WO2010133891A1 - Storage/separating materials - Google Patents

Storage/separating materials Download PDF

Info

Publication number
WO2010133891A1
WO2010133891A1 PCT/GB2010/050834 GB2010050834W WO2010133891A1 WO 2010133891 A1 WO2010133891 A1 WO 2010133891A1 GB 2010050834 W GB2010050834 W GB 2010050834W WO 2010133891 A1 WO2010133891 A1 WO 2010133891A1
Authority
WO
WIPO (PCT)
Prior art keywords
substances
framework
pores
guest
entities
Prior art date
Application number
PCT/GB2010/050834
Other languages
French (fr)
Inventor
Sihai Yang
Xiang Lin
Neil R. Champness
Martin Schroder
Original Assignee
The University Of Nottingham
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to GB0908839.4 priority Critical
Priority to GB0908839A priority patent/GB0908839D0/en
Application filed by The University Of Nottingham filed Critical The University Of Nottingham
Publication of WO2010133891A1 publication Critical patent/WO2010133891A1/en

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01GCOMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G15/00Compounds of gallium, indium or thallium
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/0005Reversible uptake of hydrogen by an appropriate medium, i.e. based on physical or chemical sorption phenomena or on reversible chemical reactions, e.g. for hydrogen storage purposes ; Reversible gettering of hydrogen; Reversible uptake of hydrogen by electrodes
    • C01B3/001Reversible uptake of hydrogen by an appropriate medium, i.e. based on physical or chemical sorption phenomena or on reversible chemical reactions, e.g. for hydrogen storage purposes ; Reversible gettering of hydrogen; Reversible uptake of hydrogen by electrodes characterised by the uptaking medium; Treatment thereof
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/0005Reversible uptake of hydrogen by an appropriate medium, i.e. based on physical or chemical sorption phenomena or on reversible chemical reactions, e.g. for hydrogen storage purposes ; Reversible gettering of hydrogen; Reversible uptake of hydrogen by electrodes
    • C01B3/001Reversible uptake of hydrogen by an appropriate medium, i.e. based on physical or chemical sorption phenomena or on reversible chemical reactions, e.g. for hydrogen storage purposes ; Reversible gettering of hydrogen; Reversible uptake of hydrogen by electrodes characterised by the uptaking medium; Treatment thereof
    • C01B3/0015Organic compounds; Solutions thereof
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17CVESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C11/00Use of gas-solvents or gas-sorbents in vessels
    • F17C11/005Use of gas-solvents or gas-sorbents in vessels for hydrogen
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00Crystal-structural characteristics
    • C01P2002/70Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/72Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00Crystal-structural characteristics
    • C01P2002/80Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70
    • C01P2002/82Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70 by IR- or Raman-data
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00Crystal-structural characteristics
    • C01P2002/80Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70
    • C01P2002/88Crystal-structural characteristics defined by measured data other than those specified in group C01P2002/70 by thermal analysis data, e.g. TGA, DTA, DSC
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00Physical properties of inorganic compounds
    • C01P2006/14Pore volume
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00Physical properties of inorganic compounds
    • C01P2006/80Compositional purity
    • Y02E60/328

Abstract

A material for the releasable storage of one or more substances comprising a framework defining one or more pores and one or more guest gate entities associated with the pores, wherein one or more of the guest gate entities are capable of reversibly at least hindering the entry into the pores, or release from the pores of said one or more substances.

Description

STORAGE/SEPARATING MATERIALS

This invention relates to the field of storage materials for the releasable storage of substances, a method of manufacturing a storage material, and use of a storage material, and to containers provided with a storage material. Another field of interest is that of separating materials.

The widespread use and application of hydrogen (H2) as a clean alternative to fossil fuels is limited by the lack of a convenient, safe and cheap storage system. Metal-organic frameworks with ultrahigh internal surface areas are currently being intensively studied for the storage of H2, and although sorption of H2 by these materials often displays excellent reversibility and fast kinetics, the weak dispersive interactions that hold H2 within the framework require low operating temperatures (often 77 K) and high pressures (up to 90 bar) to achieve the 2010 DoE storage target of 6.0 wt% (U.S. Department of Energy) .

Increasing the interaction between H2 molecules and the host framework and hence the associated isosteric heat of adsorption represents a major challenge if these systems are to find practical use at closer to ambient temperatures (Bhatia, S. K. & Myers, A. L. Optimum conditions for adsorptive storage. Langmuir 22, 1688-1700 (2006)) . Several strategies are being explored to enhance the interaction between H2 and host frameworks.

Having frameworks which have narrow pores can provide greater overlap of potential energy fields of pore walls thereby increasing the heat of H2 adsorption at low pressures compared to larger pores (Chun, H. , Dybtsev, D. N. , Kim, H. & Kim, K. Synthesis, X-ray crystal structures, and gas sorption properties of pillared square grid nets based on paddle-wheel motifs: Implications for hydrogen storage in porous materials. Chem. Euro. J. 11 , 3521-3529 (2005) ; Lin, X. et al. High H2 adsorption by coordination-framework materials. Angew. Chem. Int. Ed. 45, 7358-7364 (2006)) . However, the trade-off between strong binding energy and high storage capacity appears to limit this strategy.

Neutron diffraction experiments suggest that vacant metal co-ordination sites within the framework can provide stronger H2 binding sites than organic linkers alone, but the interaction between transition metals and H2 molecules is still insufficient to raise the storage temperature significantly (Dinca, M. et al. Observation of Cu2 + -H2 interactions in a fully desolvated sodalite-type metal-organic framework. Angew. Chem. Int. Ed. 46, 1419- 1422 (2007)) . Furthermore, these sites may saturate very quickly at low partial pressures thus not necessarily enhancing the overall storage capacity of the material (Lin, X. et al. High capacity hydrogen adsorption in Cu(II) tetracarboxylate framework materials: the role of pore size, ligand functionalization, and exposed metal sites. J. Am. Chem. Soc. 131 , 2159-2171 (2009)) .

One approach to enhancing the capacity of metal-organic frameworks to store H2 is to exploit a kinetic trap within a chemically-modified porous host. This potentially enhances gas uptake by confining the substrate (H2) within the porous material at high pressure, but with the H2 not being released until the pressure is lowered, thus facilitating H2 storage at lower pressures (Zhao, X. et al. Hysteretic adsorption and desorption of hydrogen by nanoporous metal-organic frameworks. Science 306, 1012-

1015 (2004) ; Choi, H. J. , Dinca, M. & Long, J. R. Broadly hysteretic H2 adsorption in the microporous metal-organic framework Co(1 , 4- benzenedipyrazolate) . J. Am. Chem. Soc. 130, 7848-7850 (2008) ; Ferey,

G. et al. Hydrogen adsorption in the nanoporous metal - benzenedicarboxylate M(OH) (O2C-C6H4- CO2) (M = Al3 + , Cr3 +) , MIL-53.

Chem. Commun. 2976-2977, (2003) ; Yang, C , Wang, X. & Omary, M. A. Fluorous metal-organic frameworks for high-density gas adsorption. J. Am. Chem. Soc , 129, 15454-15455 (2007)) . This hysteretic behaviour means that hydrogen storage capacity can be improved due to the conditions required to keep hydrogen adsorbed to the material in question being relatively mild.

Previous examples of hysteretic H2 adsorption by metal-organic frameworks have been found in materials that undergo structural changes upon pressurisation with the guest gas substrate (Zhao, X. et al. Hysteretic adsorption and desorption of hydrogen by nanoporous metal- organic frameworks. Science 306, 1012-1015 (2004) ; Choi, H. J. , Dinca, M. & Long, J. R. Broadly hysteretic H2 adsorption in the microporous metal-organic framework Co(l ,4-benzenedipyrazolate) . J. Am. Chem. Soc. 130, 7848-7850 (2008)) . Both examples rely upon the framework undergoing some structural modification to allow gas uptake. There are disadvantages associated with these examples in that the materials utilised are not easily adaptable to different situations. For instance, the hysteretic H2 adsorption behaviour of these examples cannot be readily modified to suit a given application. Furthermore, these examples cannot be easily adapted to suit the adsorption of a substance other than H2, or allow the separation of mixtures of substances by the preferential release of one substance over another.

According to a first aspect of the present invention, there is provided a material for the releasable storage of one or more substances comprising a framework defining one or more pores and one or more guest gate entities associated with the pores wherein one or more of the guest gate entities are capable of reversibly at least hindering the entry into the pores, or release from the pores of said one or more substances. It is to be understood that, in the context of this invention, "associated" means chemically bonded, such as by one or more of covalent bonding, ionic bonding, polar covalent bonding, coordinate covalent bonding, one- electron bonding, three-electron bonding, bent bonding, three-centre two- electron bonding, three-centre four-electron bonding, aromatic bonding, metallic bonding and intermolecular bonding.

