A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid

Autores
Pizzio, Luis Rene; Blanco, Mirta Noemi
Año de publicación
2007
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Nonstoichiometric cesium and rubidium salts of tungstosilicic acid (TSA) were synthesized by precipitation. These solids are insoluble in water, due to the low solvation energy of large cations, have high specific surface area, and a mainly microporous structure. In turn, nonstoichiometric potassium salts prepared by solution evaporation have a low specific surface area and porosity, high solubility in water, and a negligible porosity. All the synthesized tungstosilicates presented a cubic structure, with a lattice parameter that slightly decreases in the order Cs+ > Rb+ ≅ K+ salts. The salts displayed the characteristic FT-IR bands of TSA, though the band assigned to the stretching of the W{double bond, long}O terminal bond presented a slight widening and a shoulder, and the band attributed to a bridged W{single bond}O{single bond}W bond was shifted to a lower wavenumber and showed a shoulder. Such effects are indicative of the interaction between the [SiW12O40]4- anion and the alkaline cations. Assuming that an increase in 1H MAS-NMR chemical shift is due to a higher acid strength, the cesium salts would have acid sites with higher acid strength than the others. The potassium salts, however, presented protons in different acid environments, with a low proportion of very strong acid sites. The acidity measurement by potentiometric titration with n-butylamine also showed that the cesium salts have acid sites with higher strength than those of rubidium. The same behavior was observed for the potassium salts, which exhibited an acid strength higher than expected. The number of protons determined by titration decreased in the order Cs+ > Rb+ ≅ K+ salts and also decreased for the more substituted salts. © 2007 Elsevier Inc. All rights reserved.
Fil: Pizzio, Luis Rene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentina
Fil: Blanco, Mirta Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentina
Materia
Characterization
Microporous Materials
Salts
Synthesis
Tungstosilicic Acid
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:11336/54067
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/54067
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acidPizzio, Luis ReneBlanco, Mirta NoemiCharacterizationMicroporous MaterialsSaltsSynthesisTungstosilicic Acidhttps://purl.org/becyt/ford/2.4https://purl.org/becyt/ford/2Nonstoichiometric cesium and rubidium salts of tungstosilicic acid (TSA) were synthesized by precipitation. These solids are insoluble in water, due to the low solvation energy of large cations, have high specific surface area, and a mainly microporous structure. In turn, nonstoichiometric potassium salts prepared by solution evaporation have a low specific surface area and porosity, high solubility in water, and a negligible porosity. All the synthesized tungstosilicates presented a cubic structure, with a lattice parameter that slightly decreases in the order Cs+ > Rb+ ≅ K+ salts. The salts displayed the characteristic FT-IR bands of TSA, though the band assigned to the stretching of the W{double bond, long}O terminal bond presented a slight widening and a shoulder, and the band attributed to a bridged W{single bond}O{single bond}W bond was shifted to a lower wavenumber and showed a shoulder. Such effects are indicative of the interaction between the [SiW12O40]4- anion and the alkaline cations. Assuming that an increase in 1H MAS-NMR chemical shift is due to a higher acid strength, the cesium salts would have acid sites with higher acid strength than the others. The potassium salts, however, presented protons in different acid environments, with a low proportion of very strong acid sites. The acidity measurement by potentiometric titration with n-butylamine also showed that the cesium salts have acid sites with higher strength than those of rubidium. The same behavior was observed for the potassium salts, which exhibited an acid strength higher than expected. The number of protons determined by titration decreased in the order Cs+ > Rb+ ≅ K+ salts and also decreased for the more substituted salts. © 2007 Elsevier Inc. All rights reserved.Fil: Pizzio, Luis Rene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Blanco, Mirta Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaElsevier Science2007-06info: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/11336/54067Pizzio, Luis Rene; Blanco, Mirta Noemi; A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid; Elsevier Science; Microporous and Mesoporous Materials; 103; 1-3; 6-2007; 40-471387-1811CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.micromeso.2007.01.036info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S138718110700056Xinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T09:50:42Zoai:ri.conicet.gov.ar:11336/54067instacron: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 09:50:42.446CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid
title A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid
spellingShingle A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid
Pizzio, Luis Rene
Characterization
Microporous Materials
Salts
Synthesis
Tungstosilicic Acid
title_short A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid
title_full A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid
