Catalysts for oxidative steam reforming of methanol as a new and efficient method for the selective production of hydrogen for fuel cells and their synthesis method

Abstract

The present invention provides a method of producing a CuZnAlZr oxide catalyst consisting of reacting an aqueous NaOH solution and aqueous NACO 3 solution with a mixture of aqueous solutions of each nitrate of Cu, Zn, Al, and Zr, producing a precipitate by coprecipitation, aging, filtering, washing and drying this precipitate to prepare a catalyst precursor consisting of a CuZnAlZr layered double hydroxide, and then obtaining a CuZnAlZr oxide by calcining this precursor in an air ambient atmosphere, a CuZnAlZr oxide catalyst, a CuZnZrCe oxide catalyst, a CoCuZnAl oxide catalyst for producing hydrogen by oxidative steam reforming of methanol, and methods of producing hydrogen gas consisting of converting methanol to hydrogen gas by oxidative steam reforming in the presence of air and steam using these oxide catalysts.

What is claimed is:  
     
         1 . A method of producing a CuZnAlZr oxide catalyst, comprising the steps of: 
 reacting a mixture of aqueous solutions of each nitrate of Cu, Zn, Al, and Zr with an aqueous NaOH solution and aqueous NaCO 3  solution;    producing a precipitate by coprecipitation;    aging, filtering, washing, and drying this precipitate to prepare a catalyst precursor consisting of a CuZnAlZr layered double hydroxide; and    then calcining this catalyst precursor in an air ambient atmosphere to obtain a CuZnAlZr oxide.    
     
     
         2 . The method of producing a CuZnAlZr oxide catalyst according to  claim 1 , wherein the molecular ratio of Cu, Zn, Al, and Zr in the starting solution is (Cu+Zn)/(Al+Zr)=2 to 4.  
     
     
         3 . A CuZnAlZr oxide catalyst for hydrogen production by oxidative steam reforming of methanol, which is produced by the method according to  claim 1  or  claim 2 .  
     
     
         4 . A CuZnZrCe oxide catalyst for hydrogen production by oxidative steam reforming of methanol, which is produced by the steps of: 
 preparing a catalyst precursor consisting of aurichalcite; and    then calcining this catalyst precursor in an air ambient atmosphere to obtain the CuZnZrCe oxide.    
     
     
         5 . A CoCuZnAl oxide catalyst for hydrogen production by oxidative steam reforming of methanol, which is produced by the steps of: 
 preparing a catalyst precursor consisting of aurichalcite; and    then calcining this catalyst precursor in an air ambient atmosphere to obtain the CoCuZnAl oxide.    
     
     
         6 . A method of producing hydrogen gas, comprising the step of: 
 converting methanol to hydrogen gas by oxidative steam reforming of methanol in the presence of both air and steam using the oxide catalyst described in any of  claim 3  to  claim 5 .    
     
     
         7 . The method of producing hydrogen gas according to  claim 6 , wherein 
 oxygen/methanol (molar ratio)=0.1 to 0.5 and    steam/methanol (molar ratio)=0.8 to 2.0.    
     
     
         8 . The method of producing hydrogen gas according to  claim 6 , wherein the reaction temperature is 200 to 250° C.