Mixed-metal mixed-organic framework systems for selective CO2 capture

Abstract

Provided herein is an adsorbent material comprising a mixed-metal mixed-organic framework comprising metal ions of two or more distinct metals and a plurality of organic linkers. Each of the plurality of organic linkers is linked to a metal ion. The adsorbent material further comprises a plurality of ligands. In one embodiment, each of the plurality of ligands is an amine or other Lewis base (electron donor) that attaches to the metal ions of the two or more distinct elements of the mixed-metal organic framework, thereby providing a mixed-metal mixed-organic framework system.

Description

[Technical field]

[0001] The present invention relates to modified mixed metal, mixed organic framework systems for selective CO2 capture and methods of using same. [Background technology]

[0002] Burning fossil fuels results in the emission of CO2, a large component of the anthropogenic contribution to global climate change. In addition to the environmental impacts, penalties and / or tax incentives associated with CO2 emissions raise significant financial considerations for infrastructure development, energy production and manufacturing. The crux of the matter is that the concentration of emitted CO2 can vary dramatically during application and is most commonly diluted by the harmless atmospheric gas N2. Nevertheless, the amount of CO2 emitted is large. Therefore, there is a need for a technology that can selectively remove diluted CO2 from gas streams, with performance that is tunable for implementation in a variety of applications, and that can easily and economically capture CO2 for use and storage, and then regenerate the sorbent technology for reuse.

[0003] Conventional solutions for CO2 capture have mainly focused on liquid amine solutions, which are expensive to regenerate, cause engineering problems due to changes in physical properties when CO2 is adsorbed, and are somewhat corrosive. Recently developed technologies include water-lean solutions, which show optimal improvements in CO2 capture performance, but are significantly more expensive than aqueous amines and still suffer from engineering problems due to changes in physical properties. Solid-phase adsorbents such as polymers and zeolites have also been investigated for CO2 capture. The former typically have low selectivity and poor capacity, while the latter are easily deactivated by water, requiring impractical pretreatment of the emissions prior to CO2 removal.

[0004] In addition, prior art metal-organic frameworks for selective CO2 capture have been reported, prepared from single metal framework materials and post-synthetically functionalized with various diamines. These systems can provide some degree of tunable CO2 capture performance through the choice of diamine, but limitations in the variety and effectiveness of diamines reduce the extent to which the materials can be optimized for specific emissions streams. Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, a need exists for a framework system that can be tuned and / or modified to adjust CO2 adsorption to the required level to capture CO2 from different exhaust streams. [Means for solving the problem]

[0006] Provided herein is a mixed metal organic framework having two or more distinct metal elements with empirical or chemical formulas and bridged by a linker. The subject mixed metal organic framework comprises a plurality of disalicylate linkers, each linker comprising one or more aromatic rings, each aromatic ring comprising a carboxylate functional group and an alcohol functional group, the carboxylate functional group and the alcohol functional group being adjacent to each other on each aromatic ring. In addition, each aromatic ring is positioned at a maximum distance from the other.

[0007] Furthermore, the following formula: 1 x M 2 (2-x) (A) (where M 1 and M 2 are each independently a different metal cation, and A is a disalicylate organic linker. 1 and M 2 are both independently a divalent metal cation. 1 and M 2 Ca2+ , Mg 2+ , Fe 2+ , Cr 2+ , V 2+ , Mn 2+ , Co 2+ , Ni 2+ , Zn 2+ , Cu 2+ In one embodiment, A is independently selected from: [ka] (In the formula, R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 and R 20 are each independently selected from H, halogen, hydroxyl, methyl, and halogen-substituted methyl; and R 17 are a plurality of disalicylate organic linkers independently selected from the group consisting of: selected from the group consisting of substituted or unsubstituted aryl, vinyl, alkynyl, substituted or unsubstituted heteroaryl, divinylbenzene, and diacetylbenzene.

[0008] In one embodiment, the mixed metal organic framework provides an X-ray diffraction pattern having a unit cell that can be shown to be a hexagonal unit cell. In one embodiment, the unit cell is selected from space groups 168-194 as defined in the International Tables for Crystallography. In one embodiment, the mixed metal organic framework of the present invention further comprises a metal rod structure described by the Lidin-Andersson helix as described by Schoedel, Li, Li, O'Keeffe and Yaghi, Chem Rev. 2016 116, 12466-12535. In one embodiment, the mixed metal organic framework has hexagonal pores arranged parallel to the metal rod structure. In one embodiment, the mixed metal organic framework of the present invention exhibits a (3,5,7)-C msi net according to the approach described by Schoedel, Li, Li, O'Keeffe and Yaghi, Chem Rev. 2016 116, 12466-12535. In one embodiment, the mixed metal organic framework exhibits a (3,5,7)-c msg net according to the approach described by Schoedel, Li, Li, O'Keeffe and Yaghi, Chem Rev. 2016 116, 12466-12535.

[0009] In one embodiment, the subject mixed metal-organic frameworks exhibit the following peak maxima in the X-ray diffraction pattern at 30° C. after drying at 250° C. under N for 30 minutes:

[0010] [Table 1]

[0011] In one embodiment, after drying at 250° C. under N 2 for 30 minutes, the apparent peak maxima in the X-ray diffraction pattern at 30° C. are as follows:

[0012] [Table 2]

[0013] In one embodiment, the A-axis of the unit cell and the B-axis of the unit cell are each greater than 18 Å, and the c-axis is greater than 6 Å.

[0014] Further provided herein is a mixed metal mixed organic framework system comprising a subject mixed metal organic framework and a ligand comprising an amine. In one embodiment, the ligand is a diamine. In one embodiment, the diamine is a cyclic diamine. In one embodiment, the diamine is selected from the group consisting of the following: [ka] wherein Z is independently selected from carbon, silicon, germanium, sulfur, and selenium; and R1, R2, R3, R4, R5, R6, R7, R8, R9, and R 10 are each independently selected from H, halogen, methyl, halogen-substituted methyl, and hydroxyl.

[0015] In one embodiment, the diamine ligand is selected from one of dimethylethylenediamine (mmen) or 2-(aminomethyl)piperidine (2-ampd). In one embodiment, the ligand is a tetramine. In one embodiment, the tetramine is selected from one of 3-4-3 tetramine (spermine) or 2-2-2 tetramine.

[0016] In one embodiment, the mixed metal organic framework system includes a second ligand that is a triamine. [ka] is selected from.

[0017] Also provided is a method of synthesizing a mixed metal organic framework, comprising contacting a solution comprising two or more sources of two or more distinct metal elements and an organic linker capable of bridging metal cations, and heating the mixture to produce one or more of the present mixed metal organic frameworks. In one embodiment, the two or more distinct metal elements are independently selected from Ca, Mg, Fe, Cr, V, Mn, Co, Ni, Zn, Cu. In one embodiment, the solution comprises an elemental metal or a salt of the metal whose counter anion comprises nitrate, acetate, carbonate, oxide, hydroxide, fluoride, chloride, bromide, iodide, phosphate, or acetylacetonate.

[0018] Further provided is a method of synthesis of a mixed metal organic framework comprising contacting the mixed metal organic framework with a second ligand in a gas or liquid medium. In one embodiment, the ligand is an amine-containing molecule. In one embodiment, the ligand is a diamine. In one embodiment, the ligand is a triamine. In one embodiment, the ligand is a tetramine.

[0019] Provided herein are particles comprising one or more of the subject mixed metal mixed organic framework systems. Also provided herein are adsorbent materials comprising the subject mixed metal mixed organic framework systems. In one embodiment, the mixed metal mixed organic frameworks exhibit a V-shaped isotherm profile for CO2. Also provided are methods of adsorbing carbon dioxide from a carbon dioxide-containing stream by contacting the stream with one or more adsorbents of the present invention. Also provided are methods of adjusting the position of the step of the V-shaped CO2 isotherm, including changing the amount or type of metal ions of two or more distinct metals of the mixed metal organic framework or mixed metal mixed organic framework system. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 shows the powder X-ray diffraction pattern of a representative mixed metal MOF-274 framework system. [Diagram 2]2A, 2B, 2C, 2D and 2E show representative data collected by energy dispersive X-ray spectroscopy ("EDS"). [Diagram 3] Figure 3 shows normalized X-ray absorption spectroscopy data for Ni1Mg1-MOF-274 (50% Ni) recovered at the Ni K-edge. It is important to note that as the Mg:Ni ratio increases, the feature near 2.5 Å decreases. [Figure 4] FIG. 4 is a comparison of scattering paths revealing that Mg backscatters less strongly than Ni. [Diagram 5] FIG. 5 is a representative fitted extended X-ray absorption fine structure (EXAFS) spectrum for the Ni1Mg1-MOF-274 (50% Ni) framework system. [Figure 6] FIG. 6 is a representative powder X-ray diffraction pattern of the mixed metal framework system EMM-44 (based on the 2-ampd adduct mixed metal MOF-274 framework). [Figure 7] FIG. 7 is a representative 1H NMR of the mixed metal mixed organic framework system EMM-44 after digestion with DCl in DMSO-d6. [Figure 8] FIG. 8 is a CO2 isotherm for Mn0.1Mg1.9-EMM-44 (5% Mn), Mn0.2Mg1.8-EMM-44 (10% Mn), Mn0.5Mg1.5-EMM-44 (25% Mn) and Mn1Mg1-EMM44 (50% Mn) MOF-274, showing the unusual and highly desirable V-shaped isotherm. [Figure 9] FIG. 9 shows the CO2 isotherms for Mn0.1Mg1.9-EMM-44 (5% Mn), Mn0.2Mg1.8-EMM-44 (10% Mn), Mn0.5Mg1.5-EMM-44 (25% Mn) and Mn1Mg1-EMM44 (50% Mn) MOF-274 plotted on a log scale to more fully show the characteristic low-pressure step in the V-shaped isotherm. [Figure 10] FIG. 10 shows the location of the CO2 isotherm midpoint versus Mn loading for MnxMg2-x-EMM-44. [Figure 11] FIG. 11 shows the structure of the diamine-appended metal-organic framework EMM-44. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Provided herein is a mixed metal organic framework comprising a metal ion of two or more distinct elements and a plurality of organic linkers, each organic linker being linked to one of the metal ions of two or more distinct elements.Further provided is a mixed metal organic framework system comprising a mixed metal organic framework and a ligand.The mixed metal organic framework comprises a plurality of metal ions of two or more distinct elements and a plurality of organic linkers, each organic linker being linked to one of the metal ions of two or more distinct elements.

