Liquid fuel compositions for electrochemical fuel cells

Abstract

A liquid fuel composition useful for catalytic fuel cells is made up of at least two components. The primary fuel component is a surface-active compound, such as methanol, that is a source of and acts to prevent unwanted decomposition of the auxiliary fuel. The auxiliary fuel is a compound having a standard reduction potential more negative than the reduction potential of hydrogen gas, which serves as a source of energy and serves to catalyze the catalytic oxidation of the primary fuel.

1 . A method for generating electricity comprising: 
 a) providing a fuel cell that includes a cathode and an anode;    b) providing a fuel composition including a primary fuel and an auxiliary fuel wherein said primary fuel includes at least one surface active compound and wherein said auxiliary fuel includes at least one compound with a standard reduction potential more negative than the reduction potential of hydrogen gas;    c) providing a circuit connecting said cathode and said anode; and    d) contacting said fuel composition with said anode to oxidize said fuel composition.    
   
   
       2 . The method of  claim 1  wherein at least one of said at least one surface-active compounds is a compound with an —OH functional group.  
   
   
       3 . The method of  claim 1  wherein said primary fuel includes at least one compound from the group consisting of CH 4 O, C 2 H 6 O, C 3 H 8 O, C 4 H 10 O, C 5 H 12 O, C 6 H 14 O, ethylene glycol and glycerine.  
   
   
       4 . The method of  claim 1  wherein said fuel composition further includes at least one additional compound.  
   
   
       5 . The method of  claim 1  wherein said auxiliary fuel includes at least one compound from the group consisting of hydrides, formates, thiosulfates, sulfites, phosphates and hypophosphites.  
   
   
       6 . The method of  claim 5  wherein said auxiliary fuel includes at least one compound from the group consisting of LiAlH 4 , NaBH 4 , LiBH 4 , (CH 3 ) 3 NHBH 3 , NaAlH 4 , NaCNBH 3 , CaH 2 , LiH, NaH, KH, Na 2 S 2 O 3 , Na 2 SO 3 , Na 2 HPO 3 , Na 2 HPO 2 , K 2 S 2 O 3 , K 2 SO 3 , K 2 HPO 3 , K 2 HPO 2 , NaCOOH and KCOOH.  
   
   
       7 . The method of  claim 1  wherein said liquid fuel composition further includes an electrolyte and has a pH above about 7.  
   
   
       8 . The method of  claim 7  wherein said pH is above about 8.  
   
   
       9 . The method of  claim 7  wherein said electrolyte is substantially an aqueous solution of an alkali metal hydroxide.  
   
   
       10 . The method of  claim 9  wherein said electrolyte has a concentration of alkali metal hydroxide between about 3 M and about 12 M.