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Kobera L, Dedecek J, Klein P, Tabor E, Brus J, Fishchuk AV, Sklenak S. Formation and local structure of framework Al Lewis sites in beta zeolites. J Chem Phys 2022; 156:104702. [DOI: 10.1063/5.0083666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Framework AlFR Lewis sites represent a substantial portion of active sites in H-BEA zeolite catalysts activated at low temperatures. We studied their nature by 27Al WURST-QCPMG nuclear magnetic resonance (NMR) and proposed a plausible mechanism of their formation based on periodic density functional theory calculations constrained by 1H MAS, 27Al WURST-QCPMG, and 29Si MAS NMR experiments and FTIR measurements. Our results show that the electron-pair acceptor of AlFR Lewis sites corresponds to an AlTRI atom tricoordinated to the zeolite framework, which adsorbs a water molecule. This AlTRI–OH2 complex is reflected in 27Al NMR resonance with δiso = 70 ± 5 ppm and CQ = 13 ± 2 MHz. In addition, the AlTRI atom with adsorbed acetonitrile- d3 (the probe of AlFR Lewis sites in FTIR spectroscopy) exhibits a similar 27Al NMR resonance. We suggest that these AlFR Lewis sites are formed from Al–OH–Si–O–Si–O–Si–OH–Al sequences located in 12-rings (i.e., close unpaired Al atoms).
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Affiliation(s)
- Libor Kobera
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovský nám. 2, CZ 162 06 Prague 6, Czech Republic
| | - Jiri Dedecek
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, CZ 182 23 Prague 8, Czech Republic
| | - Petr Klein
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, CZ 182 23 Prague 8, Czech Republic
| | - Edyta Tabor
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, CZ 182 23 Prague 8, Czech Republic
| | - Jiri Brus
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovský nám. 2, CZ 162 06 Prague 6, Czech Republic
| | - Anna V. Fishchuk
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, CZ 182 23 Prague 8, Czech Republic
| | - Stepan Sklenak
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, CZ 182 23 Prague 8, Czech Republic
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2
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Cu(OH)2-Ni(OH)2 engulfed by zeolite-Y hydroxyl nest and multiwalled carbon nanotube for effective methanol oxidation reaction. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.139313] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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3
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Li G, Foo C, Yi X, Chen W, Zhao P, Gao P, Yoskamtorn T, Xiao Y, Day S, Tang CC, Hou G, Zheng A, Tsang SCE. Induced Active Sites by Adsorbate in Zeotype Materials. J Am Chem Soc 2021; 143:8761-8771. [PMID: 34076425 DOI: 10.1021/jacs.1c03166] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
There has been a long debate on how and where active sites are created for molecular adsorption and catalysis in zeolites, which underpin many important industrial applications. It is well accepted that Lewis acidic sites (LASs) and basic sites (LBSs) as active sites in pristine zeolites are generally believed to be the extra-framework Al species and residue anion (OH-) species formed at fixed crystallographic positions after their synthesis. However, the dynamic interactions of adsorbates/reactants with pristine zeotype materials to "create" sites during real conditions remain largely unexplored. Herein, direct experimental observation of the establishment of induced active sites in silicoaluminophosphate (SAPO) by an adsorbate is for the first time made, which contradicts the traditional view of the fixed active sites in zeotype materials. Evidence shows that an induced frustrated Lewis pair (FLP, three-coordinated framework Al as LAS and SiO (H) as LBS) can be transiently favored for heterolytic molecular binding/reactions of competitive polar adsorbates due to their ineffective orbital overlap in the rigid framework. High-resolution magic-angle-spinning solid-state NMR, synchrotron X-ray diffraction, neutron powder diffraction, in situ diffuse reflectance infrared Fourier transform spectroscopy, and ab initio molecular dynamics demonstrate the transformation of a typical Brønsted acid site (Al(OH)Si) in SAPO zeolites to new induced FLP structure for hetereolytic binding upon adsorption of a strong polar adsorbate. Our unprecedented finding opens up a new avenue to understanding the dynamic establishment of active sites for adsorption or chemical reactions under molecular bombardment of zeolitic structures.