[0022] In one embodiment, the mixed metal organic framework comprises two or more distinct elements independently selected from the group of Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu, and Zn. In one embodiment, each of the two or more distinct elements is Mg, Mn, Ni, or Zn. In one embodiment, the mixed metal organic framework comprises a ligand selected from the group of diamines, cyclic diamines, triamines, and / or tetraamines. In one embodiment, the ligand is an organic diamine. In one embodiment, the ligand is the amine 2-(aminomethyl)piperidine ("2-ampd"). In one embodiment, the mixed metal mixed organic framework system exhibits a V-shaped step CO2 isotherm profile upon exposure to carbon dioxide. In one embodiment, the V-shaped step is tuned by the metal selection and / or ratio of the metals incorporated into the mixed metal framework.

[0023] Also provided is an adsorbent material comprising the mixed metal mixed organic framework system described herein.Further provided is a method for removing carbon dioxide from a feed, comprising passing the feed over the mixed metal mixed organic framework system.In addition, provided is a method for adjusting the position of the step of the V-type isotherm, comprising varying one or more metal ions of two or more distinct elements of the mixed metal mixed organic framework system.

[0024] In one embodiment, the general structure of the compound represented herein is [ka] (In the formula, M 1 is a metal or a salt thereof, and M 2 is a metal or its salt, while M 1 is M 2 rather than; X is a value between 0.01 and 1.99; and A is a plurality of organic linkers.

[0025] Further, in one embodiment, the general structure of formula II [ka] (In the formula, M 1 is independently selected from Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu and Zn; M 2 are independently selected from Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu and Zn, and M 1 is M 2 rather than; X is a value between 0.01 and 1.99; A is an organic linker; and B is a ligand.

[0026] Before the present methods and devices are disclosed and described, it is to be understood that, unless otherwise indicated, this invention is not limited to particular compounds, components, compositions, reactants, reaction conditions, ligands, catalyst structures, metallocene structures, etc., which may vary unless otherwise specified. It is also understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[0027] For purposes of this disclosure, the following definitions apply.

[0028] As used herein, the terms "a" and "the" are understood to include plural and singular.

[0029] As used herein, the term "heteroatom" includes oxygen (O), nitrogen (N), sulfur (S) and silicon (Si), boron (B) and phosphorus (P).

[0030] The term "aryl" refers to a polyunsaturated aromatic substituent, which may be a single ring or multiple rings fused together or covalently linked, unless otherwise specified. In one embodiment, the substituent has 1 to 11 rings, or more particularly 1 to 3 rings. The term "heteroaryl" refers to an aryl substituent group (or ring) containing 1 to 4 heteroatoms selected from N, O and S, the nitrogen and sulfur atoms being optionally oxidized, and the nitrogen atom being optionally quaternized. Exemplary heteroaryl groups are 6-membered azines, such as pyridinyl, diazinyl and triazinyl. A heteroaryl group can be attached to the remainder of a molecule through a heteroatom. Non-limiting examples of aryl and heteroaryl groups include phenyl, 1-naphthyl, 2-naphthyl, 4-biphenyl, 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 3-pyrazolyl, 2-imidazolyl, 4-imidazolyl, pyrazinyl, 2-oxazolyl, 4-oxazolyl, 2-phenyl-4-oxazolyl, 5-oxazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-phenyl-4-ox ... -thiazolyl, 4-thiazolyl, 5-thiazolyl, 2-furyl, 3-furyl, 2-thienyl, 3-thienyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 2-pyrimidyl, 4-pyrimidyl, 5-benzothiazolyl, purinyl, 2-benzimidazolyl, 5-indolyl, 1-isoquinolyl, 5-isoquinolyl, 2-quinoxalinyl, 5-quinoxalinyl, 3-quinolyl, and 6-quinolyl. Substituents for each of the above noted aryl and heteroaryl ring systems are selected from the group of acceptable substituents described below.

[0031] As used herein, the terms "alkyl," "aryl," and "heteroaryl" can optionally include substituted and unsubstituted forms of the indicated species. Substituents for aryl and heteroaryl groups are generally referred to as "aryl group substituents." Substituents can include, for example, but are not limited to, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heterocycloalkyl, --OR', =O, =NR', =N--OR', --NR'R'', --SR', -halogen, --SiR'R''R''', --OC(O)R', --C(O)R', --CO.sub.2R', --CONR'R'', --OC(O)NR'R'', --NR''C(O)R', --NR'--C(O)NR' and R', --NR''C(O).sub.2R', --NR--C(NR'R''R'').dbd.NR'''', --NR--C(NR'R'')=NR''', --S(O)R', --S(O)R', --S(O)NR'R'', --NRSOR', --CN, and groups attached to the heteroaryl or heteroarene nucleus via a carbon or heteroatom (e.g., P, N, O, S, Si or B), including fluoro(C1-C4)alkoxy and fluoro(C1-C4)alkyl. Each of the above groups is attached directly or through a heteroatom (e.g., P, N, O, S, Si or B) to an aryl or heteroaryl nucleus; and R', R'', R''', and R'''' are preferably independently selected from hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl and substituted or unsubstituted heteroaryl. When a compound of the invention includes more than one R group, for example, each R group is independently selected, as are each R', R'', R''', and R'''' group when more than one of R', R'', R''' and R'''' groups is present.

[0032] The term “alkyl,” by itself or as part of another substituent, unless otherwise stated, may be fully saturated, monovalent or polyunsaturated, and can include divalent, trivalent and polyvalent groups, having the specified number of carbon atoms (i.e., C1-C 10 means 1-10 carbons), linear or branched chain, or cyclic hydrocarbon groups, or combinations thereof. Examples of saturated hydrocarbon groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, isobutyl, sec-butyl, cyclohexyl, methyl(cyclohexyl), cyclopropylmethyl, homologs and isomers such as n-pentyl, n-hexyl, n-heptyl, n-octyl, and the like. Unsaturated alkyl groups are those having one or more double or triple bonds. Examples of unsaturated alkyl groups include, but are not limited to, vinyl, 2-propenyl, crotyl, 2-isopentenyl, 2-(butadienyl), 2,4-pentadienyl, 3-(1,4-pentadienyl), ethynyl, 1- and 3-propynyl, 3-butynyl, and higher homologs and isomers. The term "alkyl," unless otherwise noted, is also meant to optionally include those derivatives of alkyl defined in more detail below, such as "heteroalkyl."

[0033] The term "heteroalkyl," by itself or in combination with another term, means, unless otherwise stated, a stable linear or branched chain, or cyclic hydrocarbon group, or combinations thereof, consisting of the specified number of carbon atoms and at least one heteroatom selected from the group consisting of O, N, Si, and S, and in which the nitrogen and sulfur atoms may be optionally oxidized, and the nitrogen heteroatom may be optionally quaternized. The heteroatoms O, N, and S, as well as Si, may be placed at any interior position of the heteroalkyl group or at the position at which the alkyl group is attached to the remainder of the molecule. Examples include, but are not limited to, --CH2--CH2--O--CH3, --CH2--CH.2--NH--CH3, --CH2--CH2--N(CH3)--CH3, --CH2--S--CH2--CH3, --CH2--CH2, --S(O)--CH3, --CH2--CH2--S(O)2--CH3, --CH=CH--O--CH3, --Si(CH3)3, --CH2-CH=N--OCH3, and --CH=CH--N(CH3)--CH3. Up to two heteroatoms may be consecutive, such as, for example, --CH2--NH--OCH3 and --CH2--O--Si(CH3)3. Similarly, the term "heteroalkylene," alone or as part of another substituent, means a divalent radical derived from heteroalkyl, such as, but not limited to, --CH2--CH2--S--CH2--CH2-- and --CH2--S--CH2--CH2--NH--CH2--. For heteroalkylene groups, heteroatoms can also occupy either or both of the chain termini (e.g., oxyalkylene, alkylenedioxy, alkyleneamino, alkylenediamino, etc.). Still further, for alkylene and heteroalkylene linking groups, no orientation of the linking group is implied by the direction in which the formula of the linking group is written. For example, the formula --CO2R'-- represents both --C(O)OR' and --OC(O)R'.

