The Synthesis of Carbon Nanotube

on Activated Carbon

Prof. Dr. Sharifah Bee Abd Hamid, Imran Syakir Mohamad, Norli Abdullah, Ali Rinaldi

Combinatorial Technology & Catalysis Research Centre (COMBICAT),

Institute of Postgraduate Studies, University of Malaya, 50603 Kuala Lumpur, Malaysia.

Introduction

• Why Activated Carbon?– Cheap and abundant resources– High thermal stability

• Why Carbon-Carbon composites?– A new trend in catalysis; metal-free catalyst by exploiting the

broad chemical functionality of carbon.– Carbon nanotube exhibit excellent activity and long term stability– However due to the compaction of CNTs bundle, it gives severe

technical difficulties– Thus immobilizing CNTs on carbon supports (to avoid chemical

discontunities) is a promissing solution

Experimental

Washing(removes

impurities; eg: Al, Si, Fe, K)

Washing(removes

impurities; eg: Al, Si, Fe, K)

Nanocarbon Growth

(Thermal-CVD)

Nanocarbon Growth

(Thermal-CVD)

CharacterizationCharacterization

• Calcination: 250oC, 5%O2 in N2• Reduction : 300oC, 5%H2 in N2• Growth : 550oC, 600oC, 700oC,

850oC

• Calcination: 250oC, 5%O2 in N2• Reduction : 300oC, 5%H2 in N2• Growth : 550oC, 600oC, 700oC,

850oC

• Compositional analysis (XRD)

• Morphology/Structure analysis (SEM, HRTEM)

• Texture/Surface Area analysis (BET)

• Thermal Gravimetric Analysis

• Compositional analysis (XRD)

• Morphology/Structure analysis (SEM, HRTEM)

• Texture/Surface Area analysis (BET)

• Thermal Gravimetric Analysis

Substrate (AC)

Substrate (AC)

ImpregnationImpregnation CNTCNT

Schematic Concept

Ni particles

Ni/AC catalystCarbon from nature source

Impregnation reduction

Activation

Activated carbon

CVD methodC2H4 → C + H2

CNFs/AC composite

Palm kernel shell

Hierarchically structured carbon

One chemical elementStrong interaction

Super adsorption properties

Image

Activated carbon support

Growth inside pore and, on the surface of AC support

2µm

200nm

200nm500nm

Result & Discussion• Ni particle on activated carbon support

• The reduced-FFT d spacings measurements indicate the sample is fully reduced to Ni0

Activated carbon support

Ni catalyst

Result & Discussion• Microstructure

550oC 600oC

700oC 850oC

by increasing the temperature growth;

• Catalyst transform from solid to liquid-like behavior

• different carbon diffusion in the catalyst

• catalyst particle size also increase

550 600 650 700 750 800 850

5

10

15

20

25

30

30

11

8

Ave

rag

e d

iam

eter

, n

m

Temperature oC

6

Result & Discussion• Textural properties

0.0 0.2 0.4 0.6 0.8 1.050

100

150

200

250

300

350

400

450

500

550

600

650

CC

/g

P/Po

AC NC1-550 NC1-600 NC1-700 NC1-850

CNF

CNT

Hysterisis CNT

Hysterisis CNF

Result & Discussion• Microstructure of the Carbon

0 10 20 30 40 50 60 70 80

Ni [1

11

]

Ni [1

01

]G

rap

hit

e [

11

1]

CNF 850oC

CNF 700oC

CNF 600oC

CNF 550oC

Inte

ns

ity

2 theta

AC

Gra

ph

ite

[0

02

]

• Increasing temperature, better graphitization

• poor graphitic arrangement

Result & Discussion

• weak metal-support interactions yield tip-growth

mode

• Growth mode in the CNT/AC composite

• strong metal-support interactions yield base-

growth mode

• the activated carbon is chemically non uniform

Result & Discussion• Growth in fluidized reactor

Advantages;• useful for bulk

application

Static furnace

Rotating furnace

Conclusion• Carbon nanotube has been successfully

synthesized by Ni catalyst supported on activated carbon.

• The CNF/CNT composition and morphology can be controlled by varying the temperature and fluidization of the catalyst support system during growth.

Carbon Team