It is to be understood that, in the context of this invention, "hindering" means slowing down/making more difficult the entry into and release from the pores of one or more substances, such that said substances may be retained, rather than meaning that the entry into and release from the pores of said substances is totally stopped/prevented.

It is to be understood that the framework defines the one or more pores on its own, without the presence of the one or more guest gate entities, in a way such that the framework is stable, has a stable shape and can exist on its own without the guest gate entities - i.e. the guest gate entities are not needed to make the framework stable and pore-defining.

The arrangement of the present invention is advantageous because the guest gate entities are distinct from the framework and may be substituted with alternative guest gate entities, which provides the opportunity to have a range of performances of the guest gate entities, and the opportunity to tailor the material to suit particular storage requirements. The guest gate entities may act as reversible gates for controlling the entry into and release from the pore by substances.

Each of said one or more guest gate entities may be associated with a different pore. Alternatively, two or more guest gate entities may be associated with the same pore. The one or more guest gate entities may be reversibly attached to the pores via intermolecular bonding. It is to be understood that, in this context, "reversibly" means that the one or more guest gate entities may be not bonded to the pores or may be bonded by one or more intermolecular bonds. The intermolecular bonding may comprise permanent dipole to permanent dipole bonding, hydrogen bonding, instantaneous dipole to induced dipole (van der Waals) bonding, cation-pi interactions and/or pi-pi interactions. The extent to which the one or more guest gate entities may hinder the entry into and release from said pores of one or more substances may depend on the frequency of said bonds. It is to be understood that, in this context, "frequency" means the total number of interactions/bonds per guest gate entity. Additionally, or alternatively, the extent to which the one or more guest gate entities may hinder the entry into and release from said pores of one or more substances may depend on the strength of said bonds.

The storage of the one or more substances may be achieved via adsorption, such as physisorption or chemisorption.

The material may exhibit hysteresis. In some embodiments the reversible hindrance of entry into the pores or release from the pores of the one or more substances includes the exhibition of hysteresis. In some embodiments the material does not exhibit hysteresis.

The framework and one or more of the guest gate entities may be neutral or charged (cationic, anionic or radical) . In some embodiments the framework is anionic and one or more of the guest gate entities may be cationic. Alternatively, the framework may be cationic and one or more of the guest gate entities may be anionic. In some embodiments the framework may be a radical and one or more of the guest gate entities may be a radical. In some embodiments the overall charge of the material is zero.

The framework may be a metal-organic framework. The framework may be a doubly-interpenetrated anionic framework, such as a framework constructed from [In2(L)2]2", wherein L4 is 1 , 1 ' ,4' , 1 " ,4" , 1 " ' - quaterphenyl-3,5, 3 ' " ,5 " ' -tetracarboxylate. The framework may be based upon a d-block transition metal such as zinc, a p- or s-block block metal or f -block lanthanide or actinide.

One or more of the guest gate entities may be a cationic metal centre, cluster, or an organic or inorganic cation. For example, the guest gate entities may be piperazinium (H2ppz2 + ) . The guest gate entity may also be anionic such as an anionic charged metal centre, cluster, or organic or inorganic anion. The use of cationic or anionic guest gate entities enables guest gate entity-dependent kinetic trapping of substances such as H2, where, for example, the (H2ppz2 + ) is itself a guest of the framework system, and this represents a new class of flexible, modifiable metal- organic frameworks capable of exhibiting hysteretic adsorption.

One or more of the guest gate entities may be one or more of Group I, II or III cations and organic cations, transition and lanthanide metal cations. For example, the guest gate entities may be Li+ , Mg2+ , or Al3 + . Guest gate entities such as Li+ , Mg2+ , or Al3 + enhance the uptake of substances such as H2 and increase the isosteric heat of adsorption of the material, which enables the uptake of substances at higher temperatures. Loading of LiVLi+ into metal-organic frameworks has received some attention due to the potential of strong binding of H2 on free Li sites. This has been supported by recent computational and theoretical studies on the modelling of H2 molecules adsorbed into LiVLi+ doped metal-organic framework hosts (Blomqvist, A. , Araύjo, C. M. , Srepusharawoot, P. & Ahuja, R. Li-decorated metal-organic framework 5: a route to achieving a suitable hydrogen storage medium. Proc. Natl. Acad. Sci. U.S.A. 104, 20173-20176 (2007) ; Han, S. S. & Goddard, W. A. High H2 storage of hexagonal metal-organic frameworks from first-principles-based grand canonical monte carlo simulations. J. Phys Chem. C. 112, 13431-13436 (2008) ; Mavrandonakis , A. , Tylianakis, E. , Stubos, A. K. & Froudakis, G. E. Why Li doping in MOFs enhances H2 storage capacity? a multi- scale theoretical study. J. Phys. Chem. C. 112, 7290-7294 (2008) ; Dalach, P. , Frost, H. , Snurr, R. Q. & Ellis, D. E. Enhanced hydrogen uptake and the electronic structure of lithium-doped metal-organic frameworks. J. Phys. Chem. C. 112, 9278-9284 (2008)) . However, doping of Li(O) into a real co-ordination framework material is intrinsically problematic due to the reactivity of Li(O) with the cationic metal clusters and organic ligands that constitute the co-ordination framework. Thus, doping with ionic Li+ offers a more controllable route to interrogate and understand H2 binding in a doped host.

The material may comprise [H2ppz] [In2(L)2] or Li1 5H0 5[In2(L)2] or any related combination of metal ions, ligands and appropriate counter-ions.

The material may exist in a solvated form such as {[H2ppz] [In2 (L)2] 3.5DMF-5H2O}, (Li1 5[[H3O]0 5[In2(L)2] - llH2O} or

[In2(L)2] (ppz)] -n(CH3)2CO.

The framework may further comprise an additional material attached to the framework that provides further storage capacity. The further storage capacity may be located beyond the one or more pores. The framework may provide further storage capacity by defining an extension of the one or more pores via the presence of one or more extended framework portions. Said extended framework portions may comprise extended ligands. Alternatively, there may be a region of framework adjacent a region of one or more other substance storage materials.

These arrangements are advantageous because they allow for a greater hydrogen storage capacity. For instance, substances that enter the one or more pores of the framework may then pass into the additional material/other substance storage materials, thereby vacating the one or more pores of the framework and enabling further substances to enter the one or more pores of the framework.

The entry of substances into the pores may be achieved via pressurisation, a change in temperature, the exchange of one or more stored substances by one or more competitor substances, the use of a supercritical fluid, the use of an ionic liquid and/or chemical modification. The pressurisation may be carried out at pressures from 0 to 109 Pa, preferably from 0 to 107 Pa, more preferably from 0 to 106 Pa, even more preferably from 0 to 5xlO5 Pa, and most preferably from 0 to 2xlO5 Pa. The chemical modification may occur via the exchange of guest gate entities in the pores.

The material may further comprise one or more substances releasably stored by the material. Said one or more substances may be one or more gas, one or more liquid or a combination of the above. These substances may be one or more of H2, N2, CO2, methane, acetylene, NO, NO2, CO, HCN, O2, volatile organic compounds. Said one or more substances releasably stored by the material may be present in an amount of at least 0.5 wt% of the volume of the material, preferably at least 1 wt%, more preferably at least 4 wt% and even more preferably at least 6 wt%. The release of substances from the pores may be achieved via a lowering of the external pressure, chemical modification, the exchange of one or more stored substances by one or more competitor substances, a change in temperature, or photochemical activation.

According to another aspect of the present invention, there is provided a method of manufacturing a material for the releasable storage of one or more substances comprising preparing a framework defining one or more pores in the presence of one or more guest gate entities, wherein the material has one or more of the guest gate entities associated with the pores and one or more of the guest gate entities are capable of reversibly at least hindering the entry into the pores, or release from the pores of said one or more substances.

The method may comprise preparing the framework and then incorporating the one or more guest gate entities, or preparing the framework and incorporating the one or more guest gate entities in the same step.

Following the preparation of the framework defining one or more pores and one or more guest gate entities associated with the pores, the method may further comprise exchanging one or more of the guest gate entities with other guest gate entities.