[0034] As used herein, the term "ligand" means a molecule that contains one or more substituents capable of functioning as a Lewis base (electron donor). In one embodiment, the ligand can be oxygen, phosphorus, or sulfur. In one embodiment, the ligand can be an amine or an amine containing 1-10 amine groups.

[0035] The terms "halo" or "halogen," by themselves or as part of another substituent, mean, unless otherwise stated, a fluorine, chlorine, bromine, or iodine atom.

[0036] The symbol "R" is a general abbreviation that represents a substituent selected from H, substituted or unsubstituted alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted aryl, substituted or unsubstituted heteroaryl, and substituted or unsubstituted heterocycloalkyl groups.

[0037] As used herein, the term "Periodic Table" means the Periodic Table of the Elements of the International Union of Pure and Applied Chemistry (IUPAC), dated December 2015.

[0038] As used herein, "isotherm" refers to the adsorption of an adsorbate corresponding to its concentration when the temperature of the system is held constant. In one embodiment, the adsorbate is CO2 and the concentration can be measured as the pressure of CO2. As described herein, isotherms can be performed using various mathematical models applied to calculate the apparent surface area with porous materials. S. Brunauer, PH Emmett and E. Teller. J. Am. Chem. Soc. 1938, 60, 309-319; K. Walton and RQ Snurr, J. Am. Chem. Soc. 2007, 129, 8552-8556; I. Langmuir, J. Am. Chem. Soc. 1916, 38, 2221.

[0039] As used herein, the term "step" in an isotherm is defined by a sigmoidal curve absorption profile (also known as a V-shaped isotherm). S. J. Gregg and K. S. W. Singh, Adsorption, Surface Area and Porosity, 2nd Ed. Academic Press Inc., New York, NY, 1982, Ch V. A step can generally be defined by a positive second derivative in the isotherm, followed by an inflection point, and then a negative second derivative in the isotherm. A step occurs when the binding sites of the adsorbent become accessible only at certain gas partial pressures, for example, when CO2 inserts into a metal-amine bond or when a dynamic framework pore is opened.

[0040] Depending on the particular ligand or substituents found in the compounds described herein, the term "salt" includes salts of compounds prepared by neutralization of an acid or base. When a compound of the present invention contains a relatively acidic functionality, a base addition salt can be obtained by contacting the neutral form of such a compound with a sufficient amount of a desired base, either neat or in a suitable inert solvent. Examples of base addition salts include sodium, potassium, calcium, ammonium, organic amino or magnesium salts or similar salts. Examples of acid addition salts include those derived from inorganic acids such as hydrochloric acid, hydrobromic acid, nitric acid, carbonic acid, monohydrogen carbonate, phosphoric acid, monohydrogen phosphate, dihydrogen phosphate, sulfuric acid, monohydrogen sulfate, hydroiodic acid, or phosphorous acid, as well as salts derived from relatively non-toxic organic acids such as acetic acid, propionic acid, isobutyric acid, butyric acid, maleic acid, malic acid, malonic acid, benzoic acid, succinic acid, suberic acid, fumaric acid, lactic acid, mandelic acid, phthalic acid, benzenesulfonic acid, p-tolylsulfonic acid, citric acid, tartaric acid, methanesulfuric acid, and the like. Certain compounds of the present disclosure contain both basic and acidic functionalities that allow the compounds to be converted into either base or acid addition salts. Salt hydrates are also included.

[0041] In any compound described herein having one or more chiral centers, unless the absolute stereochemistry is explicitly indicated, it is understood that each center may be independently in the R-configuration or S-configuration, or a mixture thereof. Thus, the compounds provided herein may be enantiomerically pure or may be stereoisomeric mixtures. In addition, in any compound described herein having one or more double bonds that result in geometric isomers that can be defined as E or Z, it is understood that each double bond may be independently in the E or Z configuration, or a mixture thereof. Similarly, in any compound described, it is understood that all tautomeric forms are intended to be included.

[0042] In addition, the compounds provided herein may contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute such compounds. For example, the compounds may contain unnatural proportions of atomic isotopes, such as tritium ( 3 H), iodine-125( 125 I) or carbon-14( 14 C). All isotopic variations of the subject compounds, whether radioactive or not, are intended to be encompassed within the scope of the present disclosure.

[0043] Provided herein is a mixed metal organic framework comprising a plurality of metal ions of two or more distinct elements and a plurality of organic linkers, each linker being linked to at least one metal ion of the plurality of metal ions of the two or more distinct elements.Also provided herein is a mixed metal organic framework system comprising a mixed metal organic framework comprising a plurality of metal ions of two or more distinct elements, and a ligand, and a plurality of organic linkers linked to one of the metal ions.

[0044] In one embodiment, the mixed metal organic frameworks presented herein have the general formula I: [ka] (In the formula, M 1is a metal and M 2 is a metal, but M 1 is M 2 rather than; X is a value between 0.01 and 1.99; and A is an organic linker as described herein.

[0045] In one embodiment, X is a value from 0.01 to 1.99. In one embodiment, X is a value from 0.1 to 1. In one embodiment, X is a value selected from the group consisting of 0.05, 0.1, 0.5, and 1. Furthermore, X and 2-X are M 1 Against M 2 Although the formulas represent relative ratios of M, it should be understood that no particular stoichiometry is implied in Formula I, Formula IA, Formula II, or Formula III described herein. As such, the mixed metal-organic frameworks of Formula I, IA, II, or III may each represent a ratio of M 1 Against M 2 In addition, it is understood that metals are typically provided in ionic form and that available valences will vary depending on the metal selected.

[0046] The metal of formulas I, IA, II and III described herein can be one of the elements of Groups IIA, IIIB, IVB, VB, VIB, VIIB, VIII, IB and IIB of the Periodic Table, Period 4, and Group IIA of the Periodic Table, Period 3, including Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu and Zn. Furthermore, the mixed metal organic frameworks can theoretically be any of the elements M 1 x M 2 y …M n z (A)(B)2|x+y+…+z=2 and M 1 ≠M 2 ≠…≠M n The term "metal oxide" includes different combinations of two or more separate elements and metals, such as:

[0047] In one embodiment, M 1is selected from Mg, V, Ca, Mn, Cr, Fe, Co, Ni, Cu and Zn; and M 2 is selected from Mg, V, Ca, Mn, Cr, Fe, Co, Ni, Cu and Zn, with the proviso that M 1 is M 2 In one embodiment, M 1 is selected from the group consisting of Mg, Mn, Ni and Zn; and M 2 is selected from the group consisting of Mg, Mn, Ni and Zn; 1 is M 2 In one embodiment, M 1 is Mg, and M 2 is Mn. In one embodiment, M 1 is Mg, and M 2 In one embodiment, M is Ni. 1 is Zn, and M 2 is Ni. Additionally, the metals are typically shown in ionic form, and it is understood that the valence will vary depending on the metal selected. Additionally, the metals can be provided as a salt or in a salt form.

[0048] In addition, the metal can be a monovalent metal that renders A a protonated form of the linker HA. For example, the metal can be Na +or one of group I. The metal can also be one of two or more divalent cations ("divalent metals") or trivalent cations ("trivalent metals"). In one embodiment, the mixed metal mixed organic framework includes metals that are in an oxidation state other than +2 (i.e., higher than just divalent, trivalent, or tetravalent). The framework can have metals that include mixtures of different oxidation states. Exemplary mixtures include Fe(II) and Fe(III), Cu(II) and Cu(I), and / or Mn(II) and Mn(III). More specifically, trivalent metals are metals that have a +3 oxidation state. Some metals used to form mixed metal organic frameworks, particularly Fe and Mn, are capable of adopting +2 (divalent) or +3 (trivalent) oxidation states under relatively mild conditions. Chem. Mater, 2017, 29, 6181. Similarly, Cu(II) can form Cu(I) under mild conditions. As such, any minor change to the oxidation state of any metal and / or selective change of the oxidation state of the metal can be used to modify the present mixed metal organic framework. Furthermore, different molecular fragments C1, C2, ... C n Finally, all of the above variations can be combined with multiple metals (two or more distinct metals), for example, with multiple valences and multiple charge-balancing molecular fragments.

