Probing the Brønsted and Lewis acidity of Fe-silicalite by FTIR spectroscopy of H2 adsorbed at 20 K: Evidences for the formation of Fe3+/H2 and Fe2+/H2 molecular adducts Full article
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Journal of Catalysis
ISSN: 0021-9517 , E-ISSN: 1090-2694 |
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| Output data | Year: 2006, Volume: 238, Number: 2, Pages: 243-249 Pages count : 7 DOI: 10.1016/j.jcat.2005.12.003 | ||
| Tags | α-Oxygen, Fe-zeolite, H2 adducts, IR spectroscopy, N 2O decomposition | ||
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Abstract:
We report on the spectroscopic characterisation of a Fe-silicalite sample in terms of Brønsted and Lewis acidity using H2 as a probe molecule at low temperature (20 K). At 20 K, H2 is able to form adducts with surface sites present in the internal (and external) surface of zeolites: Brønsted, silanols, and metal ions. The spectroscopic manifestations of the different H2 adducts are found in distinct spectral regions depending on the nature and strength of the adducts: ν¯HH modes of OH···H2 adducts are found in the 4170–4100 cm−1 region, and those of Fex+···H2 adducts are found
in the 4100–3900 cm−1 region. Four distinct Fex+ ···H2 adducts (at 4050, 4028, 3990, and 3960 cm−1) were formed on extra-framework Fe sites, created by controlled migration of Fe from the framework as a consequence of thermal treatments. The dependence on red–ox treatments of the relative concentration of these sites allowed identification of two Fe2+ and two Fe3+ distinct sites, interacting with H2 mainly by electrostatic forces. The importance of these sites as active species for the selective oxidation of hydrocarbons with N2O is discussed.
Cite:
Berlier G.
, Gribov E.
, Cocina D.
, Spoto G.
, Zecchina A.
Probing the Brønsted and Lewis acidity of Fe-silicalite by FTIR spectroscopy of H2 adsorbed at 20 K: Evidences for the formation of Fe3+/H2 and Fe2+/H2 molecular adducts
Journal of Catalysis. 2006. V.238. N2. P.243-249. DOI: 10.1016/j.jcat.2005.12.003 WOS Scopus РИНЦ ANCAN OpenAlex
Probing the Brønsted and Lewis acidity of Fe-silicalite by FTIR spectroscopy of H2 adsorbed at 20 K: Evidences for the formation of Fe3+/H2 and Fe2+/H2 molecular adducts
Journal of Catalysis. 2006. V.238. N2. P.243-249. DOI: 10.1016/j.jcat.2005.12.003 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Jul 27, 2005 |
| Accepted: | Dec 5, 2005 |
| Published online: | Jan 18, 2006 |
| Published print: | Mar 10, 2006 |
Identifiers:
| Web of science: | WOS:000235625100001 |
| Scopus: | 2-s2.0-32444437989 |
| Elibrary: | 13522866 |
| Chemical Abstracts: | 2006:128609 |
| Chemical Abstracts (print): | 144:358564 |
| OpenAlex: | W2162181199 |