Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques

Autores
Aspromonte, Soledad Guadalupe; Mizrahi, Martin Daniel; Schneeberger, Florencia A.; Ramallo Lopez, Jose Martin; Boix, Alicia Viviana
Año de publicación
2013
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
 Catalysts based on Na-mordenite (symbolized as M) exchanged with 5, 10, and 15 wt % of Ag were characterized by X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine line structure (EXAFS), X-ray absorption near edge spectroscopy (XANES) and UV-vis diffuse reflectance spectroscopy (DRS) to investigate the effect of different treatments on the chemical state and surface concentration of the silver species. The AgxM catalysts were analyzed in oxidizing (O2) or reducing (H2/Ar) atmospheres and also after being used in the selective catalytic reduction of NOx or in successive cycles of toluene adsorption/desorption. In calcined samples, EXAFS profiles showed two types of AgO spheres of coordination, one due to a dispersed phase of silver oxide and the other due to Ag+ ions in interaction with the oxygen of the zeolite framework. The UV-vis DRS spectra showed the coexistence of isolated Ag+, Agn(delta)+ (n < 10) cationic clusters and AgxO particles. In addition, through the modified Auger parameter (alpha), calculated from XPS measurements, it was possible to identify Ag+ ions at exchange sites (alpha = 722 eV) and AgxO ( alpha = 725 eV) highly dispersed on the surface. Both species constitute stable active centers for the selective catalytic reduction of NOx under severe reaction conditions. However, during the adsorption-desorption of toluene, the reduction of silver oxides produces Ag(0) due to thermal hydrocarbon decomposition.   
Fil: Aspromonte, Soledad Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Investigaciones En Catálisis y Petroquímica; Argentina. Universidad Nacional del Litoral; Argentina
Fil: Mizrahi, Martin Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; Argentina
Fil: Schneeberger, Florencia A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Investigaciones En Catálisis y Petroquímica; Argentina
Fil: Ramallo Lopez, Jose Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; Argentina
Fil: Boix, Alicia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Investigaciones En Catálisis y Petroquímica; Argentina. Universidad Nacional del Litoral; Argentina
Materia
CATALYSIS
Ag-EXCHANGED MORDENITE
XANES
EXAFS
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/5312
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/5312
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic TechniquesAspromonte, Soledad GuadalupeMizrahi, Martin DanielSchneeberger, Florencia A.Ramallo Lopez, Jose MartinBoix, Alicia VivianaCATALYSISAg-EXCHANGED MORDENITEXANESEXAFShttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1 Catalysts based on Na-mordenite (symbolized as M) exchanged with 5, 10, and 15 wt % of Ag were characterized by X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine line structure (EXAFS), X-ray absorption near edge spectroscopy (XANES) and UV-vis diffuse reflectance spectroscopy (DRS) to investigate the effect of different treatments on the chemical state and surface concentration of the silver species. The AgxM catalysts were analyzed in oxidizing (O2) or reducing (H2/Ar) atmospheres and also after being used in the selective catalytic reduction of NOx or in successive cycles of toluene adsorption/desorption. In calcined samples, EXAFS profiles showed two types of AgO spheres of coordination, one due to a dispersed phase of silver oxide and the other due to Ag+ ions in interaction with the oxygen of the zeolite framework. The UV-vis DRS spectra showed the coexistence of isolated Ag+, Agn(delta)+ (n < 10) cationic clusters and AgxO particles. In addition, through the modified Auger parameter (alpha), calculated from XPS measurements, it was possible to identify Ag+ ions at exchange sites (alpha = 722 eV) and AgxO ( alpha = 725 eV) highly dispersed on the surface. Both species constitute stable active centers for the selective catalytic reduction of NOx under severe reaction conditions. However, during the adsorption-desorption of toluene, the reduction of silver oxides produces Ag(0) due to thermal hydrocarbon decomposition.   Fil: Aspromonte, Soledad Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Investigaciones En Catálisis y Petroquímica; Argentina. Universidad Nacional del Litoral; ArgentinaFil: Mizrahi, Martin Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Schneeberger, Florencia A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Investigaciones En Catálisis y Petroquímica; ArgentinaFil: Ramallo Lopez, Jose Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Boix, Alicia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Investigaciones En Catálisis y Petroquímica; Argentina. Universidad Nacional del Litoral; ArgentinaAmerican Chemical Society2013-11info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/5312Aspromonte, Soledad Guadalupe; Mizrahi, Martin Daniel; Schneeberger, Florencia A.; Ramallo Lopez, Jose Martin; Boix, Alicia Viviana; Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques; American Chemical Society; Journal of Physical Chemistry C; 117; 48; 11-2013; 25433-254421932-7447enginfo:eu-repo/semantics/altIdentifier/doi/info:eu-repo/semantics/altIdentifier/doi/10.1021/jp4046269info:eu-repo/semantics/altIdentifier/url/http://pubs.acs.org/doi/abs/10.1021/jp4046269info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T10:40:16Zoai:ri.conicet.gov.ar:11336/5312instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 10:40:16.397CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques
title Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques
spellingShingle Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques
Aspromonte, Soledad Guadalupe
CATALYSIS
Ag-EXCHANGED MORDENITE
XANES
EXAFS
title_short Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques
title_full Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques
title_fullStr Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques
title_full_unstemmed Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques
title_sort Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques
dc.creator.none.fl_str_mv Aspromonte, Soledad Guadalupe
Mizrahi, Martin Daniel
Schneeberger, Florencia A.