[0049] Suitable organic linkers (also referred to herein as "linkers") can be determined from the structure of the mixed metal organic framework and the symmetry operations associated with the portion of the organic linker that binds to the metal node of the mixed metal organic framework. Ligands that are chemically or structurally different but allow the metal node binding regions to be related by the C2 symmetry axis form a mixed metal organic framework of the same topology. In one embodiment, the organic linker can be formed by two phenyl rings bonded at carbon 1,1', by a carboxylic acid at carbon 3,3', and by an alcohol at carbon 4,4'. Swapping the positions of the carboxylic acid and alcohol (e.g. "pc-H4DOBPDC" or "pc-MOF-274" below) does not change the topology of the mixed metal organic framework.

[0050] In one embodiment, useful linkers include: [ka] where R1 is linked to R1' and R2 is linked to R2''.

[0051] Examples of such linkers include: [ka] where R is any molecular fragment.

[0052] Examples of suitable organic linkers include para-carboxylates ("pc-linkers"), such as 4,4'-dioxidobiphenyl-3,3'-dicarboxylate (DOBPDC); 4,4''-dioxidobiphenyl-3,3''-dicarboxylate (DOTPDC); and dioxidobiphenyl-4,4'-dicarboxylate (para-carboxylate-DOBPDC, also written as PC-DOBPDC), as well as the following compounds: [ka] Includes:

[0053] In one embodiment, the organic linker has the formula: [ka] (In the formula, R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , R 18 , R 19 and R 20 are each independently selected from H, halogen, hydroxyl, methyl, and halogen-substituted methyl.

[0054] In one embodiment, the organic linker has the formula: [ka] (In the formula, R 11 , R 12 , R 13 , R 14 , R 15 and R 16 are each independently selected from H, halogen, hydroxyl, methyl, and halogen-substituted methyl.

[0055] In one embodiment, the organic linker has the formula: [ka] (In the formula, R 11 , R 12 , R 13 , R 14 , R 15 and R 16 are each independently selected from H, halogen, hydroxyl, methyl, or halogen-substituted methyl, and R 17 is selected from substituted or unsubstituted aryl, vinyl, alkynyl, and substituted or unsubstituted heteroaryl.

[0056] In one embodiment, the organic linker has the formula: [ka] (In the formula, R 11 , R 12 , R 13 , R 14 , R 15 and R 16 are each independently selected from H, halogen, hydroxyl, methyl, or halogen-substituted methyl.

[0057] R 11 , R 12 , R 13 , R 14 , R 15 and R 16 are each independently selected from H, halogen, hydroxyl, methyl, or halogen-substituted methyl, and R 17 is selected from substituted or unsubstituted aryl, vinyl, alkynyl, and substituted or unsubstituted heteroaryl.

[0058] In one embodiment, the organic linker comprises a multiple bridged aryl species, for example a molecule having two (or more) phenyl rings, or two phenyl rings joined by a vinyl or alkynyl group.

[0059] In one embodiment, a compound of formula IA: [ka] (In the formula, M 1 is independently a metal selected from Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu, or Zn or a salt thereof; M 2 is independently a metal selected from Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu, or Zn or a salt thereof, 1 is M 2 rather than; X is a value between 0.01 and 1.99; and Provided herein are mixed metal-organic frameworks of the formula: wherein A is an organic linker as described herein.

[0060] As described herein, mixed-metal mixed-organic frameworks are porous crystalline materials formed from two or more distinct metal cations, clusters or chains linked by two or more multitopic (polytopic) organic linkers.

[0061] The mixed metal organic frameworks can be appended with amine molecules, hereafter referred to as "ligands", that allow for step-type isotherms. The step-type isotherms arise from the insertion of CO2 into the metal-amine coordinate bond and then the localization of a negative charge on the oxygen of CO2. The diamine (a molecule containing two amines) allows the amine to bond with the metal and allows the second amine to be positioned below the channel of the mixed metal organic framework. Upon insertion of CO2, the second amine receives a proton, thereby becoming positively charged and balancing the negative charge on the oxygen.

[0062] In one embodiment, the mixed metal organic framework system (sometimes referred to as an "addition mixed metal organic framework") has the formula II [ka] (In the formula, M 1 are independently selected from the group consisting of Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu, and Zn; M 2 are independently selected from the group consisting of Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu and Zn, and M 1 is M 2 rather than; X is a value from 0.01 to 1.99; A is a linker as described herein; and B is a ligand containing one or more groups capable of functioning as a suitable Lewis base (electron donor), such as oxygen, phosphorus, or sulfur, or an amine having 1-10 amine groups.

[0063] Ligands suitable for use in mixed metal mixed organic framework systems can have (at least) two functional groups: 1) a functional group used to bind CO2, and 2) a functional group used to bind the metal. The second functional group that binds the metal can be an amine. It is possible to use other functional groups, for example oxygen-containing groups such as alcohols, ethers or alkoxides, carbon groups such as carbenes, or unsaturated bonds such as alkenes or alkynes, or sulfur atoms.

[0064] Similarly, triamines can also be used as ligands added to the mixed metal frameworks provided herein. However, triamines may not efficiently promote cooperative insertion of CO2. On the other hand, tetramines (molecules with four amines) can accommodate two amines that bind to the metal sites, forming binding sites for CO2, while the other two amines will be available to provide charge balance during CO2 insertion. Moreover, the inclusion of tetramines allows each amine molecule to bind more strongly to the mixed metal organic framework (two amines bind two metals per molecule rather than one amine per molecule), thus resulting in some stability improvement. Commercially available tetramines, as well as some other suitable amines, are shown below. [ka]

[0065] In addition, with the present mixed metal organic frameworks, the ligands do not have to be amines, but can be any Lewis base (electron donor) containing a variety of alternative other atoms such as oxygen, phosphorus, or sulfur.

[0066] In one embodiment, B is [ka] (wherein Z is carbon, silicon, germanium, sulfur or selenium, and R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 are ligands selected from the group consisting of H, halogen, methyl, halogen-substituted methyl, and hydroxyl. In one embodiment, R1, R2, R3, R4, R5, R6, R7, R8, R9, and R 10 R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 are each H, and Z is carbon.

[0067] In one embodiment, the ligand is 2-(aminomethyl)-piperidine (2-ampd).

[0068] As provided herein, Formula I includes M 1 x M 2 (2-x) It is possible to include a solvent molecule coordinated to the metal site, such as (DOBPDC)(solvent)2. As synthesized in the protocol below, an exemplary solvent is N,N-dimethylformamide (DMF). The solvent molecule can be removed by heating under reduced pressure, thereby resulting in an "activated" mixed metal organic framework. Alternatively, the DMF (or other solvent molecules, such as water, methanol, etc.) can be replaced by treating the mixed metal organic framework with an amine. This is described as an "addition" mixed metal organic framework, or mixed metal mixed organic framework system, and is a material that binds CO2. For example, the mixed metal mixed organic framework, amine ("2-ampd"), is represented by the exemplary formula II, M 1 x M 2 (2-x) (DOBPDC)(2-ampd)2. This material is 1 x M 2 (2-x) -Also written as EMM-44.

[0069] Thus, formulas I and M 1 x M 2 (2-x) A is for M 1 x M 2 (2-x)On the other hand, the compounds of formula II, M, may include a solvent-bound mixed metal-organic framework such as (DOBPDC)(DMF)2, and may be inactive or activated. 1 x M 2 (2-x) AB refers to a mixed metal mixed organic framework system.

[0070] As described herein, mixed-metal mixed-organic frameworks are porous crystalline materials formed from two or more distinct metal cations, clusters or chains that are linked by two or more multitopic (polytopic) organic linkers.

[0071] As such, the mixed metal mixed organic framework can be represented by formula III, M 1 x M 2 (2-x) (A 1 a A 2 b A 3 c …A n (1-a-b-c-…) )(III)(wherein, A 1 is a multitopic organic linker, and A 2 A 1 is a multitopic organic linker different from A 3 A 1 and A 2 is a multitopic organic linker different from A n A 1 , A 2 …and A (n-1) It is also possible to represent the linker as a multitopic organic linker different from

[0072] In one embodiment, the ligands providing the mixed metal mixed organic framework system can also contain other structural elements that are used to coordinate the ligand to one or more metals of the framework system, including, but not limited to, the following functional groups: carboxylate, triazolate, pyrazolate, tetrazolate, pyridine, amine, alkoxide and / or sulfate groups.

[0073] As described in the examples below, the present amine-appended mixed metal organic framework systems can be prepared in a two-step process shown in Scheme 1 below. [ka]

[0074] In step 1, M 1 and a suitable salt of M 2 is combined with linker A in a suitable solvent and heated to provide a mixed metal mixed organic framework system generally represented by formula I. As an example, MnCl2 and Mg(NO3)2.6H2O are combined with 4,4'-dioxido-3,3'-biphenyldicarboxylate (H4DOBPDC) in methanol and N,N'-dimethylformamide (DMF) to provide M 1 is Mn, and M 2 Compositions of formula I are provided where A is Mg and A is DOBPDC.