The method may be carried out in the presence of one or more solvents such as water, acetone, benzene, substituted naphthalene, poly aromatic and substituted polyaromatic compounds, 1 ,4-dioxane, THF, dichloromethane, chloroform, carbon tetrachloride, halogenated solvents, PCBs, acetonitrile, dimethylformamide, dimethyl sulfoxide, acetic acid, n-butanol, isopropanol, n-propanol, ethanol, methanol, and formic acid. Where the method provides a solvated material, the material may be desolvated by any suitable means, such as the use of a vacuum, heat, counter solvent, supercritical solvent, or ionic liquid.

The method may further be carried out in an acidic medium. The acidic medium may comprise one or more of HNO3, HCl, HBr, sulphuric acid, phosphoric acid, chromic acid, sulphonic acids, carboxylic acids and/or vinylogous carboxylic acids.

The method may further be carried out at a temperature of from 0 to 2000C, preferably 30 to 15O0C, more preferably 60 to 12O0C or even more preferably 80 to 1000C.

In one embodiment, the method may comprise mixing H4L, In(NO3)3 and one or more guest gate entities in a solvent. The one or more guest gate entities may be piperazine or any other aforementioned guest gate entities. Said solvent may be a mixture of DMF/acetonitrile (2: 1 v/v) or any other suitable solvent. The ratio of H4L:In(NO3)3:guest substances may be 1 : 1 :3 to 10, preferably 1 : 1 :3 to 8, more preferably 1 : 1 : 3 to 6 or even more preferably 1 : 1 : 3 to 5.

The method may next comprise the addition of an acidic solution such as HNO3 solution. The solution may then be heated to a temperature as detailed above for 0 to 5 days, preferably 0.25 to 3 days, more preferably 0.5 to 2 days and even more preferably 0.5 to 1.5 days. The material may then be obtained via any suitable means such as filtration and washing with an appropriate solvent such as DMF, before drying under vacuum or in air.

The step of exchanging one or more of the guest gate entities with other guest gate entities may comprise immersing the material in a solution comprising one or more guest gate entities. Said solution may comprise one or more suitable solvent such as water, acetone, 1 ,4-dioxane, THF, dichloromethane, acetonitrile, dimethylformamide, dimethyl sulfoxide, acetic acid, n-butanol, isopropanol, n-propanol, ethanol, methanol, formic acid, benzene, substituted naphthalene, poly aromatic and substituted poly aromatic compounds, chloroform, carbon tetrachloride, halogenated solvents, and PCBs. The solvent may be distilled water/acetone (1 : 1 v/v) .

The solution may be a saturated solution of the one or more guest gate entities.

The solution may be a solution comprising LiCl, LiBr, LiF, LiI, Li2O, LiOH, and salts of all possible cations and anions of these compounds, Li+ , Mg2+ , Al3 + , or other Group I, II or III cations and organic cations, transition and lanthanide metal cations.

The step of exchanging one or more of the guest gate entities with other guest gate entities may be carried out at any suitable temperature such as 0 to 4O0C, preferably 10 to 3O0C, more preferably 15 to 250C or even more preferably 18 to 220C.

The duration of this exchange step may be from 0 to 20 days, preferably 5 to 15 days, more preferably 7 to 13 days or even more preferably 9 to 11 days.

After this exchange step the solution may be removed by any suitable means such as by decanting. The material may then be rinsed and soaked in an appropriate solvent in order to remove any residual free guest gate entities. Said solvent may be one or more of the above solvents detailed in relation to the exchange step. The material may be soaked for from 0 to 10 days, preferably 0 to 7 days, more preferably 1 to 5 days or even more preferably 2 to A days.

According to a further aspect of the present invention, there is provided the use of a material according to the invention to releasably store, one or more substances; or separate two or more different substances by the preferential storage and/or release of at least one of said substances over the remaining substances.

The releasable storage may be hysteretic or, alternatively, the material may not exhibit hysteresis.

The material may be used in fuel cells, batteries, electronics, chemical storage, sensors and the delivery of pharmaceuticals. The use of the material in such applications is desirable because safety concerns are alleviated by the fact that substances can be stored at lower pressures and/or closer to ambient temperatures. Furthermore, the flexibility of the material, allowing for exchangeable guest substances that provide hysteretic properties and/or enhanced uptake of substances means that the material can be tailored to particular uses. In the case of the delivery of pharmaceuticals, the release of the substance would necessarily have to be triggered by chemical modification.

According to a further aspect of the present invention, there is provided a method of manufacturing a material comprising one or more substances releasably stored by the material comprising providing a material according to the invention and introducing the one or more substances by pressurisation, a change in temperature, the exchange of one or more stored substances by one or more competitor substances, the use of a supercritical fluid, the use of an ionic liquid and/or chemical modification. The pressurisation may be carried out at pressures from 0 to 10" Pa, preferably from 0 to 107 Pa, more preferably from 0 to 106 Pa, even more preferably from 0 to 5xlO5 Pa, and most preferably from 0 to 2xlO5 Pa.

According to another aspect of the present invention, there is provided a container enclosing a material according to the invention.

The container may further enclose one or more substances. A proportion or all of the one or more substances may be releasably stored by the material.

Such a container can be advantageously utilised in fuel cells, batteries, electronics, chemical storage and sensors.

According to a further aspect of the present invention, there is provided the use of a container according to the invention to releasably store, one or more substances; or separate two or more different substances by the preferential storage and/or release of at least one of said substances over the remaining substances.

According to another aspect of the present invention, there is provided a framework for the releasable storage of one or more substances, wherein the framework defines one or more pores, and wherein the framework is suitable to have one or more guest gate entities associated with the pores to reversibly at least hinder the entry into the pores, or release from the pores of said one or more substances.

According to a further aspect of the present invention, there is provided a method of producing H2 comprising storing H2 in a storage container containing a material according to the invention and releasing it later, over time, using the one or more guest gate entities and a pressure differential across the container to control the release of H2.

According to another aspect of the present invention, there is provided a method of separating one or more substances from a mixture of substances comprising storing one or more of said substances in a storage container containing a material according to the invention and/or releasing one or more of said substances from a storage container containing a material according to the invention, wherein the presence of the one or more guest gate entities enables the preferential storage and/or release of at least one of said substances over the remaining substances.

According to a further aspect of the present invention, there is provided a material for the releasable storage of one or more substances comprising a framework defining one or more pores and one or more guest gate entities associated with the pores, wherein one or more of the guest gate entities are capable of enhancing the uptake of one or more substances into the pores of the framework and/or the isosteric heat of adsorption of one or more substances.

It will be appreciated that optional features applicable to one aspect of the invention can be used in any combination, and in any number. Moreover, they can also be used with any of the other aspects of the invention in any combination and in any number. This includes, but is not limited to, the dependent claims from any claim being used as dependent claims for any other claim in the claims of this application.

An embodiment of the present invention will now be described herein, by way of example only, with reference to the following figures: Figure 1 - shows the chemical structure of 1 , 1 ' ,4' , 1 " ,4" , 1 ' "- quaterphenyl-3 , 5 , 3 " ' , 5 " ' -tetracarboxylic acid (H4L) ;

Figure 2 - shows 3D views of (a) { [H2ppz] [In2(L)2] - 3.5DMF-5H2O} (1-ppz-solv) according to the present invention and (b) (Li1 5[[H3O]0 5[In2(L)2] - 11H2Ol0O (1-Li- solv) according to the present invention along the b-axis showing channels A, B, and C. Channels B and C are interconnected and therefore can be regarded as part of the same pore, (c) shows a 3D view of the tetrahedral co-ordination environment of Li+ in 1-Li- solv;

Figure 3 - shows a 3D space-filling framework structure of (a) 1- ppz-solv and (b) 1-Li-solv viewed along the crystallographic b- axis;

Figure 4 - shows (a) N2 sorption isotherms for [H2ppz] [In2(L)2] (1- ppz) and Li1 5H0 5[In2(L)2] (1-Li) according to the present invention at 78K; H2 sorption isotherms for (b) 1-ppz and (c) 1-Li at 78K up to 100 000 Pa (1 bar) ; (d) adsorption enthalpy of H2 adsorption for

1-ppz and 1-Li at low surface coverage;

Figure 5a - shows a 3D view of the asymmetric unit for 1-ppz- solv;

Figure 5b - shows a 3D view of the asymmetric unit for 1-Li-solv;

Figure 6 - shows a) a 3D view of the structure of 1-ppz-solv containing two types of tetrahedral node; b) a 3D view of 1-ppz- solv along the crystallographic c-axis, showing the diamond-type framework structure; Figure 7 - shows a 3D view of the b-axis of the two-fold interpenetrated structure of 1-ppz-solv containing three channels (labelled A, B, and C) and strong π-π interactions;

