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Shahami M, Dooley KM, Shantz DF. Steam-assisted crystallized Fe-ZSM-5 materials and their unprecedented activity in benzene hydroxylation to phenol using hydrogen peroxide. J Catal 2018. [DOI: 10.1016/j.jcat.2018.10.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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DeNO x Abatement over Sonically Prepared Iron-Substituted Y, USY and MFI Zeolite Catalysts in Lean Exhaust Gas Conditions. NANOMATERIALS 2018; 8:nano8010021. [PMID: 29301370 PMCID: PMC5791108 DOI: 10.3390/nano8010021] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/19/2017] [Accepted: 12/30/2017] [Indexed: 11/17/2022]
Abstract
Iron-substituted MFI, Y and USY zeolites prepared by two preparation routes-classical ion exchange and the ultrasound modified ion-exchange method-were characterised by micro-Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet (UV)/visible diffuse reflectance spectroscopy (UV/Vis DRS). Ultrasound irradiation, a new technique for the preparation of the metal salt suspension before incorporation to the zeolite structure, was employed. An experimental study of selective catalytic reduction (SCR) of NO with NH₃ on both iron-substituted reference zeolite catalysts and those prepared through the application of ultrasound conducted during an ion-exchange process is presented. The prepared zeolite catalysts show high activity and selectivity in SCR deNOx abatement. The MFI-based iron catalysts, especially those prepared via the sonochemical method, revealed superior activity in the deNOx process, with almost 100% selectivity towards N₂. The hydrothermal stability test confirmed high stability and activity of MFI-based catalysts in water-rich conditions during the deNOx reaction at 450 °C.
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Bordiga S, Lamberti C, Bonino F, Travert A, Thibault-Starzyk F. Probing zeolites by vibrational spectroscopies. Chem Soc Rev 2015; 44:7262-341. [PMID: 26435467 DOI: 10.1039/c5cs00396b] [Citation(s) in RCA: 188] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
This review addresses the most relevant aspects of vibrational spectroscopies (IR, Raman and INS) applied to zeolites and zeotype materials. Surface Brønsted and Lewis acidity and surface basicity are treated in detail. The role of probe molecules and the relevance of tuning both the proton affinity and the steric hindrance of the probe to fully understand and map the complex site population present inside microporous materials are critically discussed. A detailed description of the methods needed to precisely determine the IR absorption coefficients is given, making IR a quantitative technique. The thermodynamic parameters of the adsorption process that can be extracted from a variable-temperature IR study are described. Finally, cutting-edge space- and time-resolved experiments are reviewed. All aspects are discussed by reporting relevant examples. When available, the theoretical literature related to the reviewed experimental results is reported to support the interpretation of the vibrational spectra on an atomic level.
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Affiliation(s)
- Silvia Bordiga
- Department of Chemistry, NIS and INSTM Reference Centers, University of Torino, Via Quarello 15, I-10135 Torino, Italy
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van Bokhoven JA, Lamberti C. Structure of aluminum, iron, and other heteroatoms in zeolites by X-ray absorption spectroscopy. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.05.013] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Zhang Z, Zhang B, Liu H, Chen Y. Facile preparation of Fe-Y catalyst under water-free conditions for selective catalytic reduction of NO x by ammonia. Sci China Chem 2013. [DOI: 10.1007/s11426-013-4955-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Bordiga S, Groppo E, Agostini G, van Bokhoven JA, Lamberti C. Reactivity of Surface Species in Heterogeneous Catalysts Probed by In Situ X-ray Absorption Techniques. Chem Rev 2013; 113:1736-850. [DOI: 10.1021/cr2000898] [Citation(s) in RCA: 488] [Impact Index Per Article: 44.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Silvia Bordiga
- Department of Chemistry and NIS Centre of Excellence, Università di Torino and INSTM Reference Center, Via P. Giuria 7, 10125 Torino, Italy
| | - Elena Groppo
- Department of Chemistry and NIS Centre of Excellence, Università di Torino and INSTM Reference Center, Via P. Giuria 7, 10125 Torino, Italy
| | - Giovanni Agostini
- Department of Chemistry and NIS Centre of Excellence, Università di Torino and INSTM Reference Center, Via P. Giuria 7, 10125 Torino, Italy
| | - Jeroen A. van Bokhoven
- ETH Zurich, Institute for Chemical and Bioengineering, HCI E127 8093 Zurich, Switzerland
- Laboratory for Catalysis and Sustainable Chemistry (LSK) Swiss Light Source, Paul Scherrer Instituteaul Scherrer Institute, Villigen, Switzerland
| | - Carlo Lamberti
