METAL-ORGANIC FRAMEWORK TEMPLATED SYNTHESIS OF POROUS INORGANIC MATERIALS AS NOVEL SORBENTS

• US 20140319058A1
• Filed: 04/01/2014
• Published: 10/30/2014
• Est. Priority Date: 04/01/2013
• Status: Active Grant

• Current Assignee: Battelle Savannah River Alliance LLC, University of Chicago, University of North Carolina At Chapel Hill (University of North Carolina System)
• Original Assignee: University of Chicago, University of North Carolina At Chapel Hill (University of North Carolina System)
• Inventors: Taylor-Pashow, Kathryn M.L., Lin, Wenbin, Abney, Carter W.
• Granted Patent: US 9,597,658 B2
• Time in Patent Office: Days
• US Class Current: 210/660
• CPC Class Codes: B01D 2253/204 Metal organic frameworks (MOF's)
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B01J 20/0211 Compounds of Ti, Zr, Hf
• CPC Class Codes: B01J 20/045 containing sulfur, e.g. sulfates, thiosulfates, gypsum
• CPC Class Codes: B01J 20/06 comprising oxides or hydroxides of metals not provided for in group B01J20/04
• CPC Class Codes: B01J 20/226 Coordination polymers, e.g. metal-organic frameworks [MOF], zeolitic imidazolate frameworks [ZIF] preparation of metal complexes containing carboxylic acid moieties C07C51/418; MOF's per se C07F
• CPC Class Codes: B01J 20/28083 being in the range 2-50 nm, i.e. mesopores
• CPC Class Codes: B01J 20/3057 Use of a templating or imprinting material molecularly imprinted polymers B01J20/268; filling pores of a substrate or matrix followed by the removal of the substrate or matrix
• CPC Class Codes: B01J 20/3085 Chemical treatments not covered by groups B01J20/3007 - B01J20/3078
• CPC Class Codes: C02F 1/281 using inorganic sorbents
• CPC Class Codes: C02F 1/285 using synthetic organic sorbents
• CPC Class Codes: C02F 1/288 using composite sorbents, e.g. coated, impregnated, multi-layered
• CPC Class Codes: C02F 2101/006 Radioactive compounds
• CPC Class Codes: C02F 2101/20 Heavy metals or heavy metal compounds
• CPC Class Codes: C02F 2103/08 Seawater, e.g. for desalination
• CPC Class Codes: C02F 2103/10 from quarries or from mining activities
• CPC Class Codes: G21F 9/12 by absorption; by adsorption; by ion-exchange
• CPC Class Codes: G21F 9/167 in polymeric matrix, e.g. resins, tars

Abstract

A novel metal-organic framework (MOF) templated process for the synthesis of highly porous inorganic sorbents for removing radionuclides, actinides, and heavy metals is disclosed. The highly porous nature of the MOFs leads to highly porous inorganic sorbents (such as oxides, phosphates, sulfides, etc) with accessible surface binding sites that are suitable for removing radionuclides from high level nuclear wastes, extracting uranium from acid mine drainage and seawater, and sequestering heavy metals from waste streams. In some cases, MOFs can be directly used for removing these metal ions as MOFs are converted to highly porous inorganic sorbents in situ.

Claims

1. A method for preparing a sorbent material comprising:

providing a MOF template having a plurality of bridging ligands;

removing the bridging ligands by exposing the MOF template to a solution selected from the group consisting of acids and bases;

incorporating into the MOF template an inorganic moiety dissolved in the solution, thereby forming an inorganic sorbent material having, a morphology similar to the MOF and wherein the sorbent material has nano-absorbent properties.

2. The method according to claim 1 wherein MOF template is selected from MOF prepared using a metal selected from the group consisting of from Group IV metals through Group XIII metals, such as Ti, Zr, and In, and combinations thereof.

3. The method according to claim 1 wherein the MOF template contains organic bridging ligands.

4. The method according to claim 1 wherein the sorbent material has a pore size ranging from about 5.6 Å

to about 100 Å

.

5. The method according to claim 1 wherein the sorbent material has a volumetric surface area equal to or greater than the volume the surface area of the MOF template.

6. The method according to claim 1 wherein the inorganic material is selected from the group consisting of TiOx, TiOxPhos, TiPhos, ZrOx, ZrOxPhos, ZrPhos, In₂S₃, and NaInS₂,

7. The method according to claim 1 wherein the sorbent material has a surface area ranging from about 10 m² g¹ to about 401 m² g⁻

1.

8. The method according to claim 1 comprising the additional step of treating the sorbent material with a peroxide to improve the sorption performance.

9. The sorbent material made according to the process of claim 1 wherein the sorbent is used for radionuclide removal from a liquid or gas stream.

10. The sorbent according to the process of claim 1 wherein the absorbent, is used to remove metal contaminants from a waste stream.

11. The sorbent material made according to method of claim 1 wherein the sorbent material is used to separate uranium from spent nuclear fuel.

12. The sorbent material made according to claim 1 wherein the material is used as a sorbent to separate actinides from fission products.

13. The sorbent material made according to claim 1 and is used to separate radionuclides from a flux associated with a nuclear fuel cycle.

14. The sorbent material made according to claim 1 and which is used as a barrier sorbent for placement around a long term storage waste material.

15. The sorbent material made according to claim 1 wherein the substrate is used as a sorbent for a waste material and the sorbent waste material is further immobilized in a matrix selected the group consisting of cement, bitumen, sludge, ceramic, and glass.

16. The sorbent material made according to claim 1 wherein the sorbent material used as a sorbent for gases.

17. The method according to claim 1 comprising the additional step of treating the sorbent material with Na₂S or Na₂Se gas to form a highly porous metal chalcogenide.

18. The sorbent material made in according to claim 1 wherein the sorbent material provides a template for housing transition metals, transition metal oxides, alkalides, alkalide earth metals, catalyst, and dopants.

19. A method of removing radionuclides from contaminated sea water comprising:

providing a MOF template having a plurality of bridging ligands;

removing the bridging ligands by exposing the MOF template to solution selected from the group consisting of acids and bases;

incorporating into the MOF template an inorganic moiety dissolved in the solution, the inorganic moiety selected from the group consisting of an oxide, a phosphate, an oxyphosphate, a sulfide and combinations thereof, thereby forming an inorganic sorbent material;

using the inorganic sorbent material to separate a radionuclide from sea water.

20. A method of removing radionuclides from high level nuclear waste (HLW) generated from processing of spent fuel comprising:

providing a MOF template having a plurality of bridging ligands;

removing the bridging ligands by exposing the MOF template to solution selected from the group consisting of acids and bases;

incorporating into the MOF template an inorganic moiety dissolved in the solution, the inorganic moiety selected from the group consisting of oxide, phosphate, oxyphosphate, and sulfide and combinations thereof, thereby forming an inorganic sorbent material;

using the inorganic sorbent material to separate a radionuclide from HLW.