Metal-organic framework-based sorbents and methods of synthesis thereof

Abstract

A carbon dioxide capture and release method of forming a MOF matrix material including at least one metal-organic-framework crystal that includes at least one metal ion or metal ion cluster coordinated to polydentate organic ligands. The method includes forming a positive moisture swing CO.sub.2 host by application of at least a portion of the MOF matrix material to at least a portion of a good, and exposing the good to a feed gas. The method also includes altering the absorption and desorption of CO.sub.2 in the CO.sub.2 host through a swing absorption/desorption process of moisture content, where an equilibrium pressure of CO.sub.2 over the CO.sub.2 host is based at least in part on the moisture content. The metal-organic-framework crystal can be UIO-66 including Zr.sub.6O.sub.4(OH).sub.4(CO.sub.2).sub.12 clusters linked by terephthalate acid ligands, and/or Zr.sub.6O.sub.4(OH).sub.4(CO.sub.2).sub.12 clusters linked by amino-terephthalic acid ligands, and/or Zr.sub.6O.sub.4(OH).sub.4(CO.sub.2).sub.12 clusters linked by nitro-terephthalic acid ligands.

Claims

1. A carbon dioxide capture and release method comprising: forming a metal-organic framework (MOF) matrix material including at least one metal-organic-framework crystal, the at least one metal-organic-framework crystal comprising at least one metal ion or metal ion cluster coordinated to polydentate organic ligands; and forming a positive moisture swing CO.sub.2 host by application of at least a portion of the MOF matrix material to at least a portion of a good; exposing the good to a feed gas, wherein the feed gas is ambient air; and altering the absorption and desorption of CO.sub.2 in the CO.sub.2 host through a swing absorption/desorption process of moisture content; and wherein an equilibrium pressure of CO.sub.2 over the CO.sub.2 host is based at least in part on the moisture content.

2. The method of claim 1, wherein the swing absorption/desorption process comprises altering the moisture content of the CO.sub.2 host.

3. The method of claim 1, wherein the moisture content is altered based on a moisture content of the feed gas.

4. The method of claim 1, wherein a positive moisture swing comprises an increase in moisture in the CO.sub.2 host and a related increase in CO.sub.2 absorption by the CO.sub.2 host.

5. The method of claim 1, wherein the at least one metal-organic-framework crystal comprises UIO-66.

6. The method claim 5, wherein the UIO-66 comprises Zr.sub.6O.sub.4(OH).sub.4(CO.sub.2).sub.12 clusters linked by terephthalate acid ligands.

7. The method claim 5, wherein the UIO-66 comprises Zr.sub.6O.sub.4(OH).sub.4(CO.sub.2).sub.12 clusters linked by amino-terephthalic acid ligands.

8. The method claim 5, wherein the UIO-66 comprises Zr.sub.6O.sub.4(OH).sub.4(CO.sub.2).sub.12 clusters linked by nitro-terephthalic acid ligands.

9. The method of claim 1, wherein the polydentate organic ligand includes at least one of terephthalate acid, amino-terephthalic acid, and nitro-terephthalic acid.

10. The method of claim 1, wherein the MOF matrix material comprises chromium (III) terephthalate.

11. The method of claim 1, wherein the MOF matrix material comprises a zeolitic imidazolate framework comprising ZIF-8.

12. The method of claim 1, wherein the good comprises glass, glass-ceramic, or ceramic oxide bead or particle.

13. The method of claim 12, wherein ceramic oxide is alumina.

14. The method of claim 1, wherein the good comprises a gas separation or storage tube or cylinder.

15. The method of claim 14, wherein the gas separation or storage tube or cylinder includes the MOF matrix material.

16. The method of claim 1, wherein the MOF matrix material is formed from a mixture of ZrCl.sub.4 and terephthalic acid in dimethylformamide and acetic acid heated to 120 C. for 24 hours.

17. The method of claim 5, wherein the equilibrium pressure of CO.sub.2 is based on the polydentate organic ligand.

18. The method of claim 5, wherein the polydentate organic ligand includes terephthalate acid, and at least one of amino-terephthalic acid, and nitro-terephthalic acid, and wherein the equilibrium pressure of CO.sub.2 over the CO.sub.2 host is based on the relative proportions of terephthalate acid, amino-terephthalic acid, and nitro-terephthalic acid.

