The present invention provides a catalyst precursor and a catalyst suitable for preparing multi-wall carbon nanotubes. The resulting multi-wall carbon nanotubes have a narrow distribution as to the number of walls forming the tubes and a narrow distribution in the range of diameters for the tubes. Additionally, the present invention provides methods for producing multi-wall carbon nanotubes having narrow distributions in the number of walls and diameters. Further, the present invention provides a composition of spent catalyst carrying multi-wall nanotubes having narrow distribution ranges of walls and diameters.
