Strong Acidity of Silanol Groups of Zeolite Beta: Evidence from the Studies by IR Spectroscopy of Adsorbed CO and 1H MAS NMR Full article
| Journal |
Microporous and Mesoporous Materials
ISSN: 1387-1811 , E-ISSN: 1873-3093 |
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| Output data | Year: 2010, Volume: 131, Number: 1-3, Pages: 210-216 Pages count : 7 DOI: 10.1016/j.micromeso.2009.12.025 | ||||
| Tags | 1H MAS NMR, Acid-form and Zn- and Ga-modified zeolite, Acidic silanol groups, BEA, IR spectroscopy | ||||
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| Affiliations |
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Funding (1)
| 1 | Russian Foundation for Basic Research | 07-03-00136 |
Abstract:
Acidic OH groups of acid-form and Zn and Ga-modified zeolite beta (BEA) have been characterized with 1H MAS NMR and by IR spectroscopy of adsorbed carbon monoxide. It is demonstrated that OH groups, which exhibit a vibration band at 3740 cm−1, reveal acidity, which is similar to that of the OH groups with the band at 3610 cm−1 according to the value of the low frequency shift of OH vibrations with adsorbed CO (ΔνOH/CO = 300 cm−1). The IR band 3740 cm−1 corresponds to the signal at ca. 2.1 ppm in 1H MAS NMR spectrum. The OH groups with signal 2.1 ppm are involved in H/D exchange with methane-d4 similar to acidic OH groups with the signals 4.0–5.1 ppm. The signals at 2.1 ppm in 1H MAS NMR and at 3740 cm−1 in IR are attributed to the strongly acidic silanol groups of the faulted structure of the zeolite. The silanols with the signals at 1.8 ppm and 3745 cm−1 are weakly acidic (ΔνOH/CO = 85 cm−1) and are not involved in the H/D exchange. Loading of the zeolite with Zn affords a notable decrease of the concentration of strongly acidic SiOHAl groups, whereas the quantity of these groups does not decrease upon loading the zeolite with Ga.
Cite:
Gabrienko A.A.
, Danilova I.G.
, Arzumanov S.S.
, Toktarev A.V.
, Freude D.
, Stepanov A.G.
Strong Acidity of Silanol Groups of Zeolite Beta: Evidence from the Studies by IR Spectroscopy of Adsorbed CO and 1H MAS NMR
Microporous and Mesoporous Materials. 2010. V.131. N1-3. P.210-216. DOI: 10.1016/j.micromeso.2009.12.025 WOS Scopus РИНЦ ANCAN OpenAlex
Strong Acidity of Silanol Groups of Zeolite Beta: Evidence from the Studies by IR Spectroscopy of Adsorbed CO and 1H MAS NMR
Microporous and Mesoporous Materials. 2010. V.131. N1-3. P.210-216. DOI: 10.1016/j.micromeso.2009.12.025 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Aug 3, 2009 |
| Accepted: | Dec 26, 2009 |
| Published online: | Jan 4, 2010 |
| Published print: | Jun 1, 2010 |
Identifiers:
| Web of science: | WOS:000276627600027 |
| Scopus: | 2-s2.0-77649232758 |
| Elibrary: | 15326087 |
| Chemical Abstracts: | 2010:301309 |
| Chemical Abstracts (print): | 153:368829 |
| OpenAlex: | W2167765454 |