[0075] In step 2, the mixed metal organic framework of formula I is combined with ligand (B) in a suitable solvent. 1 is Mn, and M 2 is Mg and A is DOBPDC combined with 2-ampd, M 1 is Mn, and M 2 A mixed metal mixed organic framework system of formula II is provided, where A is Mg, A is DOBPDC, and B is 2-ampd.

[0076] Also provided herein is an adsorbent material. The adsorbent material comprises the present mixed metal mixed organic framework. The mixed metal mixed organic framework comprises two or more metals and a plurality of organic linkers. Each organic linker is linked to a metal ion. The adsorbent material further comprises a plurality of ligands. In one embodiment, each ligand of the plurality of ligands is an amine or other Lewis base (electron donor), such as oxygen, phosphorus or sulfur, that attaches to two or more distinct elements and the metal ion of the mixed metal organic framework, providing a mixed metal mixed organic framework system.

[0077] The present mixed metal mixed organic framework systems represent a class of porous crystalline adsorbents that allow for higher functionality with less adsorptive mass and volume compared to conventional solid adsorbents. The present mixed metal mixed organic framework systems have coordinatively unsaturated metal centers (open metal sites) along the pore surfaces. The metal cations act as Lewis acids that strongly polarize the gas adsorbent to further facilitate post-synthesis functionalization. In mixed metal mixed organic framework systems with well-separated open metal sites, one amine of the diamine ligand molecule can bind to the metal cation as a Lewis base while the second amine remains available as a chemically reactive adsorption site. The metals in the mixed metal mixed organic framework systems can be individual metal atoms bridged with a set of ligands or metal clusters (collections of metal atoms as a group that interact with a set of ligands).

[0078] Some or all of the ligands of the mixed metal mixed organic framework system contain functional groups that are not coordinated to the metal cation and are available to form reversible weak chemical bonds with CO2. The reactive chemical atoms can include lone pairs including nitrogen, oxygen, sulfur and phosphorus. In one embodiment, it is a basic amine.

[0079] Carbon dioxide application As described herein, mixed metal organic frameworks containing two or more metal species ("populations") of ions are subsequently functionalized (or tagged) with diamine ligands ("ligands") to provide mixed metal mixed organic framework systems. The mixed metal mixed organic framework systems are useful as CO2 adsorbents or adsorbents in a variety of applications and exhaust streams. Each of the novel mixed metal organic frameworks described herein contains two or more metal species. Mixed metal organic frameworks can be prepared from multiple metal sources and tagged with one or more organic ligands, such as amines, to provide mixed metal mixed organic framework systems. Mixed metal mixed organic framework systems exhibit a V-shaped isotherm. By changing the ratio of metals incorporated in the mixed metal organic framework, the position of the isotherm step can be changed as a function of CO2 partial pressure.

[0080] For example, in one embodiment, the mixed metal organic framework can be subsequently functionalized with the amine 2-ampd to provide the mixed metal mixed organic framework system, EMM-44. This mixed metal mixed organic framework system is capable of reversibly and selectively binding CO2 and can be regenerated for repeated use by gentle heating or exposure to reduced pressure. The required percentage of CO2 to be adsorbed in the gas stream and the temperature required for binding can be tuned by varying the ratio of the two metal ions in the mixed metal organic framework to enable a wide distribution and implementation of CO2 capture from a variety of exhaust streams.

[0081] For example, in one embodiment, a series of several mixed metal organic frameworks, each containing both Mg and Mn ions, can be functionalized with the amine 2-ampd to provide a series of mixed metal mixed organic framework systems. When exposed to CO2, the material with the least amount of Mn and the greatest amount of Mg exhibits a V-shaped isotherm at the lowest pressure of CO2. The material with the greatest amount of Mn and the least amount of Mg exhibits a V-shaped isotherm at the highest pressure of CO2. A direct relationship is observed between the ratio of Mn to Mg contained in the mixed metal mixed organic framework system and the pressure of CO2 at which the V-shaped isotherm is observed.

[0082] As described in US Patent No. 9,861,953, "Alkylamine Functionalized Metal-Organic Frameworks for Composite Gas Separations," a metal-organic framework, MOF-274, is taught. This framework can be synthesized from individual metal precursors that allow for favorable V-type isotherms for CO2 capture, but is not a mixed metal-organic framework as provided herein. In general, adsorbent materials that exhibit a V-type isotherm have greater working capacity than adsorbents with similar total adsorption capacity, but also have the more common I-type isotherm. Other such frameworks are described in J. Am. Chem. Soc, 2012, 134, 7056-7065; Nature, 2015, 519, 303-308; J. Am. Chem. Soc, 2017, 139, 10526-10538; J. Am. Chem. Soc. 2017, 139, 13541-13553 and Chem Sci, 2018, 9, 160.

[0083] Methods of use of the present adsorbent materials include a variety of gas separation and manipulation applications, including the isolation of individual gases from combined gas streams, such as carbon dioxide / nitrogen, carbon dioxide / hydrogen, carbon dioxide / methane, carbon dioxide / oxygen, carbon monoxide / nitrogen, carbon monoxide / methane, carbon monoxide / hydrogen, hydrogen sulfide / methane and hydrogen sulfide / nitrogen.

[0084] One of the main advantages of physical adsorption onto solid materials is the low regeneration energy compared to that required for aqueous amines. However, this advantage often comes at the expense of low capacity and poor selectivity. The present system provides adsorbents (adsorbent materials) that can bridge the two approaches by incorporating sites that bind CO2 by chemical adsorption onto solid materials. These adsorbent materials can eliminate the need for aqueous solvents and have significantly lower regeneration costs compared to conventional amine scrubbers, while maintaining their special selectivity and high capacity for CO2 at low pressures.

[0085] Generally, the metal-organic frameworks are porous crystalline solids that are subsequently functionalized by the incorporation of alkylamines, as shown in Figure 11. Similarly, the mixed metal-organic frameworks provided herein are porous crystalline solids that are subsequently functionalized by the incorporation of alkylamines to exhibit enhanced basicity over aromatic amines and are capable of adsorbing acidic gases. The present disclosure teaches adsorbent materials including mixed metal-organic frameworks with two different metals that are distinguishable from prior art metal-organic frameworks with a single type of metal by a highly desirable V-shaped isotherm, and where the step position is tunable by mixed metal selection (selection of the metals) or by varying the ratio of the metals in the mixed metal-organic framework.

[0086] In one embodiment, the mixed metal organic framework system can separate gases at low temperatures and pressures. The mixed metal organic framework system is useful for pre-combustion separation of carbon dioxide and hydrogen and methane from gas streams at low pressures and concentrations, and for post-combustion separation of carbon dioxide from combustion gas streams. The mixed metal organic framework can accommodate many different separation requirements.

[0087] More specifically, in one aspect of the present disclosure, there are numerous technological applications of the disclosed sorbent material. One such application is carbon capture from coal combustion gas or natural gas combustion gas. The increasing atmospheric concentration of carbon dioxide (CO2), which contributes to global climate change, warrants new strategies to reduce CO2 emissions from point sources such as power plants. Coal-fired power plants, in particular, are responsible for 30-40% of global CO2 emissions. See Quadrelli et al., 2007, "The energy-climate challenge: Recent trends in CO2 emissions from fuel combustion," Energy Policy 35, pp. 5938-5952, incorporated herein by reference. Thus, for coal combustion gas, at ambient pressure and 40°C, CO2 (15-16%), O2 (3-4%), H2O (5-7%), N2 (70-75%) and trace impurities (e.g., SO2, NO2) are absorbed in the sorbent material. x There is a continuing need to develop novel sorbents for carbon capture from gas streams consisting of H2O (saturated), O2 (4-12%) and N2 (balance). See Planas et al., 2013, "The Mechanism of Carbon Dioxide Adsorption in an Alkylamine-Functionalized Metal-organic Framework," J. Am. Chem. Soc. 135, pp. 7402-7405, incorporated herein by reference. Similarly, extending the use of natural gas as a fuel source requires sorbents that enable CO2 capture from the flue gases of natural gas-fired power plants. The flue gases resulting from the combustion of natural gas have a lower carbon dioxide concentration of about 4-10% CO2, with the remaining stream consisting of H2O (saturated), O2 (4-12%) and N2 (balance). In particular, with respect to the temperature swing adsorption process, the adsorbent must have the following properties: (a) high working capacity with minimal temperature swing to minimize regenerative energy costs; (b) high selectivity for CO over other components of coal combustion gas; (c) 90% capture of CO under flue gas conditions; (d) effective performance under wet conditions; and (d) long-term stability to adsorption / desorption cycling under wet conditions.

[0088] Another such application is carbon capture from crude biogas. Biogas, i.e., CO2 / CH4 mixtures produced by decomposition of organic matter, is a renewable fuel source with the potential to replace traditional fossil fuel sources. Removal of CO2 from natural biogas mixtures is one of the most challenging aspects of upgrading such potential fuel sources to pipeline quality methane. Thus, the use of sorbents to selectively remove CO2 from CO2 / CH4 mixtures with high working capacity and minimal regeneration energy has the potential to greatly reduce the cost of using biogas instead of natural gas for applications in the energy sector.