Figure 8 - shows 3D views of (a) 1-ppz-solv and (b) 1-Li-solv along the crystallographic b-axis, showing piperazinium in channel B of 1-ppz-solv and Li+ in channel C of 1-Li-solv;

Figure 9 - shows 3D views of (a) 1-ppz-solv and (b) 1-Li-solv along the crystallographic c-axis;

Figure 10 - shows thermogravimetric analyses (TGA) plots for 1- ppz-solv and 1-Li-solv;

Figure 11 - shows in situ IR spectra for 1-Li over the ranges (a) 4000-600 cm"1 and (b) 4000-2800 cm 1;

Figure 12 - shows simulated and experimental powder X-ray diffraction (PXRD) patterns for 1-ppz-solv;

Figure 13 - shows simulated and experimental PXRD patterns for 1-Li-solv;

Figure 14 - shows experimental PXRD patterns for 1-ppz-solv and

1-Li-solv;

Figure 15 - shows experimental PXRD patterns for as-synthesized 1-ppz-solv and desolvated 1-ppz; Figure 16 - shows experimental PXRD patterns for as-synthesized 1-Li-solv and desolvated 1-Li;

Figure 17 - shows pore size distributions for 1-ppz and 1-Li;

Figure 18 - shows H2 sorption isotherms for 1-ppz and 1-Li at 78 K up to 100 000 Pa (1.0 bar) ;

Figure 19 - shows H2 sorption isotherms for 1-ppz and 1-Li at 78 K up to 2000 000 Pa (20 bar) ;

Figure 20 - shows an isobar for H2 desorption of 1-ppz at 100 000 Pa (1.0 bar) ;

Figure 21 - shows kinetic profiles for H2 adsorption of 1-ppz at the temperature 80.6 K;

Figure 22 - shows kinetic profiles for H2 adsorption of 1-ppz at the temperature 81.9 K;

Figure 23 - shows kinetic profiles for H2 adsorption of 1-ppz at the temperature 82.9 K;

Figure 24 - shows kinetic profiles for H2 adsorption of 1-ppz at the temperature 83.9 K;

Figure 25 - shows an Arrhenius plot of kinetic parameter k, corresponding to the diffusion of H2 along the pore entrance of 1- ppz at the temperature between 80.6 K and 83.9 K; Figure 26 - shows an Arrhenius plot of kinetic parameter k2 corresponding to the diffusion of H2 along the pore cavities of 1- ppz at the temperature between 80.6 K and 83.9 K;

Figure 27 - shows a table of kinetics rate constants (ki and k2) and their corresponding contribution coefficients (A1 and A2) estimated by fitting the adsorption kinetic profiles to double exponential model for 1-ppz;

Figure 28 - shows a virial plot for the adsorption of H2 on 1-ppz at 78 K;

Figure 29 - shows a virial plot for the adsorption of H2 on 1-ppz at 88 K;

Figure 30 - shows a virial plot for the adsorption of H2 on 1-Li at 78 K;

Figure 31 - shows a virial plot for the adsorption of H2 on 1-Li at 88 K;

Figure 32 - shows a table of physical characteristics and sorption properties of 1-ppz and 1-Li;

Figure 33 - shows a cross section of a spherical steel H2 container according to the invention containing a material according to the invention;

Figure 34 - shows a cross section of a spherical steel H2 container according to the invention containing a material according to the invention and a further storage material; Figure 35 - shows a cross section of a car fitted with a H2 fuel cell according to the invention; and

Figure 36 - shows a substance separation technique according to the invention involving a) the entry of a mixture of substances into a spherical steel container according to the invention, followed by b) the preferential release of one substance over another substance.

Detailed herein is the synthesis, structure and exchange reactions of two salts {[H2ppz] [In2(L)2] - 3.5DMF-5H2O}, 1-ppz-solv (NOTT-200) , and (Li1 5[[H3O]0 5[In2(L)2] - 11H2OIo0, 1-Li-solv (NOTT-201) of a doubly- interpenetrated anionic framework, [In2(L)2]2", 1 , constructed from 1 , 1 ' ,4' , 1 ' ' ,4" , r "-quaterphenyl-3,5, 3 " ' ,5 " ' -tetracarboxylate (L4 ) and In(III) , together with the gas (N2 and H2) adsorption properties of their desolvated derivatives, 1-ppz and 1-Li, respectively. Notably, 1-ppz shows a significant kinetic trap (hysteresis) for N2 and H2 adsorption and release, while 1-Li shows an increase in both pore volume and, significantly, a higher isosteric heat of adsorption for H2 compared to 1- ppz. The structures of both 1-ppz-solv and 1-Li-solv have been determined unambiguously and, therefore, the precise structural and chemical features of these materials that underpin the observed H2 uptake capacities and hysteresis have been defined. The material 1-Li-solv represents the first modulated metal-organic framework designed to anchor Li+ via two chelate carboxylate groups leaving, after desolvation by mild heating, accessible and exposed Li+ sites.

Solvothermal reaction of H4L (Figure 1) with In(NO3)3 in an acidic

(HNO3) mixture of DMF/CH3CN at 90 0C in the presence of piperazine (C4H10N2, ppz) affords the solvated framework complex

{[H2ppz] [In2(L)2] - 3.5DMF-5H2O}, 1-ppz-solv, (NOTT-200) . The single crystal X-ray structure of 1-ppz-solv shows a three-dimensional (4,4)- connected co-ordination framework constructed from mononuclear [In(O2CR)4] nodes bridged by the tetracarboxylate ligand (L4 ) . Each In(III) centre is 7-co-ordinate via binding to O-centres from four carboxylate groups, three adopting bidentate co-ordination and one monodentate binding, to form a tetrahedral 4-connected node with In-O distances ranging from 2.101 (8) to 2.340(6) A. This leaves one carboxylate oxygen atom (06) sited 2.805(16) A from the In(III) centre and hydrogen-bonded to the H2ppz2+ dication. Each L4 ligand binds to four separate In(III) centres and thus acts as a tetrahedral 4-connected node to give an overall 4-connected diamond-type structure for the anionic framework 1. The structure is doubly-interpenetrated and is stabilised by intermolecular π-π interactions between phenyl rings (centroid-centroid distance: 3.67 A) . The anionic framework, 1 , is porous with three inter-linked rectangular-shaped channels (A, B, and C) generated by the alternative interweaving of two interpenetrated networks (Figure 2a) . Both the [In(O2CR)4] building blocks and hydrogen of phenyl groups protrude into the rhombic channel A. Channel B is bounded by the aromatic faces of phenyl groups and by two unco- ordinated oxygen atoms, 06. The surface of channel C is similar to that of the channel B comprising of aromatic faces of phenyl groups and coordinated carboxylate groups. The approximate dimensions of the channels taking into account van der Waal's radii of the surface atoms are 6.6 x 4.4 A (channel A) , 4.3 x 4.1 A (channel B) , and 4.6 x 1.0 A (channel C) with channels B and C inter-connected along the c axis. The three pores host different guest molecules. Both channel areas A and C are occupied by free solvent molecules DMF and H2O, while channel B contains only the ordered H2ppz2+ dications. Two un-co-ordinated carboxylate oxygen atoms 06 located at the corners of channel B are involved in O H-N hydrogen-bonds with the NH2 + groups of the H2ppz2 + dications, N O = 2.88(3) A, N-H O = 175°. Thus, the H2ppz2 + dications are fully ordered and positioned in the centre of and partially blocking channel B, while the free solvent molecules DMF and H2O in channels A and C are, as expected, highly disordered. The volume fraction occupied by the guest solvent molecules, DMF/H20, in 1-ppz- solv was estimated by PLATON/SOLV (Spek, A. L. Single-crystal structure validation with the program PLATON. J. Appl. Crystallogr. 36, 7-13 (2003)) to be 35% (Figure 3a) .

