Details
| Original language | English |
|---|---|
| Pages (from-to) | 272-279 |
| Number of pages | 8 |
| Journal | Journal of membrane science |
| Volume | 389 |
| Early online date | 3 Nov 2011 |
| Publication status | Published - 1 Feb 2012 |
Abstract
A seeding-free synthesis strategy was developed for the preparation of dense and phase-pure zeolite FAU membranes using 3-aminopropyltriethoxysilane (APTES) as covalent linker between the FAU layer and the alumina support. APTES acts as molecular linker for anchoring the FAU precursors onto the support surface to promote the nucleation and the formation of a thin, well intergrown FAU membrane. Additionally, at the pH of zeolite FAU crystallization (about 11), the zeta potential of the alumina support is changed by APTES-treatment from strongly negative to neutral, which will be helpful to reduce the electrostatic rejection between the negatively charged precursor species and the alumina support. The SEM and XRD characterizations indicate that a relative thin but dense and phase-pure FAU zeolite membrane with a thickness of about 2.5μm can be formed on the α-Al 2O 3 support after crystallization at 75°C for 24h, and no cracks, pinholes or other defects are visible in the membrane layer. The zeolite FAU membranes prepared on APTES-modified Al 2O 3 supports display higher separation selectivities than those prepared on non-modified Al 2O 3 support. For binary mixtures at 100°C and 1bar, the mixed gas separation factors of H 2/CO 2, H 2/N 2, H 2/CH 4 and H 2/C 3H 8, are found to be 6.5, 6.0, 4.0 and 11.1, respectively, which are higher than the corresponding Knudsen coefficients. Further, relative high H 2 permeances of about 4.0×10 -7molm -2s -1Pa -1 can be obtained through the FAU membrane due to the thin layer and the relative wide pores of 0.74nm.
Keywords
- APTES covalent linker, Gas permeation, Molecular sieve membrane, Zeolite FAU membrane
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Biochemistry
- Materials Science(all)
- General Materials Science
- Chemistry(all)
- Physical and Theoretical Chemistry
- Chemical Engineering(all)
- Filtration and Separation
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In: Journal of membrane science, Vol. 389, 01.02.2012, p. 272-279.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Seeding-free synthesis of dense zeolite FAU membranes on 3-aminopropyltriethoxysilane-functionalized alumina supports
AU - Huang, Aisheng
AU - Wang, Nanyi
AU - Caro, Jürgen
PY - 2012/2/1
Y1 - 2012/2/1
N2 - A seeding-free synthesis strategy was developed for the preparation of dense and phase-pure zeolite FAU membranes using 3-aminopropyltriethoxysilane (APTES) as covalent linker between the FAU layer and the alumina support. APTES acts as molecular linker for anchoring the FAU precursors onto the support surface to promote the nucleation and the formation of a thin, well intergrown FAU membrane. Additionally, at the pH of zeolite FAU crystallization (about 11), the zeta potential of the alumina support is changed by APTES-treatment from strongly negative to neutral, which will be helpful to reduce the electrostatic rejection between the negatively charged precursor species and the alumina support. The SEM and XRD characterizations indicate that a relative thin but dense and phase-pure FAU zeolite membrane with a thickness of about 2.5μm can be formed on the α-Al 2O 3 support after crystallization at 75°C for 24h, and no cracks, pinholes or other defects are visible in the membrane layer. The zeolite FAU membranes prepared on APTES-modified Al 2O 3 supports display higher separation selectivities than those prepared on non-modified Al 2O 3 support. For binary mixtures at 100°C and 1bar, the mixed gas separation factors of H 2/CO 2, H 2/N 2, H 2/CH 4 and H 2/C 3H 8, are found to be 6.5, 6.0, 4.0 and 11.1, respectively, which are higher than the corresponding Knudsen coefficients. Further, relative high H 2 permeances of about 4.0×10 -7molm -2s -1Pa -1 can be obtained through the FAU membrane due to the thin layer and the relative wide pores of 0.74nm.
AB - A seeding-free synthesis strategy was developed for the preparation of dense and phase-pure zeolite FAU membranes using 3-aminopropyltriethoxysilane (APTES) as covalent linker between the FAU layer and the alumina support. APTES acts as molecular linker for anchoring the FAU precursors onto the support surface to promote the nucleation and the formation of a thin, well intergrown FAU membrane. Additionally, at the pH of zeolite FAU crystallization (about 11), the zeta potential of the alumina support is changed by APTES-treatment from strongly negative to neutral, which will be helpful to reduce the electrostatic rejection between the negatively charged precursor species and the alumina support. The SEM and XRD characterizations indicate that a relative thin but dense and phase-pure FAU zeolite membrane with a thickness of about 2.5μm can be formed on the α-Al 2O 3 support after crystallization at 75°C for 24h, and no cracks, pinholes or other defects are visible in the membrane layer. The zeolite FAU membranes prepared on APTES-modified Al 2O 3 supports display higher separation selectivities than those prepared on non-modified Al 2O 3 support. For binary mixtures at 100°C and 1bar, the mixed gas separation factors of H 2/CO 2, H 2/N 2, H 2/CH 4 and H 2/C 3H 8, are found to be 6.5, 6.0, 4.0 and 11.1, respectively, which are higher than the corresponding Knudsen coefficients. Further, relative high H 2 permeances of about 4.0×10 -7molm -2s -1Pa -1 can be obtained through the FAU membrane due to the thin layer and the relative wide pores of 0.74nm.
KW - APTES covalent linker
KW - Gas permeation
KW - Molecular sieve membrane
KW - Zeolite FAU membrane
UR - http://www.scopus.com/inward/record.url?scp=83855160753&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2011.10.036
DO - 10.1016/j.memsci.2011.10.036
M3 - Article
AN - SCOPUS:83855160753
VL - 389
SP - 272
EP - 279
JO - Journal of membrane science
JF - Journal of membrane science
SN - 0376-7388
ER -