[0089] The disclosed compositions (adsorbent materials) can be used to remove a major portion of the CO from a CO2-rich gas stream, and the CO2-enriched adsorbent material can be removed using temperature swing adsorption, pressure swing adsorption, vacuum swing adsorption, concentration swing adsorption, or combinations thereof. Examples of temperature swing adsorption and vacuum swing adsorption are disclosed in WO 2013 / 059527 A1.

[0090] The calculation of the isosteric heat of adsorption provides an indication of the strength of the interaction between the adsorbate and the adsorbent and is determined in particular from the analysis of adsorption isotherms carried out at a series of different temperatures. J. Phys. Chem. B, 1999, 103, 6539-6545; Langmuir, 2013, 29, 10416-10422. Differential scanning calorimetry is a technique that measures the amount of energy released or absorbed when a parameter (such as temperature or CO2 pressure) is changed. EXAMPLES

[0091] Example I Preparation of the mixed metal mixed organic framework system, EMM-44 Synthesis of mixed metal-organic framework, MOF-274 Mixed metal framework: MOF-274, M 1 x M2 (2-x) Synthesis of (DOBPDC): 241.15 mg of MnCl2·4H2O (1.219 mmol), 312.65 mg of Mg(NO3)2·6H2O (1.219 mmol), and 267.15 mg of 4,4'-dioxido-3,3'-biphenyldicarboxylate (H4DOBPDC, 0.975 mmol) were combined in a 250 mL three-neck round-bottom flask equipped with a stir bar. 49 mL of deoxygenated methanol and N,N'-dimethylformamide (DMF) were transferred into the solution containing the metal and ligand while stirring. The solution was stirred for 20 minutes to ensure complete dissolution of all solids. The reaction solution was divided into 15 mL aliquots and transferred into a 23 mL Teflon-lined Parr reactor. All reactors were sealed and heated at 120 °C for 96 h under static conditions. After cooling naturally to ambient temperature, the mother liquor was removed by decantation and the solid was washed with DMF three times over 24 hours, then with methanol three times over 24 hours. Approximately 40 mg of the mixed metal-organic framework was recovered, and the methanol was removed by slow centrifugation followed by pipetting. As shown in Figure 1, samples 1-5 are different batches of the same material where no amine was added and the framework was not functionalized or activated.

[0092] Amine addition: formation of the mixed metal mixed organic framework system, EMM-44: After coordination of the amine 2-ampd to the open metal sites of either MOF-274 framework, the adsorbent material becomes known as EMM-44, a mixed metal mixed organic framework system. 1 x M 2 (2-x) (DOBPDC) was washed once with toluene and resuspended in toluene, then transferred to a 20 wt% solution of the amine 2-ampd in toluene. The solution was allowed to stand for 24 hours, then collected by slow centrifugation, washed three times in toluene, and stored in toluene. These 2-ampd-appended MOFs were 1 x M 2(2-x) -EMM-44, described as a mixed metal mixed organic framework system, wherein M 1 and M 2 is the mixed metal used during synthesis, and x is the M in the adsorbent material. 1 is the amount.

[0093] Characterization of the mixed metal framework system EMM-44 Inductively Coupled Plasma-Optical Emission Spectroscopy, also known as Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES), measures element-specific emission spectra from metals, metalloids, and some nonmetals in a heated plasma. It is a common elemental analysis technique that can provide metal quantification in a given sample. ICP-OES was performed by Galbraith Laboratories, Inc, Knoxville, TN. Galbraith's general method for ICP-OES analysis is derived from nationally accepted methods, specifically EPA SW846 6010B, and also conforms to USP general guidance.

[0094] ICP-OES of the MOF-274 framework using the above synthesis Duplicate samples were provided from the same synthesis batch (Table 1A). As shown in Table 1B, the data indicated that each of the samples contained both metals contained in the initial synthesis solution, which is the desired result.

[0095] [Table 3]

[0096] [Table 4]

[0097] Characterization of mixed metal-organic frameworks Powder X-ray diffraction (PXRD). The mixed metal-organic frameworks were suspended in methanol by mixing and sonication and drop cast onto a zero-background cell. Powder X-ray diffraction data were collected on a Bruker D8 Endeavor instrument with an X-ray generator operating at 45 kV / 40 mA. Spectra were collected between 4 and 50° 2-theta for 10 minutes at an aperture of 0.02°. A representative powder X-ray diffraction pattern of MOF-274 is shown in Figure 1. Samples 1-5 are different batches of the same material where no amines were added and the framework was not functionalized or activated. A representative powder X-ray diffraction pattern of MOF-274 is shown in Figure 1.

[0098] Energy Dispersive X-ray Spectroscopy (EDS). Dilute solutions of the mixed metal-organic frameworks in ethanol were suspended by sonication, drop-cast onto doped Si chips, and fixed to aluminum SEM stubs with carbon tape. EDS data were collected on a ZEISS FIB-SEM Crossbeam 540 at 3 kV, <1-5 nA, and "short" dwell times. Figures 2A-2D show representative data collected by energy dispersive X-ray spectroscopy ("EDS"), demonstrating that the manganese and magnesium mixed metal-organic frameworks are co-located in the same crystal, with the manganese and magnesium co-located. These mixed metal-organic frameworks do not form separate crystalline domains.

[0099] X-ray Absorption Spectroscopy (XAS) and Extended X-ray Absorption Fine Structure (EXAFS). 50 mg of each mixed metal-organic framework analyzed was recovered from methanol by centrifugation and the solvent removed by decantation. Sufficient BN was added to each mixed metal-organic framework to dilute the concentration of the X-ray absorbing metal between 1.25 and 1.75 edge steps. The mixture was sonicated to achieve a uniform dispersion and a sufficient volume of methanol was added to allow complete resuspension of the mixed metal-organic framework and BN. The mixture was recollected by centrifugation and the solvent removed by decantation. Under an inert atmosphere, approximately 10 mg of each mixed metal-organic framework / BN mixture was loaded into a free-standing pellet for XAS analysis.

[0100] X-ray absorption data were collected at the metal K-edge in transmission mode after a conventional data run to collect X-ray absorption data. S. Calvin. XAFS for Everyone, CRC Press, Boca Raton, FL, 2013. In particular, the X-rays were monochromated and detuned to reduce the contribution of higher harmonics. A reference foil of the same metal being analyzed was measured simultaneously during data collection for energy calibration and data alignment. The incident beam, transmitted beam and reference fluxes were all measured in a 20 cm ionization chamber with appropriate gas compositions to absorb approximately 10%, 10% and 100% of the X-ray flux, respectively.

[0101] Data were processed and analyzed using the Athena and Artemis programs of the IFEFFIT package based on FEFF 6. B. Ravel and M. Newville, J. Synchrotron Radiat., 2005, 12, 537-541; JJ Rehr and RC Albers, Rev. Mod. Phys., 2000, 72, 621-654. Reference spectra were aligned to the first zero crossing of the second derivative of the normalized μ(E) data. This was then calibrated to the literature value for E0 of the corresponding metal K-edge. The aligned spectra were averaged in μ(E) before normalization. The background of the XAS spectra was removed by spline fitting and the data were fitted with an R of 1.0. bkg values ​​were assigned. The window used to fit the extended X-ray absorption fine structure (EXAFS) data was determined so that a common window could be used for all samples of a given mixed metal class (e.g., all mixed metal MOFs containing Mn and Mg). R-space was fitted over the first two shells of atoms surrounding the absorbing atom, typically from 1-3 Å. k-space data was fitted from approximately 3-11 Å. -1 window and the exact value was determined by when the data crossed the x-axis to minimize end effects.

[0102] Normalized Fourier transform extended X-ray absorption spectroscopy data of the mixed metal-organic framework Ni1Mg1-MOF-274 (50% Ni) collected at the Ni K-edge. Figure 3. It is noteworthy that the feature at about 2.5 Å decreases with increasing Mg:Ni ratio. Comparison of the scattering paths shows that Mg is weaker backscattering than Ni. Thus, inclusion of Mg in the Ni coordination environment may result in suppression of the feature at 2.5 Å. However, this behavior is not observed when the metals segregate in separate regions of the same mixed metal-organic framework or when they form a mixture of segregated crystallites. When Mg and Ni are located at the same position in the same framework, Mg can exist in the local Ni environment, presumably with a random distribution.