To establish the influence of the cationic species on the adsorption properties, H2ppz2+ dications were replaced by Li+ by ion-exchange under mild conditions to give (Li1 5[[H3O]0 5[In2(L)2] - 11H2Ol00, 1-Li-solv, (NOTT-201) . To achieve this, crystals of as-synthesized 1-ppz-solv were immersed in a saturated solution of LiCl in deionised water/acetone (v/v = l/l) at room temperature. The crystals were soaked for 10 days, during which time the LiCl solution was refreshed three times daily. Upon decanting the metal chloride solutions, the cation-exchanged crystals of 1-Li-solv were rinsed and soaked in distilled water/acetone (v/v = l/l) for up to 3 days to remove residual LiCl from the framework. Elemental analysis of a bulk sample of 1-Li-solv confirms that no N is present in this material, and XPS confirms that no residual Cl remains in the sample. The single crystal X-ray structure of 1-Li-solv shows a similar topology to that in 1-ppz-solv, namely a doubly-interpenetrated 4,4-connected diamond-type framework. The crystal structure of 1-Li- solv confirms that all the H2ppz2+ dications have indeed been removed from channel B, consistent with the results from elemental analysis, and, significantly, the precise crystallographic location of the Li+ cations in 1- Li-solv within the framework structure is well-defined. The In(III) centre in 1-Li-solv can be regarded as 8-co-ordinate with In-O bond lengths to the carboxylate groups ranging from 2.154(9) - 2.527(10) A. Interestingly, 06 in channel B, which lies 2.805(12) A distant from the In(III) centre and hydrogen-bonded to the H2ppz2+ dications in 1-ppz-solv, is now bound to In(III) in 1-Li-solv [In-O = 2.223(8) A] . The O-centre 07 in channel C, which is co-ordinated to In(III) only in 1-ppz-solv [In-O = 2.292(8) A] , is now co-ordinated at long range in 1-Li-solv [In-07 = 2.527(10) A] (Figures 2a and 2b) . Two distinct water molecules (09 and 01O) are well located within channel C, and these hydrogen-bond to 07 via O-H O interactions, O O = 2.80(2) , 2.87(3) A. These two water molecules and two co-ordinated oxygen atoms (03 and 02) from carboxylate groups constitute a tetrahedral environment for Li+ to form a tetrahedral LiO4 moiety within channel C with Li-O distance ranging from 1.85(5) to 2.03(4) A, and Li-In distance 3.17(5) A (Figure 2c) (Yang, T. , Yang, S. , Liao, F. & Lin, J. Two isotypic diphosphates LiM2H3 (P2O7)2 (M = Ni, Co) containing ferromagnetic zigzag MO6 chains. J. Solid State Chem. 181 , 1347-1353 (2006)) . Thus, on going from 1-ppz-solv to 1-Li- solv the H2ppz2+ dications in channel B are replaced by Li+ cations located within channel C thereby modulating the potential porosity of the framework materials by freeing channel B via co-ordinative reorganisation of the cationic guests.

In-situ IR spectroscopy of 1-Li-solv confirms that the water molecules co- ordinated to Li+ can be removed by heating at 100-1500C under helium flow. This is consistent with the TGA results which indicate no further weight loss observed between 1200C and 4000C. In fully dehydrated 1- Li, no combination of carboxylate groups is able to fully saturate the coordination sphere around the desolvated Li+ cation thus leaving the Li + centre partially exposed. The experimentally observed crystallographic position of Li+ centres in 1-Li-solv is in good agreement with that obtained from classical valence force fields and semi-empirical quantum modelling studies on Li-doped IRMOFl , where the minimum-energy position of Li+ has been modelled to occupy a position between two oxygen atoms from carboxylate group close to Zn(II) (Fuentes-Cabrera, M. , Nicholson, D. M. & Sumpter, B. G. Electronic structure and properties of isoreticular metal-organic frameworks: the case of M- IRMOFl (M = Zn, Cd, Be, Mg, and Ca). J. Chem. Phys. 123, 124713- 124718 (2005)) . The molar ratio between Li and In within 1-Li-solv was determined by ICPMAS to be 0.75 with the remaining charge taken up by protonated carboxylate groups the presence of which were confirmed by IR spectroscopy. Powder X-ray diffraction of bulk samples of 1-ppz-solv and 1-Li-solv are consistent with the single crystal X-ray data for each, and also confirm that the framework structure remains intact after Li + exchange. The volume fraction occupied by the guest H2O solvent molecules in 1-Li-solv was estimated by PLATON/SOLV to be 42%. The composition and bulk phase purity of 1-ppz-solv and 1-Li-solv were confirmed by single crystal X-ray diffraction, elemental analysis, TGA, IR spectroscopy, ICPMAS and powder X-ray diffraction (see below) .

An acetone-exchanged sample of 1-ppz-solv, [In2(L)2] (ppz)] -n(CH3)2CO, and the Li+ -exchanged sample 1-Li-solv are stable after degassing at 1200C and 10 5 Pa (10 10 bar) for 24 h to give fully desolvated samples, 1- ppz and 1-Li, respectively. The N2 adsorption and desorption isotherms of 1-ppz at 78 K show a marked hysteresis loop (Figure 4a) while, in contrast, those of 1-Li show typical Type-I adsorption behaviour with full reversibility and no hysteresis (Figure 4a) . The BET surface areas calculated within the pressure range P/P0 < 0.2 for 1-ppz and 1-Li were estimated as 191 ± 2 and 568 ± 3 m2gΛ, respectively, indicating that the adsorption capacities of 1-Li is some 197% greater than that of 1-ppz. Applying Dubinin-Astakhov analysis to the isotherm data confirms that the pore sizes are distributed widely around 4.3 A for 1-ppz, and narrowly around 8.3 A for 1-Li, indicating that the multiple pore size distribution in 1-ppz has been simplified in 1-Li, consistent with the removal of bulky H2ppz2+ dications and replacement with smaller Li + cations. The pore volumes for 1-ppz and 1-Li calculated from the maximum N2 adsorption are 0.136 and 0.239 g cm 3, respectively. The significant difference in sorption behaviour for 1-ppz and 1-Li is due to a kinetic trap created by the bulky H2ppz2+ dications in 1-ppz acting as a reversible gate modulating the access and release of N2 into and from channel B. A similar kinetic trap effect was also observed in the H2 sorption isotherms at 78K of 1-ppz. Figure 4b confirms that 89% of the adsorbed H2 is trapped in the framework when the pressure was reduced from 100 000 Pa (1.0 bar) to 30 000 Pa (0.3 bar) , and 60% of the adsorbed H2 remains when the pressure is further reduced to 500 Pa (0.005 bar) . An isobar plot at 100 000 Pa (1.0 bar) confirms that all the trapped H2 can be completely released by gradually raising the system temperature. The adsorption/desorption kinetic data confirm the equilibrium time to be above 30 minutes, much longer than the typical H2 equilibrium step (within 3 minutes) . Fitting the kinetic profiles of H2 adsorption between 10 and 30 mbar in the temperature range 80.6 - 83.9 K using a double-exponential expression gives an estimate of the barrier for diffusion of H2 at the pore entrance and along the pore cavities of 1- ppz, Ea = 15.06 and 5.05 kJ/mol, respectively. In contrast, H2 isotherms of 1-Li show full reversibility with no hysteresis. Furthermore, the kinetic data confirm that equilibrium is achieved rapidly, within ca. 1-3 mins of the isotherm pressure step (Figure 4c) . Interestingly and importantly, the present invention presents the first example of guest gate entity-dependent hysteretic substance sorption, with the hysteresis tuneable by post-synthetic guest gate entity exchange. This is distinct from previously reported hysteretic H2 sorption in flexible metal-organic frameworks which are based upon the kinetics of pore windows opening and closing (Zhao, X. et al. Hysteretic adsorption and desorption of hydrogen by nanoporous metal-organic frameworks. Science 306, 1012- 1015 (2004) ; Choi, H. J. , Dinca, M. & Long, J. R. Broadly hysteretic H2 adsorption in the microporous metal-organic framework Co(1 , 4- benzenedipyrazolate) . J. Am. Chem. Soc. 130, 7848-7850 (2008) ; Ferey, G. et al. Hydrogen adsorption in the nanoporous metal - benzenedicarboxylate M(OH) (O2C-C6H4- CO2) (M = Al3 + , Cr3 +) , MIL-53. Chem. Commun. 2976-2977, (2003) ; Yang, C , Wang, X. & Omary, M. A. Fluorous metal-organic frameworks for high-density gas adsorption. J. Am. Chem. Soc , 129, 15454-15455 (2007)) .

