Mesoporous carbon composite containing carbon nanotube

Abstract

Provided are a CNT-mesoporous silica composite, a CNT-mesoporous carbon composite, a supported catalyst using the CNT-mesoporous carbon composite as a support, and a fuel cell using the supported catalyst as the anode, cathode, or both anode and cathode. The CNT-mesoporous carbon composite is prepared using the CNT-mesoporous silica composite. The CNT-mesoporous carbon composite has a high electrical conductivity due to the CNTs contained therein, and thus, when the CNT-mesoporous carbon composite is used in an electrode of a fuel cell, the fuel cell has a remarkably improved performance relative to the conventional catalyst support which does not contain CNTs.

1 . A carbon nanotube (CNT)-mesoporous silica composite comprising CNTs and mesoporous silica. 
     
     
         2 . The CNT-mesoporous silica composite of  claim 1 , wherein the concentration of the CNTs is about 0.3% to about 10% by weight of the CNT-mesoporous silica composite. 
     
     
         3 . A method of preparing a CNT-mesoporous silica composite, comprising the steps of:
 dissolving a surfactant in water and adding CNTs to form a mixture;   adding a silica source and water to said mixture to form a solution;   adding an acid to said solution to adjust the pH of said solution;   stirring said solution;   heating said solution to obtain powders;   separating said powders from the solution;   washing said powders at least one time; and   calcining said powders.   
     
     
         4 . The method of  claim 3 , wherein the concentration of said surfactant is about 1,000 to about 100,000 parts by weight based on 100 parts by weight of said CNTs. 
     
     
         5 . The method of  claim 3 , wherein the concentration of said silica source is about 3,000 to about 300,000 parts by weight based on 100 parts by weight of said CNTs. 
     
     
         6 . The method of  claim 3 , wherein the silica source consists of tetraethoxysilane, tetramethoxysilane, or sodium silicate. 
     
     
         7 . The method of  claim 3 , wherein said pH is about −0.7 to about −7.0 and said acid is nitric acid, hydrochloric acid, sulfuric acid, or acetic acid. 
     
     
         8 . The method of  claim 3 , wherein said heating is performed at about 80° C. to about 160° C. 
     
     
         9 . The method of  claim 3 , wherein said heating is performed for about 30 minutes to about 120 minutes. 
     
     
         10 . The method of  claim 3 , wherein said separating is performed by filtration or centrifuging. 
     
     
         11 . The method of  claim 3 , wherein said calcining is performed at about 300° C. to about 550° C. 
     
     
         12 . The method of  claim 3 , wherein said calcining is performed for about 3 hours to about 15 hours. 
     
     
         13 . The method of  claim 3 , wherein the CNTs are single-walled CNTs (SWNT), multi-walled CNTs (MWNTs), or carbon nano fibers (CNFs). 
     
     
         14 . A method of preparing a CNT-mesoporous carbon composite, comprising the steps of:
 preparing a carbon precursor sol by mixing a polymerizable carbon-containing compound with a carrier;   impregnating a CNT-mesoporous silica composite with said carbon precursor sol;   polymerizing said carbon precursor sol penetrated into said CNT-mesoporous silica composite to obtain a carbon precursor penetrated into said CNT-mesoporous silica composite;   thermally decomposing said carbon precursor to obtain a carbon structure penetrated into said CNT-mesoporous silica composite;   treating said carbon structure penetrated into said CNT-mesoporous silica composite with a solution capable of dissolving silica to remove the silica.   
     
     
         15 . The method of  claim 14 , wherein said CNT-mesoporous silica composite comprises CNTs and mesoporous silica. 
     
     
         16 . The method of  claim 14 , wherein said CNT-mesoporous silica composite is prepared by:
 dissolving a surfactant in water and adding CNTs to form a mixture;   adding a silica source and water to said mixture to form a solution;   adding an acid to said solution to adjust the pH of said solution;   stirring said solution;   heating said solution to obtain powders;   separating said powders from the solution;   washing said powders at least one time; and   calcining said powders.   
     
     
         17 . The method of  claim 14 , wherein said polymerizable carbon-containing compound is a carbohydrate or monomer. 
     
     
         18 . The method of  claim 14 , wherein said carrier is water or an organic solvent. 
     
     
         19 . The method of  claim 14 , wherein an acid is added while preparing the carbon precursor sol. 
     
     
         20 . The method of  claim 14 , wherein said polymerizing is performed by heat-treatment comprising heating said carbon precursor sol penetrated into said CNT-mesoporous silica composite at about 50° C. to about 250° C. 
     
     
         21 . The method of  claim 20 , wherein said heat-treatment comprises a first heat-treatment of said carbon precursor sol penetrated into said CNT-mesoporous silica composite at about 50° C. to about 150° C. and a second heat-treatment of said carbon precursor sol penetrated into said CNT-mesoporous silica composite at about 150° C. to about 250° C., in sequence. 
     
     
         22 . The method of  claim 14 , wherein said polymerizing is performed by exposing said carbon precursor sol penetrated into said CNT-mesoporous silica composite to UV irradiation. 
     
     
         23 . The method of  claim 14 , wherein said impregnating and said polymerizing is repeated at least once in sequence prior to said thermally decomposing. 
     
     
         24 . The method of  claim 14 , wherein said thermally decomposing comprises heating said carbon precursor at about 600° C. to about 1400° C. 
     
     
         25 . The method of  claim 14 , wherein said solution capable of dissolving silica is aqueous hydrofluoric acid, aqueous sodium hydroxide, or any solution or combination thereof. 
     
     
         26 . A supported catalyst comprising:
 a CNT-mesoporous carbon composite comprising CNTs and mesoporous carbon; and   metal catalyst particles uniformly supported on said CNT-mesoporous carbon composite.   
     
     
         27 . The supported catalyst of  claim 26 , wherein mesopores of said CNT-mesoporous carbon composite have an average diameter of about 2 nm to about 10 nm. 
     
     
         28 . The supported catalyst of  claim 26 , wherein said CNT-mesoporous carbon composite has a specific surface area of about 800 m 2 /g to about 3500 m 2 /g. 
     
     
         29 . The supported catalyst of  claim 26 , wherein the concentration of said metal catalyst particles is about 40% to about 80% by weight of said supported catalyst. 
     
     
         30 . The supported catalyst of  claim 26 , wherein said CNT-mesoporous carbon composite comprises CNTs and mesoporous carbon, wherein the concentration of said CNTs is about 0.6% to about 20% by weight of said CNT-mesoporous carbon composite. 
     
     
         31 . The supported catalyst of  claim 26 , wherein said CNT-mesoporous carbon composite comprises CNTs and mesoporous silica. 
     
     
         32 . A fuel cell comprising:
 a cathode;   an anode; and   an electrolyte membrane interposed between the cathode and the anode,   wherein either the cathode, the anode, or both the cathode and the anode comprises the supported catalyst disclosed in  claim 26 .