Hydrogen production using ammonia borane

1. A method for producing hydrogen (“H 2 ”) comprising: combining ammonia borane with a sub-stoichiometric amount of a catalyst complex of the formula L n Fe—X wherein n is 1 or greater, wherein X comprises an anionic ligand selected from the group consisting of a nitrogen-containing ligand, a phosphorus-containing ligand and hydride, and wherein L comprises a neutral ancillary ligand selected from the group consisting of a phosphorus-containing ligand and a nitrogen-containing ligand, whereby hydrogen (H 2 ) is produced.

2. The method of claim 1 , wherein the neutral ancillary ligand is a monodentate ligand.

3. The method of claim 1 , wherein the neutral ancillary ligand is a polydentate ligand.

4. The method of claim 3 , wherein the polydentate ligand is selected from the group consisting of a bidentate nitrogen-containing ligand and a bidentate phosphorus-containing ligand.

5. The method of claim 4 , wherein the bidentate phosphine ligand is a bis(dialkylphosphino)alkane.

6. The method of claim 5 , wherein the bis(dialkylphosphino)alkane is selected from the group consisting of 1,2-bis(dicyclohexylphosphinoethane) and 1,3-bis(diphenylphosphino)propane.

7. The method of claim 4 , wherein the bidentate amine ligand is N,N′-bis(p-methoxyphenyl)ethylenediamine.

8. A method for producing hydrogen (“H 2 ”), comprising:

combining Iron bis(hexamethyldisilazane) and N,N′-bis(p-methoxyphenyl)ethylenediamine in a solvent to form a solution, and thereafter

adding a bis(dialkylphosphino)alkane to the solution, whereby a solution of catalyst complex is produced, and thereafter

adding ammonia borane to the solution of catalyst complex, whereby hydrogen is produced.

9. The method of claim 8 , wherein the bis(dialkylphosphino)alkane is 1,2-bis(dicyclohexylphosphinoethane) or 1,3-bis(diphenylphosphino)propane.