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Affiliation(s)
- Guangchao Li
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China.,Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford OX1 3QR, U.K.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Christopher Foo
- Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford OX1 3QR, U.K.,Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K
| | - Xianfeng Yi
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China
| | - Wei Chen
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China
| | - Pu Zhao
- Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford OX1 3QR, U.K
| | - Pan Gao
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Tatchamapan Yoskamtorn
- Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford OX1 3QR, U.K
| | - Yao Xiao
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Sarah Day
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K
| | - Chiu C Tang
- Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, U.K
| | - Guangjin Hou
- State Key Laboratory of Catalysis, National Laboratory for Clean Energy, 2011-Collaborative Innovation Center of Chemistry for Energy Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China
| | - Anmin Zheng
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China
| | - Shik Chi Edman Tsang
- Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford OX1 3QR, U.K
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4
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Weissenberger T, Machoke AGF, Kolle JM, Avadhut YS, Hartmann M, Schwieger W. Synthesis and Catalytic Performance of Aluminium‐containing Mesoporous, Spherical Silica Particles. CHEM-ING-TECH 2021. [DOI: 10.1002/cite.202000183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tobias Weissenberger
- University of Erlangen-Nuremberg Institute of Chemical Reaction Engineering Egerlandstrasse 3 91058 Erlangen Germany
| | - Albert G. F. Machoke
- University of Erlangen-Nuremberg Institute of Chemical Reaction Engineering Egerlandstrasse 3 91058 Erlangen Germany
| | - Joel M. Kolle
- University of Erlangen-Nuremberg Institute of Chemical Reaction Engineering Egerlandstrasse 3 91058 Erlangen Germany
| | - Yamini S. Avadhut
- University of Erlangen-Nuremberg Erlangen Center for Interface Research and Catalysis Egerlandstrasse 3 91058 Erlangen Germany
| | - Martin Hartmann
- University of Erlangen-Nuremberg Erlangen Center for Interface Research and Catalysis Egerlandstrasse 3 91058 Erlangen Germany
| | - Wilhelm Schwieger
- University of Erlangen-Nuremberg Institute of Chemical Reaction Engineering Egerlandstrasse 3 91058 Erlangen Germany
- University of Erlangen-Nuremberg Erlangen Center for Interface Research and Catalysis Egerlandstrasse 3 91058 Erlangen Germany
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Vinaches P, Gonçalves EC, Variani Y, Rojas A, Rodríguez-Castellón E, Pergher SB. Aluminium introduction on the STF zeolite synthesized with the organic structure-directing agent 123TE4MI. Catal Today 2020. [DOI: 10.1016/j.cattod.2019.08.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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6
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Ravi M, Sushkevich VL, van Bokhoven JA. Towards a better understanding of Lewis acidic aluminium in zeolites. NATURE MATERIALS 2020; 19:1047-1056. [PMID: 32958864 DOI: 10.1038/s41563-020-0751-3] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 06/29/2020] [Indexed: 05/15/2023]
Abstract
Zeolites are a class of materials that are of great relevance for industrial catalysis. Several fundamental questions relating to the structure and role of the Lewis acid sites in these materials remain unanswered. Proposals for the origin of such species can broadly be classified into three categories, which have distinct structures: extra-framework, framework-associated and framework aluminium. In this Perspective, we review each of these proposals and proceed to analyse their suitability to understand experimental results. Contrary to traditional belief, the number of Lewis acid sites does not always correlate to extra-framework aluminium content. As a result, we highlight that the terms 'extra-framework' and 'framework-associated' aluminium should be used with caution. We propose how the usage of different characterization techniques can enable the closure of knowledge gaps concerning the strength, multiplicity, localization and structure of catalytically active Lewis acid sites in zeolites.
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Affiliation(s)
- Manoj Ravi
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Vitaly L Sushkevich
- Laboratory for Catalysis and Sustainable Chemistry, Paul Scherrer Institute, Villigen, Switzerland
| | - Jeroen A van Bokhoven
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland.
- Laboratory for Catalysis and Sustainable Chemistry, Paul Scherrer Institute, Villigen, Switzerland.
