Filamentous growth of carbon through benzene decomposition

Catalytic growth of carbon filaments

▪ Abstract This account reviews the discovery, synthesis, properties, and the latest research advances of carbon nanotubes developed over the past 12 years. Because of their remarkable electronic and mechanical properties, carbon nanotubes are unique and exciting. The field has been developed rapidly, and the number of publications per year is increasing almost exponentially. Various technological applications are likely to arise using nanotubes for fabrication of flat panel displays, gas storage devices, toxic gas sensors, Li+ batteries, robust and lightweight composites, conducting paints, electronic nanodevices, etc. Further experimental and theoretical research is still necessary so that novel technologies will become a reality in the early twenty-first century.

Science and Technology of the Twenty-First Century: Synthesis, Properties, and Applications of Carbon Nanotubes

Carbon nanofibers (sometimes known as carbon filaments) can be produced in a relative large scale by the catalytic decomposition of certain hydrocarbons on small metal particles. The diameter of the nanofibers is governed by that of the catalyst particles responsible for their growth. By careful manipulation of various parameters it is possible to generate carbon nanofibers in assorted conformations and at the same time also control the degree of their crystalline order. This paper is a review of the recent advances made in the development of these nanostructures, with emphasis both on the fundamental aspects surrounding the growth of the material and a discussion of the key factors which enable one to control their chemical and physical properties. Attention is also given to some of the possible applications of the nanostructures which center around the unique blend of properties exhibited by the material.

A review of catalytically grown carbon nanofibers

Deactivation of supported metal catalysts by carbon or coke formation is a problem of serious magnitude in steam reforming, methanation, and other important catalytic processes. Its causes are generally threefold: (1) fouling of the metal surface, (2) blockage of catalysts pores and voids, and/or (3) actual physical disintegration of the catalyst support. Since loss of catalytic activity and physical destruction of the catalyst by carbon deposits can occur rapidly (within hours or days) under unfavorable conditions, understanding and control of these effects are of major technological and economical importance.

Carbon Deposition in Steam Reforming and Methanation

Carbon formation on iron and nickel foils by hydrocarbon pyrolysis—reactions at 700°C

THE existence of fibrous or whisker carbon has been reported in both synthetic studies of graphite1,2 and in naturally occurring graphite3. The synthetic studies involved decomposition of hydrocarbons over metals1 and decomposition of carbon monoxide over iron2 and, particularly in the second of these studies, the occurrence of metal catalyst within the fibre was observed. Furthermore, it has been established1 that the average orientation of the carbon crystallites is with their (0002) orientation parallel to the axis of the fibre. In this communication we describe the use of high resolution electron microscopy to establish the precise relationship between the orientation of the graphite planes and the catalyst particle within the fibre.

B. Grant

Papers

Carbon formation on iron and nickel foils by hydrocarbon pyrolysis—reactions at 700°C

Structure of Fibrous Carbon