Production of high quality single-walled carbon nanotubes in a nano-agglomerated fluidized bed reactor
- PDF / 1,619,807 Bytes
- 6 Pages / 595 x 842 pts (A4) Page_size
- 89 Downloads / 186 Views
D9.4.1
Production of high quality single-walled carbon nanotubes in a nano-agglomerated fluidized bed reactor Qixiang Wang, Guoqing Ning, Fei Wei, and Guohua Luo Department of Chemical Engineering, Tsinghua University, Beijing 100084, China. E-mail: [email protected], FAX: 86-10-62772051, Tel: 86-10-62796109
ABSTRACTS Single-walled carbon nanotubes (SWNTs) have attracted much attention due to their unique structural, mechanical, chemical, and electrical properties. Catalytic chemical vapor deposition (CCVD) through decomposition of hydrocarbons is one of the most challenging synthesis methods to produce SWNTs in large scale. In this paper, high quality SWNTs prepared in a nano-agglomerated fluidized bed reactor (NAFBR) was reported. The reactor is a vertical quartz tube with the inner diameter of about 50 mm. Catalysts nanoparticles used for the production of SWNTs were prepared with Fe metal nanoparticles carried on the surface of MgO. About 150g catalysts powders were loaded on the gas distribution grid. The reaction temperature was controlled at not less than 1123 K. The carrier gas of argon was used to maintain turbulent fluidization of the catalysts powders in FBR. The hydrogen gas was used to reduce the catalysts and to synergize the growth of SWNTs with methane. The powder products were spherical agglomerates of SWNTs bundles tangling with the catalysts particles. By optimizing the process parameters of CCVD, the products of SWNTs with the diameter about 0.9 ~ 1.8 nm were prepared, without any multi-walled carbon nanotubes (MWNTs) or amorphous carbon. The microstructure of SWNTs products were characterized by the methods of high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), Raman spectra, etc. The NAFBR is a commercially viable (effective and continuous production at a low cost) process for the production of SWNTs.
INTRODUCTION Single walled carbon nanotubes (SWNTs) are molecular wires that are of fundamental scientific interests and have shown novel mechanical, electrical, chemical properties for future generations of nanodevices, such as the nanoelectromechanical systems (NEMS) [1-4]. Chemical vapor deposition of carbon related materials on catalytic particles, comparing to carbon arc-discharge and laser ablation of carbon, is the most scalable and customizable SWNTs’ production process [5-8]. Production of fine particles in a fluidized bed reactor is a challenge task in the field of powder technology research [9]. The SWNTs are unique structures with diameter of 0.4~5 nm, the length about 0.1~100 mm, the axial ratio more than several thousands, which is difficult to be operated in powder technology [10,11]. The CCVD process coupled with suitable reactor technologies successfully led to the mass production of MWNTs with controllable microstructure in a nano agglomerates fluidized bed reactor (NAFBR) in industrial scale [11-14]. In this study, a commercial and reliable route to the mass production of SWNTs was
D9.4.2
successfully realized in a NAFBR.
Data Loading...
