Hydrogen evolution reaction catalysts, electrodes and electrolyzers based thereon and methods of fabrication thereof

Abstract

The invention provides, in some aspects, methods for fabricating an electrode comprising a nickel/molybdenum (NiMo) hydrogen evolution reaction catalyst on a carbon support, e.g., for use as a cathode in an electrolyzer. A catalyst of the type described above can be prepared by co-precipitation of nickel and molybdenum oxide species on the carbon support followed by its reduction through heat treatment in the presence of nitrogen. Such a catalyst can alternatively be prepared through the thermal degradation of metal-organic complexes of nickel and molybdenum in the presence of the carbon support. Further aspects of the invention comprise a cathode, e.g., for an anion exchange membrane electrolyzer, comprising a nickel/molybdenum hydrogen evolution reaction catalyst as described above. Still further aspects of the invention comprise an anion exchange membrane electrolyzer with a cathode as described above.

In view of the foregoing, what is claimed is: 
     
         1 . A method of preparing a hydrogen evolution reaction catalyst comprising:
 A. co-precipitating nickel and molybdenum oxides on a carbon support to form a catalyst precursor,   B. annealing the catalyst precursor in the presence of hydrogen to reduce the nickel and molybdenum oxides and, thereby, to yield a hydrogen evolution reaction catalyst.   
     
     
         2 . The method of  claim 1 , wherein step (A) comprises forming aminated salts of nickel and molybdenum. 
     
     
         3 . The method of  claim 2 , wherein step (A) comprises preparing a solution by adding the aminated salts to a dispersion of the carbon support in a solvent. 
     
     
         4 . The method of  claim 3 , comprising heating the solution to precipitate the nickel and molybdenum oxides onto the carbon support. 
     
     
         5 . An electrode comprising the catalyst prepared in  claim 1 . 
     
     
         6 . An electrolyzer comprising a cathode formed of the catalyst prepared in  claim 1 . 
     
     
         7 . The method of  claim 1 , comprising forming the catalyst into an electrode. 
     
     
         8 . A method of fabricating an electrode comprising
 A. co-precipitating nickel and molybdenum oxides on a carbon support to form a catalyst precursor,   B. annealing the catalyst precursor in the presence of hydrogen to reduce the nickel and molybdenum oxides and, thereby, to yield a hydrogen evolution reaction catalyst, and   C. forming the catalyst into an electrode.   
     
     
         9 . The method of  claim 8 , wherein step (A) comprises forming aminated salts of nickel and molybdenum. 
     
     
         10 . The method of  claim 9 , wherein step (A) comprises preparing a solution by adding the aminated salts to a dispersion of the carbon support in a solvent. 
     
     
         11 . The method of  claim 10 , comprising heating the solution to precipitate the nickel and molybdenum oxides onto the carbon support. 
     
     
         12 . A method of preparing a hydrogen evolution reaction catalyst comprising:
 A. coating a carbon support in nickel chelates and molybdenum chelates, and   B. collapsing the nickel chelates and molybdenum chelates to yield a hydrogen evolution reaction catalyst.   
     
     
         13 . The method of  claim 12 , wherein step (A) comprises
 dissolving nickel and molybdenum salts in water to form respective salt solutions,   bringing the respective salt solutions to pH,   adding a chelating agent to the respective salt solutions, and   washing, filtering and drying chelate complexes resulting from addition of said chelating agent.   
     
     
         14 . The method of  claim 13 , comprising
 dissolving the chelate complexes in a solvent into which a carbon support is added, and   forming a catalyst precursor by removing the solvent and drying.   
     
     
         15 . The method of  claim 14 , wherein step (B) comprises annealing the catalyst precursor. 
     
     
         16 . An electrode comprising the catalyst prepared in  claim 12 . 
     
     
         17 . An electrolyzer comprising a cathode formed of the catalyst prepared in  claim 12 . 
     
     
         18 . The method of  claim 12 , comprising forming the catalyst into an electrode. 
     
     
         19 . A method of fabricating an electrode comprising
 A. coating a carbon support in nickel chelates and molybdenum chelates, and   B. collapsing the nickel chelates and molybdenum chelates to yield a hydrogen evolution reaction catalyst, and   C. forming the catalyst into an electrode.   
     
     
         20 . The method of  claim 19 , wherein step (A) comprises
 dissolving nickel and molybdenum salts in water to form respective salt solutions,   bringing the respective salt solutions to pH,   adding a chelating agent to the respective salt solutions, and   washing, filtering and drying chelate complexes resulting from addition of said chelating agent.   
     
     
         21 . The method of  claim 20 , comprising
 dissolving the chelate complexes in a solvent into which a carbon support is added, and   forming a catalyst precursor by removing the solvent and drying.   
     
     
         22 . The method of  claim 21 , wherein step (B) comprises annealing the catalyst precursor.