title_fullStr A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid
title_full_unstemmed A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid
title_sort A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid
dc.creator.none.fl_str_mv Pizzio, Luis Rene
Blanco, Mirta Noemi
author Pizzio, Luis Rene
author_facet Pizzio, Luis Rene
Blanco, Mirta Noemi
author_role author
author2 Blanco, Mirta Noemi
author2_role author
dc.subject.none.fl_str_mv Characterization
Microporous Materials
Salts
Synthesis
Tungstosilicic Acid
topic Characterization
Microporous Materials
Salts
Synthesis
Tungstosilicic Acid
purl_subject.fl_str_mv https://purl.org/becyt/ford/2.4
https://purl.org/becyt/ford/2
dc.description.none.fl_txt_mv Nonstoichiometric cesium and rubidium salts of tungstosilicic acid (TSA) were synthesized by precipitation. These solids are insoluble in water, due to the low solvation energy of large cations, have high specific surface area, and a mainly microporous structure. In turn, nonstoichiometric potassium salts prepared by solution evaporation have a low specific surface area and porosity, high solubility in water, and a negligible porosity. All the synthesized tungstosilicates presented a cubic structure, with a lattice parameter that slightly decreases in the order Cs+ > Rb+ ≅ K+ salts. The salts displayed the characteristic FT-IR bands of TSA, though the band assigned to the stretching of the W{double bond, long}O terminal bond presented a slight widening and a shoulder, and the band attributed to a bridged W{single bond}O{single bond}W bond was shifted to a lower wavenumber and showed a shoulder. Such effects are indicative of the interaction between the [SiW12O40]4- anion and the alkaline cations. Assuming that an increase in 1H MAS-NMR chemical shift is due to a higher acid strength, the cesium salts would have acid sites with higher acid strength than the others. The potassium salts, however, presented protons in different acid environments, with a low proportion of very strong acid sites. The acidity measurement by potentiometric titration with n-butylamine also showed that the cesium salts have acid sites with higher strength than those of rubidium. The same behavior was observed for the potassium salts, which exhibited an acid strength higher than expected. The number of protons determined by titration decreased in the order Cs+ > Rb+ ≅ K+ salts and also decreased for the more substituted salts. © 2007 Elsevier Inc. All rights reserved.
Fil: Pizzio, Luis Rene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentina
Fil: Blanco, Mirta Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentina
description Nonstoichiometric cesium and rubidium salts of tungstosilicic acid (TSA) were synthesized by precipitation. These solids are insoluble in water, due to the low solvation energy of large cations, have high specific surface area, and a mainly microporous structure. In turn, nonstoichiometric potassium salts prepared by solution evaporation have a low specific surface area and porosity, high solubility in water, and a negligible porosity. All the synthesized tungstosilicates presented a cubic structure, with a lattice parameter that slightly decreases in the order Cs+ > Rb+ ≅ K+ salts. The salts displayed the characteristic FT-IR bands of TSA, though the band assigned to the stretching of the W{double bond, long}O terminal bond presented a slight widening and a shoulder, and the band attributed to a bridged W{single bond}O{single bond}W bond was shifted to a lower wavenumber and showed a shoulder. Such effects are indicative of the interaction between the [SiW12O40]4- anion and the alkaline cations. Assuming that an increase in 1H MAS-NMR chemical shift is due to a higher acid strength, the cesium salts would have acid sites with higher acid strength than the others. The potassium salts, however, presented protons in different acid environments, with a low proportion of very strong acid sites. The acidity measurement by potentiometric titration with n-butylamine also showed that the cesium salts have acid sites with higher strength than those of rubidium. The same behavior was observed for the potassium salts, which exhibited an acid strength higher than expected. The number of protons determined by titration decreased in the order Cs+ > Rb+ ≅ K+ salts and also decreased for the more substituted salts. © 2007 Elsevier Inc. All rights reserved.
publishDate 2007
dc.date.none.fl_str_mv 2007-06
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/11336/54067
Pizzio, Luis Rene; Blanco, Mirta Noemi; A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid; Elsevier Science; Microporous and Mesoporous Materials; 103; 1-3; 6-2007; 40-47
1387-1811
CONICET Digital
CONICET
url http://hdl.handle.net/11336/54067
identifier_str_mv Pizzio, Luis Rene; Blanco, Mirta Noemi; A contribution to the physicochemical characterization of nonstoichiometric salts of tungstosilicic acid; Elsevier Science; Microporous and Mesoporous Materials; 103; 1-3; 6-2007; 40-47
1387-1811
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1016/j.micromeso.2007.01.036
info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S138718110700056X
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 Elsevier Science
publisher.none.fl_str_mv Elsevier Science
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 13.069144

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