19. The method of claim 1, wherein the application comprises depositing the MOF matrix material on or in at least a portion of the good.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates representations of UiO-66 MOF in accordance with some embodiments of the invention.

(2) FIG. 2 illustrates the nitrogen isotherm at 77K of UiO-66 in accordance with some embodiments of the invention.

(3) FIG. 3 illustrates the CO.sub.2 capacity of UiO-66 in accordance with some embodiments of the invention.

(4) FIG. 4 illustrates data from a moisture swing adsorption test showed a swing of approximately 150 ppm CO.sub.2 with a sample of approximately 100 mg UiO-66 when moisture switched between 5 and 25 parts per thousand in accordance with some embodiments of the invention.

(5) FIG. 5 illustrates a ligand structure of UiO-66-NH.sub.2 MOF in accordance with some embodiments of the invention.

(6) FIG. 6 illustrates the nitrogen isotherm at 77K of UiO-66-NH.sub.2 in accordance with some embodiments of the invention

(7) FIG. 7 illustrates the CO.sub.2 capacity of UiO-66-NH.sub.2 in accordance with some embodiments of the invention.

(8) FIG. 8 illustrates data from a moisture swing adsorption test showed a swing of approximately 150 ppm CO.sub.2 with a sample of approximately 100 mg UiO-66-NH.sub.2 when moisture switched between 5 and 25 parts per thousand in accordance with some embodiments of the invention.

(9) FIG. 9 illustrates a ligand structure of UiO-66-NO.sub.2 MOF in accordance with some embodiments of the invention.

(10) FIG. 10 illustrates the nitrogen isotherm at 77K of UiO-66-NO.sub.2 in accordance with some embodiments of the invention

(11) FIG. 11 illustrates the CO.sub.2 capacity of UiO-66-NO.sub.2 in accordance with some embodiments of the invention.

(12) FIG. 12 illustrates data from a moisture swing adsorption test showed a swing of approximately 150 ppm CO.sub.2 with a sample of approximately 100 mg UiO-66-NO.sub.2 when moisture switched between 5 and 25 parts per thousand in accordance with some embodiments of the invention.

(13) FIG. 13 illustrates a ligand structure of MIL-101(Cr) MOF in accordance with some embodiments of the invention.

(14) FIG. 14 illustrates the nitrogen isotherm at 77K of MIL-101(Cr) MOF in accordance with some embodiments of the invention

(15) FIG. 15 illustrates the CO.sub.2 capacity of MIL-101(Cr) MOF in accordance with some embodiments of the invention.

(16) FIG. 16 illustrates data from a moisture swing adsorption test showed a swing of approximately 150 ppm CO.sub.2 with a sample of approximately 100 mg MIL-101(Cr) MOF when moisture switched between 5 and 25 parts per thousand in accordance with some embodiments of the invention.

(17) FIG. 17 illustrates a ligand structure of ZIF-8 MOF in accordance with some embodiments of the invention.

(18) FIG. 18 illustrates the nitrogen isotherm of ZIF-8 MOF in accordance with some embodiments of the invention.

(19) FIG. 19 illustrates the CO.sub.2 capacity of ZIF-8 MOF in accordance with some embodiments of the invention.

(20) FIG. 20 illustrates data from a moisture swing adsorption test of ZIF-8 MOF in accordance with some embodiments of the invention.

DETAILED DESCRIPTION

(21) Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of including, comprising, or having and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms mounted, connected, supported, and coupled and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, connected and coupled are not restricted to physical or mechanical connections or couplings.

(22) The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention. Skilled artisans will recognize the examples provided herein have many useful alternatives that fall within the scope of embodiments of the invention.

(23) MOFs as a new class of materials can be used to capture CO.sub.2 from air in dry conditions and release CO.sub.2 in wet conditions by a moisture swing behavior. Flexibility in design and synthesis of MOF structures makes it possible to deploy environmental-friendly, economic-effective materials that offer significant design flexibility. For example, MOFs are known to be highly modifiable, and therefore can be tailored a specific device, apparatus or system.

