The effect of phase separation in Fe/Mg/Al/O catalysts on the synthesis of DWCNTs from methane

被引：42

作者：

Zhang, Qiang ^{[1
]}

Qian, Weizhong ^{[1
]}

Wen, Qian ^{[1
]}

Liu, Yi ^{[1
]}

Wang, Dezheng ^{[1
]}

Wei, Fei ^{[1
]}

机构：

[1] Tsing Hua Univ, Dept Chem Engn, Key Lab Green Chem React Engn & Technol, Beijing 100084, Peoples R China

来源：

CARBON | 2007年 / 45卷 / 08期

基金：

中国国家自然科学基金;

关键词：

D O I：

10.1016/j.carbon.2007.03.045

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Double-walled carbon nanotubes (DWCNTs) were prepared by methane decomposition on Fe/Al/Mg/O catalysts with a fixed iron loading of 1.5%. Increasing Al/Mg ratio in the catalyst resulted in the formation of a new MgAl2O4 phase, which was characterized by XRD. The size of the MgO crystallites in the support was decreased, due to the phase separation, from 35 run to 20 nm in the Al/Mg ratio range of 0:1-4:1. At an Al/Mg ratio of 1:200, this effect prevented the sintering of iron on the MgO support and resulted in the synthesis of high-purity DWCNTs in high-yield. Very high-Al/Mg ratio induced the formation of the MgAl2O4 phase, which became another catalyst support material. This had a negative effect on the synthesis of DWCNTs due to its acidity and hardness. Simultaneously maintaining MgO as the dominant catalyst support and decreasing its particle size by the phase separation effect are important for good metal dispersion and, consequently, the yield and purity of DWCNTs. (c) 2007 Elsevier Ltd. All rights reserved.

引用

页码：1645 / 1650

页数：6

共 27 条

[1] Roles of metal-support interaction in growth of single- and double-walled carbon nanotubes studied with diameter-controlled iron particles supported on MgO [J].