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

• US 7,282,466 B2
• Filed: 11/05/2004
• Issued: 10/16/2007
• 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 united states of america as represented by the secretary of the navy
• Inventors: Rolison, Debra R, Long, Jeffrey W, Baker, Wendy
• Primary Examiner(s): Lorengo; J. A.
• Assistant Examiner(s): Hailey; Patricia L.
• Application Number:
  US10/985,072
• Publication Number:
  US 20060099139A1
• Time in Patent Office: 1,075 Days
• Field of Search: 502/159, 502/185, 528/129, 528/158, 521/181, 521/186, 521/189, 521/919
• US Class Current: 502/185
• 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 carbon gel comprising a sulfur group;

wherein the sulfur group is elemental sulfur, sulfide, heterocyclic sulfur, or thiophene.

2. The carbon gel of claim 1, 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.

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

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

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

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

7. The carbon gel of claim 1, wherein the carbon gel is an aerogel.

8. The carbon gel of claim 1, wherein the carbon gel is a xerogel.

9. The carbon gel of claim 1, wherein the carbon gel is an ambigel.

10. The carbon gel of claim 1, further comprising a metal nanoparticle bound to the sulfur group.

11. The carbon gel of claim 10, wherein the metal nanoparticle is a platinum nanoparticle.

12. The carbon gel of claim 10, 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.

13. The carbon gel of claim 1, wherein the sulfur group is elemental sulfur, heterocyclic sulfur, or thiophene.

14. A method of making a composite, 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 sulfur-functionalized carbon gel.

15. The method of claim 14, wherein the phenol is resorcinol and the sulfur compound is 3-thiophenecarboxaldehyde.

16. The method of claim 14, further comprising the step of:

impregnating the sulfur-functionalized carbon gel with metal nanoparticles.

17. The method of claim 16, wherein the metal nanoparticles are platinum nanoparticles.

18. The method of claim 17, wherein the impregnating step comprising

exposing the sulfur-functionalized carbon gel to a colloidal suspension of the platinum nanoparticles.

19. The method of claim 17, wherein the impregnating step comprises exposing the sulfur-functionalized carbon gel to a platinum salt solution and reducing the platinum.

20. The method 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.

21. The method of claim 14, wherein the sulfur functionalization is elemental sulfur, sulfide, heterocyclic sulfur, or thiophene.

22. The method of claim 14, wherein the sulfur functionalization is elemental sulfur, heterocyclic sulfur, or thiophene.

23. A carbon gel comprising a sulfur group and a metal nanoparticle bound to the sulfur group.

24. The carbon gel of claim 23, wherein the metal nanoparticle is a platinum nanoparticle.

25. The carbon gel of claim 23, 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.