Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst

Autores
Collins, Sebastián Enrique; Baltanas, Miguel Angel; Bonivardi, Adrian Lionel
Año de publicación
2005
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The thermal decomposition of adsorbed methanol on 2 wt.% Pd/silica, 2 wt.% Pd/gallia and pure gallia, was studied by temperatureprogrammed surface reaction (TPSR), between 323 and 723 K under He flow, using FT-IR spectroscopy. After methanol adsorption on Pd/silica at 323 K, the concentration of methoxy species on the silica decreased during the TPRS experiment, but some methoxy groups still remained on this support even at 723 K. Simultaneously, methanol decomposed over metallic palladium to yield, stepwise, HCO and CO with the consequent release of H2 (g). On clean gallia, methanol is Lewis-bound adsorbed to the surface, as well as dissociatively adsorbed as methoxy (CH3O), but the position of the infrared bands indicates a stronger interaction of these species on gallium oxide than on silica. Methoxy species on gallia are decomposed to (mono- and bi-dentate) formate groups (m- and b-HCOO, respectively) at T > 473 K. We suggest that CO and CO2 are further produced by nonstoichiometric transformation of these formates, leading to the release of atomic hydrogen on the surface of the oxide, as detected by the Ga–H stretching infrared band, and surface anion vacancies. In the presence of Pd on the gallia surface, the dehydrogenation of CH3O species proceeds faster than over the pure oxide, and we propose the following mechanism for methanol decomposition: (i) methanol reacts with OH groups on the gallia surface to produce water and methoxy species, (ii) the dehydrogenation of the latter carbonaceous group leads to H2COO, first, and then to mand b-HCOO, (iii) the hydrogen atoms released in the previous steps are transferred from gallia to the Pd surface where they recombine and desorb as H2 (g).
Fil: Collins, Sebastián Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina
Fil: Baltanas, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina
Fil: Bonivardi, Adrian Lionel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina
Materia
Methanol
Decomposition
Palladium
Gallia
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:11336/26604
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/26604
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalystCollins, Sebastián EnriqueBaltanas, Miguel AngelBonivardi, Adrian LionelMethanolDecompositionPalladiumGalliahttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1The thermal decomposition of adsorbed methanol on 2 wt.% Pd/silica, 2 wt.% Pd/gallia and pure gallia, was studied by temperatureprogrammed surface reaction (TPSR), between 323 and 723 K under He flow, using FT-IR spectroscopy. After methanol adsorption on Pd/silica at 323 K, the concentration of methoxy species on the silica decreased during the TPRS experiment, but some methoxy groups still remained on this support even at 723 K. Simultaneously, methanol decomposed over metallic palladium to yield, stepwise, HCO and CO with the consequent release of H2 (g). On clean gallia, methanol is Lewis-bound adsorbed to the surface, as well as dissociatively adsorbed as methoxy (CH3O), but the position of the infrared bands indicates a stronger interaction of these species on gallium oxide than on silica. Methoxy species on gallia are decomposed to (mono- and bi-dentate) formate groups (m- and b-HCOO, respectively) at T > 473 K. We suggest that CO and CO2 are further produced by nonstoichiometric transformation of these formates, leading to the release of atomic hydrogen on the surface of the oxide, as detected by the Ga–H stretching infrared band, and surface anion vacancies. In the presence of Pd on the gallia surface, the dehydrogenation of CH3O species proceeds faster than over the pure oxide, and we propose the following mechanism for methanol decomposition: (i) methanol reacts with OH groups on the gallia surface to produce water and methoxy species, (ii) the dehydrogenation of the latter carbonaceous group leads to H2COO, first, and then to mand b-HCOO, (iii) the hydrogen atoms released in the previous steps are transferred from gallia to the Pd surface where they recombine and desorb as H2 (g).Fil: Collins, Sebastián Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Baltanas, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Bonivardi, Adrian Lionel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaElsevier Science2005-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/26604Collins, Sebastián Enrique; Baltanas, Miguel Angel; Bonivardi, Adrian Lionel; Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst; Elsevier Science; Applied Catalysis A: General; 296; 2; 12-2005; 126-1330926-860XCONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1016/j.apcata.2005.07.053info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0926860X05005715info:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-22T11:40:51Zoai:ri.conicet.gov.ar:11336/26604instacron: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:34982025-10-22 11:40:51.693CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst
title Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst
spellingShingle Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst
Collins, Sebastián Enrique
Methanol
Decomposition
Palladium
Gallia
title_short Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst
