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Recent Understanding of Low-Temperature Copper Dynamics in Cu-Chabazite NH3-SCR Catalysts. Catalysts 2021. [DOI: 10.3390/catal11010052] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dynamic motion of NH3-solvated Cu sites in Cu-chabazite (Cu-CHA) zeolites, which are the most promising and state-of-the-art catalysts for ammonia-assisted selective reduction of NOx (NH3-SCR) in the aftertreatment of diesel exhausts, represents a unique phenomenon linking heterogeneous and homogeneous catalysis. This review first summarizes recent advances in the theoretical understanding of such low-temperature Cu dynamics. Specifically, evidence of both intra-cage and inter-cage Cu motions, given by ab initio molecular dynamics (AIMD) or metadynamics simulations, will be highlighted. Then, we will show how, among others, synchrotron-based X-ray spectroscopy, vibrational and optical spectroscopy (diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) and diffuse reflection ultraviolet-visible spectroscopy (DRUVS)), electron paramagnetic spectroscopy (EPR), and impedance spectroscopy (IS) can be combined and complement each other to follow the evolution of coordinative environment and the local structure of Cu centers during low-temperature NH3-SCR reactions. Furthermore, the essential role of Cu dynamics in the tuning of low-temperature Cu redox, in the preparation of highly dispersed Cu-CHA catalysts by solid-state ion exchange method, and in the direct monitoring of NH3 storage and conversion will be presented. Based on the achieved mechanistic insights, we will discuss briefly the new perspectives in manipulating Cu dynamics to improve low-temperature NH3-SCR efficiency as well as in the understanding of other important reactions, such as selective methane-to-methanol oxidation and ethene dimerization, catalyzed by metal ion-exchanged zeolites.
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Kvande K, Pappas DK, Borfecchia E, Lomachenko KA. Advanced X‐ray Absorption Spectroscopy Analysis to Determine Structure‐Activity Relationships for Cu‐Zeolites in the Direct Conversion of Methane to Methanol. ChemCatChem 2020. [DOI: 10.1002/cctc.201902371] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Karoline Kvande
- Centre for Materials Science and Nanotechnology Department of Chemistry University of Oslo Sem Sælands vei 26 0371 Oslo Norway
| | - Dimitrios K. Pappas
- Centre for Materials Science and Nanotechnology Department of Chemistry University of Oslo Sem Sælands vei 26 0371 Oslo Norway
| | - Elisa Borfecchia
- Department of Chemistry, NIS Center and INSTM Reference Center University of Turin Via P. Giuria 7 10125 Turin Italy
| | - Kirill A. Lomachenko
- European Synchrotron Radiation Facility 71 Avenue des Martyrs, CS 40220 Grenoble Cedex 9 38043 France
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Pankin IA, Martini A, Lomachenko KA, Soldatov AV, Bordiga S, Borfecchia E. Identifying Cu-oxo species in Cu-zeolites by XAS: A theoretical survey by DFT-assisted XANES simulation and EXAFS wavelet transform. Catal Today 2020. [DOI: 10.1016/j.cattod.2019.09.032] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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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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Rudolph J, Jacob CR. Computational Insights into the Mechanism of the Selective Catalytic Reduction of NO x : Fe- versus Cu-Exchanged Zeolite Catalysts. ACS OMEGA 2019; 4:7987-7993. [PMID: 31172035 PMCID: PMC6545547 DOI: 10.1021/acsomega.9b00600] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 04/02/2019] [Indexed: 06/09/2023]
Abstract
We computationally investigate the mechanism of the reduction half-cycle of the selective catalytic reduction of nitrogen oxides with ammonia. We compare both Fe- and Cu-exchanged zeolite catalysts and aim at exploring all accessible reaction pathways. From our calculations, a comprehensive picture emerges that unifies several previous mechanistic proposals. We find that both for Fe and for Cu catalysts different reaction pathways are feasible but some of the possible reaction pathways differ in these two cases. Our computational results provide a basis for the interpretation of in situ spectroscopic investigations that can possibly distinguish the different mechanistic pathways.
