Long and Narrow Diameter Carbon Nanotubes and Catalysts for Producing Same
A bundle of carbon nanotubes (CNT), comprising a plurality of CNT with lengths of at least about 7 microns, wherein the bundle has a diameter of less than about 12 nm.
1 . A carbon nanotube (CNT) bundle, comprising:
a catalyst construction comprising:
a metal oxide support; and
a nanocluster of active metal nanoparticles supported by the metal oxide support; and
a group of CNT comprising a plurality of separate, closely spaced CNT grown on the active metal nanoparticles;
wherein a length of the bundle is at least 7 microns, and the bundle has a diameter of less than 12 nanometers.
2 . The CNT bundle of claim 1 , wherein at least some of the CNT are straight.
3 . The CNT bundle of claim 1 , wherein the active metal nanoparticles comprise at least one of cobalt, molybdenum, and nickel.
4 . The CNT bundle of claim 1 , wherein most of the CNT have diameters of less than one nanometer.
5 . The CNT bundle of claim 1 , wherein at least about 90% of the CNT have a diameter of less than one nanometer.
6 . The CNT bundle of claim 1 , wherein the nanoparticles have sizes of about 0.6 to 0.9 nanometers.
7 . The CNT bundle of claim 1 , wherein the bundle diameter is from 3 to 12 nanometers.
8 . The CNT bundle of claim 1 , wherein the catalyst construction comprises about the same weight percent of cobalt and molybdenum.
9 . The CNT bundle of claim 1 , wherein the catalyst construction comprises a molybdenum to cobalt weight ratio of less than 1.
10 . The CNT bundle of claim 1 , wherein the catalyst construction comprises about 0.1 weight percent cobalt and a molybdenum to cobalt weight ratio of about 0.5.
11 . The CNT bundle of claim 1 , wherein the nanocluster has a size in the range of from about 0.6 nanometers to about 1.0 nanometers.
12 . The CNT bundle of claim 1 with a length to diameter (L/D) aspect ratio of at least about 1,000.
13 . The CNT bundle of claim 1 , wherein the CNT purity is at least about 95%.
14 . The CNT bundle of claim 1 , wherein the bundle has a length from 8-16 microns.
15 . The CNT bundle of claim 1 , wherein the active metal nanoparticles comprise cobalt and molybdenum.
16 . The CNT bundle of claim 15 , wherein the active metal nanoparticles comprise less than 0.1% cobalt and less than 0.1% molybdenum.
17 . The CNT bundle of claim 15 , wherein the active metal nanoparticles comprise a molybdenum to cobalt atomic ratio of less than one.
18 . The CNT bundle of claim 17 , wherein the active metal nanoparticles comprise a molybdenum to cobalt atomic ratio of at least 0.5.
19 . The CNT bundle of claim 1 , wherein the metal oxide support surface comprises silica.
20 . The CNT bundle of claim 19 , wherein the silica comprises colloidal silica particles.
21 . The CNT bundle of claim 1 , wherein the active metal makes up less than 0.2 weight % of the catalyst construction.
22 . The CNT bundle of claim 1 , wherein at least some of the CNT are single wall CNT (SWCNT).