Aqueous route to nitrogen-doped mesoporous carbons

Patent metadata

Field	Value
Publication number	US-11891305-B2
Application number	US-202217959913-A
Country	US
Kind code	B2
Filing date	Oct 4, 2022
Priority date	Sep 4, 2018
Publication date	Feb 6, 2024
Grant date	Feb 6, 2024

Abstract

A method for preparation of mesoporous nitrogen-doped carbon includes forming a composition by solubilizing a nitrogen-containing polymer in an aqueous solution of ZnCl2 and drying the aqueous solution, the method further includes heating the composition after drying to a temperature sufficiently high to carbonize the nitrogen-containing polymer to form the mesoporous nitrogen-doped carbon.

First claim

What is claimed is:

1. A method for preparation of mesoporous nitrogen-doped carbon comprising forming a composition by solubilizing a nitrogen-containing polymer in an aqueous solution of ZnCl 2 and drying the aqueous solution, the method further comprising heating the composition after drying to a temperature to carbonize the nitrogen-containing polymer to form the mesoporous nitrogen-doped carbon.

2. The method of claim 1 further comprising dispersing a plurality of porogenic fillers in the aqueous solution of the composition prior to drying the composition.

3. The method of claim 2 wherein the porogenic fillers comprise at least one of silica particles, cellulose-based nanocrystals or filter paper.

4. The method of claim 2 wherein the composition is cast into a desired form before heating.

5. The method of claim 2 wherein drying comprises freeze-drying.

6. The method of claim 2 wherein the nitrogen-containing polymer is polyacrylonitrile.

7. The method of claim 6 wherein the composition is stabilized by heating at a temperature below 300° C. after drying and before heating the composition to carbonize the nitrogen-containing polymer, wherein the temperature to carbonize the nitrogen-containing polymer is less than 850° C.

8. The method of claim 6 wherein the degree of polymerization of the polyacrylonitrile is 100 or less.

9. The method of claim 6 wherein the degree of polymerization of the polyacrylonitrile is 50 or less.

10. The method of claim 6 wherein the dispersity of the polyacrylonitrile is less than 2.0.

11. The method of claim 6 wherein the dispersity of the polyacrylonitrile is less than 1.5.

12. The method of claim 6 wherein the dispersity of the polyacrylonitrile is less than 1.3.

13. The method of claim 6 wherein the mesoporous nitrogen-doped carbon comprises interconnected pores.

14. The method of claim 6 wherein the mesoporous nitrogen-doped carbon has a surface area greater than or equal to 750 m 2 /g.

15. The method of claim 6 wherein the mesoporous nitrogen-doped carbon has a surface area greater than or equal to 1,000 m 2 /g.

16. The method of claim 14 wherein a percentage of the surface area arising from mesopores is at least 84%.

17. The method of claim 6 wherein the mesoporous nitrogen-doped carbon comprise both graphitic and disordered carbons.

18. The method of claim 17 wherein the graphitic carbons comprise catalytically active edge on pyridine oxide-N, pyrrolic- or pyridonic-N, and pyridinic-N(N—P) nitrogens.

19. The method of claim 6 wherein the ratio of fillers to PAN is selected to provide sufficient PAN to fill the majority of the interstitial volume between the fillers, thereby forming a coherent structure.

Assignees

• Univ Carnegie Mellon

Inventors

• Matyjaszewski Krzysztof
• Zhang Jianan
• Bockstaller Michael R

Classifications

• C01B32/354 Primary

  After-treatment · CPC title

• C01B32/05

  Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30 · CPC title

• C01B32/21

  After-treatment · CPC title

• C01B32/348

  Metallic compounds · CPC title

• C08L33/20

  Homopolymers or copolymers of acrylonitrile (C08L55/02 takes precedence) · CPC title