Quantitative IR studies of the concentration of and sites in zeolites CoZSM-5 and CoFER

2009
journal article
article
41
cris.lastimport.wos2024-04-10T00:19:01Z
dc.abstract.enQuantitative IR experiments were realized to determine the concentration of cobalt in a form of trivalent cations being in the oxide form as well as divalent ions in exchange positions, oxide-like clusters and cobalt oxide, present in a series of cobalt-exchanged zeolites. The first step of such quantitative studies was to elaborate the experimental conditions in which probe molecules NO and CO should react selectively with either of these sites. Subsequently, the values of absorption coefficients of the 1940$cm^{-1}$ band of $Co^{3+}$–NO and the 2204$cm^{-1}$ band of $Co^{2+}$–CO for $Co^{2+}$ in exchange positions, together with the 2194$cm^{-1}$ band of $Co^{2+}$–CO for $Co^{2+}$ in oxide-like clusters were determined. The linear plots of the band intensities versus the concentration of NO and CO interacting with cationic sites showed the correlation coefficients higher than 0.99. Three zeolites were investigated: CoZSM-5 (Si/Al = 15) in which most of $Co^{2+}$ occupied the exchange positions, CoZSM-5 (Si/Al = 40) in which most of $Co^{2+}$ was in the form of oxide-like clusters and CoO, and CoFER prepared by the contact-induced ion exchange with nearly equal amount of $Co^{2+}$ in either type of the sites. The sum of the concentration of Co sites ($Co^{3+}$ and $Co^{2+}$) determined by IR spectroscopy was very close to the values obtained from the chemical analysis (AAS). The concentration ill-defined oxide form of $Co^{3+}$ was surprisingly high as in CoZSM-5 of Si/Al = 15 it constituted about half of the overall cobalt content, and in CoFER the contribution of $Co^{3+}$ reached almost 30%.pl
dc.affiliationWydział Chemii : Zakład Chemii Nieorganicznejpl
dc.contributor.authorGóra-Marek, Kinga - 128133 pl
dc.contributor.authorGil, Barbara - 128059 pl
dc.contributor.authorDatka, Jerzy - 127692 pl
dc.date.accessioned2015-09-25T12:44:28Z
dc.date.available2015-09-25T12:44:28Z
dc.date.issued2009pl
dc.description.number1pl
dc.description.physical117-122pl
dc.description.volume353pl
dc.identifier.doi10.1016/j.apcata.2008.10.034pl
dc.identifier.eissn1873-3875pl
dc.identifier.issn0926-860Xpl
dc.identifier.urihttp://ruj.uj.edu.pl/xmlui/handle/item/15800
dc.languageengpl
dc.language.containerengpl
dc.rightsDodaję tylko opis bibliograficzny*
dc.rights.licencebez licencji
dc.rights.uri*
dc.subject.enCoZSM-5pl
dc.subject.enCoFERpl
dc.subject.enIR spectroscopypl
dc.subject.enabsorption coefficientpl
dc.subtypeArticlepl
dc.titleQuantitative IR studies of the concentration of $Co^{2+}$ and $Co^{3+}$ sites in zeolites CoZSM-5 and CoFERpl
dc.title.journalApplied Catalysis. A, Generalpl
dc.typeJournalArticlepl
dspace.entity.typePublication
cris.lastimport.wos
2024-04-10T00:19:01Z
dc.abstract.enpl
Quantitative IR experiments were realized to determine the concentration of cobalt in a form of trivalent cations being in the oxide form as well as divalent ions in exchange positions, oxide-like clusters and cobalt oxide, present in a series of cobalt-exchanged zeolites. The first step of such quantitative studies was to elaborate the experimental conditions in which probe molecules NO and CO should react selectively with either of these sites. Subsequently, the values of absorption coefficients of the 1940$cm^{-1}$ band of $Co^{3+}$–NO and the 2204$cm^{-1}$ band of $Co^{2+}$–CO for $Co^{2+}$ in exchange positions, together with the 2194$cm^{-1}$ band of $Co^{2+}$–CO for $Co^{2+}$ in oxide-like clusters were determined. The linear plots of the band intensities versus the concentration of NO and CO interacting with cationic sites showed the correlation coefficients higher than 0.99. Three zeolites were investigated: CoZSM-5 (Si/Al = 15) in which most of $Co^{2+}$ occupied the exchange positions, CoZSM-5 (Si/Al = 40) in which most of $Co^{2+}$ was in the form of oxide-like clusters and CoO, and CoFER prepared by the contact-induced ion exchange with nearly equal amount of $Co^{2+}$ in either type of the sites. The sum of the concentration of Co sites ($Co^{3+}$ and $Co^{2+}$) determined by IR spectroscopy was very close to the values obtained from the chemical analysis (AAS). The concentration ill-defined oxide form of $Co^{3+}$ was surprisingly high as in CoZSM-5 of Si/Al = 15 it constituted about half of the overall cobalt content, and in CoFER the contribution of $Co^{3+}$ reached almost 30%.
dc.affiliationpl
Wydział Chemii : Zakład Chemii Nieorganicznej
dc.contributor.authorpl
Góra-Marek, Kinga - 128133
dc.contributor.authorpl
Gil, Barbara - 128059
dc.contributor.authorpl
Datka, Jerzy - 127692
dc.date.accessioned
2015-09-25T12:44:28Z
dc.date.available
2015-09-25T12:44:28Z
dc.date.issuedpl
2009
dc.description.numberpl
1
dc.description.physicalpl
117-122
dc.description.volumepl
353
dc.identifier.doipl
10.1016/j.apcata.2008.10.034
dc.identifier.eissnpl
1873-3875
dc.identifier.issnpl
0926-860X
dc.identifier.uri
http://ruj.uj.edu.pl/xmlui/handle/item/15800
dc.languagepl
eng
dc.language.containerpl
eng
dc.rights*
Dodaję tylko opis bibliograficzny
dc.rights.licence
bez licencji
dc.rights.uri*
dc.subject.enpl
CoZSM-5
dc.subject.enpl
CoFER
dc.subject.enpl
IR spectroscopy
dc.subject.enpl
absorption coefficient
dc.subtypepl
Article
dc.titlepl
Quantitative IR studies of the concentration of $Co^{2+}$ and $Co^{3+}$ sites in zeolites CoZSM-5 and CoFER
dc.title.journalpl
Applied Catalysis. A, General
dc.typepl
JournalArticle
dspace.entity.type
Publication

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