the synthesis of carbon nanotube on activated carbon prof. dr. sharifah bee abd hamid, imran syakir...
TRANSCRIPT
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