Metal Alloy Catalysts for Fuel Cell Anodes

Abstract

A catalyst for a fuel cell anode comprises an alloy of Pd and at least two other transition metals, at least one of which which binds to hydrogen and/or carbon monoxide at least as strongly as Pd does. Suitable transition metals which bind more strongly are Co, W, Ti, V, Cr, Fe, Mo, Nb, Hf, Ta, Zr and Re. PdCoW is the most preferred alloy. The catalyst is used on the anode of a hydrogen oxidising fuel cell, such as a PEMFC to catalyse the hydrogen oxidation reaction.

1 - 31 . (canceled) 
     
     
         32 . A catalyst for a fuel cell anode comprising an alloy of Pd and at least two other transition metals, at least one of which binds to hydrogen and/or carbon monoxide at least as strongly as Pd does. 
     
     
         33 . A catalyst according to  claim 32 , wherein two of the at least two other transition metals bind to hydrogen and/or carbon monoxide at least as strongly as Pd does. 
     
     
         34 . A catalyst according to  claim 32 , wherein at least one of the other transition metals binds to hydrogen and/or carbon monoxide more strongly than Pd does. 
     
     
         35 . A catalyst according to  claim 32 , wherein two of the at least two other transition metals bind to hydrogen and/or carbon monoxide more strongly than Pd does. 
     
     
         36 . A catalyst according to  claim 32 , consisting essentially of Pd and at least two other metals. 
     
     
         37 . A catalyst according to  claim 32 , wherein one or more of the at least two other transition metals is selected from the group consisting of: Co, W, Ti, V, Cr, Fe, Mo, Nb, Hf, Ta, Zr and Re. 
     
     
         38 . A catalyst according to  claim 32 , wherein at least two other transition metals are selected from the group consisting of: Co, W, Ti, V, Cr, Fe, Mo, Nb, Hf, Ta, Zr and Re. 
     
     
         39 . A catalyst according to  claim 32 , wherein one of the at least two other transition metals is Co. 
     
     
         40 . A catalyst according to  claim 32 , wherein one of the at least two other transition metals is W. 
     
     
         41 . A catalyst according to  claim 32 , wherein the alloy is selected from the group consisting of PdCoW, PdCoAu, PdCoMo, PdCoCr, PdFeCr, PdCoAg, PdCoTa, PdCoNb, PdFeMo, PdFeAu, PdFeAg, PdFeNb, and PdFeTi. 
     
     
         42 . A catalyst according to  claim 41 , wherein the alloy is selected from the group consisting of: PdCoW, PdCoMo, PdCoCr, and PdFeCr 
     
     
         43 . A catalyst according to  claim 42 , consisting essentially of Pd, Co and W. 
     
     
         44 . A catalyst according to  claim 43 , comprising 20-70 at. % (atomic percent) Pd, 10-70 at. % Co, and up to 30 at. % W. 
     
     
         45 . A catalyst according to  claim 44 , comprising about 50 at. % Pd, 43 at. % Co and 7 at. % W. 
     
     
         46 . A catalyst according to  claim 32 , supported on a support. 
     
     
         47 . A catalyst according to  claim 46 , wherein the support is non-metallic. 
     
     
         48 . A catalyst according to  claim 47 , wherein the support is carbon. 
     
     
         49 . A fuel cell anode comprising a substrate and a catalyst according to  claim 32 . 
     
     
         50 . A hydrogen oxidising fuel cell anode according to  claim 49 . 
     
     
         51 . A fuel cell comprising:
 the anode of  claim 49 ;   a cathode;   an electrolyte;   a fuel supply; and   a supply of oxidant.   
     
     
         52 . A fuel cell according to  claim 51 , wherein the fuel supply supplies hydrogen gas. 
     
     
         53 . A fuel cell according to  claim 51 , wherein the electrolyte comprises a proton exchange membrane.