[0103] Fourier transform extended X-ray absorption fine structure (EXAFS) data were fitted by using typical best practices. A structural model was obtained by modifying the cif file of MOF-274(Zn) to make the metal of the mixed metal organic framework the metal of interest. R. Siegelman, T. McDonald et al., J. Am. Chem. Soc., 2017, 139, 10526-10538. Direct scattering paths between metals representing M1-M1 as found in MOFs containing only metals and M1-M2 as found in mixed metal organic frameworks were also prepared by modifying the cif file. Sample families were fitted simultaneously (e.g. 100% Mn, 50% Mn, 25% Mn, 10% Mn and 5% Mn) using scattering paths calculated from the structural model. Global parameters were the amplitude reduction factor (S0 2 ); Photoelectron energy shift (ΔE0); (Mg(ΔR Mg ) and Mn(ΔR Mn ) R of scattering paths from the two nearest neighbor oxygens, nearest neighbor carbons, and nearest neighbor metals eff (ΔR i ) and (light elements (σ o 2 ) or metal (σ M 2 ) containing the mean squared relative displacements of the scattering elements. Except for the metal-metal scattering paths, all scattering path alterations were defined based on the coordination environment observed in the structural model. Initial fits were obtained with k-weights equal to 1, 2 and 3, before a final fit was obtained with only the k-3 weighted data for each sample. All data were fitted to R-space. According to the Nyquist criterion, the variation was not allowed to exceed 2 / 3 of the number of independent points. S. Calvin, XAFS for Everyone, CRC Press, Boca Raton, FL, 2013.

[0104] To determine the contribution of scattering from M1-M1 to M1-M2 in mixed metal-organic frameworks, a freely varying parameter (e.g., “frac”) representing the fraction of M1-M2 scattering was created and refined as part of the fitting process. This parameter was then calculated as the S0 of the M1-M2 scattering pathway. 2 S0 due to parameter multiplication and scattering path degeneracy 2 The contribution to the fit for the direct correlation of was reduced. The complementary contribution from M1-M1 scattering was then defined as (1-frac), which is then subtracted from the S0 contribution of the M1-M1 scattering path. 2 parameters were multiplied. In a given mixed metal series, different parameters were created for each sample. (For example, different "frac" parameters were created for 50% Mn, 25% Mn, 10% Mn, and 5% Mn systems so that each could be refined to a different ratio of scattering contributions, representing a different metal distribution, although the 100% Mn system does not require any scattering parameters at all, since all scattering contributions are necessarily M1-M1.) Thus, in addition to providing high quality fits, physically meaningful M1:M2 ratios can be demonstrated by EXAFS analysis for bulk samples.

[0105] FIG. 4 provides a representative fitted extended X-ray absorption fine structure (EXAFS) spectrum for the Ni1Mg1-MOF-274 (50% Ni) system. The spectrum was fitted using a combination of Ni-Ni and Ni-Mg scattering paths to represent the feature at 2.5 Å, as described above. The fit was 0.5 Mg 1.5 Data was also collected on Mg / Mn MOF-274 and Zn / Ni MOF-274. These preliminary results are consistent with the Mg / Ni results below.

[0106] The EXAFS results confirm that the Ni atoms are not localized in isolated regions but are instead distributed throughout the mixed metal-organic frameworks, as shown in Figure 5. Thus, these are true mixed metal-organic frameworks and not a mixture of two metal-organic frameworks where each metal-organic framework contains only one metal species.

[0107] activation In FIG. 6, a representative powder X-ray diffraction pattern of the mixed metal mixed-organic framework system EMM-44 (2-ampd adducted mixed metal MOF-274) demonstrates that crystallinity is preserved after the addition of amines to the framework.

[0108] Mixed metal-organic frameworks were prepared according to protocols clearly described in the literature. 1 The 1H NMR spectra of the mixed metal-organic framework system EMM-44 after digestion with DCl in DMSO-d6 were analyzed. P. Milner, R. Siegelman et al., J. Am. Chem. Soc. 2017, 139, 13541-13553. Figure 7 shows a representative 1H NMR spectrum of the mixed metal-organic framework system EMM-44 after digestion with DCl in DMSO-d6. 1 The H NMR spectrum of the mixed metal framework system Mn 0.5 Mg 1.5 - Regarding EMM-44, Mn 0.5 Mg 1.5 -MOF-274 was functionalized by 92% with 2-ampd. Comparable loadings were obtained for several samples of the mixed metal organic framework EMM-44 prepared with various Mg:Mn ratios.

[0109] As shown in FIG. 8, the mixed metal organic framework system: Mn 0.1 Mg 1.9 -EMM-44 (5% Mn), Mn 0.2 Mg 1.8 -EMM-44 (10% Mn), Mn 0.5 Mg 1.5The CO2 isotherms for Mn1Mg1-EMM-44 (25% Mn) and Mn1Mg1-EMM-44 (50% Mn) MOF-274, respectively, show an exceptional and highly desirable V-shaped isotherm.

[0110] Figure 9 shows the mixed metal / mixed organic framework system Mn plotted on a log scale to more fully show the characteristic low pressure "step" in the V-shaped isotherm. 0.1 Mg 1.9 -EMM-44 (5% Mn), Mn 0.2 Mg 1.8 -EMM-44 (10% Mn), Mn 0.5 Mg 1.5 Figure 2 shows the CO2 isotherms for Mn1Mg1-EMM-44 (25% Mn) and Mn1Mg1-EMM-44 (50% Mn) MOF-274. By increasing the fraction of Mn in the mixed metal-organic framework, the CO2 partial pressure required to induce CO2 uptake increases.

[0111] FIG. 10 shows the Mn loading of the mixed metal-organic framework Mn as a function of Mn loading, replotted from the data presented above. x Mg 2-x - The location of the CO2 isotherm midpoint for EMM-44. In summary, the mixed metal mixed-organic framework system EMM-44 is an adsorbent material that exhibits a V-shaped step CO2 isotherm profile, where the step location can be tuned by the choice of mixed metals or the ratio of metals in the mixed metal organic framework. This characterization showed that the metals are co-located in the mixed metal organic framework crystals, rather than in separate metal chains or separate crystallites.

[0112] Certain features have been described using combinations of numerical upper limits and combinations of numerical lower limits. It should be recognized that ranges from any lower limit to any upper limit are contemplated unless otherwise stated. Specific lower limits, upper limits and ranges appear in one or more claims below. All numerical values ​​account for experimental error and variations that would be expected by one of ordinary skill in the art.

[0113] Various terms have been defined above. To the extent a term used in the claims is not defined above, it should be given the broadest definition that one of ordinary skill in the art would give to that term as reflected in at least one printed publication or issued patent. Furthermore, all patents, test procedures, and other documents cited in this application are incorporated by reference in their entirety to the extent such disclosure is not inconsistent with this application, and for all jurisdictions where such incorporation is permitted.

[0114] The above description of the disclosure illustrates and describes the methodology. Moreover, while the disclosure illustrates and describes exemplary methods, it should be understood that various other combinations, modifications and environments may be utilized, and that the method is capable of changes or modifications within the scope of the concepts expressed herein and commensurate with the teachings of the above and / or skill or knowledge of the relevant art. The present disclosure also includes the following aspects. [1] A mixed metal organic framework having an empirical or chemical formula of two or more distinct metal elements and bridged by a linker, said mixed metal organic framework comprising a plurality of disalicylate linkers, each linker comprising one or more aromatic rings, each aromatic ring comprising a carboxylate functional group and an alcohol functional group, said carboxylate functional groups and said alcohol functional groups being adjacent to each other on each aromatic ring, and each aromatic ring being positioned at a maximum distance from the other. [2] Formula:M 1 x M 2 (2-x) (A) (where M 1 and M 2 are each independently a different metal cation, and A is a disalicylate organic linker. [3] M 1 and M 2 are both independently divalent metal cations. [4] M 1 and M 2 But, Ca 2+ , Mg 2+ , Fe 2+ 、Cr 2+ 、V 2+ , Mn2+ , Co 2+ , Ni 2+ , Zn 2+ , Cu 2+ The mixed metal-organic framework according to any one of [1] to [3], wherein the mixed metal-organic framework is independently selected from the following: [5] A is the following:

change

[10] The mixed metal organic framework according to any one of [1] to [9], wherein the mixed metal organic framework exhibits a (3,5,7)-c msi network.

[11] The mixed metal organic framework according to any one of [1] to

[10] , wherein the mixed metal organic framework exhibits a (3,5,7)-c msg net.

[12] The mixed metal organic framework is heated to 30° C. for 30 minutes under N 2 The mixed metal-organic framework according to any one of [1] to

[11] , which exhibits the following peak maxima in an X-ray diffraction pattern at 30° C. after drying at 250° C. under reduced pressure:

Table 1

[13] N for 30 min 2 The mixed metal-organic framework according to any one of [1] to

[12] , which exhibits the following peak maxima in an X-ray diffraction pattern at 30° C. after drying at 250° C. under reduced pressure:

Table 2

[14] 13. The metal-organic framework of any one of [6], [7], [8], [9],

[10] , or

[11] , wherein the a-axis of the unit cell and the b-axis of the unit cell are each greater than 18 Å, and the c-axis is greater than 6 Å.

[15] A mixed metal organic framework system comprising the mixed metal organic framework according to any one of [1] to

[14] and a ligand.

