Growth of carbon nanotubes and microfibers over stainless steel mesh by cracking of methane

The ${La}_{2}{NiO}_{4}$ film was synthesized on the 304 stainless steel (SS) mesh. The hydrogen reduction of La2NiO4 generated homogeneous nanocatalyst particles (probably ${Ni}/{La}_2{O}_{3}$) over which methane was cracked, producing carbon notubes/microfibers and hydrogen. The carbon nanotubes/microfibers were strongly bonded to the SS mesh. It was observed that the methane conversion always reached its maximum at the cracking temperature of 750 °C regardless of its concentration varying from 5% to 100%. The cracking of 5% methane diluted in nitrogen generated multiwalled carbon nanotubes while the cracking of 10–100% methane resulted in the formation of carbon solid microfibers together with globular carbon particles. Higher concentration of methane created thicker carbon fibers and a 30% concentration of methane resulted in the highest deposits of carbon on the mesh. After a compressed air blow and ultrasonic treatment, the carbon deposits were still strongly adhered to the mesh. As a result of the carbon tubes/fibers coverage, the specific surface area of the SS mesh was enhanced significantly from 0.03 ${m}^{2}/g$ to 21–45 ${m}^{2}/g$. XRD, HRTEM and Raman studies confirmed that the carbon products were of graphitic structure. Such advanced mesh material would have great application potential in industrial catalysis and other areas.