Synthesis of SAPO-34 Molecular Sieve Membranes by Steam-assisted Conversion Seeding and Their Characterization

doi:10.15541/jim20140487

Abstract

Abstract:

A new seeding method, the steam-assisted conversion seeding, was used to prepare the high-quality SAPO-34 molecular sieve membranes by secondary growth method on the low cost macroporous α-Al₂O₃ supports. The seeds with different sizes of 2 μm, 1 μm, 500 nm, and 100 nm were mixed in the synthesis solution to prepare the seeds-containing pastes which was coated on the surface of the support. The effects of the particle size on the paste layers, seed layers and membranes were investigated. A perfect seed layer was formed and effectively modified the defects of the macroporous α-Al₂O₃ support and then, induced a continuous, compact and unconspicuousl pinholes SAPO-34 membrane. The SAPO-34 membrane displayed high performance in the pervaporation dehydration of 90wt% IPA/water mixtures at 348 K, showing water ?ux up to 1.396 kg/(m²·h) and separation factor at 973.

Key words: SAPO-34 membrane, macroporous support, steam-assisted conversion, pervaporation performance

CLC Number:

O614

ZHOU Liang, YANG Jian-Hua, WANG Jin-Qu, LU Jin-Ming, ZHANG Yan, YIN De-Hong. Synthesis of SAPO-34 Molecular Sieve Membranes by Steam-assisted Conversion Seeding and Their Characterization[J]. Journal of Inorganic Materials, 2015, 30(3): 294-298.

Figures/Tables 6

Table 1 SAPO-34 membranes prepared from paste composed of various sizes of seeds

Membrane	Seed layer				Membrane
Membrane	Seed layer	Seed size/μm	SAC temperature/K	SAC time/h	Synthesis temperature/K	Synthesis time/h
M1	S1	2.0	473	24	473	24
M2	S2	1.0	473	24	473	24
M3	S3	0.5	473	24	473	24
M4	S4	0.1	473	24	473	24

Fig. 1 SEM images of the α-Al2O3 support (a, b) and the paste layer with different sizes of seeds (2 μm (c, d), 1 μm (e, f), 0.5 μm (g, h) and 0.1 μm (i, j)) on the supports

Fig. 2 SEM images of seed layers of S1 (a, b), S2 (c, d), S3 (e, f), and S4 (g, h)

Fig. 3 XRD patterns of membranes M1-M4

Table 2 PV performances of membranes M1-M4 at 75℃

Membrane	Water/IPA (10/90 w/w)
Membrane	Flux/ (kg·m^-2·h^-1)	α_W/IPA
M1	0.624	1093
M2	0.587	1122
M3	1.396	973
M4	2.785	34

Fig. 4 SEM images of membranes of M1(a, b), M2(c, d), M3 (e, f), and M4 (g, h)

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