Process for producing single wall nanotubes using unsupported metal catalysts and single wall nanotubes produced according to this method

• US 7,074,379 B2
• Filed: 04/20/2001
• Issued: 07/11/2006
• Est. Priority Date: 08/04/1997
• Status: Expired due to Fees

• Current Assignee: Hyperion Catalysis International Incorporated
• Original Assignee: Hyperion Catalysis International Incorporated
• Inventors: Moy, David, Chishti, Asif
• Primary Examiner(s): HENDRICKSON, STUART L
• Application Number:
  US09/839,932
• Publication Number:
  US 20030190277A1
• Time in Patent Office: 1,908 Days
• Field of Search: 423/447.3, 977/167
• US Class Current: 423/447.3
• CPC Class Codes: B01J 19/121 Coherent waves, e.g. laser beams lasers per se H01S3/00
• CPC Class Codes: B01J 19/26 Nozzle-type reactors, i.e. the distribution of the initial reactants within the reactor is effected by their introduction or injection through nozzles
• CPC Class Codes: B01J 2219/0875 Gas
• CPC Class Codes: B01J 3/04 Pressure vessels, e.g. autoclaves
• CPC Class Codes: B01J 3/042 in the form of a tube
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C01B 2202/02 Single-walled nanotubes
• CPC Class Codes: C01B 32/162 characterised by catalysts
• CPC Class Codes: D01F 9/127 by thermal decomposition of hydrocarbon gases or vapours or other carbon-containing compounds in the form of gas or vapour, e.g. carbon monoxide, alcohols
• CPC Class Codes: D01F 9/1278 Carbon monoxide
• CPC Class Codes: Y10S 977/742 Carbon nanotubes, CNTs
• CPC Class Codes: Y10S 977/75 Single-walled
• CPC Class Codes: Y10S 977/842 for carbon nanotubes or fullerenes
• CPC Class Codes: Y10S 977/843 Gas phase catalytic growth, i.e. chemical vapor deposition
• CPC Class Codes: Y10S 977/896 Chemical synthesis, e.g. chemical bonding or breaking

Abstract

A process for producing hollow, single-walled carbon nanotubes by catalytic decomposition of one or more gaseous carbon compounds by first forming a gas phase mixture carbon feed stock gas comprising one or more gaseous carbon compounds, each having one to six carbon atoms and only H, O, N, S or el as hetero atoms, optionally admixed with hydrogen, and a gas phase metal containing compound which is unstable under reaction conditions for said decomposition, and which forms a metal containing catalyst which acts as a decomposition catalyst under reaction conditions; and then conducting said decomposition reaction under decomposition reaction conditions, thereby producing said nanotubes.

Claims

1. A method for producing single wall carbon nanotube products comprising the steps of:

providing a CO gas stream;

providing a gaseous catalyst precursor stream comprising a gaseous catalyst precursor that is capable of supplying atoms of a transition metal selected from the group consisting of Fe, Co, Mn, Ni, and Mo, said gaseous catalyst precursor stream being provided at a temperature below the decomposition temperature of said catalyst precursor;

heating said CO gas stream to a temperature that is (i) above the decomposition temperature of said catalyst precursor and (ii) above the CO decomposition initiation temperature, to form a heated CO gas stream; and

mixing said heated CO gas stream with said gaseous catalyst precursor stream to rapidly heat said catalyst precursor to a temperature that is (i) above the decomposition temperature of said catalyst precursor, (ii) sufficient to promote the rapid formation of catalyst metal atom clusters and (iii) sufficient to promote the initiation and growth of single wall nanotube by the CO decomposition reaction, to form a suspension of single wall carbon nanotube products in the resulting gaseous stream.

2. The method of claim 1 further comprising the step of separately recovering said single wall carbon nanotube products from said resulting gaseous stream.

3. The method of claim 1 wherein said catalyst precursors is a metal-containing compound of a metal selected from the groups consisting of molybdenum, iron, nickel, cobalt, and manganese.

4. The method of claim 3 wherein said metal-containing compound is a metal carbonyl.

5. The method of claim 4 wherein said metal carbonyl is selected from the group consisting of Fe(CO)₅ or Mo(CO)₆ and mixture thereof.

6. The method of claim 1 wherein said CO gas stream is provided at a pressure of about 0 p.s.i.g. to about 100 p.s.i.g.

7. The method of claim 1 wherein said gaseous catalyst precursor stream is supplied in a CO gas stream.

8. The method of claim 7 wherein the partial pressure of said catalyst precursor in said high pressure CO gas stream is from about 0.25 Torr to about 100 Torr.

9. The method of claim 1 wherein said gaseous catalyst precursor stream is supplied at a temperature in the range of from about 70°

C. to about 80°

C.

10. The method of claim 1 wherein said CO gas stream is heated to a temperature in the range of from about 400°

C. to about 1300°

C.

11. The method of claim 1 wherein said catalyst precursor is heated to a temperature in the range of from about 400°

C. to about 1300°

C.

12. The method of claim 2 wherein said single wall carbon nanotube products are substantially free of solid contaminants other than catalyst atoms.

13. The method of claim 2 wherein said single wall carbon nanotube products have a tube diameter about 1 nm.

14. The method of claim 1 further comprising the step of controlling the diameter of the single wall carbon nanotube products recovered by controlling the catalyst cluster size at the time the growth reaction is initiated.

15. The method of claim 14 wherein said catalyst cluster size is controlled by controlling the temperature or controlling the vapor pressure of the gaseous catalyst precursor.