Porous and Lamella-like Fe/MgO Catalysts Prepared under Hydrothermal Conditions for High-Yield Synthesis of Double-Walled Carbon Nanotubes
详细信息 查看全文
- 作者：Guoqing Ning ; Yi Liu ; Fei Wei ; Qian Wen ; Guohua Luo
- 刊名：Journal of Physical Chemistry C
- 出版年：2007
- 出版时间：February 8, 2007
- 年：2007
- 卷：111
- 期：5
- 页码：1969 - 1975
- 全文大小：584K
- 年卷期：v.111,no.5(February 8, 2007)
- ISSN：1932-7455
文摘
Hydrothermal treatments are used to reform Fe/MgO catalysts into lamella-like Fe/Mg(OH)2 catalysts, resultingin specific surface areas (SSAs) of more than 100 m2/g. Porous and lamella-like Fe/MgO catalyst can beobtained under the reaction condition. In the materials prepared by CH4 cracking at 850 
C over the hydrotherm-treated catalysts, more than 70% of the nanotubes are found to be double-walled carbon nanotubes (DWNTs).With the catalyst after a 180-220 C hydrothermal treatment, a high purity of DWNTs and a yield up tonearly 3 times that obtained with the original catalyst are achieved at the same reaction condition, ascharacterized by scanning electron microscope, thermogravimetric, and Raman analysis. The porous structurewith high surface area of the hydrotherm-treated catalysts and the good dispersion of Fe species on Mg(OH)2layers are considered as the main factors for the improvement of nanotube yield. Considering the goodhydrophilicity of MgO, hydrothermal treatments are promising in being applied to other metal catalystssupported by hydrophilic oxides.
C over the hydrotherm-treated catalysts, more than 70% of the nanotubes are found to be double-walled carbon nanotubes (DWNTs).With the catalyst after a 180-220 C hydrothermal treatment, a high purity of DWNTs and a yield up tonearly 3 times that obtained with the original catalyst are achieved at the same reaction condition, ascharacterized by scanning electron microscope, thermogravimetric, and Raman analysis. The porous structurewith high surface area of the hydrotherm-treated catalysts and the good dispersion of Fe species on Mg(OH)2layers are considered as the main factors for the improvement of nanotube yield. Considering the goodhydrophilicity of MgO, hydrothermal treatments are promising in being applied to other metal catalystssupported by hydrophilic oxides.