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7
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Xin S, Wang Q, Xu J, Chu Y, Wang P, Feng N, Qi G, Trébosc J, Lafon O, Fan W, Deng F. The acidic nature of "NMR-invisible" tri-coordinated framework aluminum species in zeolites. Chem Sci 2019; 10:10159-10169. [PMID: 32055370 PMCID: PMC6979346 DOI: 10.1039/c9sc02634g] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 09/11/2019] [Indexed: 01/19/2023] Open
Abstract
The unambiguous characterization of different acid sites in zeolites is of great importance for understanding their catalytic performance and the rational design of highly efficient zeolite catalysts. In addition to various well-characterized extra-framework Al species, a tri-coordinated framework aluminum species can also serve as a Lewis acid site in zeolites, which is "NMR-invisible" owing to its extremely distorted local environment. Here we provide a feasible and reliable approach to elucidate the acidic nature of the tri-coordinated framework Al in dehydrated H-ZSM-5 zeolites via sensitivity-enhanced two-dimensional (2D) multiple nuclear correlation NMR experiments coupled with trimethylphosphine oxide (TMPO) probe molecules. Two types of tri-coordinated framework Al sites have been unambiguously identified, which amount to 11.6% of the total Brønsted and Lewis acid sites. Furthermore, it was found that synergistic effects arising from the close spatial proximity between the tri-coordinated framework Al site and the Brønsted acid site lead to the generation of superacidity (with an acid strength stronger than 100% H2SO4) in the zeolite.
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Affiliation(s)
- Shaohui Xin
- National Centre for Magnetic Resonance in Wuhan , State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics , CAS Key Laboratory of Magnetic Resonance in Biological Systems , Wuhan Institute of Physics and Mathematics , Chinese Academy of Sciences , Wuhan 430071 , China . ; .,University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Qiang Wang
- National Centre for Magnetic Resonance in Wuhan , State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics , CAS Key Laboratory of Magnetic Resonance in Biological Systems , Wuhan Institute of Physics and Mathematics , Chinese Academy of Sciences , Wuhan 430071 , China . ;
| | - Jun Xu
- National Centre for Magnetic Resonance in Wuhan , State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics , CAS Key Laboratory of Magnetic Resonance in Biological Systems , Wuhan Institute of Physics and Mathematics , Chinese Academy of Sciences , Wuhan 430071 , China . ;
| | - Yueying Chu
- National Centre for Magnetic Resonance in Wuhan , State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics , CAS Key Laboratory of Magnetic Resonance in Biological Systems , Wuhan Institute of Physics and Mathematics , Chinese Academy of Sciences , Wuhan 430071 , China . ;
| | - Pengfei Wang
- State Key Laboratory of Coal Conversion , Institute of Coal Chemistry , Chinese Academy of Sciences , P.O. Box 165 , Taiyuan , Shanxi 030001 , P. R. China
| | - Ningdong Feng
- National Centre for Magnetic Resonance in Wuhan , State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics , CAS Key Laboratory of Magnetic Resonance in Biological Systems , Wuhan Institute of Physics and Mathematics , Chinese Academy of Sciences , Wuhan 430071 , China . ;
| | - Guodong Qi
- National Centre for Magnetic Resonance in Wuhan , State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics , CAS Key Laboratory of Magnetic Resonance in Biological Systems , Wuhan Institute of Physics and Mathematics , Chinese Academy of Sciences , Wuhan 430071 , China . ;
| | - Julien Trébosc
- Univ. Lille , CNRS , ENSCL , UMR 8181 , Unité de Catalyse et de Chimie du Solide , 59000 Lille , France
| | - Olivier Lafon
- Univ. Lille , CNRS , ENSCL , UMR 8181 , Unité de Catalyse et de Chimie du Solide , 59000 Lille , France.,Institut Universitaire de France , 75231 Paris , France
| | - Weibin Fan
- State Key Laboratory of Coal Conversion , Institute of Coal Chemistry , Chinese Academy of Sciences , P.O. Box 165 , Taiyuan , Shanxi 030001 , P. R. China
| | - Feng Deng
- National Centre for Magnetic Resonance in Wuhan , State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics , CAS Key Laboratory of Magnetic Resonance in Biological Systems , Wuhan Institute of Physics and Mathematics , Chinese Academy of Sciences , Wuhan 430071 , China . ;
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8
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Introduction of Al into the HPM-1 Framework by In Situ Generated Seeds as an Alternative Methodology. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8091634] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
An alternative method for the introduction of aluminum into the STW zeolitic framework is presented. HPM-1, a chiral STW zeolite with helical pores, was synthesized in the pure silica form, and an aluminum source was added by in situ generated seeds. Displacements of the peak positions in the Al samples were found in the X-ray diffractograms, indicating the possible incorporation of the heteroatom into the framework. Using an analysis of the 29Si and 27Al magic-angle spinning nuclear magnetic resonance (MAS NMR) spectra, we concluded that the aluminum was effectively introduced into the framework. The (AlTETRAHEDRAL/AlOCTAHEDRAL) ratio and its textural properties were studied to explain the catalytic ethanol conversion results at medium temperatures. The sample with the lowest Si/Al ratio showed the best results due to its higher surface area and pore volume, in comparison to those observed for the sample with the highest Si/Al ratio, and due to its higher bulk tetrahedral aluminum content, in comparison to the intermediate Si/Al ratio sample. All catalysts were selective to ethylene and diethyl ether, confirming the presence of acidic sites.
