TJU

纪镁铃，刘国柱，王莅 *，张香文

天津大学 化工学院 化学工艺

b-b-轴取向轴取向 HZSM-5HZSM-5分子筛涂层的合成分子筛涂层的合成及其催化裂解正十二烷性能研究及其催化裂解正十二烷性能研究

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* Email: wlytj @tju.edu.cn

Catalysts

Adsorbents

Ion exchangers

b-轴取向 HZSM-5 催化涂层

Chemical sensors

Corrosion protection coatings

Separation membranes

Zeolite film for catalysis

······

Excellent

Our workOur work

bb-oriented HZSM-5 -oriented HZSM-5 catalytic coaitngscatalytic coaitngs

Preferred-oriented MFI membranes

Low-k dielectrics

Zeolites Zeolite membranes/coatings

1

anisotropic pore structure

Faster diffusion pathway

OH OH OHOHOH OH OHOH

1. dip coating with TiO2 sols

2. in-situ growth

Rough surface

TiO2 layer

b-oriented ZSM-5 zeolite coating

b-轴取向 HZSM-5 催化涂层（单层）

Meiling Ji, Guozhu Liu, Chen Chen, Li Wang, Xiangwen Zhang, Micropor Mesopor Mater, 2012, 155:117-.123

Stainless steel tube

2

Positive effects of TiO2 interlayer:

provide a smooth surface provide high density of Ti-OH groupspromote the attraction forces between the substrate and the zeolite crystals

10 20 30 40 50

stainless steel

0100

080

06004

0

In

tens

ity

202

0

b-oriented HZSM-5 coating on SST

Fig.1 SEM images of b-HZSM-5 monolayer. Fig.2 XRD pattern of b-HZSM-5 monolayer.

3 µm

10 µm

3

b-轴取向 HZSM-5 催化涂层（单层）

怎么样得到 b-取向 HZSM-5 涂层（多层） ?

10 20 30 40 50

171819 262728 353637 44 46

stainless steel

Inte

nsit

y

2

200/

020

400

040

060

600

080

800

0100

1000

Method 1:Direct secondary growth

Fig.3 SEM images of a&b-HZSM-5 bi-layer. Fig.4 XRD pattern of a&b-HZSM-5 bi-layer.

10 µm

3 µm3 µm

10 µm

4

Solution 2:With TiO2 modification

5 μm

1 μmTiOTiO22

ZSM-5ZSM-5

10 20 30 40 50

171819 262728 353637 44 46

stainless steel

Inte

nsity

2

020

040

060

080

0100

1000

Fig.5 SEM images of b@b-HZSM-5 bi-layer. Fig.6 XRD pattern of b@b-HZSM-5 bi-layer.

TiO2

5

怎么样得到 b-取向 HZSM-5 涂层（多层） ?

Samples Si/Al ratioZeolite thickness

(nm)

Mass loading

(mg·cm-2)

b-HZSM-5 12.8 450 0.17±0.04

b&b-HZSM-5 13.0 800 0.31±0.04

a&b-HZSM-5 13.4 800 0.46 ±0.11

TiO2

Table 1.Si/Al ratio, zeolite thickness and mass loading of the zeolite film.

分子筛催化涂层表征

6

Catalytic cracking of n-dodecane over prepared oriented HZSM-5 films as a function of stream time. (pressure=4 MPa, LHSV=637 h-1, temperature=550 ºC).

7

0 10 20 30 400

5

10

15

20

25

30

Con

vers

ion

(%)

Time on stream / min

b&b-HZSM-5 b-HZSM-5 a&b-HZSM-5

≈ 45% improvement

分子筛催化涂层反应活性— 正十二烷催化裂解反应反应装置示意图 conversion

N2

back-pressure regulator

Zeolite layer

分子筛催化涂层渗透性能

渗透装置示意图

PSS b-HZSM-5 b&b-HZSM-5 a&b-HZSM-50.0

1.0x10-5

2.0x10-5

3.0x10-5

4.0x10-5

5.0x10-5

6.0x10-5

7.0x10-5

8.0x10-5

Per

mea

tion

(mol

/m2 S

Pa)

Permeance of N2 gas through the porous stainless steel support and the zeolite coatings.

permeation

8

100 200 300 400 500 600 700 800

Rel

ativ

e ca

rbon

sig

nal

Temperature /C

TPO

0 10 20 30 40 50

0

20

40

60

80

100

Estimated depth (m)

b&b-HZSM-5 b-HZSM-5 a&b-HZSM-5

Ato

mic

Con

cent

ratio

n of

C (

%)

Sputter time (min)

XPS depth profile

0.0 0.3 0.6 0.9 1.2 1.5

9

a Estimated from the XPS profiles;

b Calculated from the intergral areas of the TPO

profiles.

The total amount of coke and the penetration depth of the carbonaceous deposit.

分子筛催化涂层积碳分析

SamplesThiele modulus

ϕ

Effectiveness factor

η

Effective diffusion coefficient

DA (m2/s)

b- 0.90 0.80 1.007×10-12

b&b- 1.64 0.57 1.002×10-12

a&b- 4.24 0.24 2.178×10-13

有效扩散因子 η的估算

Stainless steel

L

reactant

Z dZ

Zeolite coating

10

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n-dodecane coken-dodecane coke

b-HZSM-5 b&b-HZSM-5a&b-HZSM-5

讨论：分子筛取向对反应活性的影响

11

小结

提出一种合成 b- 轴 HZSM-5 催化涂层（多层）的制备方法。

TiO2 中间层是合成 b- 轴 HZSM-5 催化涂层（多层）的关键之一。

b-轴取向 ZSM-5孔道有利于提高涂层扩散性能和催化反应活性。

12

TJU

纪镁铃，刘国柱，王莅 *，张香文

天津大学 化工学院 化学工艺

* Email: wlytj @tju.edu.cn