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.

What is claimed is:  
     
         1 . A fuel cell for the generation of electrical power, comprising 
 a) an anode;    b) a cathode; and    c) a liquid 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.    
     
     
         2 . The fuel cell 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 fuel cell 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 fuel cell of  claim 1  wherein said fuel composition further includes at least one additional compound.  
     
     
         5 . The fuel cell 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 fuel cell 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 fuel cell of  claim 1  wherein said liquid fuel composition further includes an electrolyte and has a pH above about 7.  
     
     
         8 . The fuel cell of  claim 7  wherein said pH is above about 8.  
     
     
         9 . The fuel cell of  claim 7  wherein said electrolyte is substantially an aqueous solution of an alkali metal hydroxide.  
     
     
         10 . The fuel cell of  claim 9  wherein said electrolyte has a concentration of alkali metal hydroxide between about 3 M and about 12 M.  
     
     
         11 . 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.    
     
     
         12 . The method of  claim 11  wherein at least one of said at least one surface-active compounds is a compound with an —OH functional group.  
     
     
         13 . The method of  claim 11  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.  
     
     
         14 . The method of  claim 11  wherein said fuel composition further includes at least one additional compound.  
     
     
         15 . The method of  claim 11  wherein said auxiliary fuel includes at least one compound from the group consisting of hydrides, formates thiosulfates , sulfites, phosphates and hypophosphites.  
     
     
         16 . The method of  claim 15  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.  
     
     
         17 . The method of  claim 11  wherein said liquid fuel composition further includes an electrolyte and has a pH above about 7.  
     
     
         18 . The method of  claim 17  wherein said pH is above about 8.  
     
     
         19 . The method of  claim 17  wherein said electrolyte is substantially an aqueous solution of an alkali metal hydroxide.  
     
     
         20 . The method of  claim 19  wherein said electrolyte has a concentration of alkali metal hydroxide between about 3 M and about 12 M.  
     
     
         21 . A liquid fuel composition for use in an electrochemical fuel cell, comprising 
 a) a primary fuel including at least one surface-active compound; and    b) an auxiliary fuel including at least one compound with a standard reduction potential more negative than the reduction potential of hydrogen gas.    
     
     
         22 . The fuel composition of  claim 21  wherein said surface-active compound is a compound with an —OH functional group.  
     
     
         23 . The fuel composition of  claim 21  wherein said surface-active compound 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.  
     
     
         24 . The fuel composition of  claim 21  further comprising at least one additional compound.  
     
     
         25 . The fuel composition of  claim 21  wherein said auxiliary fuel includes at least one compound from the group consisting of hydrides, formates, thiosulfates, sulfites, phosphates and hypophosphites.  
     
     
         26 . The fuel composition of  claim 25  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.  
     
     
         27 . The fuel composition of  claim 21  further comprising an electrolyte with a pH above about  7 .  
     
     
         28 . The fuel composition of  claim 27  wherein said pH is above about 8.  
     
     
         29 . The fuel composition of  claim 27  wherein said electrolyte is substantially an aqueous solution of an alkali metal hydroxide.  
     
     
         30 . The fuel composition of  claim 29  wherein said alkali metal hydroxide is KOH.  
     
     
         31 . The fuel composition of  claim 26  wherein said electrolyte has a concentration of KOH between about 3 M and about 12 M.  
     
     
         32 . The fuel composition of  claim 30  wherein said concentration is substantially 6 M.  
     
     
         33 . The fuel composition of  claim 27  comprising between 2 weight percent and 60 weight percent of said primary fuel and between 1 weight percent and saturation of said auxiliary fuel.