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9
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Mild-acid-assisted thermal or hydrothermal dealumination of zeolite beta, its regulation to Al distribution and catalytic cracking performance to hydrocarbons. J Catal 2018. [DOI: 10.1016/j.jcat.2018.03.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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10
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Perea DE, Arslan I, Liu J, Ristanović Z, Kovarik L, Arey BW, Lercher JA, Bare SR, Weckhuysen BM. Determining the location and nearest neighbours of aluminium in zeolites with atom probe tomography. Nat Commun 2015; 6:7589. [PMID: 26133270 PMCID: PMC4506508 DOI: 10.1038/ncomms8589] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/21/2015] [Indexed: 01/30/2023] Open
Abstract
Zeolite catalysis is determined by a combination of pore architecture and Brønsted acidity. As Brønsted acid sites are formed by the substitution of AlO4 for SiO4 tetrahedra, it is of utmost importance to have information on the number as well as the location and neighbouring sites of framework aluminium. Unfortunately, such detailed information has not yet been obtained, mainly due to the lack of suitable characterization methods. Here we report, using the powerful atomic-scale analysis technique known as atom probe tomography, the quantitative spatial distribution of individual aluminium atoms, including their three-dimensional extent of segregation. Using a nearest-neighbour statistical analysis, we precisely determine the short-range distribution of aluminium over the different T-sites and determine the most probable Al–Al neighbouring distance within parent and steamed ZSM-5 crystals, as well as assess the long-range redistribution of aluminium upon zeolite steaming. Substitution of framework silicon for aluminium in zeolites affects Brønsted acidity and subsequently catalytic activity. Here, the authors use atom probe tomography to obtain quantitative insights into the spatial distribution of individual aluminium atoms, including their distribution and segregation.
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Affiliation(s)
- Daniel E Perea
- Pacific Northwest National Laboratory, Environmental Molecular Science Laboratory, 3335 Innovation Boulevard, Richland, Washington 99352, USA
| | - Ilke Arslan
- Pacific Northwest National Laboratory, Institute for Integrated Catalysis, 902 Battelle Boulevard, Richland, Washington 99352, USA
| | - Jia Liu
- Pacific Northwest National Laboratory, Environmental Molecular Science Laboratory, 3335 Innovation Boulevard, Richland, Washington 99352, USA
| | - Zoran Ristanović
- Faculty of Science, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, The Netherlands
| | - Libor Kovarik
- Pacific Northwest National Laboratory, Environmental Molecular Science Laboratory, 3335 Innovation Boulevard, Richland, Washington 99352, USA
| | - Bruce W Arey
- Pacific Northwest National Laboratory, Environmental Molecular Science Laboratory, 3335 Innovation Boulevard, Richland, Washington 99352, USA
| | - Johannes A Lercher
- Pacific Northwest National Laboratory, Institute for Integrated Catalysis, 902 Battelle Boulevard, Richland, Washington 99352, USA.,Department of Chemistry, TU Munich, Lichtenbergstrasse 4, Garching 85748, Germany
| | - Simon R Bare
- UOP LLC, a Honeywell Company, 25 E. Algonquin Road Des Plaines, Illinois 60016, USA
| | - Bert M Weckhuysen
- Faculty of Science, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, Utrecht 3584 CG, The Netherlands
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11
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Brus J, Kobera L, Schoefberger W, Urbanová M, Klein P, Sazama P, Tabor E, Sklenak S, Fishchuk AV, Dědeček J. Structure of Framework Aluminum Lewis Sites and Perturbed Aluminum Atoms in Zeolites as Determined by27Al{1H} REDOR (3Q) MAS NMR Spectroscopy and DFT/Molecular Mechanics. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201409635] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Brus J, Kobera L, Schoefberger W, Urbanová M, Klein P, Sazama P, Tabor E, Sklenak S, Fishchuk AV, Dědeček J. Structure of framework aluminum Lewis sites and perturbed aluminum atoms in zeolites as determined by 27Al{1H} REDOR (3Q) MAS NMR spectroscopy and DFT/molecular mechanics. Angew Chem Int Ed Engl 2014; 54:541-5. [PMID: 25393612 DOI: 10.1002/anie.201409635] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Indexed: 11/07/2022]
Abstract
Zeolites are highly important heterogeneous catalysts. Besides Brønsted SiOHAl acid sites, also framework AlFR Lewis acid sites are often found in their H-forms. The formation of AlFR Lewis sites in zeolites is a key issue regarding their selectivity in acid-catalyzed reactions. The local structures of AlFR Lewis sites in dehydrated zeolites and their precursors--"perturbed" AlFR atoms in hydrated zeolites--were studied by high-resolution MAS NMR and FTIR spectroscopy and DFT/MM calculations. Perturbed framework Al atoms correspond to (SiO)3AlOH groups and are characterized by a broad (27)Al NMR resonance (δi = 59-62 ppm, CQ = 5 MHz, and η = 0.3-0.4) with a shoulder at 40 ppm in the (27)Al MAS NMR spectrum. Dehydroxylation of (SiO)3AlOH occurs at mild temperatures and leads to the formation of AlFR Lewis sites tricoordinated to the zeolite framework. Al atoms of these (SiO)3Al Lewis sites exhibit an extremely broad (27)Al NMR resonance (δi ≈ 67 ppm, CQ ≈ 20 MHz, and η ≈ 0.1).