(24) In certain embodiments, the invention includes materials and methods related to any MOF materials, wherein the MOF material includes one or more metal ions or metal ion clusters comprising a metal atom of group 4 or 6. For example, in some embodiments, the invention relates to any MOF matrices including metal ions comprising Zirconium and/or Chromium. In some other embodiments, the invention relates to any MOF matrices, wherein the metal ion or cluster comprises a metal atom of groups 3, 5, and/or 7-12. In some embodiments, different ligands such as terephthalic acid, amino-terephthalic acid, and nitro-terephthalic acid can be used to increase positive moisture swing behavior.

(25) In some embodiments of the invention, any of the MOF materials described herein can be integrated with an article of manufacture such as a commercially sold and distributed good. The good can be any useful article that can be deployed for selective capture and release of CO.sub.2 or other gases. The good can be an individual feature, article, device, material, kit, or system, and/or methods, or combinations thereof that include any one of the MOF materials described herein. In addition, any combination of two or more such individual features, articles, devices, materials, kits, or systems and/or methods, if such individual features, articles, devices, materials, kits, or systems are not mutually inconsistent, is included within the scope of the invention. For example, in one non-limiting example embodiment, the good can comprise granules or pellets of materials used for CO.sub.2 capture or release. In some embodiments, the MOF materials can be used with along or in combination with other materials. In some other embodiments, the good can include any article of manufacture that includes any one or more of the aforementioned MOF materials integrated with or applied within another article of manufacture that is used to selective store and release CO.sub.2. For example, in some embodiments, any of the MOF materials described herein can be applied to a base material (e.g., such as a granule, particle, or pellet) that can provide mechanical support for transport and use in an apparatus for selective capture and release of CO.sub.2.

(26) Some embodiments include a method of forming a good for selective storing and releasing of CO.sub.2. For example, some embodiments include forming a MOF matrix including one or more of the metal-organic-framework crystal materials described here, and contacting, coating or integrating the MOF matrix with the good. In this instance, the MOF matrix can include the at least one metal-organic-framework crystal material comprising at least one metal ion or metal ion cluster coordinated to at least one polydentate organic ligand. The method can include contacting, coating or integrating the MOF matrix with at least a portion of the good. For instance, in some embodiments, in some embodiments, any of the MOF materials described herein can be applied to an inert base substrate such as a glass, glass-ceramic, or ceramic oxide bead or particle (such as Al.sub.2O.sub.3) and used within one or more gas separation or storage tubes or cylinders.

(27) The MOF materials described herein can be tested for moisture swing using a two-step process. First, the material is tested for its ability to bind and release a gas such as CO.sub.2. The material is then exposed to increased levels of moisture and monitored for the release of CO.sub.2. Since the MOF materials are intended as collectors of CO.sub.2 from air, where the concentration is of CO.sub.2 is relatively low, the testing can use low concentrations of CO.sub.2 (400 ppm) when detecting moisture swing behavior.

(28) The apparatus used to study the behavior of candidate MOF materials can utilize a small closed gas loop where a finite volume of gas circulates through a reaction chamber, a humidistat and a CO.sub.2 and water vapor detector. The humidistat consists of a simple Peltier element that can warm or cool a small chamber that contains moisture. When heated, some of the water vapor in the chamber enters the gas flowing through it and thus raises its humidity. When cooled, the chamber will condense some of the water drying the gas circulating in the test volume. After the gas exits the humidistat, it can be heated to a fixed temperature of about 52 C. as it flows through an infrared gas analyzer. The sample chamber is thermally isolated from the temperature fluctuations inside the Peltier element. Further, a water vapor reading from the gas analyzer is used to adjust the humidity in the gas volume to a desired value. The presence of a moisture swing within a sample can be tested in the chamber as the CO.sub.2 stabilizes at one level of moisture, e.g., a low level. The water vapor concentration in the gas can be raised, and the sample can be monitored for CO.sub.2 release until the CO.sub.2 concentration in the chamber is in equilibrium with the loading state on the sorbent. A moisture swing can be manifested by the response of the system to a change in moisture. The fact that CO.sub.2 can be released with increased moisture demonstrates the sorbents CO.sub.2 capacity, and the fact that the equilibrium pressure over the sorbent is moisture dependent establishes the moisture swing property of the material.

