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dc.contributor.author
Garetto, Teresita Francisca
dc.contributor.author
Apesteguia, Carlos Rodolfo
dc.date.available
2018-02-23T20:21:19Z
dc.date.issued
2000-12
dc.identifier.citation
Garetto, Teresita Francisca; Apesteguia, Carlos Rodolfo; Oxidative catalytic removal of hydrocarbons over Pt/Al2O3 catalysts; Elsevier Science; Catalysis Today; 62; 2-3; 12-2000; 189-199
dc.identifier.issn
0920-5861
dc.identifier.uri
http://hdl.handle.net/11336/37066
dc.description.abstract
The reaction kinetics, structure sensitivity, and in situ activation of cyclopentane and methane combustions were studied on Pt/Al2O3 catalysts of different platinum and chlorine loadings. The catalyst activities were evaluated through both conversion vs. temperature (light-off curves) and conversion vs. time catalytic tests. Cyclopentane oxidation turnover rates (TOF) increased dramatically with increasing Pt crystallite size while TOF values for methane oxidation increased only three times by diminishing the Pt dispersion from 65 to 15%. The reaction orders in oxygen were one (cyclopentane) and zero (CH4). For both reactions, the orders and activation energies did not change by changing the Pt dispersion. Results are interpreted in
basis of two different reaction mechanisms over the metallic Pt active sites. Cyclopentane oxidation proceeds via a surface redox mechanism, being the dissociative adsorption of oxygen the rate-determining step. The observed turnover rate increase with increasing Pt particle size reflects an increase in the density of reactive Pt–O species resulting from higher Pt oxidation rates. The methane oxidation mechanism is interpreted in terms of Mars–van Kravelen reduction–oxidation pathways which include the abstraction of the first hydrogen on the adsorbed methane molecule as the rate-determining step. Low-conversion
catalytic tests performed at constant temperature showed that on well-dispersed Pt/Al2O3 catalysts the cyclopentane conversion increases with time on stream, while the methane activity decreases. Activating induction periods during the oxidation
of cyclopentane are related to the sintering of the metallic phase in reaction conditions. Hot-spots on the metallic particles together with the presence of gaseous water cause the formation of larger, more reactive, Pt crystallites, even at mild reaction conditions. The activation phenomenon ab initio of the reaction is not verified for methane oxidation on Pt/Al2O3 catalysts. The different structure sensitivity of the slowest steps in the reaction–oxidation mechanisms explains the existence of induction periods on well-dispersed Pt catalysts only for cyclopentane oxidation.
dc.format
application/pdf
dc.language.iso
eng
dc.publisher
Elsevier Science
dc.rights
info:eu-repo/semantics/openAccess
dc.rights.uri
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.subject
Hydrocarbon Combustion
dc.subject
Pt/Al2o3 Catalysts
dc.subject
Methane Oxidation Mechanism
dc.subject
Cyclopentane Oxidation Mechanism
dc.subject.classification
Otras Ingeniería Química
dc.subject.classification
Ingeniería Química
dc.subject.classification
INGENIERÍAS Y TECNOLOGÍAS
dc.title
Oxidative catalytic removal of hydrocarbons over Pt/Al2O3 catalysts
dc.type
info:eu-repo/semantics/article
dc.type
info:ar-repo/semantics/artículo
dc.type
info:eu-repo/semantics/publishedVersion
dc.date.updated
2018-02-21T21:41:29Z
dc.journal.volume
62
dc.journal.number
2-3
dc.journal.pagination
189-199
dc.journal.pais
Países Bajos
dc.journal.ciudad
Amsterdam
dc.description.fil
Fil: Garetto, Teresita Francisca. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentina
dc.description.fil
Fil: Apesteguia, Carlos Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentina
dc.journal.title
Catalysis Today
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/pii/S092058610000420X
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.1016/S0920-5861(00)00420-X
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