- Department of Chemistry and NIS Centre of Excellence, Università di Torino and INSTM Reference Center, Via P. Giuria 7, 10125 Torino, Italy
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Lamberti C, Zecchina A, Groppo E, Bordiga S. Probing the surfaces of heterogeneous catalysts by in situ IR spectroscopy. Chem Soc Rev 2010; 39:4951-5001. [PMID: 21038053 DOI: 10.1039/c0cs00117a] [Citation(s) in RCA: 358] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This critical review describes the reactivity of heterogeneous catalysts from the point of view of four simple, but essential for Chemistry, molecules (namely dihydrogen, carbon monoxide, nitrogen monoxide and ethylene) that are considered as probes or as reactants in combination with "in situ" controlled temperature and pressure Infrared spectroscopy. The fundamental properties of H(2), CO, NO and C(2)H(4) are shortly described in order to justify their different behaviour in respect of isolated sites in different environments, extended surfaces, clusters, crystalline or amorphous materials. The description is given by considering some "key studies" and trying to evidence similarities and differences among surfaces and probes (572 references).
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Affiliation(s)
- Carlo Lamberti
- Department of Inorganic, Physical and Materials Chemistry, NIS Centre of Excellence, University of Turin. Via P. Giuria 7, 10125 Torino, Italy
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Bonino F, Damin A, Piovano A, Lamberti C, Bordiga S, Zecchina A. Direct Evidence of Highly Dispersed Iron in Fe-silicalite: A Raman Spectroscopic Study. ChemCatChem 2010. [DOI: 10.1002/cctc.201000265] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Bakhmutov VI. Strategies for solid-state NMR studies of materials: from diamagnetic to paramagnetic porous solids. Chem Rev 2010; 111:530-62. [PMID: 20843066 DOI: 10.1021/cr100144r] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Berlier G, Lamberti C, Rivallan M, Mul G. Characterization of Fe sites in Fe-zeolites by FTIR spectroscopy of adsorbed NO: are the spectra obtained in static vacuum and dynamic flow set-ups comparable? Phys Chem Chem Phys 2010; 12:358-64. [DOI: 10.1039/b917646m] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Zecchina A, Rivallan M, Berlier G, Lamberti C, Ricchiardi G. Structure and nuclearity of active sites in Fe-zeolites: comparison with iron sites in enzymes and homogeneous catalysts. Phys Chem Chem Phys 2007; 9:3483-99. [PMID: 17612716 DOI: 10.1039/b703445h] [Citation(s) in RCA: 195] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fe-ZSM-5 and Fe-silicalite zeolites efficiently catalyse several oxidation reactions which find close analogues in the oxidation reactions catalyzed by homogeneous and enzymatic compounds. The iron centres are highly dispersed in the crystalline matrix and on highly diluted samples, mononuclear and dinuclear structures are expected to become predominant. The crystalline and robust character of the MFI framework has allowed to hypothesize that the catalytic sites are located in well defined crystallographic positions. For this reason these catalysts have been considered as the closest and best defined heterogeneous counterparts of heme and non heme iron complexes and of Fenton type Fe(2+) homogeneous counterparts. On this basis, an analogy with the methane monooxygenase has been advanced several times. In this review we have examined the abundant literature on the subject and summarized the most widely accepted views on the structure, nuclearity and catalytic activity of the iron species. By comparing the results obtained with the various characterization techniques, we conclude that Fe-ZSM-5 and Fe-silicalite are not the ideal samples conceived before and that many types of species are present, some active and some other silent from adsorptive and catalytic point of view. The relative concentration of these species changes with thermal treatments, preparation procedures and loading. Only at lowest loadings the catalytically active species become the dominant fraction of the iron species. On the basis of the spectroscopic titration of the active sites by using NO as a probe, we conclude that the active species on very diluted samples are isolated and highly coordinatively unsaturated Fe(2+) grafted to the crystalline matrix. Indication of the constant presence of a smaller fraction of Fe(2+) presumably located on small clusters is also obtained. The nitrosyl species formed upon dosing NO from the gas phase on activated Fe-ZSM-5 and Fe-silicalite, have been analyzed in detail and the similarities and differences with the cationic, heme and non heme homogeneous counterparts have been evidenced. The same has been done for the oxygen species formed by N(2)O decomposition on isolated sites, whose properties are more similar to those of the (FeO)(2+) in cationic complexes (included the [(H(2)O)(5)FeO](2+)"brown ring" complex active in Fenton reaction) than to those of ferryl groups in heme and non heme counterparts.