(29) FIG. 1 illustrates representations of UiO-66 MOF in accordance with some embodiments of the invention. The UiO-66 is built up from Zr.sub.6O.sub.4(OH)4(CO.sub.2).sub.12 clusters 101 linked by terephthalate acid ligands 105, leading to a three-dimensional arrangement of micropores, in which each larger octahedral cage is surrounded by eight smaller tetrahedral cages. These two cages (8 and 11 in diameter, respectively) are connected through narrow windows of 6 in diameter. In some embodiments, solvothermal reactions can be used to prepare UiO-66 MOF materials. For example, in some embodiments, UiO-66 MOF synthesis can be carried out in a Teflon lined autoclave by mixing about 0.357 grams of ZrCl.sub.4 and about 0.254 grams of terephthalic acid in about 21 mL of dimethylformamide (DMF) and about 8.6 mL of acetic acid. The mixture solution can be heated to about 120 C. for about 24 hours, and then cooled to room temperature yielding white colored crystals. The synthesized sample (comprising UiO-66 crystals) can be obtained by filtration, and dried in air for about 24 hours before use.

(30) Referring to FIG. 2, showing a graph 200 illustrating the nitrogen isotherm at UiO-66, and FIG. 3, showing graph 300 illustrating the CO.sub.2 capacity of UiO-66 in accordance with some embodiments of the invention, the nitrogen isotherm at 77K of UiO-66, and has a BET surface area of 1188 m.sup.2/g, which is in close agreement to the maximum values reported previously. In some embodiments of the invention, the CO.sub.2 capacity is about 55 cm.sup.3/g at 100 kPa. FIG. 4 shows a graph 400 illustrating data from a moisture swing adsorption test showed a swing of approximately 150 ppm CO.sub.2 with a sample of approximately 100 mg UiO-66 when moisture switched between 5 and 25 parts per thousand in accordance with some embodiments of the invention. For example, data line 425 shows the concentration of CO.sub.2 as a function of time, while data line 450 shows water concentration in parts per thousand (ppt).

(31) In some embodiments, the terephthalic acid ligand can be replaced with other ligands to produce additional MOF materials demonstrating positive moisture swing gas absorption. For example, in some embodiments, amino-terephthalic acid can be used to increase positive moisture swing behavior. In some embodiments, the amino-terephthalic acid can be used as the sole ligand molecule in the MOF, whereas in other embodiments, the amino-terephthalic acid can be used with one or more other ligands, including terephthalic acid. For example, FIG. 5 illustrates a ligand structure 500 of UiO-66-NH.sub.2 MOF in accordance with some embodiments of the invention. In some embodiments, the UiO-66-NH.sub.2 crystal structure is substantially identical to UiO-66 with an additional amine group on the terephthalic ligand.

(32) FIG. 6 shows a graph 600 illustrating the nitrogen isotherm at 77K of UiO-66-NH.sub.2 in accordance with some embodiments of the invention, and FIG. 7 shows a graph 700 illustrating the CO.sub.2 capacity of UiO-66-NH.sub.2 in accordance with some embodiments of the invention. The nitrogen adsorption measurement of UiO-66-NH.sub.2 shows a corresponding BET surface area of 539 m.sup.2/g, and the CO.sub.2 capacity is about 60 cm.sup.3/g at 100 kPa. FIG. 8 shows a graph 800 illustrating data from a moisture swing adsorption test showed a swing of UiO-66-NH.sub.2 in accordance with some embodiments of the invention. The moisture swing adsorption test shows a swing of approximately 20 ppm CO.sub.2 with a sample of approximately 100 mg UiO-66-NH.sub.2 when moisture is switched between 5 and 25 ppt. For example, data line 825 shows the concentration of CO.sub.2 as a function of time, while data line 850 shows water concentration in parts per thousand (ppt).

(33) In some embodiments, the MOF ligand can be replaced with different ligands to produce additional MOF materials demonstrating positive moisture swing gas absorption. For example, in some embodiments, nitro-terephthalic acid can be used as a ligand in a MOF material demonstrating positive moisture swing behavior. In some embodiments, the nitro-terephthalic acid can be used as the sole ligand molecule in the MOF, whereas in other embodiments, the nitro-terephthalic acid can be used with one or more other ligands, including terephthalic acid and/or amino-terephthalic acid. For example, FIG. 9 illustrates a ligand structure 900 of UiO-66-NO.sub.2 MOF in accordance with some embodiments of the invention. The UiO-66-NO.sub.2 crystal structure is identical to UiO-66 with an additional nitro group on the terephthalic ligand.