The total H2 uptakes at 100 000 Pa (1.0 bar) for 1-ppz and 1-Li are 0.96 wt% and 1.02 wt%, respectively. Although the N2 isotherms show a twofold increase in storage capacity on going from 1-ppz to desolvated 1-Li, the H2 isotherms at 78K do not give such an enhancement (Figure 4a-4c) . This most likely originates from the different kinetic diameters of H2 (2.89 A) and N2 (2.99 A) molecules, since there are voids which are too small to incorporate N2 molecules but which can accommodate H2. Considering the identical framework topology and pore surface chemistry in 1-ppz and 1-Li, it is assumed that the high energy barrier (5-15 kj/mol) for diffusion of H2 is due to the bulky H2ppz2+ dications sited in channel B and the overall relatively small pore size of 1-ppz. By using a density of 0.0708 g cm 3 of H2 at its boiling point at 20.28 K (CRC Handbook of Chemistry and Physics, 74th ed. , CRC Boca Ratan (1993)) , it can be deduced that the volumes of H2 adsorbed in 1-ppz and 1-Li at 100 000 Pa (1.0 bar) are 0.136 and 0.144 cm3 g 1, respectively. This corresponds to 47% and 40% filling of the total crystallographically- determined extra-framework/cation pore volume of 0.289 and 0.360 cm3 g ' for 1-ppz and 1-Li, respectively. At 2000 000 Pa (20 bar) up to 67% and 76% of the total pore volume can be filled by H2 molecules in 1-ppz and 1-Li, respectively. These values are reasonable considering that the adsorption temperature is well above the H2 critical temperature (33 K) and similar to those observed in other metal-organic framework materials (Zhao, X. et al. Hysteretic adsorption and desorption of hydrogen by nanoporous metal-organic frameworks. Science 306, 1012-1015 (2004)) . It is also reasonable to expect increased H2 uptake for 1-Li in comparison to 1-ppz and this can be attributed to an increase in the available pore volume in the host material (Yang, S. et al. Enhancement of H2 adsorption in Li + -exchanged co-ordination framework materials. Chem. Commun. 6108-6110 (2008)) . It should also be noted that the pore volumes calculated from single crystal X-ray data are often larger than those determined from N2 isotherms since not all the void space within a porous material is necessarily accessible by the gaseous substrate.

It has been established that small pores result in strong overlapping potentials and thus high H2 adsorption heat (Lin, X. et al. High H2 adsorption by coordination-framework materials. Angew. Chem. Int. Ed. 45, 7358-7364 (2006) ; Dinca, M. et al. Observation of Cu2+-H2 interactions in a fully desolvated sodalite-type metal-organic framework. Angew. Chem. Int. Ed. 46, 1419-1422 (2007) ; Lin, X. et al. High capacity hydrogen adsorption in Cu(II) tetracarboxylate framework materials: the role of pore size, ligand functionalization, and exposed metal sites. J. Am. Chem. Soc. 131 , 2159-2171 (2009)) . Virial analysis (Cole, J. H. et al. Thermodynamics of high temperature adsorption of some permanent gases by porous carbons. J. Chem. Soc. Faraday Trans. 70, 2154-2169 (1974) ; Chen, B. et al. Surface interactions and quantum kinetic molecular sieving for H2 and D2 adsorption on a mixed metal- organic framework material. J. Am. Chem. Soc. 130, 6411-6423 (2008)) of the H2 adsorption isotherms measured at 78 K and 88 K revealed that the isosteric heat of adsorption of the small-pored 1-ppz at zero surface coverage is 9.0 kJ mol 1, higher than most metal organic frameworks with large pores (Lin, X. , Jia, J. , Hubberstey, P. , Schroder, M. & Champness, N. R. Hydrogen storage in metal-organic frameworks. CrystEngComm. 9, 438-448 (2007) ; Ferey, G. et al. A chromium terephthalate-based solid with unusually large pore volumes and surface area. Science 309, 2040-2042 (2005) . Correction : Ferey, G. Science, 310, 1119 (2005) ; Yang, S. et al. Enhancement of H2 adsorption in Li + - exchanged co-ordination framework materials. Chem. Commun. 6108- 6110 (2008)) . However the most intriguing result is that 1-Li, even though it has a larger overall pore volume, gives a higher value of 10.1 kJ mol"1 for the isosteric heat of adsorption for H2 uptake at zero surface coverage, and furthermore, it is ~ 1.0 kJ mol"1 higher than 1-ppz at all measured H2 loading (Figure 4d) . This is very unusual, given that 1-ppz and 1-Li have the same framework structure and the same pore surface chemistry defined by the carboxylate ligand and the In(III) building blocks. Significantly, the smaller pore size of 1-ppz (4.3 A) does not afford a higher H2 adsorption isosteric heat than large-pored 1-Li (8.3 A) . It is reasonable, therefore, to conclude that the exposed Li+ ion in 1-Li is able to provide a strong non-dissociative interaction with H2 molecules in accord with theoretical and modelling predictions (Blomqvist, A. , Araύjo, C. M. , Srepusharawoot, P. & Ahuja, R. Li-decorated metal-organic framework 5: a route to achieving a suitable hydrogen storage medium. Proc. Natl. Acad. Sci. U.S.A. 104, 20173-20176 (2007) ; Han, S. S. & Goddard, W. A. Lithium-doped metal-organic frameworks for reversible H2 storage at ambient temperature. J. Am. Chem. Soc. 129, 8422-8423 (2007) ; Han, S. S. & Goddard, W. A. High H2 storage of hexagonal metal-organic frameworks from first-principles-based grand canonical monte carlo simulations. J. Phys Chem. C. 112, 13431-13436 (2008) ; Klontzas, E. , Mavrandonakis , A. , Tylianakis, E. & Froudakis, G. E. Improving hydrogen storage capacity of MOF by functionalization of the organic linker with lithium atoms. Nano Letters 8, 1572-1576 (2008) ; Mavrandonakis, A. , Tylianakis, E. , Stubos, A. K. & Froudakis, G. E. Why Li doping in MOFs enhances H2 storage capacity? a multi-scale theoretical study. J. Phys. Chem. C. 112, 7290-7294 (2008) ; Dalach, P. , Frost, H. , Snurr, R. Q. & Ellis, D. E. Enhanced hydrogen uptake and the electronic structure of lithium-doped metal-organic frameworks. J. Phys. Chem. C. 112, 9278-9284 (2008)) . These results relate to the DFT modelling studies on Li-doped [Zn2(BPDC)2(DPNI)] (BPDC2" = biphenyl- 4,4'-dicarboxylate; DPNI = N,N'-di(4-pyridyl)-l ,4,5,8- naphthalenetetracarboxydiimide) in which Li+ binds to the corner-post O- centres in [Zn2(O2CR)4] paddle-wheel building blocks, and the corresponding modelling study shows that the Li+ can enhance the H2 binding energies (Dalach, P. , Frost, H. , Snurr, R. Q. & Ellis, D. E. Enhanced hydrogen uptake and the electronic structure of lithium-doped metal-organic frameworks. J. Phys. Chem. C. 112, 9278-9284 (2008)) . It is interesting to note that Hupp et al. have reported Li(0)-doping ( ~ 5 mol % Li) of a metal-organic framework via chemical reaction with Li(O) , and confirmed improvements of both the isosteric heat and the overall H2 adsorption uptake (Mulfort, K. L. & Hupp, J. T. Chemical reduction of metal-organic framework materials as a method to enhance gas uptake and binding. J. Am. Chem. Soc. 129, 9604-9605 (2007) ; Mulfort, K. L. & Hupp, J. T. Alkali metal cation effects on hydrogen uptake and binding in metal-organic frameworks. Inorg. Chem. 47, 7936-7938 (2008)) . However, this improvement in these Li-doped materials has been largely attributed to favourable displacement of interpenetrated frameworks during the intense chemical reduction and incorporation of LiVLi+ , rather than direct Li + -H2 interactions (Mulfort, K. L. & Hupp, J. T. Alkali metal cation effects on hydrogen uptake and binding in metal-organic frameworks. Inorg. Chem. 47, 7936-7938 (2008)) . More recently, Eddaoudi et al. have reported the enhanced isosteric heat of H2 adsorption in a Li + -exchanged Li-rΛo-ZMOF material. However, in this study the Li+ centres are highly disordered through the framework and are not structurally located. In the corresponding desolvated material the Li + cations remain fully co-ordinated to four water molecules, the removal of which at 3000C leads to framework collapse. Thus the Li+ centres are not accessible to H2 molecules and the enhancement of the heat of adsorption has been attributed to the presence of electrostatic field in the cavity from the charged framework and counterions (Nouar, F, Eckert, J. , Eubank, J. F. , Forster, P. & Eddaoudi, M. Zeolite-like metal-organic frameworks (ZMOFs) as hydrogen storage platform: lithium and magnesium ion- exchange and H2-(rho-ZMOF) interaction studies. J. Am. Chem. Soc. 131,

2864-2870 (2009)) .

