Solvent-free syntheses of silver products produced thereby

Patent metadata

Field	Value
Publication number	US-9982322-B2
Application number	US-201314423870-A
Country	US
Kind code	B2
Filing date	Aug 29, 2013
Priority date	Aug 30, 2012
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

Described herein are methods of making metallic or elemental silver in the solid state. These methods generally include a step of forming an at least substantially solvent-free solid state reaction mixture that includes a silver-containing compound and an organic acid, followed by heating the reaction mixture at a temperature and for a time effective to form metallic silver from a cationic silver species of the silver-containing compound. Also described herein are metallic or elemental silver produced by these methods.

First claim

What is claimed is:

1. A method for making metallic silver, the method comprising:
contacting a silver-containing compound with an organic acid to form an at least substantially solvent-free solid state reaction mixture, wherein the concentration of the organic acid is equimolar to or in a stoichiometric excess of the concentration of the cationic silver species in the silver-containing compound, the contacting is performed in a presence of an alkali metal-containing compound; and
heating the at least substantially solvent-free solid state reaction mixture to a temperature less than the melting temperature of the organic acid for a time effective to produce a reaction product comprising metallic silver from the cationic silver species of the silver-containing compound.

2. The method of claim 1 , wherein the silver-containing compound comprises silver nitrate, silver nitrite, silver oxide, silver sulfate, silver phosphate, a silver halide, or a mixture thereof.

3. The method of claim 1 , wherein the organic acid comprises lactic acid, citric acid, oxalic acid, ascorbic acid, fumaric acid, maleic acid, or a mixture thereof.

4. The method of claim 1 , wherein the alkali metal-containing compound comprises a sodium-containing compound, a potassium-containing compound or a mixture thereof.

5. The method of claim 4 , wherein the sodium-containing compound is sodium nitrate, and the potassium containing compound is potassium nitrate.

6. The method of claim 4 , wherein an anionic species of the alkali metal-containing compound is the same as an anionic species of the silver-containing compound.

7. The method of claim 1 , wherein the temperature of the heating is at least about 50 degrees Celsius.

8. The method of claim 1 , wherein the temperature of the heating is about 100 degrees Celsius to about 150 degrees Celsius.

9. The method of claim 1 , wherein the time of the heating is about 10 minutes to about 24 hours.

10. The method of claim 1 , wherein the time of the heating is about 15 minutes to about 5 hours.

11. The method of claim 1 , further comprising recovering the metallic silver from the reaction product.

12. The method of claim 11 , wherein the recovering comprises:
disposing the reaction product in a solvent; and
separating the metallic silver from the solvent.

13. The method of claim 11 , further comprising cooling the reaction product before recovering the metallic silver from the reaction product.

14. The method of claim 1 , wherein the metallic silver is produced in a fractional yield of greater than 90 percent.

15. A method for making metallic silver, the method comprising:
contacting a silver-containing compound with an organic acid in the presence of a catalytically effective amount of a catalyst comprising an alkali metal-containing compound to form an at least substantially solvent-free solid state reaction mixture, wherein the concentration of the organic acid is equimolar to or in a stoichiometric excess of the concentration of the cationic silver species in the silver-containing compound;
heating the at least substantially solvent-free solid state reaction mixture to a temperature less than the melting temperature of the organic acid for about 10 minutes to about 24 hours to produce a reaction product comprising metallic silver from the cationic silver species of the silver-containing compound;
cooling the reaction product;
disposing the cooled reaction product in a solvent, wherein the metallic silver is dispersed in the solvent; and
separating the metallic silver from the solvent.

16. The method of claim 15 , wherein the silver-containing compound is silver nitrate, the organic acid is ascorbic acid, and the alkali metal-containing compound is sodium nitrate.

Assignees

• Corning Inc

Inventors

• Johnson Benedict Yorke
• Owusu Samuel Odei

Classifications

• B22F9/20

  starting from solid metal compounds · CPC title

• B22F1/0018

  Operations & Transport · mapped topic

• C22B11/02 Primary

  by dry processes · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C22C5/06

  Alloys based on silver · CPC title