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Affiliation(s)
- Adriano Zecchina
- Università di Torino, NIS Centre of Excellence, University of Torino, Dipartimento di Chimica Inorganica, Fisica e dei Materiali, Via P. Giuria 7, 10125, Torino, Italy.
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Bordiga S, Bonino F, Damin A, Lamberti C. Reactivity of Ti(iv) species hosted in TS-1 towards H2O2–H2O solutions investigated by ab initio cluster and periodic approaches combined with experimental XANES and EXAFS data: a review and new highlights. Phys Chem Chem Phys 2007; 9:4854-78. [PMID: 17912416 DOI: 10.1039/b706637f] [Citation(s) in RCA: 174] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
This work is intended to underline how the most-advanced experimental and theoretical physical chemistry tools must be used synergistically to understand the reactivity of Ti-silicalite-1 (TS-1) in an important number of low-temperature oxidation reactions with aqueous H(2)O(2) as the oxidant. Literature results are carefully reviewed and accompanied with new, unpublished highlights of both experimental and computational origin. The first part of this work is devoted to a discussion of the defective nature of the material and to the synergic role played by Si vacancies and Ti insertion in the framework. A summary of the experimental Ti-K-edge EXAFS and XANES literature concerning the activated material in vacuo conditions is then presented and compared to the corresponding Ti geometries obtained by ab initio calculations. From such a comparison, the excellent agreement between experiment and theory is evident. A very good agreement is also obtained for the interaction with water and ammonia. For both H(2)O and NH(3), the agreement is due to the possibility to perform experiments in which the probe molecule is dosed from the gas phase, thus allowing to reach the 1 : 1 (or 1 : 2) ratio between the adsorbing Ti sites and the adsorbed molecule. Then, interaction with hydrogen peroxide is discussed, underlining the problems faced in reaching a common view between experimental and theoretical results, owing to the difficulties both in performing experiments where anhydrous H(2)O(2) is dosed on TS-1, and in taking into account the role played by the aqueous medium in the reactivity of Ti(iv) centres toward H(2)O(2) using ab initio calculations. Only once such difficulties have been overcome, by increasing the complexities of both experiments and ab initio models, is a joint-view finally obtained. Where needed, comparison with other experimental results (X-ray and neutron diffraction, NMR, IR, Raman, UV-vis and resonant Raman) is made.
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Affiliation(s)
- Silvia Bordiga
- Department of Inorganic, Physical and Materials Chemistry and NIS Centre of Excellence, Università di Torino, Via P. Giuria 7, 10125, Torino, Italy
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Pirngruber GD, Grunwaldt JD, van Bokhoven JA, Kalytta A, Reller A, Safonova OV, Glatzel P. On the Presence of Fe(IV) in Fe-ZSM-5 and FeSrO3-xUnequivocal Detection of the 3d4 Spin System by Resonant Inelastic X-ray Scattering. J Phys Chem B 2006; 110:18104-7. [PMID: 16970419 DOI: 10.1021/jp063812b] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The contribution of a 3d(4) spin configuration to the valence electronic structure of Fe compounds can be probed via spin-selective Fe K-pre-edge absorption spectra, using resonant inelastic X-ray scattering (RIXS). The 3d(4) configuration of Fe(IV) can be unequivocally detected even in a mixture with the high-spin 3d(5) configuration of Fe(III). This is demonstrated on the perovskite FeSrO(3-x) with formal oxidation state Fe(IV). When the technique was applied to an Fe-ZSM-5 catalyst during reaction with N(2)O, no 3d(4) configuration was detected. The formation of Fe(IV) upon reaction of Fe-ZSM-5 with N(2)O can, therefore, be ruled out.
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