Effect of acid treatment on the surface of multiwalled carbon nanotubes prepared from Fe-Co supported on CaCO3: Correlation with Fischer-Tropsch catalyst activity

被引：98
作者：
Motchelaho, Myriam A. M. [1 ,2 ]
Xiong, Haifeng [2 ,3 ]
Moyo, Mahluli [1 ,2 ]
Jewell, Linda L. [1 ]
Coville, Neil J. [2 ,3 ]
机构：
[1] Univ Witwatersrand, Sch Chem & Met Engn, ZA-2050 Johannesburg, South Africa
[2] Univ Witwatersrand, Inst Mol Sci, Sch Chem, ZA-2050 Johannesburg, South Africa
[3] Univ Witwatersrand, DST NRF Ctr Excellence Strong Mat, ZA-2050 Johannesburg, South Africa
来源：
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL | 2011年 / 335卷 / 1-2期
基金：
新加坡国家研究基金会; 美国安德鲁·梅隆基金会;
关键词：
Iron-cobalt catalyst; CaCO3; support; Fischer-Tropsch activity; Multiwalled carbon nanotubes; RESONANCE RAMAN; PURIFICATION; OXIDATION; GROWTH; NANOFIBERS; DISPERSION; TEXTURE; ARRAYS; OXIDES; XPS;
D O I：
10.1016/j.molcata.2010.11.033
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：
Carbon nanotubes (CNTs) were obtained through the catalytic decomposition of C2H2 at 700 degrees C over Fe-Co supported on CaCO3 and confirmed by TEM to be composed of multiwalled carbon nanotubes. The CNTs were refluxed in 30% and 55% HNO3 for 2 and 6 h in order to remove impurities and introduce oxygen surface groups. This rendered the CNTs less hydrophobic. The morphology, microstructure, surface area, pore volume and surface chemical properties of the acid treated CNTs were analysed by TEM, N-2 physisorption, TGA, FTIR, Raman spectroscopy and zeta potential measurements. The surface roughness, together with the degree of surface functionalization correlated with the harshness (time and concentration) of the acid treatment. Fischer-Tropsch synthesis studies (275 degrees C, 8 bar) were performed on all the Fe loaded (10%)/CNT catalysts and activity studies revealed that the more severe the acid treatment the higher the activity of the catalysts. (C) 2010 Elsevier B.V. All rights reserved.
引用
收藏
页码：189 / 198
页数：10
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