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, 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) Characterization Calcination: 250 o C, 5%O 2 in N2 Reduction : 300 o C, 5%H 2 in N2 Growth : 550 o C, 600 o C, 700 o C, 850 o C Calcination: 250 o C, 5%O 2 in N2 Reduction : 300 o C, 5%H 2 in N2 Growth : 550 o C, 600 o C, 700 o C, 850 o C 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) Impregnation CNT

Schematic Concept Ni particles Ni/AC catalyst Carbon from nature source Impregnation reduction Activation Activated carbon CVD method C 2 H 4 → C + H 2 CNFs/AC composite Palm kernel shell Hierarchically structured carbon One chemical element Strong interaction Super adsorption properties

Image Activated carbon support Growth inside pore and, on the surface of AC support 2µm 200nm 500nm

Result & Discussion Ni particle on activated carbon support The reduced-FFT d spacings measurements indicate the sample is fully reduced to Ni 0 Activated carbon support Ni catalyst

Result & Discussion Microstructure 550 o C600 o C 700 o C 850 o C by increasing the temperature growth; Catalyst transform from solid to liquid- like behavior different carbon diffusion in the catalyst catalyst particle size also increase

Result & Discussion Textural properties CNF CNT Hysterisis CNT Hysterisis CNF

Result & Discussion Microstructure of the Carbon 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