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Affiliation(s)
- Jiří Brus
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky sq. 2, 162 06 Prague 6 (Czech Republic)
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Valtchev V, Majano G, Mintova S, Pérez-Ramírez J. Tailored crystalline microporous materials by post-synthesis modification. Chem Soc Rev 2013; 42:263-90. [DOI: 10.1039/c2cs35196j] [Citation(s) in RCA: 342] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Nyalosaso JL, Derrien G, Charnay C, de Menorval LC, Zajac J. Aluminium-derivatized silica monodisperse nanospheres by a one-step synthesis-functionalization method and application as acid catalysts in liquid phase. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c1jm14412j] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Malola S, Svelle S, Bleken FL, Swang O. Detailed reaction paths for zeolite dealumination and desilication from density functional calculations. Angew Chem Int Ed Engl 2011; 51:652-5. [PMID: 22147388 DOI: 10.1002/anie.201104462] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 10/04/2011] [Indexed: 11/05/2022]
Affiliation(s)
- Sami Malola
- inGAP Center for Research-Based Innovation, Department of Chemistry, University of Oslo, P. O. Box 1033 Blindern, 0315 Oslo, Norway
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16
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Detailed Reaction Paths for Zeolite Dealumination and Desilication From Density Functional Calculations. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201104462] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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17
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Wilson K, Lee A. Applications of XPS to the study of inorganic compounds. SPECTROSCOPIC PROPERTIES OF INORGANIC AND ORGANOMETALLIC COMPOUNDS 2010. [DOI: 10.1039/9781849730853-00072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The surface behaviour of materials is crucial to our everyday lives. Studies of the corrosive, reactive, optical and electronic properties of surfaces are thus of great importance to a wide range of industries including the chemical and electronics sectors. The surface properties of polymers can also be tuned for use in packaging, non stick coatings or for use in medical applications. Methods to characterise surface composition and reactivity are thus critical to the development of next generation materials. This report will outline the basic principles of X-ray photoelectron spectroscopy and how it can be applied to analyse the surfaces of inorganic materials. The role of XPS in understanding the nature of the active site in heterogeneous catalysts will also be discussed.
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Affiliation(s)
- Karen Wilson
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University Cardiff, CF10 3AT UK
| | - Adam Lee
- Cardiff Catalysis Institute, School of Chemistry, Cardiff University Cardiff, CF10 3AT UK
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18
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Guan J, Li X, Yang G, Zhang W, Liu X, Han X, Bao X. Interactions of phosphorous molecules with the acid sites of H-Beta zeolite: Insights from solid-state NMR techniques and theoretical calculations. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.molcata.2009.06.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Lemos de Macedo J, Ferreira Ghesti G, Alves Dias J, Cláudia Loureiro Dias S. Liquid phase calorimetry and adsorption analyses of zeolite beta acidity. Phys Chem Chem Phys 2008; 10:1584-92. [DOI: 10.1039/b715142j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Pollock N, Fowler G, Twyman LJ, McArthur SL. Synthesis and characterization of immobilized PAMAM dendrons. Chem Commun (Camb) 2007:2482-4. [PMID: 17563803 DOI: 10.1039/b701550j] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This communication describes the synthesis and characterization of immobilized PAMAM dendrons onto a surface modified silicon wafer substrate (functionalized using plasma polymerized PAA) using a "growing from" strategy.
