Abstract
Zeolite BEA with SiO2/Al2O3 ratios ranging from 30 to 740 were crystallized at 413 and 453 K by the dry gel conversion technique. The particle size of the products increased with increasing SiO2/Al2O3 ratio as well as with increasing crystallization temperature. In as-synthesized BEA, the TEA+ ions interacting with Si-O- decomposed between 473 and 673 K and those interacting with Al-O- were cleaved between 673 and 798 K. During their elimination, the TEA+ ions interacting with Al-O- underwent higher degradation than those interacting with Si-O-. Chemical compositions showed the least influence on the fractions of decomposition product during the elimination between 473 and 673 K. The framework of H-BEA and NH4-BEA zeolites with SiO2/Al2O3 ratios ranging from 400 to 740 were stable even at 1373 K, whereas H-BEA with SiO2/Al2O3 = 30 was stable only up to 1173 K and became amorphous when calcined at 1373 K. After calcination at 1373 K, Na-BEA with SiO2/Al2O3 = 400 and 730 were transformed to tridymite (dense phase) whereas that with SiO2/Al2O3 = 30 became amorphous. The elimination of Na+ ions is necessary to have a BEA remain stable above 1173 K.
| Original language | English |
|---|---|
| Pages (from-to) | 305-313 |
| Number of pages | 9 |
| Journal | Microporous and Mesoporous Materials |
| Volume | 21 |
| Issue number | 4-6 |
| Publication status | Published - 1998 May |
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Keywords
- Crystallization
- Dry gel conversion
- High silica zeolite
- Interaction of TEA ions with zeolite
- Thermal stability
- Zeolite BEA (beta)
ASJC Scopus subject areas
- Catalysis
- Materials Science(all)
Cite this
Synthesis of BEA by dry gel conversion and its characterization. / Hari Prasad Rao, P. R.; Leon Y Leon, C. A.; Ueyama, K.; Matsukata, Masahiko.
In: Microporous and Mesoporous Materials, Vol. 21, No. 4-6, 05.1998, p. 305-313.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Synthesis of BEA by dry gel conversion and its characterization
AU - Hari Prasad Rao, P. R.
AU - Leon Y Leon, C. A.
AU - Ueyama, K.
AU - Matsukata, Masahiko
PY - 1998/5
Y1 - 1998/5
N2 - Zeolite BEA with SiO2/Al2O3 ratios ranging from 30 to 740 were crystallized at 413 and 453 K by the dry gel conversion technique. The particle size of the products increased with increasing SiO2/Al2O3 ratio as well as with increasing crystallization temperature. In as-synthesized BEA, the TEA+ ions interacting with Si-O- decomposed between 473 and 673 K and those interacting with Al-O- were cleaved between 673 and 798 K. During their elimination, the TEA+ ions interacting with Al-O- underwent higher degradation than those interacting with Si-O-. Chemical compositions showed the least influence on the fractions of decomposition product during the elimination between 473 and 673 K. The framework of H-BEA and NH4-BEA zeolites with SiO2/Al2O3 ratios ranging from 400 to 740 were stable even at 1373 K, whereas H-BEA with SiO2/Al2O3 = 30 was stable only up to 1173 K and became amorphous when calcined at 1373 K. After calcination at 1373 K, Na-BEA with SiO2/Al2O3 = 400 and 730 were transformed to tridymite (dense phase) whereas that with SiO2/Al2O3 = 30 became amorphous. The elimination of Na+ ions is necessary to have a BEA remain stable above 1173 K.
AB - Zeolite BEA with SiO2/Al2O3 ratios ranging from 30 to 740 were crystallized at 413 and 453 K by the dry gel conversion technique. The particle size of the products increased with increasing SiO2/Al2O3 ratio as well as with increasing crystallization temperature. In as-synthesized BEA, the TEA+ ions interacting with Si-O- decomposed between 473 and 673 K and those interacting with Al-O- were cleaved between 673 and 798 K. During their elimination, the TEA+ ions interacting with Al-O- underwent higher degradation than those interacting with Si-O-. Chemical compositions showed the least influence on the fractions of decomposition product during the elimination between 473 and 673 K. The framework of H-BEA and NH4-BEA zeolites with SiO2/Al2O3 ratios ranging from 400 to 740 were stable even at 1373 K, whereas H-BEA with SiO2/Al2O3 = 30 was stable only up to 1173 K and became amorphous when calcined at 1373 K. After calcination at 1373 K, Na-BEA with SiO2/Al2O3 = 400 and 730 were transformed to tridymite (dense phase) whereas that with SiO2/Al2O3 = 30 became amorphous. The elimination of Na+ ions is necessary to have a BEA remain stable above 1173 K.
KW - Crystallization
KW - Dry gel conversion
KW - High silica zeolite
KW - Interaction of TEA ions with zeolite
KW - Thermal stability
KW - Zeolite BEA (beta)
UR - http://www.scopus.com/inward/record.url?scp=0032068235&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032068235&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0032068235
VL - 21
SP - 305
EP - 313
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
SN - 1387-1811
IS - 4-6
ER -