title_full Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst
title_fullStr Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst
title_full_unstemmed Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst
title_sort Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst
dc.creator.none.fl_str_mv Collins, Sebastián Enrique
Baltanas, Miguel Angel
Bonivardi, Adrian Lionel
author Collins, Sebastián Enrique
author_facet Collins, Sebastián Enrique
Baltanas, Miguel Angel
Bonivardi, Adrian Lionel
author_role author
author2 Baltanas, Miguel Angel
Bonivardi, Adrian Lionel
author2_role author
author
dc.subject.none.fl_str_mv Methanol
Decomposition
Palladium
Gallia
topic Methanol
Decomposition
Palladium
Gallia
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv The thermal decomposition of adsorbed methanol on 2 wt.% Pd/silica, 2 wt.% Pd/gallia and pure gallia, was studied by temperatureprogrammed surface reaction (TPSR), between 323 and 723 K under He flow, using FT-IR spectroscopy. After methanol adsorption on Pd/silica at 323 K, the concentration of methoxy species on the silica decreased during the TPRS experiment, but some methoxy groups still remained on this support even at 723 K. Simultaneously, methanol decomposed over metallic palladium to yield, stepwise, HCO and CO with the consequent release of H2 (g). On clean gallia, methanol is Lewis-bound adsorbed to the surface, as well as dissociatively adsorbed as methoxy (CH3O), but the position of the infrared bands indicates a stronger interaction of these species on gallium oxide than on silica. Methoxy species on gallia are decomposed to (mono- and bi-dentate) formate groups (m- and b-HCOO, respectively) at T > 473 K. We suggest that CO and CO2 are further produced by nonstoichiometric transformation of these formates, leading to the release of atomic hydrogen on the surface of the oxide, as detected by the Ga–H stretching infrared band, and surface anion vacancies. In the presence of Pd on the gallia surface, the dehydrogenation of CH3O species proceeds faster than over the pure oxide, and we propose the following mechanism for methanol decomposition: (i) methanol reacts with OH groups on the gallia surface to produce water and methoxy species, (ii) the dehydrogenation of the latter carbonaceous group leads to H2COO, first, and then to mand b-HCOO, (iii) the hydrogen atoms released in the previous steps are transferred from gallia to the Pd surface where they recombine and desorb as H2 (g).
Fil: Collins, Sebastián Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina
Fil: Baltanas, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina
Fil: Bonivardi, Adrian Lionel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina
description The thermal decomposition of adsorbed methanol on 2 wt.% Pd/silica, 2 wt.% Pd/gallia and pure gallia, was studied by temperatureprogrammed surface reaction (TPSR), between 323 and 723 K under He flow, using FT-IR spectroscopy. After methanol adsorption on Pd/silica at 323 K, the concentration of methoxy species on the silica decreased during the TPRS experiment, but some methoxy groups still remained on this support even at 723 K. Simultaneously, methanol decomposed over metallic palladium to yield, stepwise, HCO and CO with the consequent release of H2 (g). On clean gallia, methanol is Lewis-bound adsorbed to the surface, as well as dissociatively adsorbed as methoxy (CH3O), but the position of the infrared bands indicates a stronger interaction of these species on gallium oxide than on silica. Methoxy species on gallia are decomposed to (mono- and bi-dentate) formate groups (m- and b-HCOO, respectively) at T > 473 K. We suggest that CO and CO2 are further produced by nonstoichiometric transformation of these formates, leading to the release of atomic hydrogen on the surface of the oxide, as detected by the Ga–H stretching infrared band, and surface anion vacancies. In the presence of Pd on the gallia surface, the dehydrogenation of CH3O species proceeds faster than over the pure oxide, and we propose the following mechanism for methanol decomposition: (i) methanol reacts with OH groups on the gallia surface to produce water and methoxy species, (ii) the dehydrogenation of the latter carbonaceous group leads to H2COO, first, and then to mand b-HCOO, (iii) the hydrogen atoms released in the previous steps are transferred from gallia to the Pd surface where they recombine and desorb as H2 (g).
publishDate 2005
dc.date.none.fl_str_mv 2005-12
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/11336/26604
Collins, Sebastián Enrique; Baltanas, Miguel Angel; Bonivardi, Adrian Lionel; Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst; Elsevier Science; Applied Catalysis A: General; 296; 2; 12-2005; 126-133
0926-860X
CONICET Digital
CONICET
url http://hdl.handle.net/11336/26604
identifier_str_mv Collins, Sebastián Enrique; Baltanas, Miguel Angel; Bonivardi, Adrian Lionel; Mechanism of the decomposition of adsorbed methanol over a Pd/α,β-Ga2O3 catalyst; Elsevier Science; Applied Catalysis A: General; 296; 2; 12-2005; 126-133
0926-860X
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.apcata.2005.07.053
info:eu-repo/semantics/altIdentifier/url/http://www.sciencedirect.com/science/article/pii/S0926860X05005715
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
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 12.982451

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