Single-wall carbon nanotube synthesis by CO disproportionation on nickel-incorporatedMCM-41

Abstract

Both Ni- and Co-MCM-41 may be used for the synthesis of single-wall carbon nanotubes(SWNT). We present a comparative investigation that demonstrates that smaller diameterSWNT with a narrower distribution of diameters are produced using Co-MCM-41.Temperature-programmed reduction and x-ray absorption spectroscopy were used tomeasure the reducibility and metal cluster growth of Ni- and Co-MCM-41 in He,H2 and under CO disproportionation reaction. The differences between these two catalysts canbe attributed to a greater reducibility of and a greater CO affinity for Ni relative to Co.