[16] 2. The metal-organic framework system according to claim 1, wherein the ligand comprises an amine.

[17] 2. The metal-organic framework system according to claim 1, wherein the ligand is a diamine.

[18] The metal-organic framework system according to

[17] , wherein the diamine is a cyclic diamine.

[19] The diamine is selected from the group consisting of:

change

[20] 20. The mixed metal organic framework system according to

[17] , wherein the diamine ligand is selected from one of dimethylethylenediamon (mmen) or 2-(aminomethyl)piperidine 2-ampd.

[21] The mixed metal organic framework system according to

[15] , wherein the ligand is a tetramine.

[22] 21. The mixed metal-organic framework system according to

[21] , wherein the tetramine is selected from one of 3-4-3 tetramine (spermine) or 2-2-2 tetramine.

[23] The mixed metal organic framework system according to

[15] , further comprising a ligand which is a triamine.

[24] The ligand is

change

[15] , selected from:

[25] 1) contacting a solution containing two or more sources of two or more distinct metal elements with an organic linker capable of bridging metal cations; 2) heating the mixture to produce the mixed metal-organic framework according to any one of claims 1 to 24. A method for synthesizing the mixed metal-organic framework according to any one of [1] to

[14] , comprising:

[26] The method according to

[25] , wherein the metal elements are independently selected from Ca, Mg, Fe, Cr, V, Mn, Co, Ni, Zn and Cu.

[27] 25. The method of claim 25, wherein the solution comprises an elemental metal or a salt of the metal whose counter anion comprises nitrate, acetate, carbonate, oxide, hydroxide, fluoride, chloride, bromide, iodide, phosphate, or acetylacetonate.

[28] A method for synthesizing the mixed metal organic framework according to any one of

[10] to

[24] , comprising a step of contacting the mixed metal organic framework with a second ligand in a gas or liquid medium.

[29] The method of claim 28, wherein the ligand is an amine-containing molecule.

[30] The method according to

[28] , wherein the ligand is a diamine.

[31] The method according to

[28] , wherein the ligand is a triamine.

[32] The method according to

[28] , wherein the ligand is tetramine.

[33]

[32] A particle comprising the mixed metal-organic framework system according to any one of [1] to

[32] .

[34] An adsorptive material comprising the mixed metal-organic framework system according to any one of [1] to

[33] .

[35] The mixed metal mixed organic framework is 2 The adsorbent according to

[34] exhibits a V-shaped isotherm profile with respect to

[36] A method for adsorbing carbon dioxide from a carbon dioxide-containing stream by contacting the stream with the adsorbent according to

[34] .

[37]

[36] A method for producing a V-type CO2 composition comprising the step of changing the amount or type of metal ions of two or more distinct metals in the mixed metal organic framework or the mixed metal organic framework system according to any one of [1] to

[36] . 2 How to adjust the position of the isotherm steps.

Claims

1. A mixed metal mixed organic framework system comprising a mixed metal mixed organic framework and a ligand, The mixed metal mixed organic framework system has two or more distinct metal elements and is bridged by a linear disalicylate organic linker, the mixed metal mixed organic framework system comprises a plurality of the linear disalicylate organic linkers, and the mixed metal mixed organic framework system has the chemical formula: M １ ｘ M ２ （２－ｘ） (A) (B) (wherein, M １ and M. ２ are each independently selected from Mg, Ca, V, Mn, Cr, Fe, Co, Ni, Cu and Zn, and M １ is M ２ X is a value between 0.01 and 1.99; A is a linear disalicylate organic linker; and B is an amine-containing ligand, each linear disalicylate organic linker comprising two or more aromatic rings, two aromatic rings bonded to a carboxylate functional group and an alcohol functional group, the carboxylate functional group and the alcohol functional group being adjacent to one another on each aromatic ring, and the two aromatic rings being located at each end of the linear disalicylate organic linker, and A is 4,4'-dioxidobiphenyl-3,3'-dicarboxylate; 4,4''-dioxido-[1,1':4',1''-terphenyl]-3,3''-dicarboxylate; dioxidobiphenyl-4,4'-dicarboxylate; and the following chemical formulas: 【Chemistry 1】 1. A mixed metal mixed organic framework system, comprising linear disalicylate organic linkers independently selected from the group consisting of at least one or more linkers represented by the formula:

2. M １ and M. ２ The mixed metal mixed organic framework system of claim 1 , wherein both are independently a divalent metal cation.

3. 3. The mixed metal mixed organic framework system of claim 1 or 2, wherein the mixed metal mixed organic framework system provides an X-ray diffraction pattern that can be shown as a hexagonal unit cell.

4. The mixed metal mixed organic framework system of claim 3, wherein the unit cell is selected from space groups 168-194.

5. The mixed metal mixed organic framework system according to any one of claims 1 to 4, further comprising metallic rod structures.

6. 6. The mixed metal mixed-organic framework system of claim 5 having hexagonal pores arranged parallel to the metal rod structures.

7. The mixed metal mixed organic framework system according to any one of claims 1 to 6, wherein the mixed metal mixed organic framework system exhibits a (3,5,7)-c msi net.

8. The mixed metal mixed organic framework system according to any one of claims 1 to 7, wherein the mixed metal mixed organic framework system exhibits a (3,5,7)-c msg net.

9. The mixed metal organic framework system is heated to 30 minutes under N ２ 9. The mixed metal mixed organic framework system according to any one of claims 1 to 8, after drying at 250°C under reduced pressure, exhibits the following peak maxima in the X-ray diffraction pattern at 30°C: 【Table 1】

10. 30 minutes N ２ 10. The mixed metal mixed organic framework system according to any one of claims 1 to 9, after drying at 250°C under reduced pressure, exhibits the following peak maxima in its X-ray diffraction pattern at 30°C: 【Table 2】

11. 9. The mixed metal mixed organic framework system of claim 3, 4, 5, 6, 7, or 8, wherein the a-axis of the unit cell and the b-axis of the unit cell are each greater than 18 Å and the c-axis is greater than 6 Å.

12. The mixed metal mixed organic framework system of claim 1 , wherein the ligand is a diamine.

13. The mixed metal mixed organic framework system of claim 12 , wherein the diamine is a cyclic diamine.

14. The diamine is selected from the group consisting of: 【Chemistry 2】 wherein Z is independently selected from carbon, silicon, germanium, sulfur, and selenium; and R １ , R ２ , R ３ , R ４ , R ５ , R ６ , R ７ , R ８ , R ９ and R １０ is independently selected from H, halogen, methyl, halogen-substituted methyl, and hydroxyl.

15. 13. The mixed metal mixed organic framework system of claim 12, wherein the diamine ligand is selected from one of dimethylethylenediamon (mmen) or 2-(aminomethyl)piperidine 2-ampd.

16. 2. The mixed metal mixed organic framework system of claim 1, wherein the ligand is a tetraamine.

17. 17. The mixed metal mixed organic framework system of claim 16, wherein the tetraamine is selected from one of 3-4-3 tetramine (spermine) or 2-2-2 tetramine.

18. 2. The mixed metal mixed organic framework system of claim 1, further comprising a ligand that is a triamine.

19. The ligand is 【Chemistry 3】 2. The mixed metal mixed organic framework system of claim 1, selected from:

20. 1) contacting a solution containing two or more sources of two or more distinct metal elements with a linear disalicylate organic linker capable of bridging metal cations; 2) heating the mixture to produce a mixed metal-organic framework; 3) contacting the mixed metal organic framework with a second ligand in a gas or liquid medium; Including, 12. The method of synthesis of a mixed metal mixed organic framework system according to any one of claims 1 to 11, wherein the second ligand is an amine-containing molecule.

21. 21. The method of claim 20, wherein the metallic elements are independently selected from Ca, Mg, Fe, Cr, V, Mn, Co, Ni, Zn, and Cu.

22. 21. The method of claim 20, wherein the solution comprises an elemental metal or a salt of the metal whose counter anion comprises nitrate, acetate, carbonate, oxide, hydroxide, fluoride, chloride, bromide, iodide, phosphate, or acetylacetonate.

23. 21. The method of claim 20, wherein the ligand is a diamine.

24. 21. The method of claim 20, wherein the ligand is a triamine.

25. 21. The method of claim 20, wherein the ligand is a tetraamine.

26. A particle comprising the mixed metal mixed organic framework system of any one of claims 1 to 18.

27. An adsorptive material comprising the mixed metal mixed organic framework system of any one of claims 1 to 18.

28. The mixed metal mixed organic framework system is ２ 28. The adsorbent material of claim 27, which exhibits a V-shaped isotherm profile versus

29. 30. A method for adsorbing carbon dioxide from a carbon dioxide containing stream by contacting the stream with the adsorbent material of claim 27.

30. A method for preparing a V-type CO2 composite comprising the step of varying the amount or type of metal ions of two or more distinct metals of the mixed metal mixed organic framework system according to any one of claims 1 to 18. ２ How to adjust the position of the isotherm steps.

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