Details
| Original language | English |
|---|---|
| Pages (from-to) | 339-346 |
| Number of pages | 8 |
| Journal | Microporous and Mesoporous Materials |
| Volume | 90 |
| Issue number | 1-3 SPEC. ISS. |
| Early online date | 29 Nov 2005 |
| Publication status | Published - 20 Mar 2006 |
Abstract
Zeolite HY was steamed at 1 bar water pressure in steps of 100 K from 473 K to 1073 K in dependence of the time (0.5-20 h). Three routes of hydrothermal reactions can be outlined: At low temperature (473 K), a partly framework dissolution occurs accompanied by the formation of X-ray amorphous material. At intermediate temperatures (773-873 K), framework dealumination takes place with the occurrence of different non-framework species. Thereby, with increasing steaming time, saturation of the Si/Al ratio occurs on low levels (Si/Al ratios of about 4 and 5, respectively). At 973 K, a crossover from a low level saturation in Si/Al (6) towards higher values (11) is observed, which is accompanied by a partial amorphization of the zeolite with formation of aluminium oxide and silica gel and a significant decrease in crystal size as well. At high temperatures (1073 K), a fast thermal decomposition occurs. The IR spectra directly reveal an aluminosilicate phase as decomposition product of the framework. At 573 K, the zeolite framework remains unchanged.
Keywords
- Amorphization, Dealumination, Steaming, Zeolites
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
- Engineering(all)
- Mechanics of Materials
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In: Microporous and Mesoporous Materials, Vol. 90, No. 1-3 SPEC. ISS., 20.03.2006, p. 339-346.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Effect of temperature and time in the hydrothermal treatment of HY zeolite
AU - Salman, N.
AU - Rüscher, C. H.
AU - Buhl, J. Chr
AU - Lutz, W.
AU - Toufar, H.
AU - Stöcker, M.
PY - 2006/3/20
Y1 - 2006/3/20
N2 - Zeolite HY was steamed at 1 bar water pressure in steps of 100 K from 473 K to 1073 K in dependence of the time (0.5-20 h). Three routes of hydrothermal reactions can be outlined: At low temperature (473 K), a partly framework dissolution occurs accompanied by the formation of X-ray amorphous material. At intermediate temperatures (773-873 K), framework dealumination takes place with the occurrence of different non-framework species. Thereby, with increasing steaming time, saturation of the Si/Al ratio occurs on low levels (Si/Al ratios of about 4 and 5, respectively). At 973 K, a crossover from a low level saturation in Si/Al (6) towards higher values (11) is observed, which is accompanied by a partial amorphization of the zeolite with formation of aluminium oxide and silica gel and a significant decrease in crystal size as well. At high temperatures (1073 K), a fast thermal decomposition occurs. The IR spectra directly reveal an aluminosilicate phase as decomposition product of the framework. At 573 K, the zeolite framework remains unchanged.
AB - Zeolite HY was steamed at 1 bar water pressure in steps of 100 K from 473 K to 1073 K in dependence of the time (0.5-20 h). Three routes of hydrothermal reactions can be outlined: At low temperature (473 K), a partly framework dissolution occurs accompanied by the formation of X-ray amorphous material. At intermediate temperatures (773-873 K), framework dealumination takes place with the occurrence of different non-framework species. Thereby, with increasing steaming time, saturation of the Si/Al ratio occurs on low levels (Si/Al ratios of about 4 and 5, respectively). At 973 K, a crossover from a low level saturation in Si/Al (6) towards higher values (11) is observed, which is accompanied by a partial amorphization of the zeolite with formation of aluminium oxide and silica gel and a significant decrease in crystal size as well. At high temperatures (1073 K), a fast thermal decomposition occurs. The IR spectra directly reveal an aluminosilicate phase as decomposition product of the framework. At 573 K, the zeolite framework remains unchanged.
KW - Amorphization
KW - Dealumination
KW - Steaming
KW - Zeolites
UR - http://www.scopus.com/inward/record.url?scp=32644449025&partnerID=8YFLogxK
U2 - 10.1016/j.micromeso.2005.09.032
DO - 10.1016/j.micromeso.2005.09.032
M3 - Article
AN - SCOPUS:32644449025
VL - 90
SP - 339
EP - 346
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
SN - 1387-1811
IS - 1-3 SPEC. ISS.
ER -