In summary, this invention establishes a new protocol to modulate hysteretic H2 adsorption behaviour in metal-organic frameworks by judicious choice of guest gate entities within parent frameworks. The relatively bulky, hydrogen-bonded H2ppz2 + dication gives rise to a framework that acts as a kinetic trap for H2, with the dication acting as a reversible gate controlling entry and release of gaseous substrates. Cation exchange and incorporation of exposed Li+ sites within the framework polymers increases both porosity and the isosteric heat of adsorption for H2, and leads to a loss of hysteretic adsorption properties. It is anticipated that the invention disclosed herein, which may be based upon post-synthetic guest gate entity exchange, allows for the effective and efficient design and optimization of new exposed-Li + containing substance storage materials with hysteretic adsorption properties operating at ambient temperatures.

1. Experimental section

1.1 Materials and Measurements

All reagents and solvents were used as received from commercial suppliers without further purification. Analyses for C, H, and N were carried out on a CE-440 elemental analyzer. Thermogravimetric analyses (TGA) were performed under a nitrogen atmosphere (100 ml/min) using a TA SDT-600 thermogravimetric analyzer with a heating rate of 2 °C/min. IR spectra were recorded using a Nicolet Avatar 360 FT-IR spectrophotometer, and the in-situ IR spectra of 1-Li-solv were recorded using a Bruker TENSER 27 FT-IR spectrophotometer in KBr mode under He flow with heating rate 20 °C/min. Analyses for Li and In were carried out using an ICP-MAS analyzer. Calibration curves for ICP-MAS were prepared by dilution of commercially available standards with the sample dissolved in concentrated HNO3, and diluted to an appropriate concentration for measurement. Analysis for Cl was carried on a Kratos Axis Ultra XPS spectrometer. Powder X-ray diffraction (PXRD) data were collected over the 2Θ range 4-50° on a Philips X'pert diffractometer using Cu Ka radiation (λ = 1.5418 A, 40 kV/40mA) or on a Bruker Advanced D8 diffractometer using Cu Ka radiation (λ = 1.5423 A, 40 kV/40mA) .

1.2 Methods

Synthesis of H4L:

1 , 1 ' ,4' , 1 " ,4" , r "-quaterphenyl-3,5, 3 " ' ,5 " ' -tetracarboxylic acid was synthesized using the literature method (Lin, X. et al. High H2 adsorption by coordination-framework materials. Angew. Chem. Int. Ed. 45, 7358- 7364 (2006)) . All other reagents were purchased from Sigma- Aldrich or Acros.

Syntheses of { [H2ppz] [In2(L)2] - 3.5DMF-5H2O} (1-ppz-solv) and {Li1 5(H3O)0 5[In2(L)2] llH2O} (l-Li-solv): H4L (0.015 g, 0.05 mmol) , In(NO3)3 (0.0137 g, 0.05 mmol) , and piperazine (0.015g, 0.18 mmol) were mixed and dispersed in a mixture of DMF/acetonitrile (3 ml, 2: 1 v/v) . The resulting white slurry turned clear upon addition of two drops of 6M HNO3 solution. The solution was then heated to 900C for 1 day and colourless octahedral crystals of 1-ppz-solv were separated by filtration and washed sequentially by DMF, and dried in air. Yield: 0.09 g (70%) . To prepare the Li + -exchanged sample, crystals of as-synthesized 1-ppz-solv were immersed in a saturated solution of LiCl in distilled water/acetone (1 : 1 v/v) at room temperature. The crystals were soaked for ten days, and the LiCl solution refreshed three times daily. Upon decanting the metal chloride solutions, the cation-exchanged crystals of 1-Li-solv were rinsed and soaked in distilled water/acetone (1:1 v/v) for 3 days to remove residual free LiCl.

Elemental analysis (% calc/found): for 1-ppz-solv, In2O245C705H745N55 (C 52.25/52.19; H 4.63/4.45; N 4.75/4.65); for 1-Li-solv, In2O275C56H515Li15 (C 47.62/47.89; H 3.76/3.70; N 0.0/0.0). The volatility of crystallization solvents in the samples contributes to the discrepancy in elemental analytical data.

Selected IR: for 1-ppz-solv, v = 3630(w), 3015(w), 2946(w), 2811(w), 2324(w), 1718(s), 1572(m), 1435(m), 1365(vs), 1251(m), 1021 (m), 918(m), 826(m), 776(s), 751(s), 663(w); for 1-Li-solv, 3621(w), 3031(w), 2947(w), 2161(m), 1700(m), 1617(s), 1560(s), 1362(vs), 1248(m), 1076(m), 916(m), 857(m), 774(s), 754(s), 661(w).

Crystal data for 1-ppz-solv: [(InC28O8H1J2(C4H12N2)] (C3H7NO)35(H2O)5. Colourless block-like crystal (0.06 x 0.06 x 0.04 mm). C2/m, a = 36.525(1), b = 9.8281(3), c = 10.1059(4) A, β = 105.68(l), V = 3492.7(2) A3, Z = A, Deύe = 1.541 g cm3, μ = 0.746 mm1, F(OOO) = 1660. A total of 28201 reflections was collected, of which 3267 were unique, with Rinl = 0.086. Final R1 (wR2) = 0.078 (0.200) with GOF = 1.07. The final difference Fourier extrema were 1.26 and -1.79 e/A3.

Crystal data for 1-Li-solv: [(InC28O8H1J2Li15(H3O)05](H2O)11. Colourless block-like crystal (0.05 x 0.04 x 0.04 mm). C2/c, a = 36.601(3), b =

9.7691(9), c = 19.670(2) A, β = 103.88(1), V = 6827.9(10) A3, Z = 8,

Aaic = 1-366 g cm3, μ = 0.752 mm1, F(OOO) = 2840. A total of 33489 reflections was collected, of which 5807 were unique, with Rmt = 0.079.

Final R1 (wR2) = 0.117 (0.330) with GOF = 1.04. The final difference Fourier extrema were 2.11 and -2.52 e/A3. 1.2 X-ray single crystal diffraction.

The X-ray diffraction data for 1-ppz-solv and 1-Li-solv were collected 120(2) K on a Bruker Nonius APEXII CCD area detector using graphite- monochromated Mo-Ka radiation. Structures were solved by direct methods and developed by difference Fourier techniques using the SHELXTL software package (G. M. Sheldrick, Acta Crystallogr. Section A 64, 112 (2008)) . The hydrogen atoms on the ligand were placed geometrically and refined using a riding model. The unit cell volume includes a large region of disordered solvent which could not be modelled as discrete atomic sites. PLATON/SQUEEZE (A. L. Spek, J. Appl. Crystallogr. 36, 7 (2003) ; P. v.d. Sluis, A. L. Spek, Acta Crystallogr. Sect. A 46, 19 '4 (1990)) was employed to calculate the contribution to the diffraction from the solvent region and thereby produced a set of solvent- free diffraction intensities. The final formula was calculated from the SQUEEZE results combined with elemental analysis and TGA data: the contents of the solvent region are therefore included in the unit cell contents but not in the refinement model. Details are included in CIF format in Figures 5 to 9.

1.3 Nitrogen and Hydrogen adsorption isotherms.

N2 and H2 adsorption isotherms (0-100 000 Pa, 0-1.0 bar) were recorded at the University of Nottingham on an IGA system with high resolution pressure transducer (Hiden Isochema, Warrington, UK) under ultra high vacuum in a clean system with a diaphragm and turbo pumping system. In a typical procedure, ~ 100 mg dry sample were used for measurement. Ultra-pure plus grade (99.9995%) H2 was purchased from BOC and purified further using calcium alumino silicate and activated carbon adsorbents to remove trace amounts of water and other impurities before introduction into the IGA system. The density of bulk H2 at 78 K in the buoyancy correction was calculated by the Redlich-Kwong-Soave equation of state of H2 incorporated in the IGASWIN software of the IGA system. The density of liquid H2 at the boiling point (0.0708 g cm 3) was used for the adsorbate buoyancy correction. Adsorption isotherms (0-2000 000 Pa, 0-20 bar) were also measured using a Hiden Isochema Intelligent Gravimetric Analyzer, which is an ultra high vacuum, clean system with a diaphragm and turbo pumping system. Kinetic studies were carried out using a Hiden Isochema Intelligent Gravimetric Analyzer and a cryogen- furnace system with temperature stability of ± 0.1 0C.

2. X-ray crystal structure for 1-ppz-solv and 1-Li-solv In the crystal structure of 1-ppz-solv, one of the phenyl ring groups on the ligand is disordered over two equally-occupied orientations (ClIa, ClIb, C12a, C12b) . The disordered phenyl ring group in 1-ppz-solv becomes ordered leading to an approximate doubling of the c-axis in 1-Li- solv relative to 1-ppz-solv (Figure 5) .

