Novel catalysts and processes for their preparation

• US 20050164297A1
• Filed: 02/11/2003
• Published: 07/28/2005
• Est. Priority Date: 02/11/2002
• Status: Active Grant

• Current Assignee: Aquahydrex, Inc.
• Original Assignee: University Of Wollongong
• Inventors: Too, Chee O., Chen, Jun, Wallace, Gordon G., Swiegers, Gerhard F.
• Granted Patent: US 7,572,750 B2
• Time in Patent Office: Days
• US Class Current: 435/7.100
• CPC Class Codes: B01J 2531/842 Iron
• CPC Class Codes: B01J 31/069 Hybrid organic-inorganic polymers, e.g. silica derivatized with organic groups nitrogen containing groups on mineral substrates B01J31/0254; organometallic polymers B01J31/123; coordination complexes immobilised on an inorganic support B01J31/1616; coordination polymers, e.g. metal-organic frameworks B01J31/1691
• CPC Class Codes: B01J 31/2295 Cyclic compounds, e.g. cyclopentadienyls
• CPC Class Codes: C08G 61/124 with a five-membered ring containing one nitrogen atom in the ring
• CPC Class Codes: C25B 11/04 characterised by the material
• CPC Class Codes: H01M 8/16 Biochemical fuel cells, i.e. cells in which microorganisms function as catalysts
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

Accordingly, in an aspect of the invention, and not necessarily the broadest aspect, there is provided a hybrid homogeneous-heterogeneous catalyst containing catalytic groups, wherein the catalytic activity of the catalyst is largely provided as a result of the interaction of catalytic groups in a suitable proximity and disposition to other catalytic groups, the proximity and disposition resulting from statistical considerations.

Claims

1. A hybrid homogeneous-heterogeneous catalyst containing catalytic groups, wherein the catalytic activity of the catalyst is largely provided as a result of the interaction of catalytic groups in a suitable proximity and disposition to other catalytic groups, the proximity and disposition resulting from statistical considerations.

4. The catalyst of claim 1 or 2 wherein each catalytic groups are incorporated within separate compounds bound to a support structure.

6. The catalyst of any one of claims 1 to 3 or 5 wherein the support structure is a porous framework.

2. A hybrid homogeneous-heterogeneous catalyst formed by locating adequate numbers of catalytic groups in a discrete volume so as to thereby locate sufficient numbers of catalytic groups at a suitable distance and disposition relative to other catalytic groups so as to facilitate the reaction of one or more reagents.

3. A hybrid homogeneous-heterogeneous catalyst having multiple different catalytic groups for facilitating the reaction of one or more reagents, prepared by locating adequate numbers of compounds containing at least one catalytic group in a discrete volume so that sufficient numbers of the catalytic groups located in different compounds are positioned at a suitable distance and in a suitable disposition relative to each to facilitate the reaction of one or more reagents.

5. A hybrid homogeneous-heterogeneous catalyst containing sufficient numbers of catalytic groups incorporated within compounds immobilised on a support structure at a suitable distance and disposition relative to other catalytic groups to facilitate the reaction of one or more reagents, characterised in that when the compounds containing the catalytic groups are located in a more dispersed form in homogenous environment, the groups exhibit no or little significant catalytic activity.

7. A hybrid homogeneous-heterogeneous catalyst characterised by the property that when only the concentration of the catalytic groups within a discrete volume is increased by a factor X, X being greater than 1, the catalytic activity or selectivity of the catalyst is increased by a factor Y, where Y is greater than X, the catalytic activity being a function of the statistical distribution of the catalytic groups and thereby the proximities between the catalytic groups.

8. A hybrid homogeneous-heterogeneous catalyst characterised by the property that its catalytic activity at a constant concentration M, is increased by a factor X, X being greater than 1, upon the application of new conditions which cause a change in the statistical distribution of the catalytic groups and thereby the proximities between the catalytic groups.

9. The catalyst of claim 8 wherein the conditions include changes in temperature, acidity, polarity, solvent, solute, or the establishment of new supramolecular interactions between the catalytic groups.

10. An assay for determining whether a statistical proximity effect is influencing catalytic activity of a test catalyst by using kinetic studies to determine whether:

—

(i) the observed catalysis occurs as a result of the interaction of one or more types of catalytic groups with a reagent or intermediate; and

whether

(ii) the mechanism of catalysis involves the simultaneous interaction of two or more separate catalytic groups with a reagent or intermediate; and

whether

(iii) the interaction of two or more separate catalytic groups with the reagent or intermediate largely occurs when catalyst is formed or used under conditions which favourably influence the statistical distribution of proximities between the catalytic groups involved.

11. The assay of claim 10 wherein the means of favourably influencing the statistical distribution of the proximities of the catalysts is selected from modifying the concentration of catalytic groups on a substrate, the temperature at which the catalyst is used, the polarity of the solute, the solvent system and supramolecular interactions between the catalytic groups.

13. A statistical proximity catalyst identified by the assays of any one of claims 10 to 12.

12. An assay for determining whether a statistical proximity effect is influencing catalytic activity of a test catalyst by:

(i) providing a test catalyst having catalytic activity as the result of the interaction of one or more types of catalytic groups with a reagent or intermediate;

(ii) providing comparative systems which contain the same catalytic groups as the test catalyst covalently tethered to each other in varying proximities and/or dispositions;

(iii) analysing whether the test catalyst is disproportionately more active or selective than the comparative systems.

14. A statistical proximity catalyst which incorporates optional substituted ferrocene groups as the catalytic group.

16. The catalyst of claim 14 or 15 wherein the ferrocene groups are substituted.

15. A statistical proximity catalyst suitable for use in the generation of hydrogen gas from an acidic aqueous solution, comprising optionally substituted ferrocene groups incorporated within a conducting polymer or other support.

17. Use of optionally substituted ferrocene groups as the catalytic group in statistical proximity catalysts for the generation of hydrogen from aqueous acidic solution.

18. An electrode which incorporates optionally substituted ferrocene groups as statistical proximity catalysts for use in the generation of hydrogen gas from an acidic aqueous solution.

19. The electrode of claim 18 wherein the optionally substituted ferrocene groups are coated onto the surface of an electrode substrate as part of a polymeric coating.

20. The electrode of claim 19 wherein the polymeric coating is a conducting electroactive polymer containing anionic ferrocenes as counter ions.

21. The electrode of claim 19 wherein the ferrocene groups include reactive substituents which allow the incorporation of the groups as monomers into a polymer which is dynamically attached to an underlying support.

22. Polypyrrole-ferrocene monosulfonate of forumula (IV)