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The reduction and oxidation of Co species in CoZSM-5 zeolites studied by IR spectroscopy
CoZSM-5 zeolite
reduction
oxidation
IR spectroscopy
The process of reducing Co ions in zeolite CoZSM-5 by NO,
| cris.lastimport.scopus | 2024-04-07T18:01:55Z | |
| cris.lastimport.wos | 2024-04-10T00:36:57Z | |
| dc.abstract.en | The process of reducing Co ions in zeolite CoZSM-5 by NO, $H_{2}$ and CO, as well as of oxidizing them by $O_{2}$ was studied by IR spectroscopy with CO as the probe molecule for $Co^{2+}$ and NO as the probe for $Co^{3+}$. Two zeolites of different Co status were used: in the first, $Co^{2+}$ ions were localized mostly in cation exchange positions, and in the second most of the $Co^{2+}$ occurred in the form of CoO and oxide-like clusters. IR studies evidenced that NO reduced some $Co^{3+}$ to $Co^{2+}$ already at room temperature, and also reduced some $Co^{2+}$ to lower oxidation states (probably $Co^{+}$) at 670 and 1070 K. Only $Co^{2+}$ in exchange positions could be reduced with NO. The treatment of zeolite CoZSM-5 with $H_{2}$ or with CO at 670 and 1070 K made the reduction of $Co^{3+}$ to $Co^{2+}$ (the contribution of $Co^{3+}$ decreased and the contribution of $Co^{2+}$ increased). IR studies illustrated that the most electron-acceptor $Co^{3+}$ (characterized by a high frequency $Co^{3+}$–NO band) were transformed, by reduction, into the most electron-acceptor $Co^{2+}$ (characterized by a high frequency $Co^{2+}$–CO band). The treatment of zeolite CoZSM-5 with oxygen at 670–1070 K resulted in the oxidation of $Co^{2+}$ to $Co^{3+}$ (the contribution of $Co^{2+}$ decreased while the contribution of $Co^{3+}$ increased). | pl |
| dc.affiliation | Wydział Chemii : Zakład Chemii Nieorganicznej | pl |
| dc.contributor.author | Góra-Marek, Kinga - 128133 | pl |
| dc.date.accessioned | 2015-09-25T12:26:34Z | |
| dc.date.available | 2015-09-25T12:26:34Z | |
| dc.date.issued | 2009 | pl |
| dc.description.number | 8 | pl |
| dc.description.physical | 1023-1029 | pl |
| dc.description.volume | 52 | pl |
| dc.identifier.doi | 10.1007/s11244-009-9260-y | pl |
| dc.identifier.eissn | 1572-9028 | pl |
| dc.identifier.issn | 1022-5528 | pl |
| dc.identifier.uri | http://ruj.uj.edu.pl/xmlui/handle/item/15798 | |
| dc.language | eng | pl |
| dc.language.container | eng | pl |
| dc.rights | Dodaję tylko opis bibliograficzny | * |
| dc.rights.licence | bez licencji | |
| dc.rights.uri | * | |
| dc.subject.en | CoZSM-5 zeolite | pl |
| dc.subject.en | reduction | pl |
| dc.subject.en | oxidation | pl |
| dc.subject.en | IR spectroscopy | pl |
| dc.subtype | Article | pl |
| dc.title | The reduction and oxidation of Co species in CoZSM-5 zeolites studied by IR spectroscopy | pl |
| dc.title.journal | Topics in Catalysis | pl |
| dc.title.volume | Catalysis for society | pl |
| dc.type | JournalArticle | pl |
| dspace.entity.type | Publication |