Catalytic synthesis of carbon nanotubes over Co, Fe and Ni containing conventional and solâ gel silicaâ aluminas
Kukovecz, à .; Kónya, Z.; Nagaraju, N.; Willems, I.; Tamási, A.; Fonseca, A.; Nagy, J. B.; Kiricsi, I.; Kukovecz à .; Uni.italv;ersity of Szeged, Department of Applied and En.italv;ironmental Chemistry; Kónya Z.; Uni.italv;ersity of Szeged, Department of Applied and En.italv;ironmental Chemistry; Facultés Uni.italv;ersitaires Notre-Dame de la Paix, Laboratoire de R.M.N., Département de Chimie; Nagaraju N.; Facultés Uni.italv;ersitaires Notre-Dame de la Paix, Laboratoire de R.M.N., Département de Chimie; St. Joseph's College, Department of Chemistry; Willems I.; Facultés Uni.italv;ersitaires Notre-Dame de la Paix, Laboratoire de R.M.N., Département de Chimie; Tamási A.; Uni.italv;ersity of Szeged, Department of Applied and En.italv;ironmental Chemistry; Fonseca A.; Facultés Uni.italv;ersitaires Notre-Dame de la Paix, Laboratoire de R.M.N., Département de Chimie; Nagy J. B.; Facultés Uni.italv;ersitaires Notre-Dame de la Paix, Laboratoire de R.M.N., Département de Chimie; Kiricsi I.; Uni.italv;ersity of Szeged, Department of Applied and En.italv;ironmental Chemistry
Журнал:
Physical Chemistry Chemical Physics
Дата:
2000
Аннотация:
An attempt has been made to synthesise multiwalled carbon nanotubes using cobalt, iron and nickel supported on different types of silicaâ aluminas to investigate the rules governing their nanotube producing activity. Acetylene was used as the source of carbon. Decomposition of acetylene has been carried out at atmospheric pressure. The effect of reaction temperature in the 770â 970 K range and the flow rate of the hydrocarbon has been investigated. The catalysts were analysed by XRD, UVâ VIS, surface area and porosity measurements. Formation of carbon nanotubes was followed by electron microscopy. The amount of deposited carbon increased with increasing reaction temperature and the flow rate of acetylene, but decreased with increasing concentration of alumina in the catalyst support. Each catalyst showed high production of carbon nanotubes at 970 K; however, they were inactive at 770 K. The yield of tube formation was very low at 870 K. The high-resolution transmission electron microscopic (HREM) analysis showed that the outer diameter of the tubes generated varied from 8 to 40 nm, the tubes were multiwalled, and the number of the layers was between 8 and 30. Solâ gel derived samples were also found to be working catalysts, indicating the existence of an optimal metal particle size.
548.6Кб