | - Silvia Zanoni
- Inorganic Chemistry and Catalysis Group; Debye Institute for Nanomaterials Science; Utrecht University; Universiteitsweg 99 3584 CG Utrecht The Netherlands
| | - Sang-Ho Chung
- Inorganic Chemistry and Catalysis Group; Debye Institute for Nanomaterials Science; Utrecht University; Universiteitsweg 99 3584 CG Utrecht The Netherlands
- Van 't Hoff Institute for Molecular Sciences (HIMS); University of Amsterdam; PO Box 94157 1090 GD Amsterdam The Netherlands
| | - Koen Bossers
- Inorganic Chemistry and Catalysis Group; Debye Institute for Nanomaterials Science; Utrecht University; Universiteitsweg 99 3584 CG Utrecht The Netherlands
| | - Maarten K. Jongkind
- Inorganic Chemistry and Catalysis Group; Debye Institute for Nanomaterials Science; Utrecht University; Universiteitsweg 99 3584 CG Utrecht The Netherlands
| | - Gianluca Fiore
- Department of Chemistry, INSTM and NIS Centre; University of Torino; Via Quarello 15A 10135 Torino Italy
| | - Elena Groppo
- Department of Chemistry, INSTM and NIS Centre; University of Torino; Via Quarello 15A 10135 Torino Italy
| | - 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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31
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Yuan N, Pascanu V, Huang Z, Valiente A, Heidenreich N, Leubner S, Inge AK, Gaar J, Stock N, Persson I, Martín-Matute B, Zou X. Probing the Evolution of Palladium Species in Pd@MOF Catalysts during the Heck Coupling Reaction: An Operando X-ray Absorption Spectroscopy Study. J Am Chem Soc 2018; 140:8206-8217. [PMID: 29890070 DOI: 10.1021/jacs.8b03505] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The mechanism of the Heck C-C coupling reaction catalyzed by Pd@MOFs has been investigated using operando X-ray absorption spectroscopy (XAS) and powder X-ray diffraction (PXRD) combined with transmission electron microscopy (TEM) analysis and nuclear magnetic resonance (1H NMR) kinetic studies. A custom-made reaction cell was used, allowing operando PXRD and XAS data collection using high-energy synchrotron radiation. By analyzing the XAS data in combination with ex situ studies, the evolution of the palladium species is followed from the as-synthesized to its deactivated form. An adaptive reaction mechanism is proposed. Mononuclear Pd(II) complexes are found to be the dominant active species at the beginning of the reaction, which then gradually transform into Pd nanoclusters with 13-20 Pd atoms on average in later catalytic turnovers. Consumption of available reagent and substrate leads to coordination of Cl- ions to their surfaces, which causes the poisoning of the active sites. By understanding the deactivation process, it was possible to tune the reaction conditions and prolong the lifetime of the catalyst.
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Affiliation(s)
- Ning Yuan
- Berzelii Center EXSELENT on Porous Materials , Stockholm University , SE-106 91 Stockholm , Sweden.,Department of Materials and Environmental Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden.,Department of Molecular Sciences , Swedish University of Agricultural Sciences , P.O. Box 7015, SE-750 07 Uppsala , Sweden
| | - Vlad Pascanu
- Berzelii Center EXSELENT on Porous Materials , Stockholm University , SE-106 91 Stockholm , Sweden.,Department of Organic Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Zhehao Huang
- Berzelii Center EXSELENT on Porous Materials , Stockholm University , SE-106 91 Stockholm , Sweden.,Department of Materials and Environmental Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Alejandro Valiente
- Berzelii Center EXSELENT on Porous Materials , Stockholm University , SE-106 91 Stockholm , Sweden.,Department of Organic Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Niclas Heidenreich
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel , DE-24118 Kiel , Germany
| | - Sebastian Leubner
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel , DE-24118 Kiel , Germany
| | - A Ken Inge
- Berzelii Center EXSELENT on Porous Materials , Stockholm University , SE-106 91 Stockholm , Sweden.,Department of Materials and Environmental Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Jakob Gaar
- Department of Organic Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Norbert Stock
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel , DE-24118 Kiel , Germany
| | - Ingmar Persson
- Department of Molecular Sciences , Swedish University of Agricultural Sciences , P.O. Box 7015, SE-750 07 Uppsala , Sweden
| | - Belén Martín-Matute
- Berzelii Center EXSELENT on Porous Materials , Stockholm University , SE-106 91 Stockholm , Sweden.,Department of Organic Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Xiaodong Zou
- Berzelii Center EXSELENT on Porous Materials , Stockholm University , SE-106 91 Stockholm , Sweden.,Department of Materials and Environmental Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
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33
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Fong A, Vandervelden C, Scott SL, Peters B. Computational Support for Phillips Catalyst Initiation via Cr–C Bond Homolysis in a Chromacyclopentane Site. ACS Catal 2018. [DOI: 10.1021/acscatal.7b03724] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anthony Fong
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
| | - Craig Vandervelden
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
| | - Susannah L. Scott
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106-9510, United States
| | - Baron Peters
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106-5080, United States
- Department of Chemistry & Biochemistry, University of California, Santa Barbara, California 93106-9510, United States
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34
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Affiliation(s)
| | - Ted H. Cymbaluk
- Chevron Phillips Chemical Company, Pasadena, Texas 77506, United States
| | - Michael D. Jensen
- Formosa Plastics
Corporation, Polyolefins Technology Division, Point Comfort, Texas 77978, United States
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