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Chen HY, Kollar M, Wei Z, Gao F, Wang Y, Szanyi J, Peden CH. Formation of NO+ and its possible roles during the selective catalytic reduction of NOx with NH3 on Cu-CHA catalysts. Catal Today 2019. [DOI: 10.1016/j.cattod.2017.12.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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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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Zhang R, McEwen JS. Local Environment Sensitivity of the Cu K-Edge XANES Features in Cu-SSZ-13: Analysis from First-Principles. J Phys Chem Lett 2018; 9:3035-3042. [PMID: 29665684 DOI: 10.1021/acs.jpclett.8b00675] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Cu K-edge X-ray absorption near-edge spectra (XANES) have been widely used to study the properties of Cu-SSZ-13. In this Letter, the sensitivity of the XANES features to the local environment for a Cu+ cation with a linear configuration and a Cu2+ cation with a square-linear configuration in Cu-SSZ-13 is reported. When a Cu+ cation is bonded to H2O or NH3 in a linear configuration, the XANES has a strong peak at around 8983 eV. The intensity of this peak decreases as the linear configuration is broken. As for the Cu2+ cations in a square-planar configuration with a coordination number of 4, two peaks at around 8986 and 8993 eV are found. An intensity decrease for both peaks at around 8986 and 8993 eV is found in an NH3_4_Z2Cu model as the N-Cu-N angle changes from 180 to 100°. We correlate these features to the variation of the 4p state by PDOS analysis. In addition, the feature peaks for both the Cu+ cation and Cu2+ cation do not show a dependence on the Cu-N bond length. We further show that the feature peaks also change when the coordination number of the Cu cation is varied, while these feature peaks are independent of the zeolite topology. These findings help elucidate the experimental XANES features at an atomic and an electronic level.
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Affiliation(s)
- Renqin Zhang
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering , Washington State University , Pullman , Washington 99164 , United States
| | - Jean-Sabin McEwen
- The Gene and Linda Voiland School of Chemical Engineering and Bioengineering , Washington State University , Pullman , Washington 99164 , United States
- Department of Physics and Astronomy , Washington State University , Pullman , Washington 99164 , United States
- Department of Chemistry , Washington State University , Pullman , Washington 99164 , United States
- Department of Biological Systems Engineering , Washington State University , Pullman , Washington 99164 , United States
- Institute for Integrated Catalysis , Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
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Gallo E, Gorelov E, Guda AA, Bugaev AL, Bonino F, Borfecchia E, Ricchiardi G, Gianolio D, Chavan S, Lamberti C. Effect of Molecular Guest Binding on the d–d Transitions of Ni2+ of CPO-27-Ni: A Combined UV–Vis, Resonant-Valence-to-Core X-ray Emission Spectroscopy, and Theoretical Study. Inorg Chem 2017; 56:14408-14425. [DOI: 10.1021/acs.inorgchem.7b01471] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Erik Gallo
- NIS and INSTM Reference
Center, Department of Chemistry, University of Turin, Via Quarello
15, I-10135 Torino, Italy
- European Synchrotron Radiation Facility (ESRF), 6 Rue Jules Horowitz, BP 220, 38043, Grenoble Cedex
9, France
| | - Evgeny Gorelov
- European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Alexander A. Guda
- International Research Center “Smart Materials”, Southern Federal University, Zorge Street 5, 344090 Rostov-on-Don, Russia
| | - Aram L. Bugaev
- NIS and INSTM Reference
Center, Department of Chemistry, University of Turin, Via Quarello
15, I-10135 Torino, Italy
- International Research Center “Smart Materials”, Southern Federal University, Zorge Street 5, 344090 Rostov-on-Don, Russia
