Fuel electrode for solid electrolyte fuel cells and a method for manufacture of the electrode

Abstract

The invention relates to a fuel electrode for high-temperature solid electrolyte fuel cells and a process for manufacture of the electrode. The fuel electrode of the invention is a porous element composed of a high-melting metal, such as ruthenium, osmium, rhodium or iridium, or an alloy containing the metal. The process for manufacture of the fuel electrode comprises coating an electrode material with a solution or dispersion of the high-melting metal and/or its chloride, sintering the same and finally reducing the product.

1 . A fuel electrode for high-temperature solid electrolyte fuel cells which is a porous element composed of a high-melting metal having a melting point of not less than 1,900° C. or an alloy containing said high-melting metal.  
     
     
         2 . A fuel electrode according to  claim 1  wherein said high-melting metal is at least one member selected from the group consisting of ruthenium, osmium, rhodium and iridium.  
     
     
         3 . A fuel electrode according to  claim 1  which is a porous element composed of ruthenium metal.  
     
     
         4 . A process for manufacturing a fuel electrode according to  claim 1  which comprises dissolving or dispersing at least one member of the group consisting of ruthenium, osmium, rhodium, iridium, ruthenium chloride, osmium chloride, rhodium chloride and iridium chloride in an organic solvent or water, coating an electrode material with the resulting solution or dispersion, sintering the same and finally reducing it.  
     
     
         5 . A process according to  claim 4  wherein said sintering is performed at 400 to 1,000° C. followed by reduction at 500 to 1,300° C.  
     
     
         6 . A process according to  claim 4  wherein said organic solvent is an alcohol of 1 to 6 carbon atoms.  
     
     
         7 . A process according to  claim 6  wherein a high molecular compound soluble in the alcohol is concomitantly employed.  
     
     
         8 . A process according to  claim 4  wherein a high molecular compound soluble in water is concomitantly employed.  
     
     
         9 . A process according to  claim 8  wherein said high molecular compound is polyvinyl alcohol.