Hydrothermal synthesis of ZSM-5 membranes

Outline content

1. In situ growth

2. Secondary growth

3. Work plan

1.

In situ growth

crystallization conditions

Time & Temperature

165℃， 4 h165℃， 4 h

165℃， 12 h165℃， 12 h

165℃， 24 h165℃， 24 h

185℃， 4 h185℃， 4 h

185℃， 24 h185℃， 24 h

165℃， 12 h165℃， 12 h 165℃， 12 h165℃， 12 h

substrate

165℃， 24 h165℃， 24 h 165℃， 24 h165℃， 24 h

Crystallization Time

nucleation

crystal growthC1

t1

t3 24 h

t2

t4

0 10 20 30 40 50 60

inte

nsity

2

substrate 3 sample 3

0 10 20 30 40 50 60

inte

nsity

2

substrate 2 sample 2

020

surface roughness

2.

Secondary growth

Random orientationRandom orientation

Random orientationRandom orientation

Random orientationRandom orientation

0 10 20 30 40 50 60

intensity

2Thickness ~1.8μmThickness ~1.8μm

101

200/020

332/051

151/303

133

Reproducity of secondary growth

Random orientationRandom orientationgood intergrowthgood intergrowth

0.36TPAOH:1TEOS:58H2O:4EtOHaging

Crystallization98℃， 48 h

Centrifugation10000 r/min for 10 min

The amount of seed can be easily controlled.

The obtained seed can be stored in a desiccator for later use.

weighing

Ultrasonication15 min

Preparation of seed

0 1 2 3 4 5

0.1

0.2

0.3

0.4

0.5

Δm

%（

）

concentration(mg/mL)

Impact of seed concentration

Random orientationRandom orientation

seed obtained after centrifugation5 mg/mL in EtOH

25SiO2 ： 9TPAOH ： 1450H2O: 100EtOH

100 ℃ ， 48 h

A gel layer formed Discrete zeolite particles

PH = 12.49 PH = 6.16

Seed coated

Effect of Al

•It facilitate the formation of the gel layer on the support.

•It retard zeolitization in this gel layer.

JH Koegler, H Bekkum, et al., Zeolites,1997,19(4): 262-269.

Re Lai, Yushan Yan, George R. Gavalas, Micropor Mesopor Mater, 2000,37(1-2):9-19

good

stable

unstable

agglomerate

Si/Al

Zet

a p

ote

nti

al(m

v)

Adv. Funct. Mater. 2008, 18, 952–958

Figure1. Zeta potential vs. PH for zeolite silicalite-1 crystals in aqueous suspension.

2 4 6 8 10 12 14-70

-60

-50

-40

-30

-20

-10

0

10

20

zeta

pot

entia

l(mv)

PH

100% （ 101）

100% （ 101）

100% （ 101）

21.9% （ 051）

56.8% （ 051）

59.0% （ 051）

PDF ： #44-0003ZSM-5:Al2O354SiO2

0mg/mL

2mg/mL

5mg/mL

CPO(101)/(051) = ? Concentration（ mg/mL） CPO

I: intensity of （ 101 ） and （ 051）P: PDF#44-0003S: 0mg/mL 、 2mg/mL 、 5mg/mL

0

2 0.0373

5 0.6288

I:intensity of a peak P:powder reference S:film sample

Characteristic planes and growing axis for MFI type zeolite

Plane(Miller index) Growing axis Reference

(501) a-axis [1]

(051) b-axis [2]

[(200)+(020)] [a+b]-axis [1]

(002) c-axis [2,3,4]

(101) Oblique c-axis [3]

(133) Oblique c-axis [1,2,4]

[1] Microporous and Mesoporous Materials, 1999. 28(1): 185-194[2] Journal of Materials Chemistry, 1998, 8(10): 2217-2221.[3]Microporous and Mesoporous Materials, 2009,123(1-3):113-112[4]Microporous and Mesoporous Materials, 2008, 115(1-2): 113-122.

I:intensity of a peak P:powder reference S:film sample

Fig.1. Typical shape of MFI-typ zeolite crystals

CPO definition

100% （ 101）

100% （ 101）

100% （ 101）

21.9% （ 051）

56.8% （ 051）

59.0% （ 051）

PDF ： #44-0003ZSM-5:Al2O354SiO2

0mg/mL

2mg/mL

5mg/mL

CPO(101)/(051) = ? Concentration（ mg/mL） CPO

I: intensity of （ 101 ） and （ 051）P: PDF#44-0003S: 0mg/mL 、 2mg/mL 、 5mg/mL

0

2 0.0373

5 0.6288

3.

Work plan

Work plan

1Sub-layer

SiO2 、 TiO2

ZrO2 、 Al2O3

2Cationic polymer layer

3Characterization

AFMXRD(pole figure 、 GID)

Zeta potential measurement

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Q&AThanks

for your time！