Single-walled carbon nanotube catalyst

Abstract

An activated catalyst capable of selectively growing single-walled carbon nanotubes when reacted with carbonaceous gas is provided. The activated catalyst is formed by reducing a catalyst that comprises a complex oxide. The complex oxide may be of formula A x B y O z , wherein x/y≦2 and z/y≦4, A being a Group VIII element and B being an element such that an oxide of element B is not reducible in the presence of hydrogen at a temperature less than or equal to about 900° C. Methods of making, uses for and carbon fibril-containing product made with these activated catalysts are also provided.

1 . A method of making single walled carbon nanotubes comprising:
 providing a composition comprising a complex oxide having a formula A x B y O z ,
 wherein 
 x/y≦2 and z/y≦4, 
 A is a Group VIII element; 
 B is an element different from A and is an element whose simple oxide, in which B is at the same valence state as in the complex oxide, is not reducible in the presence of hydrogen gas at a temperature less than about 900° C.; 
   reducing said composition to form an activated catalyst;   contacting a carbonaceous gas with said activated catalyst under suitable conditions for growing single walled carbon nanotubes, said suitable conditions including pressure greater than about 1 atmosphere and less than about 10 atmospheres and temperature greater than about 400° C. and less than about 950° C.; and   growing carbon nanotubes on said activated catalyst, said carbon nanotubes comprising single walled carbon nanotubes.   
     
     
         2 . The method of  claim 1 , wherein said A is cobalt, iron or nickel. 
     
     
         3 . The method of  claim 1 , wherein said B is aluminum, lanthanum, magnesium, silicon, titanium, zinc, zirconium, yttrium, calcium, strontium or barium. 
     
     
         4 . The method of  claim 1 , wherein said carbon nanotubes comprise at least 50% single walled carbon nanotubes. 
     
     
         5 . The method of  claim 1 , wherein said B is magnesium. 
     
     
         6 . The method of  claim 5 , wherein said A is cobalt. 
     
     
         7 . The method of  claim 6 , wherein the complex oxide is Co 2 MgO 4 . 
     
     
         8 . The method of  claim 1 , wherein said reducing step and said contacting step occur contemporaneously. 
     
     
         9 . A method of making single walled carbon nanotubes comprising:
 contacting a carbonaceous gas with an activated catalyst in a reaction zone at suitable conditions for growing single walled carbon nanotubes, said suitable conditions including a pressure greater than about 1 atmosphere and less than about 10 atmospheres and temperature greater than about 400° C. and less than about 950° C.,   said activated catalyst comprising a reduced form of a complex oxide, said complex oxide having a formula A x B y O z , wherein
 x/y≦2 and z/y≦4, 
 A is a Group VIII element; 
 B is an element different from A and is an element whose simple oxide, in which B is at the same valence state as in the complex oxide, is not reducible in the presence of hydrogen gas at a temperature less than about 900° C.; and 
   growing carbon nanotubes on said activated catalyst, said carbon nanotubes comprising single walled carbon nanotubes.   
     
     
         10 . The method of  claim 9 , wherein said A is cobalt, iron or nickel. 
     
     
         11 . The method of  claim 9 , wherein the B is aluminum, lanthanum, magnesium, silicon, titanium, zinc, zirconium, yttrium, calcium, strontium or barium. 
     
     
         12 . The method of  claim 9 , said carbon nanotubes comprise at least 50% single walled carbon nanotubes. 
     
     
         13 . The method of  claim 9 , wherein said B is magnesium. 
     
     
         14 . The method of  claim 13 , wherein said A is cobalt. 
     
     
         15 . The method of  claim 14 , wherein the complex oxide is Co 2 MgO 4 . 
     
     
         16 - 19 . (canceled)