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Affiliation(s)
- Neal Pollock
- Department of Chemistry, Dainton Building, Brook Hill, The University of Sheffield, Sheffield, UK
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21
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Synthesis of nanocrystalline zeolite beta in supercritical fluids, characterization and catalytic activity. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.molcata.2006.02.044] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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The effect of chemical composition and structure on XPS binding energies in zeolites. RECENT ADVANCES IN THE SCIENCE AND TECHNOLOGY OF ZEOLITES AND RELATED MATERIALS PART B, PROCEEDINGS OF THE 14TH INTERNATIONAL ZEOLITE CONFERENCE 2004. [DOI: 10.1016/s0167-2991(04)80654-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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van Bokhoven JA, van der Eerden AMJ, Koningsberger DC. Three-coordinate aluminum in zeolites observed with in situ x-ray absorption near-edge spectroscopy at the Al K-edge: flexibility of aluminum coordinations in zeolites. J Am Chem Soc 2003; 125:7435-42. [PMID: 12797818 DOI: 10.1021/ja0292905] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Application of in situ X-ray absorption near-edge spectroscopy (XANES) at the Al K-edge provides unique insight into the flexibilty of the aluminum coordinations in zeolites as a function of treatment or during true reaction conditions. A unique, previously not observed, pre-edge feature is detected in zeolites H-Mordenite and steamed and unsteamed H-Beta at temperatures above 675 K. Spectra simulations using the full multiple scattering code Feff8 identify the unique pre-edge feature as three-coordinate aluminum. The amount of three-fold coordinated aluminum is a function of temperature and pretreatment of a zeolite: a steamed zeolite Beta contains more three-coordinate aluminum than an unsteamed sample. No clear differences between zeolites H-Mordenite and H-Beta were observed. Octahedrally coordinated aluminum forms in zeolites H-Mordenite and H-Beta at room temperature in a stream of wet helium. This octahedrally coordinated aluminum is unstable at temperatures higher than 395 K, where it quantitatively reverts to the tetrahedral coordination.
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Affiliation(s)
- Jeroen A van Bokhoven
- Institute for Chemical and Bioengineering, ETH Hönggerberg, CH-8093 Zurich, Switzerland.
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Buckley AN, Hartmann AJ, Lamb RN, Stampfl APJ, Freeland JW, Coulthard I. Threshold Al KLL Auger spectra of oxidized aluminium foils. SURF INTERFACE ANAL 2003. [DOI: 10.1002/sia.1626] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Gijzeman OLJ, Mens AJM, van Lenthe JH, Mortier WJ, Weckhuysen BM. The Effect of Chemical Composition and Structure on XPS Binding Energies in Zeolites. J Phys Chem B 2002. [DOI: 10.1021/jp021948d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Onno L. J. Gijzeman
- Department of Inorganic Chemistry and Catalysis, Debye Institute, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands, Theoretical Chemistry Group, Debye Institute, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands, and ExxonMobil Chemical Europe Inc., European Technology Research Center, Hermeslaan 2, B-1831 Machelen, Belgium
| | - Ad J. M. Mens
- Department of Inorganic Chemistry and Catalysis, Debye Institute, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands, Theoretical Chemistry Group, Debye Institute, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands, and ExxonMobil Chemical Europe Inc., European Technology Research Center, Hermeslaan 2, B-1831 Machelen, Belgium
| | - Joop H. van Lenthe
- Department of Inorganic Chemistry and Catalysis, Debye Institute, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands, Theoretical Chemistry Group, Debye Institute, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands, and ExxonMobil Chemical Europe Inc., European Technology Research Center, Hermeslaan 2, B-1831 Machelen, Belgium
| | - Wifried J. Mortier
- Department of Inorganic Chemistry and Catalysis, Debye Institute, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands, Theoretical Chemistry Group, Debye Institute, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands, and ExxonMobil Chemical Europe Inc., European Technology Research Center, Hermeslaan 2, B-1831 Machelen, Belgium
| | - Bert M. Weckhuysen
- Department of Inorganic Chemistry and Catalysis, Debye Institute, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands, Theoretical Chemistry Group, Debye Institute, Utrecht University, P.O. Box 80083, 3508 TB Utrecht, The Netherlands, and ExxonMobil Chemical Europe Inc., European Technology Research Center, Hermeslaan 2, B-1831 Machelen, Belgium
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