Ion conducting nanofiber fuel cell electrodes

Abstract

The present invention is directed to methods of making a nanofiber-nanoparticle network to be used as electrodes of fuel cells. The method comprises electrospinning a polymer-containing material on a substrate to form nanofibers and electrospraying a catalyst-containing material on the nanofibers on the same substrate. The nanofiber-nanoparticle network made by the methods is suitable for use as electrodes in fuel cells.

What is claimed is: 
     
         1 . A structure comprising:
 a polymer fiber structure comprising fibers having a fiber diameter of less than 1 micron; and   a plurality of catalytic material particles supported on the polymer fiber structure.   
     
     
         2 . A structure as claimed in  claim 1 , where in the polymer fiber structure comprises aligned fibers. 
     
     
         3 . A structure as claimed in  claim 1 , wherein the catalytic material has a particle size of less than 50 nm. 
     
     
         4 . A structure as claimed in  claim 1 , wherein the catalytic material has a particle size of less than 20 nm. 
     
     
         5 . A structure as claimed in  claim 1 , wherein the catalyst loading is less than 0.1 mg of catalyst per square centimeter. 
     
     
         6 . A structure as claimed in  claim 1 , wherein the catalyst loading is less than 0.05 mg of catalyst per square centimeter. 
     
     
         7 . A structure as claimed in  claim 1 , wherein the catalyst loading is less than 0.01 mg of catalyst per square centimeter. 
     
     
         8 . An electrode comprising the structure of  claim 1 . 
     
     
         9 . A fuel cell comprising the electrode of  claim 8 . 
     
     
         10 . A method for making nanofiber-nanoparticle network to be used as electrode of a fuel cell, the method comprises the step of:
 electrospinning a polymer-containing material onto a substrate for forming nanofibers on the substrate, and   electrospraying a catalyst-containing material onto the polymer-containing material or nanofibers.   
     
     
         11 . The method of  claim 10 , wherein said electrospinning and said electrospraying are carried out simultaneously. 
     
     
         12 . The method of  claim 10 , wherein the polymer comprises at least one polymer selected from the group consisting of Nafion, sulfonated poly(ether ether ketone), sulfonated polyer(styrene-b-ethylene-r-butadiene-b-styrene), sulfonated poly(styrene), sulfonated poly(arylene ether) copolymer, sulfonated poly(styrene-b-isobutylene-b-styrene). 
     
     
         13 . The method of  claim 10 , wherein said polymer is a sulfonated tetrafluoroethylenes. 
     
     
         14 . The method of  claim 10 , wherein said polymer-containing material is a solution. 
     
     
         15 . The method of  claim 10 , wherein said polymer-containing material is molten polymer. 
     
     
         16 . The method of  claim 10 , wherein the catalyst comprises at least one material selected from the group consisting palladium, platinum, gold, silver, nickel, rhodium, ruthenium, rhenium, osmium, iridium, iron, chromium, cobalt, copper, manganese, tungsten, niobium, titanium, tantalum, lead, indium, cadmium, tin, bismuth and gallium, as well as compounds and alloys of these metals. 
     
     
         17 . The method of  claim 16 , wherein said at least one fuel cell catalyst is synthetic platinum on carbide derived carbon support. 
     
     
         18 . The method of  claim 16 , wherein said catalyst-containing material is a solution. 
     
     
         19 . The method of  claim 1 , further comprising the step of heating the materials. 
     
     
         20 . A catalyst for a fuel cell selected from the group consisting of platinum on carbide derived carbon support.