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Bimetallic AgFe Systems on Mordenite: Effect of Cation Deposition Order in the NO Reduction with C3H6/CO. Catalysts 2019. [DOI: 10.3390/catal9010058] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Mono- and bimetallic systems of Ag, Fe, and Ag–Fe exchanged in sodium mordenite zeolite were studied in the reaction of NO reduction. The transition metal cations Ag and Fe were introduced by ion exchange method both at room temperature and 60 °C; modifying the order of component deposition in bimetallic systems. These materials were characterized by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), ultraviolet-visible spectroscopy (UV-Vis), X-Ray photoelectron Spectroscopy (XPS) and High-resolution transmission electron microscopy (HR-TEM). The XPS and UV–Vis spectra of bimetallic samples revealed that under certain preparation conditions Ag+ is reduced with the participation of the Fe2+/Fe3+ ions transition and is present in the form of a Ag reduced state in different proportions of Agm clusters and Ag0 NPs, influenced by the cation deposition order. The catalytic results in the NO reduction reaction using C3H6/CO under an oxidizing atmosphere show also that the order of exchange of Ag and Fe cations in mordenite has a strong effect on catalytic active sites for the reduction of NO.
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Popovych N, Kyriienko P, Soloviev S, Baran R, Millot Y, Dzwigaj S. Identification of the silver state in the framework of Ag-containing zeolite by XRD, FTIR, photoluminescence, 109Ag NMR, EPR, DR UV-vis, TEM and XPS investigations. Phys Chem Chem Phys 2018; 18:29458-29465. [PMID: 27738686 DOI: 10.1039/c6cp05263k] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Silver has been identified in the framework of AgxSiBEA zeolites (where x = 3-6 Ag wt%) by the combined use of XRD, 109Ag MAS NMR, FTIR, diffuse reflectance UV-visible, EPR and XPS spectroscopy. The incorporation of Ag ions into the framework of SiBEA zeolite has been evidenced by XRD. The consumption of OH groups as a result of their reaction with the silver precursor has been monitored by FTIR and photoluminescence spectroscopy. The changes in the silver state as a function of Ag content and thermal and hydrogen treatment at 573 K have been identified by 109Ag MAS NMR, EPR, DR UV-visible, TEM and XPS investigations. The acidity of AgSiBEA has been investigated by FTIR spectroscopy of adsorbed CO and pyridine used as probe molecules.
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Affiliation(s)
- Nataliia Popovych
- L.V. Pisarzhevsky Institute of Physical Chemistry of the NAS of Ukraine, 31 Prosp. Nauky, 03028 Kyiv, Ukraine
| | - Pavlo Kyriienko
- L.V. Pisarzhevsky Institute of Physical Chemistry of the NAS of Ukraine, 31 Prosp. Nauky, 03028 Kyiv, Ukraine
| | - Sergiy Soloviev
- L.V. Pisarzhevsky Institute of Physical Chemistry of the NAS of Ukraine, 31 Prosp. Nauky, 03028 Kyiv, Ukraine
| | - Rafal Baran
- AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow, Poland and Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7197, Laboratoire de Réactivité de Surface, 4 place Jussieu, F-75252, Paris, France.
| | - Yannick Millot
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7197, Laboratoire de Réactivité de Surface, 4 place Jussieu, F-75252, Paris, France.
| | - Stanislaw Dzwigaj
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7197, Laboratoire de Réactivité de Surface, 4 place Jussieu, F-75252, Paris, France.
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Xu L, Stangland EE, Mavrikakis M. A DFT study of chlorine coverage over late transition metals and its implication on 1,2-dichloroethane hydrodechlorination. Catal Sci Technol 2018. [DOI: 10.1039/c7cy02647a] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chlorine coverage and its impact on 1,2-dichloroethane hydrodechlorination over ten late transition metals, predicted using DFT-based phase diagrams.
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Affiliation(s)
- Lang Xu
- Department of Chemical and Biological Engineering
- University of Wisconsin-Madison
- Madison
- USA
| | | | - Manos Mavrikakis
- Department of Chemical and Biological Engineering
- University of Wisconsin-Madison
- Madison
- USA
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