Selective generation of multi-metallic sites on substrates and associated products

• US 20060057400A1
• Filed: 08/29/2005
• Published: 03/16/2006
• Est. Priority Date: 07/30/2004
• Status: Active Grant

• Current Assignee: University of Utah Research Foundation (State of Utah)
• Original Assignee: University of Utah Research Foundation (State of Utah)
• Inventors: Eyring, Edward M., Dunn, Brian C., Ernst, Richard D., Turpin, Gregory C.
• Granted Patent: US 7,429,404 B2
• Time in Patent Office: Days
• US Class Current: 428/432
• CPC Class Codes: B01J 23/462 Ruthenium
• CPC Class Codes: B01J 23/745 Iron
• CPC Class Codes: B01J 23/75 Cobalt
• CPC Class Codes: B01J 23/8913 Cobalt and noble metals
• CPC Class Codes: B01J 31/1625 immobilised by covalent linkages, i.e. pendant complexes with optional linking groups
• CPC Class Codes: B01J 35/30 characterised by their physical properties
• CPC Class Codes: B01J 37/0203 the impregnation liquid containing organic compounds
• CPC Class Codes: B01J 37/0209 involving a reaction between the support and a fluid
• CPC Class Codes: C10G 2/33 characterised by the catalyst used
• CPC Class Codes: C10G 2/332 of the iron-group
• CPC Class Codes: C23C 18/1639 Substrates other than metallic, e.g. inorganic or organic or non-conductive
• CPC Class Codes: C23C 18/1651 Two or more layers only obtained by electroless plating
• CPC Class Codes: Y10T 428/1259 Oxide
• CPC Class Codes: Y10T 428/12611 Oxide-containing component
• CPC Class Codes: Y10T 428/12806 Refractory [Group IVB, VB, or VIB] metal-base component
• CPC Class Codes: Y10T 428/12875 Platinum group metal-base component

Abstract

A method for forming multi-metallic sites on a substrate is disclosed and described. A substrate including active groups such as hydroxyl can be reacted with a pretarget metal complex. The target metal attached to the active group can then be reacted with a secondary metal complex such that an oxidation-reduction (redox) reaction occurs to form a multi-metallic species. The substrate can be a highly porous material such as aerogels, xerogels, zeolites, and similar materials. Additional metal complexes can be reacted to increase catalyst loading or control co-catalyst content. The resulting compounds can be oxidized to form oxides or reduced to form metals in the ground state which are suitable for practical use.

Claims

1. A method of incorporating metals on a substrate, comprising the steps of:

a) reacting a pretarget metal complex with an active group on a substrate to form a target metal species, said target metal species capable of reacting with a secondary metal complex in an oxidation-reduction reaction; and

b) reacting the secondary metal complex with the target metal species in an oxidation-reduction reaction to form a multi-metallic compound on the substrate.

2. The method of claim 1, further comprising the step of oxidizing the target metal species to form an oxidized target metal on the substrate prior to the step of reacting the secondary metal complex, said secondary metal complex acting as a reducing agent.

3. The method of claim 1, further comprising the step of reducing the target metal species to form a reduced target metal on the substrate prior to the step of reacting the secondary metal complex, said secondary metal complex acting as an oxidizing agent.

4. The method of claim 1, wherein the substrate comprises a member selected from the group consisting of aerogel, xerogel, zeolite, silica, alumina, silica gel, and composites or combinations thereof.

5. The method of claim 4, wherein the substrate comprises an aerogel.

6. The method of claim 1, wherein the pretarget metal complex and secondary metal complex are independently selected from the group consisting of metallocenes, open metallocenes, and combinations or derivatives thereof.

7. The method of claim 1, wherein at least one of the pretarget metal complex and secondary metal complex have the formula

M-L_n

where M is a transition, actinide, lanthanide, or main group metal, L is a complexing ligand, and n is from one to five.

8. The method of claim 7, wherein M is Fe, Co, Ru, or Ce and L is a dienyl compound.

9. The method of claim 1, wherein at least one of the pretarget metal complex and secondary metal complex are independently selected from the group consisting of Fe(C₅H₅)(2,4-C₇H₁₁), ferrocene, cobaltocene, ruthenocene, cerium alkoxides,

10. The method of claim 1, wherein the active group is hydroxyl.

11. The method of claim 1, further comprising the step of oxidizing said multi-metallic compound to remove organic portions of said multi-metallic compound and to form a multi-metallic oxide compound.

12. The method of claim 11, further comprising reducing the multi-metallic oxide compound to form a multi-metallic metal having an oxidation state of zero.

13. The method of claim 1, further comprising the step of reacting additional metal-containing species with the multi-metallic compound.

14. A multi-metallic coated substrate, comprising a substrate having a multi-metallic coating on at least a portion thereof, said multi-metallic coating including a first metal and a second metal associated with the substrate and the multi-metallic coating being formed by the steps comprising:

a) reacting a pretarget metal complex with an active group on the substrate to form a target metal species including the first metal, said target metal species capable of reacting with a secondary metal complex in an oxidation-reduction reaction;

b) reacting the secondary metal complex with the target metal species in an oxidation-reduction reaction to form a multi-metallic compound, said secondary metal complex including the second metal; and

c) treating the multi-metallic compound to form a multi-metallic coating on the substrate.

15. The multi-metallic coated substrate of claim 14, wherein the substrate is a porous substrate comprising a member selected from the group consisting of aerogel, xerogel, zeolite, silica, alumina, aluminum phosphates, and combinations or composites thereof.

16. The multi-metallic coated substrate of claim 14, wherein the first metal and second metal are metal oxides.

17. The multi-metallic coated substrate of claim 14, wherein the first metal and second metal have an oxidation state of zero.

18. The multi-metallic coated substrate of claim 17, wherein the first metal and second metal is an alloy.

19. The multi-metallic coated substrate of claim 14, wherein the multi-metallic coating comprises from about 2 wt % to about 50 wt % of the multi-metallic coated substrate.

20. The multi-metallic coated substrate of claim 19, wherein the multi-metallic coating comprises from about 15 wt % to about 40 wt % of the multi-metallic coated substrate.

21. The multi-metallic coated substrate of claim 14, wherein the first metal and second metal are independently selected from the group consisting of cobalt, ruthenium, iron, cobalt, titanium, vanadium, chromium, zirconium, osmium, platinum, palladium, silver, nickel, molybdenum, tungsten, and oxides or alloys thereof.

22. The multi-metallic coated substrate of claim 14, wherein each of the pretarget metal complex and secondary metal complex has the formula

M-L_n

where M is a transition, actinide, lanthanide, or main group metal, L is a complexing ligand, and n is from one to five.