Support effect on carbon nanotube growth by methane chemical vapor deposition on cobalt catalysts

Journal of the Brazilian Chemical Society

Hugo A. Oliveira²  Dante F. Franceschini¹  Fabio B. Passos² 

[1] ,Universidade Federal Fluminense Departamento de Engenharia Química e Petróleo Niterói RJ ,Brazil

关键词: carbon nanotubes;    cobalt;    catalyst support;    chemical vapor deposition;    methane;   

DOI  :  10.1590/S0103-50532012000500012

来源: SciELO

【 摘 要 】

The influence of the support on carbon nanotube production by methane chemical vapor deposition (CVD) on cobalt catalysts was investigated. N2 physisorption, X-ray diffractometry (XRD), temperature programmed reduction (TPR) and H2 and CO chemisorption techniques were used to characterize the structure of cobalt catalysts supported on different metal oxides (Al2O3, SiO2, Nb2O5 and TiO2). Raman spectroscopy, temperature programmed oxidation (TPO) and scanning electron microscopy (SEM) were used for the characterization and quantification of produced carbon species. On carbon nanotube growth, the catalyst produced three main carbon species: amorphous carbon, single walled carbon nanotubes (SWNT) and multi walled carbon nanotubes (MWNT). The characterization techniques showed that the catalyst selectivity to each kind of nanotube depended on the cobalt particle size distribution, which was influenced by the textural properties of the support. Co/TiO2 showed the highest selectivity towards single wall nanotube formation. This high selectivity results from the narrow size distribution of cobalt particles on TiO2.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License