Sulfur-functionalized carbon nanoarchitectures as porous, high-surface-area supports for precious metal catalysts

• US 20060099139A1
• Filed: 11/05/2004
• Published: 05/11/2006
• Est. Priority Date: 10/04/2004
• Status: Active Grant

• Current Assignee: The U.S.A. As Represented By The Secretary Of Navy
• Original Assignee: The U.S.A. As Represented By The Secretary Of Navy
• Inventors: Baker, Wendy Sue, Rolison, Debra Rose, Webster Long, L. Jeffrey
• Granted Patent: US 7,282,466 B2
• Time in Patent Office: Days
• US Class Current: 423/567.1
• CPC Class Codes: C01B 32/00 Carbon; Compounds thereof C01B21/00, C01B23/00 take precedence; percarbonates C01B15/10; carbon black C09C1/48
• CPC Class Codes: H01M 4/90 Selection of catalytic material
• CPC Class Codes: H01M 4/92 Metals of platinum group H01M4/94 , H01M4/9058 take precedence
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10S 521/919 Sintered product
• CPC Class Codes: Y10S 526/904 Monomer polymerized in presence of transition metal containing catalyst at least part of which is supported on a polymer, e.g. prepolymerized catalysts

Abstract

The invention relates to sulfur-functionalized polymer gels and carbon gels, including aerogels, and such carbon gels containing platinum or metal nanoparticles. The platinum-containing gels may be useful as fuel-cell electrodes.

Claims

1. A polymer gel comprising a sulfur functionalization.

2. The polymer gel of claim 1, wherein the organic gel is made by a process comprising the steps of:

reacting a phenol with formaldehyde in a condensation reaction to form a precursor gel; and

reacting the precursor gel with a sulfur compound.

3. The polymer gel of claim 2, wherein the phenol is resorcinol.

4. The polymer gel of claim 2, wherein the phenol is selected from the group consisting of phenols have more than one hydroxyl group.

5. The polymer gel of claim 2, wherein the sulfur compound is 3-thiophenecarboxaldehyde.

6. The polymer gel of claim 2, wherein the sulfur compound comprises a sulfur atom and an aldehyde group.

7. A carbon gel comprising a sulfur group.

8. The carbon gel of claim 7, wherein the carbon gel is made by a process comprising the steps of:

reacting a phenol with formaldehyde in a condensation reaction to form a precursor gel;

reacting the precursor gel with a sulfur compound to form a sulfur-modified gel; and

pyrolyzing the sulfur-modified gel to form a carbon gel comprising a sulfur functionalization.

9. The carbon gel of claim 8, wherein the phenol is resorcinol.

10. The carbon gel of claim 8, wherein the phenol is selected from the group consisting of phenols have more than one hydroxyl group.

11. The carbon gel of claim 7, wherein the carbon gel is an aerogel.

12. The carbon gel of claim 7, wherein the carbon gel is a xerogel.

13. The carbon gel of claim 7, wherein the carbon gel is an ambigel.

14. The carbon gel of claim 8, wherein the sulfur compound is 3-thiophenecarboxaldehyde.

15. The carbon gel of claim 8, wherein the sulfur compound comprises a sulfur atom and an aldehyde group.

16. The carbon gel of claim 7, further comprising a metal nanoparticle bound to the sulfur functionalization.

17. The carbon gel of claim 16, wherein the metal nanoparticle is a platinum nanoparticle.

18. The carbon gel of claim 16, wherein the metal nanoparticle comprises a metal selected from the group consisting of palladium, platinum alloy, platinum ruthenium alloy, silver, noble metals, and metals capable of bonding to sulfur atoms.

19. A method of making a composite, comprising the steps of:

reacting a phenol with formaldehyde in a condensation reaction to form a precursor gel; and

reacting the precursor gel with a sulfur compound to form a sulfur-modified gel.

20. The method of claim 19, wherein the phenol is resorcinol and the sulfur compound is 3-thiophenecarboxaldehyde.

21. The method of claim 19, further comprising the step of:

pyrolyzing the sulfur-modified gel to form a sulfur-functionalized carbon gel.

22. The method of claim 21, further comprising the step of:

impregnating the sulfur-functionalized carbon gel with metal nanoparticles.

23. The method of claim 22, wherein the metal nanoparticles are platinum nanoparticles.

24. The method of claim 23, wherein the impregnating step comprising exposing the sulfur-functionalized carbon gel to a colloidal suspension of the platinum nanoparticles.

25. The method of claim 23, wherein the impregnating step comprises exposing the sulfur-functionalized carbon gel to a platinum salt solution and reducing the platinum.

26. The method of claim 22, wherein the metal nanoparticle comprises a metal selected from the group consisting of palladium, platinum alloy, platinum ruthenium alloy, silver, noble metals, and metals capable of bonding to sulfur atoms.