硫对浮动催化法制备碳纳米管的影响

为了解浮动催化裂解工艺制备碳纳米管中硫元素对产物形态的影响规律 ,采用透射电子显微镜 (TEM)对产物进行了观察分析 ,结果表明过高或过低的硫含量都不能得到理想的碳纳米管。对碳管端部的催化剂颗粒进行了成分分析 ,并通过热力学和动力学分析 ,认为硫元素不是通过液化铁颗粒起催化活化的作用 ,而是由于硫原子吸附在铁颗粒的表面 ,部分地覆盖了铁颗粒 ,使碳氢分子的吸附和碳纳米管的析出能够连续地进行 ,从而起到催化活化的作用

Effect of sulfur on the growth of carbon nanotubes by the floating catalyst method

Sulfur added to the starting materials is a crucial factor for Fe catalysts to grow carbon nanotubes by the floating catalyst method. This work shows that only the optimal amount of sulfur additive (thiophene) can produce filamentous carbon product. The effect of sulfur on the catalytic activity was then discussed. The sulfur composition in the iron catalyst particles is too low to liquefy them. Thermodynamic and kinetic analyses indicate that liquefying the iron particles is not the main reason for the effect of sulfur, but the geometric effect of the sulfur atoms on the outer layers of the catalyst particles increases the catalytic activity, and carbon nanotubes can grow continuously from them.