| | - Francesca Bonino
- NIS and INSTM Reference
Center, Department of Chemistry, University of Turin, Via Quarello
15, I-10135 Torino, Italy
| | - Elisa Borfecchia
- NIS and INSTM Reference
Center, Department of Chemistry, University of Turin, Via Quarello
15, I-10135 Torino, Italy
| | - Gabriele Ricchiardi
- NIS and INSTM Reference
Center, Department of Chemistry, University of Turin, Via Quarello
15, I-10135 Torino, Italy
| | - Diego Gianolio
- Harwell
Science and Innovation Campus, Diamond Light Source Ltd., OX11 0DE Didcot, United Kingdom
| | - Sachin Chavan
- Department of
Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo, Norway
| | - Carlo Lamberti
- International Research Center “Smart Materials”, Southern Federal University, Zorge Street 5, 344090 Rostov-on-Don, Russia
- CrisDi and INSTM Reference Center, Department of Chemistry, University of Turin, Via P. Giuria 7, I-10125 Torino, Italy
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Lomachenko KA, Borfecchia E, Negri C, Berlier G, Lamberti C, Beato P, Falsig H, Bordiga S. The Cu-CHA deNOx Catalyst in Action: Temperature-Dependent NH3-Assisted Selective Catalytic Reduction Monitored by Operando XAS and XES. J Am Chem Soc 2016; 138:12025-8. [PMID: 27532483 DOI: 10.1021/jacs.6b06809] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The small-pore Cu-CHA zeolite is today the object of intensive research efforts to rationalize its outstanding performance in the NH3-assisted selective catalytic reduction (SCR) of harmful nitrogen oxides and to unveil the SCR mechanism. Herein we exploit operando X-ray spectroscopies to monitor the Cu-CHA catalyst in action during NH3-SCR in the 150-400 °C range, targeting Cu oxidation state, mobility, and preferential N or O ligation as a function of reaction temperature. By combining operando XANES, EXAFS, and vtc-XES, we unambiguously identify two distinct regimes for the atomic-scale behavior of Cu active-sites. Low-temperature SCR, up to ∼200 °C, is characterized by balanced populations of Cu(I)/Cu(II) sites and dominated by mobile NH3-solvated Cu-species. From 250 °C upward, in correspondence to the steep increase in catalytic activity, the largely dominant Cu-species are framework-coordinated Cu(II) sites, likely representing the active sites for high-temperature SCR.
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Affiliation(s)
- Kirill A Lomachenko
- Department of Chemistry, NIS Centre and INSTM Reference Center, University of Turin , via P. Giuria 7, 10125 Turin, Italy.,IRC "Smart Materials", Southern Federal University , Zorge Street 5, 344090 Rostov-on-Don, Russia
| | - Elisa Borfecchia
- Department of Chemistry, NIS Centre and INSTM Reference Center, University of Turin , via P. Giuria 7, 10125 Turin, Italy
| | - Chiara Negri
- Department of Chemistry, NIS Centre and INSTM Reference Center, University of Turin , via P. Giuria 7, 10125 Turin, Italy
| | - Gloria Berlier
- Department of Chemistry, NIS Centre and INSTM Reference Center, University of Turin , via P. Giuria 7, 10125 Turin, Italy
| | - Carlo Lamberti
- Department of Chemistry, NIS Centre and INSTM Reference Center, University of Turin , via P. Giuria 7, 10125 Turin, Italy.,IRC "Smart Materials", Southern Federal University , Zorge Street 5, 344090 Rostov-on-Don, Russia
| | - Pablo Beato
- Haldor Topsøe A/S , Haldor Topsøes Allé 1, 2800 Kgs. Lyngby, Denmark
| | - Hanne Falsig
- Haldor Topsøe A/S , Haldor Topsøes Allé 1, 2800 Kgs. Lyngby, Denmark
| | - Silvia Bordiga
- Department of Chemistry, NIS Centre and INSTM Reference Center, University of Turin , via P. Giuria 7, 10125 Turin, Italy
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Catalysis Science of NOx Selective Catalytic Reduction With Ammonia Over Cu-SSZ-13 and Cu-SAPO-34. ADVANCES IN CATALYSIS 2016. [DOI: 10.1016/bs.acat.2016.10.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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