(34) FIG. 10 shows a graph 1000 illustrating the nitrogen isotherm at 77K of UiO-66-NO.sub.2 in accordance with some embodiments of the invention, and FIG. 11 shows a graph 1100 illustrating the CO.sub.2 capacity of UiO-66-NO.sub.2 in accordance with some embodiments of the invention. The nitrogen adsorption measurement of UiO-66-NO.sub.2 shows a corresponding BET surface area of 470 m.sup.2/g, and the CO.sub.2 capacity is about 6 cm.sup.3/g at 100 kPa. FIG. 12 shows a graph 1200 illustrating data from a moisture swing adsorption test of UiO-66-NO.sub.2 in accordance with some embodiments of the invention. The moisture swing adsorption shows a swing of approximately 12 ppm CO.sub.2 with a sample of approximately 100 mg UiO-66-NO.sub.2 when moisture switched between 5 and 25 parts per thousand (ppt). For example, data line 1225 shows the concentration of CO.sub.2 as a function of time, while data line 1250 shows water concentration in parts per thousand (ppt).

(35) In some embodiments, the invention includes materials and methods related to any MOF materials using one or more alternative metal ions or metal ion clusters comprising a metal atom. For example, in some embodiments, the invention relates to any MOF matrices including Chromium. For example, chromium (III) terephthalate (MIL-101) can be a positive moisture swing gas absorption material in some embodiments. FIG. 13 illustrates a ligand structure of MIL-101(Cr) MOF in accordance with some embodiments of the invention. MIL-101(Cr) is built up from corner-sharing tetrahedrons, each of which is made from the self-assembly of CrO inorganic trimers and terephthalate acid ligands (structure 1305) forming a porous framework (structure 1310) with one type of micropore and two types of mesopores. The micropore has 8.6 free aperture for the windows and two mesopores have an internal free diameter of 29 and 34 , respectively.

(36) FIG. 14 shows a graph 1400 illustrating the nitrogen isotherm at 77K of MIL-101(Cr) MOF in accordance with some embodiments of the invention, and FIG. 15 shows a graph 1500 illustrating the CO.sub.2 capacity of MIL-101(Cr) MOF in accordance with some embodiments of the invention. The nitrogen adsorption measurement of MIL-101(Cr) shows a corresponding BET surface area of 1748 m.sup.2/g, and the CO.sub.2 capacity is only about 8 cm.sup.3/g at 100 kPa. FIG. 16 shows a graph 1600 illustrating data from a moisture swing adsorption test of MIL-101(Cr) MOF in accordance with some embodiments of the invention. The moisture swing adsorption test shows a swing of approximately 10 ppm CO.sub.2 with a sample of approximately 100 mg MIL-101(Cr) when moisture switched between 5 and 25 ppt.

(37) Other MOF materials can show varying levels of gas absortion and desorption. For example, ZIF-8 (a zeolitic imidazolate), which is a MOF formed by zinc ions coordinated by four imidazolate rings was tested for CO.sub.2 absorption and desorption. FIG. 17 illustrates a ligand structure 1700 of ZIF-8 MOF, and FIG. 18 shows a graph 1800 that illustrates the nitrogen isotherm of ZIF-8 MOF. The nitrogen adsorption measurement of ZIF-8 shows a corresponding BET surface area of 1693 m.sup.2/g, and the CO.sub.2 capacity is about 30 cm.sup.3/g at 100 kPa (shown in graph 1900 of FIG. 19, illustrating the CO.sub.2 capacity of ZIF-8 MOF.)

(38) FIG. 20 shows a graph 2000 illustrating data from a moisture swing adsorption test showing a swing of ZIF-8 MOF. In comparison with embodiments of the invention described herein, the moisture swing adsorption test showed a negligible swing capacity in 100 mg ZIF-8 when moisture switched between 5 and 25 ppt. For example, data line 2025 shows the concentration of CO.sub.2 as a function of time, while data line 2050 shows water concentration in parts per thousand (ppt).