Ligand-modified metal clusters for gas separation and purification
Provided is an organic ligand-bound metal surface that selects one gaseous species over another. The species can be closely sized molecular species having less than 1 Angstrom difference in kinetic diameter. In one embodiment, the species comprise carbon monoxide and ethylene. Such organic ligand-bound metal surfaces can be successfully used in gas phase separations or purifications, sensing, and in catalysis.
1. An organic ligand-bound metal surface, which is on a solid support, having one or more vacant binding sites that selects one fluid species over another, which sites have been created by flowing of inert gas over the metal surface for CO dissociation.
2. The ligand-bound metal surface of claim 1 , wherein the selection of fluid species is between two closely sized molecular species having less than 5 Angstrom difference in kinetic diameter.
3. The ligand-bound metal surface of claim 1 , wherein the selection of fluid species is between two closely sized molecular species having less than 3 Angstrom difference in kinetic diameter.
4. The ligand-bound metal surface of claim 1 , wherein the selection of fluid species is between two closely sized molecular species having less than 2 Angstrom difference in kinetic diameter.
5. The ligand-bound metal surface of claim 1 , wherein the selection of fluid species is between two closely sized molecular species having less than 1 Angstrom difference in kinetic diameter.
6. The ligand-bound metal surface of claim 5 , wherein the two molecular species include carbon monoxide and ethylene.
7. The ligand-bound metal surface of claim 1 , wherein the metal is a metal cluster with a tetrahedral framework.
8. The ligand-bound metal surface of claim 7 , wherein the metal is a metal cluster or a metal nanoparticle.
9. The ligand-bound metal surface of claim 8 , wherein the metal is a metal cluster.
10. The ligand-bound metal surface of claim 9 , wherein the metal cluster comprises an Ir 4 or Ir 6 cluster.
11. The ligand-bound metal surface of claim 9 , wherein the metal cluster comprises a Rh 4 or Rh 6 cluster.
12. The ligand-bound metal surface of claim 1 , wherein the ligand is an electron donating ligand.
13. The ligand-bound metal surface of claim 12 , wherein the ligand incorporates a phosphine group.
14. The ligand-bound metal surface of claim 12 , wherein the ligand incorporates a calixarene.
15. A ligand-bound metal surface, which is on a solid support, having one or more vacant binding sites that selects one fluid species over another.
16. The ligand-bound metal surface of claim 15 , wherein the selection of fluid species is between two closely sized molecular species having less than 5 Angstrom difference in kinetic diameter.
17. The ligand-bound metal surface of claim 15 , wherein the selection of fluid species is between two closely sized molecular species having less than 3 Angstrom difference in kinetic diameter.
18. The ligand-bound metal surface of claim 15 , wherein the selection of fluid species is between two closely sized molecular species having less than 1 Angstrom difference in kinetic diameter.
19. The ligand-bound metal surface of claim 15 , wherein the selection of fluid species is between two closely sized molecular species having less than 1 Angstrom difference in kinetic diameter.
20. The ligand-bound metal surface of claim 19 , wherein the two molecular species include carbon monoxide and ethylene.
21. The ligand-bound metal surface of claim 15 , wherein the metal is that of a metal cluster with a tetrahedral framework.
22. The ligand-bound metal surface of claim 21 , wherein the metal cluster comprises an Ir 4 or Ir 6 cluster.
23. The ligand-bound metal cluster of claim 21 , wherein the metal cluster comprises a Rh 4 or Rh 6 cluster.
24. The ligand-bound metal cluster of claim 21 , wherein the ligand is an electron donating ligand.
25. The ligand-bound metal cluster of claim 24 , wherein the ligand incorporates a phosphine group.
26. The ligand-bound metal cluster of claim 24 , wherein the ligand incorporates a calixarene.
27. The ligand-bound metal cluster of claim 21 , wherein the radius of curvature of at least one of the ligands is greater than that of the metal cluster.
28. A method of separating one or more fluid species from others, comprising passing a mixture of fluid species over the ligand-bound metal surface of claim 1 , and recovering a fluid stream comprising the fluid species not bound to the ligand-bound metal surface.
29. The method of claim 28 , wherein the mixture comprises carbon monoxide and ethylene.
30. The method of claim 28 , wherein the ligand-bound metal surface is on either a metal, metal-oxide, or ceramic support.
31. A sensor for carbon monoxide, which comprises the ligand-bound metal surface of claim 1 .
32. A catalyst comprised of the ligand-bound metal surface of claim 1 .
33. The ligand-bound metal surface of claim 1 , wherein the metal surface is on a silica support.
34. The method of claim 30 , wherein the support is a silica support.