Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdate...

Autores
Briand, Laura Estefania; Hirt, Andrew M.; Wachs, Israel E.
Año de publicación
2001
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The present work investigates the number and nature of the surface active sites and the catalytic activity of bulk metal molybdates and bulk metal oxides on methanol selective oxidation. Bulk metal molybdates were synthesized by coprecipitation and characterized by laser Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and specific surface area analysis. The number of surface active sites (Ns) was determined by measuring the amount of methoxy species produced by methanol chemisorption on the catalysts at 100°C. The specific activity values (TOFs) were calculated by normalizing the reaction rate by the number of surface active sites. The significant differences in catalytic behavior of bulk metal molybdates and bulk metal oxides, and the surface molybdenum enrichment observed on metal molybdates, gave evidences that the surface of bulk metal molybdates may be composed only by molybdenum oxide species in a two-dimensional overlayer. It was not possible to establish the structure of surface molybdenum oxide species; however, it can be concluded that the structure of surface active sites species of bulk metal molybdates and monolayer supported oxide catalysts are different according to the dispersion of the Ns values of these systems. This work shows, for the first time in the literature, that bulk metal molybdates and monolayer supported molybdenum oxide catalysts possess similar activity and TOF in methanol selective oxidation. The number of active surface sites and the specific activity toward selective oxidation products (TOF redox), CO2 (TOF basic), and dimethyl ether (TOF acid) of bulk metal oxides were also determined. In contrast to bulk metal molybdates, most bulk metal oxides catalyze the total combustion of methanol even at low methanol conversion.
Fil: Briand, Laura Estefania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas ; Argentina
Fil: Hirt, Andrew M.. Materials Research Laboratories; Estados Unidos
Fil: Wachs, Israel E.. Lehigh University; Estados Unidos
Materia
Methanol Chemisorption
Metal Molybdates
Surface Active Sites
Methanol Oxidation
Turnover Frequency
Selective Oxidation
Bulk Catalysts
Supported Catalysts
Metal Oxides
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/42332
Acceder
id CONICETDig_a42385177ff9f082e34bac2b29d94887
oai_identifier_str oai:ri.conicet.gov.ar:11336/42332
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide CatalystsBriand, Laura EstefaniaHirt, Andrew M.Wachs, Israel E.Methanol ChemisorptionMetal MolybdatesSurface Active SitesMethanol OxidationTurnover FrequencySelective OxidationBulk CatalystsSupported CatalystsMetal Oxideshttps://purl.org/becyt/ford/2.4https://purl.org/becyt/ford/2The present work investigates the number and nature of the surface active sites and the catalytic activity of bulk metal molybdates and bulk metal oxides on methanol selective oxidation. Bulk metal molybdates were synthesized by coprecipitation and characterized by laser Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and specific surface area analysis. The number of surface active sites (Ns) was determined by measuring the amount of methoxy species produced by methanol chemisorption on the catalysts at 100°C. The specific activity values (TOFs) were calculated by normalizing the reaction rate by the number of surface active sites. The significant differences in catalytic behavior of bulk metal molybdates and bulk metal oxides, and the surface molybdenum enrichment observed on metal molybdates, gave evidences that the surface of bulk metal molybdates may be composed only by molybdenum oxide species in a two-dimensional overlayer. It was not possible to establish the structure of surface molybdenum oxide species; however, it can be concluded that the structure of surface active sites species of bulk metal molybdates and monolayer supported oxide catalysts are different according to the dispersion of the Ns values of these systems. This work shows, for the first time in the literature, that bulk metal molybdates and monolayer supported molybdenum oxide catalysts possess similar activity and TOF in methanol selective oxidation. The number of active surface sites and the specific activity toward selective oxidation products (TOF redox), CO2 (TOF basic), and dimethyl ether (TOF acid) of bulk metal oxides were also determined. In contrast to bulk metal molybdates, most bulk metal oxides catalyze the total combustion of methanol even at low methanol conversion.Fil: Briand, Laura Estefania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas ; ArgentinaFil: Hirt, Andrew M.. Materials Research Laboratories; Estados UnidosFil: Wachs, Israel E.. Lehigh University; Estados UnidosAcademic Press Inc Elsevier Science2001-09-23info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/42332Briand, Laura Estefania; Hirt, Andrew M.; Wachs, Israel E.; Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide Catalysts; Academic Press Inc Elsevier Science; Journal of Catalysis; 202; 2; 23-9-2001; 268-2780021-9517CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1006/jcat.2001.3289info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0021951701932890info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-10T13:18:06Zoai:ri.conicet.gov.ar:11336/42332instacron: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:34982025-09-10 13:18:06.799CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide Catalysts
title Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide Catalysts
spellingShingle Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide Catalysts
Briand, Laura Estefania
Methanol Chemisorption
Metal Molybdates
Surface Active Sites
Methanol Oxidation
Turnover Frequency
Selective Oxidation
Bulk Catalysts
Supported Catalysts
Metal Oxides
title_short Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide Catalysts
title_full Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide Catalysts
title_fullStr Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide Catalysts
title_full_unstemmed Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide Catalysts
title_sort Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide Catalysts
dc.creator.none.fl_str_mv Briand, Laura Estefania
Hirt, Andrew M.