Ramallo Lopez, Jose Martin
Boix, Alicia Viviana
author Aspromonte, Soledad Guadalupe
author_facet Aspromonte, Soledad Guadalupe
Mizrahi, Martin Daniel
Schneeberger, Florencia A.
Ramallo Lopez, Jose Martin
Boix, Alicia Viviana
author_role author
author2 Mizrahi, Martin Daniel
Schneeberger, Florencia A.
Ramallo Lopez, Jose Martin
Boix, Alicia Viviana
author2_role author
author
author
author
dc.subject.none.fl_str_mv CATALYSIS
Ag-EXCHANGED MORDENITE
XANES
EXAFS
topic CATALYSIS
Ag-EXCHANGED MORDENITE
XANES
EXAFS
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv  Catalysts based on Na-mordenite (symbolized as M) exchanged with 5, 10, and 15 wt % of Ag were characterized by X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine line structure (EXAFS), X-ray absorption near edge spectroscopy (XANES) and UV-vis diffuse reflectance spectroscopy (DRS) to investigate the effect of different treatments on the chemical state and surface concentration of the silver species. The AgxM catalysts were analyzed in oxidizing (O2) or reducing (H2/Ar) atmospheres and also after being used in the selective catalytic reduction of NOx or in successive cycles of toluene adsorption/desorption. In calcined samples, EXAFS profiles showed two types of AgO spheres of coordination, one due to a dispersed phase of silver oxide and the other due to Ag+ ions in interaction with the oxygen of the zeolite framework. The UV-vis DRS spectra showed the coexistence of isolated Ag+, Agn(delta)+ (n < 10) cationic clusters and AgxO particles. In addition, through the modified Auger parameter (alpha), calculated from XPS measurements, it was possible to identify Ag+ ions at exchange sites (alpha = 722 eV) and AgxO ( alpha = 725 eV) highly dispersed on the surface. Both species constitute stable active centers for the selective catalytic reduction of NOx under severe reaction conditions. However, during the adsorption-desorption of toluene, the reduction of silver oxides produces Ag(0) due to thermal hydrocarbon decomposition.   
Fil: Aspromonte, Soledad Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Investigaciones En Catálisis y Petroquímica; Argentina. Universidad Nacional del Litoral; Argentina
Fil: Mizrahi, Martin Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; Argentina
Fil: Schneeberger, Florencia A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Investigaciones En Catálisis y Petroquímica; Argentina
Fil: Ramallo Lopez, Jose Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico la Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina. Universidad Nacional de La Plata; Argentina
Fil: Boix, Alicia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto de Investigaciones En Catálisis y Petroquímica; Argentina. Universidad Nacional del Litoral; Argentina
description  Catalysts based on Na-mordenite (symbolized as M) exchanged with 5, 10, and 15 wt % of Ag were characterized by X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine line structure (EXAFS), X-ray absorption near edge spectroscopy (XANES) and UV-vis diffuse reflectance spectroscopy (DRS) to investigate the effect of different treatments on the chemical state and surface concentration of the silver species. The AgxM catalysts were analyzed in oxidizing (O2) or reducing (H2/Ar) atmospheres and also after being used in the selective catalytic reduction of NOx or in successive cycles of toluene adsorption/desorption. In calcined samples, EXAFS profiles showed two types of AgO spheres of coordination, one due to a dispersed phase of silver oxide and the other due to Ag+ ions in interaction with the oxygen of the zeolite framework. The UV-vis DRS spectra showed the coexistence of isolated Ag+, Agn(delta)+ (n < 10) cationic clusters and AgxO particles. In addition, through the modified Auger parameter (alpha), calculated from XPS measurements, it was possible to identify Ag+ ions at exchange sites (alpha = 722 eV) and AgxO ( alpha = 725 eV) highly dispersed on the surface. Both species constitute stable active centers for the selective catalytic reduction of NOx under severe reaction conditions. However, during the adsorption-desorption of toluene, the reduction of silver oxides produces Ag(0) due to thermal hydrocarbon decomposition.   
publishDate 2013
dc.date.none.fl_str_mv 2013-11
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/5312
Aspromonte, Soledad Guadalupe; Mizrahi, Martin Daniel; Schneeberger, Florencia A.; Ramallo Lopez, Jose Martin; Boix, Alicia Viviana; Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques; American Chemical Society; Journal of Physical Chemistry C; 117; 48; 11-2013; 25433-25442
1932-7447
url http://hdl.handle.net/11336/5312
identifier_str_mv Aspromonte, Soledad Guadalupe; Mizrahi, Martin Daniel; Schneeberger, Florencia A.; Ramallo Lopez, Jose Martin; Boix, Alicia Viviana; Study of the Nature and Location of Silver in Ag-Exchanged Mordenite Catalysts. Characterization by Spectroscopic Techniques; American Chemical Society; Journal of Physical Chemistry C; 117; 48; 11-2013; 25433-25442
1932-7447
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/
info:eu-repo/semantics/altIdentifier/doi/10.1021/jp4046269
info:eu-repo/semantics/altIdentifier/url/http://pubs.acs.org/doi/abs/10.1021/jp4046269
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv American Chemical Society
publisher.none.fl_str_mv American Chemical Society
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 13.070432

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