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Spectroscopic characterization of hydroxyl groups in SAPO-40. Part I: Study of the template-free samples and their interaction with ammonia

1996Journal article Restricted
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dc.contributor.authorOnida, B.
dc.contributor.authorGabelica, Z.
dc.contributor.authorLourenço, J. P.
dc.contributor.authorGarrone, E.
dc.date.accessioned2013-01-04T12:09:48Z
dc.date.available2013-01-04T12:09:48Z
dc.date.issued1996
dc.date.updated2013-01-03T10:11:11Z
dc.description.abstractFTIR, MAS 1H-NMR, and molecular graphics data are reported concerning the hydroxyl species in a series of SAPO-40 samples with variable Si contents, as well as FTIR data concerning the interaction of ammonia with the different acid sites. Up to seven types of Si(OH)Al Brønsted sites are present, mainly differing by the O-H stretching frequency. Three high-frequency bands (3637-3624 cm-1) correspond to hydroxyls located in the 12-member channels and two low-frequency bands (3559 and 3528 cm-1) to OH species in eight-member rings and side pockets of the AFR structure. Two bands at exceptionally low frequency (3485 and 3445 cm-1 ) are due to OH species interacting with silica islands. All low-frequency bands behave with temperature as H-bonded species. All types of hydroxyls form ammonium ions, the thermal decomposition of which shows some difference in acidity among the OH species. IR evidence indicates that NH4 + species interact strongly with the basic oxygen atoms of the lattice. No Lewis sites were evidenced by ammonia adsorption.por
dc.identifier.citationOnida, B.; Gabelica, Z.; Lourenço, J.P.; Garrone, E. Spectroscopic characterization of hydroxyl groups in SAPO-40. Part I: Study of the template-free samples and their interaction with ammonia, J. Phys. Chem. 100, 11072-11079, 1996.por
dc.identifier.otherAUT: JLO01215;
dc.identifier.urihttp://hdl.handle.net/10400.1/2048
dc.language.isoengpor
dc.peerreviewedyespor
dc.publisherAmerican Chemical Societypor
dc.subjectAcidity characterizationpor
dc.subjectFTIRpor
dc.subjectAmonia adsorptionpor
dc.subjectSAPO-40por
dc.titleSpectroscopic characterization of hydroxyl groups in SAPO-40. Part I: Study of the template-free samples and their interaction with ammoniapor
dc.typejournal article
dspace.entity.typePublication
oaire.citation.endPage11072por
oaire.citation.startPage11072por
oaire.citation.titleJournal of Physical Chemistrypor
oaire.citation.volume100por
person.familyNameLourenço
person.givenNameJoão P.
person.identifier634248
person.identifier.ciencia-idF81F-A1F0-2A7C
person.identifier.orcid0000-0002-0501-6672
person.identifier.ridA-7758-2008
person.identifier.scopus-author-id57195730600
rcaap.rightsrestrictedAccesspor
rcaap.typearticlepor
relation.isAuthorOfPublicationf66ab886-d989-4c1d-9550-527507723c26
relation.isAuthorOfPublication.latestForDiscoveryf66ab886-d989-4c1d-9550-527507723c26

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