Wachs, Israel E.
author Briand, Laura Estefania
author_facet Briand, Laura Estefania
Hirt, Andrew M.
Wachs, Israel E.
author_role author
author2 Hirt, Andrew M.
Wachs, Israel E.
author2_role author
author
dc.subject.none.fl_str_mv Methanol Chemisorption
Metal Molybdates
Surface Active Sites
Methanol Oxidation
Turnover Frequency
Selective Oxidation
Bulk Catalysts
Supported Catalysts
Metal Oxides
topic Methanol Chemisorption
Metal Molybdates
Surface Active Sites
Methanol Oxidation
Turnover Frequency
Selective Oxidation
Bulk Catalysts
Supported Catalysts
Metal Oxides
purl_subject.fl_str_mv https://purl.org/becyt/ford/2.4
https://purl.org/becyt/ford/2
dc.description.none.fl_txt_mv The present work investigates the number and nature of the surface active sites and the catalytic activity of bulk metal molybdates and bulk metal oxides on methanol selective oxidation. Bulk metal molybdates were synthesized by coprecipitation and characterized by laser Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and specific surface area analysis. The number of surface active sites (Ns) was determined by measuring the amount of methoxy species produced by methanol chemisorption on the catalysts at 100°C. The specific activity values (TOFs) were calculated by normalizing the reaction rate by the number of surface active sites. The significant differences in catalytic behavior of bulk metal molybdates and bulk metal oxides, and the surface molybdenum enrichment observed on metal molybdates, gave evidences that the surface of bulk metal molybdates may be composed only by molybdenum oxide species in a two-dimensional overlayer. It was not possible to establish the structure of surface molybdenum oxide species; however, it can be concluded that the structure of surface active sites species of bulk metal molybdates and monolayer supported oxide catalysts are different according to the dispersion of the Ns values of these systems. This work shows, for the first time in the literature, that bulk metal molybdates and monolayer supported molybdenum oxide catalysts possess similar activity and TOF in methanol selective oxidation. The number of active surface sites and the specific activity toward selective oxidation products (TOF redox), CO2 (TOF basic), and dimethyl ether (TOF acid) of bulk metal oxides were also determined. In contrast to bulk metal molybdates, most bulk metal oxides catalyze the total combustion of methanol even at low methanol conversion.
Fil: Briand, Laura Estefania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas ; Argentina
Fil: Hirt, Andrew M.. Materials Research Laboratories; Estados Unidos
Fil: Wachs, Israel E.. Lehigh University; Estados Unidos
description The present work investigates the number and nature of the surface active sites and the catalytic activity of bulk metal molybdates and bulk metal oxides on methanol selective oxidation. Bulk metal molybdates were synthesized by coprecipitation and characterized by laser Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and specific surface area analysis. The number of surface active sites (Ns) was determined by measuring the amount of methoxy species produced by methanol chemisorption on the catalysts at 100°C. The specific activity values (TOFs) were calculated by normalizing the reaction rate by the number of surface active sites. The significant differences in catalytic behavior of bulk metal molybdates and bulk metal oxides, and the surface molybdenum enrichment observed on metal molybdates, gave evidences that the surface of bulk metal molybdates may be composed only by molybdenum oxide species in a two-dimensional overlayer. It was not possible to establish the structure of surface molybdenum oxide species; however, it can be concluded that the structure of surface active sites species of bulk metal molybdates and monolayer supported oxide catalysts are different according to the dispersion of the Ns values of these systems. This work shows, for the first time in the literature, that bulk metal molybdates and monolayer supported molybdenum oxide catalysts possess similar activity and TOF in methanol selective oxidation. The number of active surface sites and the specific activity toward selective oxidation products (TOF redox), CO2 (TOF basic), and dimethyl ether (TOF acid) of bulk metal oxides were also determined. In contrast to bulk metal molybdates, most bulk metal oxides catalyze the total combustion of methanol even at low methanol conversion.
publishDate 2001
dc.date.none.fl_str_mv 2001-09-23
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/11336/42332
Briand, Laura Estefania; Hirt, Andrew M.; Wachs, Israel E.; Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide Catalysts; Academic Press Inc Elsevier Science; Journal of Catalysis; 202; 2; 23-9-2001; 268-278
0021-9517
CONICET Digital
CONICET
url http://hdl.handle.net/11336/42332
identifier_str_mv Briand, Laura Estefania; Hirt, Andrew M.; Wachs, Israel E.; Quantitative Determination of the Number of Surface Active Sites and the Turnover Frequencies for Methanol Oxidation over Metal Oxide Catalysts: Application to Bulk Metal Molybdates and Pure Metal Oxide Catalysts; Academic Press Inc Elsevier Science; Journal of Catalysis; 202; 2; 23-9-2001; 268-278
0021-9517
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1006/jcat.2001.3289
info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S0021951701932890
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Academic Press Inc Elsevier Science
publisher.none.fl_str_mv Academic Press Inc 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 12.993085

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