Method for storage and release of hydrogen

Patent metadata

Field	Value
Publication number	US-10618807-B2
Application number	US-201816235032-A
Country	US
Kind code	B2
Filing date	Dec 28, 2018
Priority date	Nov 6, 2013
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

The invention provides a process for the production of hydrogen, comprising catalytically decomposing a concentrated aqueous solution of potassium formate in a reaction vessel to form bicarbonate slurry and hydrogen, discharging the hydrogen from said reaction vessel, and treating a mixture comprising the bicarbonate slurry and the catalyst with an oxidizer, thereby regenerating the catalyst. Pd/C catalysts useful in the process are also described.

First claim

The invention claimed is:

1. A Pd/C catalyst wherein Pd loading is in the range from 0.15 to 0.5 wt %, and wherein at least a portion of the palladium is present on the support in the form of sub-nanometer particles (<1 nm).

2. The Pd/C catalyst according to claim 1 , wherein the Pd loading is from 0.2 to 0.5 wt %.

3. A process for preparing Pd/C catalyst according to claim 1 , comprising dissolving in water a palladium (Pd 2+ ) salt, adding to the solution heat-treated activated carbon, stirring the so-formed mixture, reducing the Pd 2+ to Pd 0 with the aid of formate, collecting a powder consisting of Pd/C, washing and drying same,
wherein the Pd loading is in the range from 0.15 to 0.5 wt %, and at least a portion of the palladium is present on the support in the form of sub-nanometer particles (<1 nm).

4. The process according to claim 3 , wherein the activated carbon bears acidic groups.

5. A process according to claim 4 , wherein the formate is potassium formate and the concentration of said formate in the reaction mixture is from 0.005 to 0.12 M.

6. The process according to claim 3 , wherein the formate is potassium formate and the potassium is incorporated into the Pd/C catalyst, and wherein regions of the Pd/C catalyst where sub-nanometer Pd is present are potassium-free.

7. The Pd/C catalyst according to claim 1 , wherein the carbon support of the Pd/C catalyst is activated carbon bearing acidic groups.

8. The Pd/C catalyst according to claim 1 , wherein potassium is incorporated into the Pd/C catalyst, and wherein regions of the Pd/C catalyst where sub-nanometer Pd is present are potassium-free.

9. A reaction medium for catalytic production of hydrogen comprising:
an aqueous potassium formate solution, an acid, and a catalyst according to claim 1 ,
wherein concentration of the aqueous potassium formate solution is not less than 4 M, and the molar ratio of potassium formate to the acid is from 10:1 to 10:10.

10. A reaction medium according to claim 9 , wherein the molar ratio of potassium formate to the acid is from 10:2 to 10:6.

11. A reaction medium according to claim 9 , wherein the acid is formic acid.

12. A reaction medium according to claim 11 , wherein the molar ratio of potassium formate to the acid is from 10:1 to 10:3.

13. A reaction medium according to claim 9 , wherein the ratio of potassium formate to palladium catalyst is 2000:1.

14. A reaction medium for catalytic production of hydrogen comprising:
an aqueous potassium formate solution and a catalyst according to claim 1 ,
wherein concentration of the aqueous potassium formate solution is not less than 4 M, and the molar ratio of potassium formate to palladium catalyst is from 2000:1 to 6000:1.

Assignees

• Yissum Res Dev Co Of Hebrew Univ Jerusalem Ltd

Inventors

• Sasson Yoel
• Wiener Harold
• Givant Ariel

Classifications

• B01J38/12

  Treating with free oxygen-containing gas · CPC title

• C01B2203/1064

  Platinum group metal catalysts · CPC title

• B01J37/16

  Reducing · CPC title

• C01B2203/0277

  containing a catalytic decomposition step · CPC title

• H01M8/0612

  from carbon-containing material · CPC title