3. TGA plots for 1-ppz-solv and 1-Li-solv.

The unco-ordinated solvent molecules in 1-ppz-solv can be readily exchanged for acetone and/or removed by heating at 2000C either under a flow of N2 gas or in vacuo. TGA measurements show that the as-synthesized sample 1 loses solvent slowly between 20 and 4000C (Figure 10) . The weight loss of 27.0% from 1-ppz-solv correlates with solvent loss based upon 1.75 DMF and 2.5 water molecules per indium. 1-Li-solv loses solvent rapidly between 20 and 1500C, with the solvent loss of 23.0% from 1-Li-solv correlating to 5.75 molecules of water per indium, but undergoes no further significant changes below 3900C. Above 4000C both 1-ppz-splv and 1-Li-solv decompose rapidly. The volatility of crystallization solvents in the samples contributes to the discrepancies between room temperature and 3000C.

4. In-situ IR Spectra To probe the change of both the adsorbed and co-ordinated water molecules in 1-Li-solv, the in-situ IR spectra were recorded from 300C to 3000C. Approximately 5% of a 1-Li-solv sample was mixed with oven- dried KBr and ground for 20 min to give a fine powder. The powder was loaded into a crucible in the sample cell inside a glove box. Then the sample cell was kept under He gas ( > 99.9%) , and the IR spectra were recorded from 4000-600 cm 1 at 8 different temperatures as shown in Figure 11. The intensity of the peaks due to the water molecules start to decrease with increasing temperature, while the other peaks remain the same. The bands centred around 3500 cm 1 decrease upon heating confirming the loss of unco-ordinated water molecules from the channels (J. W. Ward, J. Phys Chem. 72, 4211 (1968)) . Bands of water molecules co-ordinated to Li+ were observed at 3140 cm 1, consistent with that found in Li(O2CCH3)-2H2O (E. S. Stoyanov, Y. A. Chesalov, J. Chem. Soc. Faraday Trans. 92, 1725 (1996) ; M. Cadene, A. M. Vergnoux, Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy 28, 1663 (1972) ; M. Cadene, J. Molecular Structure 2, 193 (1968)) . These co-ordinated water molecules are removed only slowly on heating compared to the adsorbed water, since there is strong bonding with Li + ion as indicated by the X-ray structure determination. At 150 0C, the coordinated water molecules are almost completely removed and the remaining bands around 3254cm"1 are assigned to a disordered COOH group (A. Witkowski, J. Chem. Phys. 47, 3645 (1967)) , required to balance the charge of the framework.

5. Powder X-Ray diffraction

Powder X-ray diffraction confirms the identities of 1-ppz-solv (Figure 12) and 1-Li-solv (Figure 13) in the bulk phase. Comparison of the PXRD traces of 1-ppz-solv and 1-Li-solv clearly shows no new peaks or shifting of peaks, suggesting that the structure of framework remains intact after Li+ exchange (Figure 14) . The desolvated 1-ppz and 1-Li were also stable in air but will take up water from the atmosphere (Figures 15 and 16) .

6. Pore size distribution for 1-ppz and 1-Li. Pore size distribution (PSD) data for 1-ppz and 1-Li were obtained by applying Dubinin- Astakhov analysis to N2 isotherms at 78K (Figure 17) . The analyses were carried out with IGASwin Vl .03.181 , and the constants for N2 are: Sorbate phase density = 0.808 g/cc; surface tension = 8.85mN/m; DA interaction constant = 2.96 kJnm3/mol.

7. Comparison of H2 Adsorption by 1-ppz and 1-Li.

Premier Plus 99.999% H2 was further purified by passing over zeolites and activated carbon and then used for sorption studies. Nearly 50% of the adsorbed H2 taken up at 2 000 000 Pa (20 bar) can be trapped in the framework when pressure is reduced to 2 000 Pa (0.02 bar) (Figure 19) . Although the N2 isotherms show a 2-fold increase in storage capacity, BET surface area and pore volume on going from 1-ppz to desolvated 1- Li, the H2 isotherms at 78K do not give such an enhancement (Figures 18 and 19) . At 100 000 Pa (1 bar) , H2 capacity increases by 6.0%, from 4.69 to 4.97 mmol/g, while at 2 000 000 Pa (20 bar) , it increases by 11.2 %, from 6.64 to 7.38 mmol/g. This most likely originates from the different kinetic diameters of H2 (2.89 A) and N2 (2.99 A) molecules, since there are voids which are too small to incorporate N2 molecules but which can accommodate H2.

8. Isobar of H2 desorption.

To examine the reversibility of the trapped H2 gas in 1-ppz, the isobar was recorded at 100 000 Pa (1.0 bar) , while the temperature was gradually raised from -1950C to room temperature. It is evident that H2 adsorption decreases rapidly with increasing temperature and is barely detectable at -600C (Figure 20) . The lack of desorption of H2 up to about -1800C is consistent with the isotherm hysteresis. As T is increased, thermal motion allows desorption of the trapped H2 guest to occur, which becomes noticeable at -1800C, with complete desorption at about -600C.

9. H2 Adsorption Kinetic for 1-ppz.

To investigate the mechanism of the kinetic trap of H2 within 1-ppz, kinetic profiles were measured over a narrow temperature range (80.6- 83.9 ± 0.1 K) where the compound was expected to display comparable uptake capacities. In these experiments, samples were exposed to a pressure of H2 in the range of 1000-3000 Pa (10-30 mbar) , corresponding to 0.5-1.0 H2 per In, and the amount of H2 adsorbed was monitored as a function of time. As shown in Figures 21-24, the kinetics profiles at 80.6, 81.9, 82.9 and 83.9 K exhibit exponential behaviour and the data were fitted using a double-exponential expression employed previously to model gas sorption kinetics in metal-organic frameworks (A. J. Fletcher, E. J. Cussen, D. Bradshaw, M. J. Rosseinsky, K. M. Thomas, J. Am. Chem. Soc. 126, 9750 (2004) ; H. J. Choi, M. Dinca, J. R. Long, J. Am. Chem. Soc. 130, 7840 (2008)) . Mt

= 4(i - 6Tv) + 4(i - e~M)

Equation (1) where M1 and Me represent the adsorbed amount of H2 at time t and at equilibrium, respectively, kλ and k2 are the rate constants, and A1 and A2 are the relative contributions of two distinct barriers controlling the overall adsorption, with A1 + A2 = 1. This model assumes the existence of two barriers associated with (i) diffusion at the pore entrance, and (ii) diffusion along the pore cavities. The activation energy barrier Zs12, which depends on the rate constant k of H2 adsorption on the temperature T, can be obtained by fitting to the Arrhenius equation (2) .

Figure imgf000038_0001
Equation (2) where R is the gas constant.

Thus, for an adsorption profile which has a rate constant k obeying the Arrhenius equation, a plot of In(A:) versus T Λ gives a straight line, whose slope can be used to determine EΛ.

Fitting each kinetic profile using the above model, while allowing a free refinement of A1 and A2, gave a sequence of values for the two rate constants (Ic1 and k2) , with k2 being larger for all temperatures (Figure 27) . The value for k2, corresponding to the diffusion of H2 within the pore cavities, is indeed expected to be higher than Ic1 corresponding to diffusion at the pore entrance. Thus, the smaller value, Ic1, is associated with the rate-determining step of the adsorption profile. The linear fit to the Arrhenius plot of IMk1) or ln(k2) versus 1/T enabled estimation of the barrier Ea of 15.06 and 5.05 kJ/mol for the diffusion of H2 at the pore entrance and along the pore cavities of 1-ppz, respectively (Figures 25- 26) . This is much larger than that observed in [Co(BPD)] (H2BPD = 1 ,4- benzenedi(4'-pyrazolyl)) (0.62 kJ/mol) , which displays broadly hysteretic H2 adsorption behaviour, and the values obtained for the diffusion of H2 in zeolites (1-3 kJ/mol) (H. J. Choi, M. Dinca, J. R. Long, J. Am. Chem. Soc. 130, 7840 (2008) ; S. -H. Jhi, Microporous Mesoporous Mater. 89, 138 (2006) ; A. V. Anil Kumar, H. Jobic, S. K. Bhatia, Adsorption 13, 501 (2007)) . However, it is comparable to the simulation results for M'MOFl at the zero surface coverage (8-13 kJ/mol) (B. Chen, X. Zhao, A. Putkham, K. Hong, E. B. Lobkovsky, E. J. Hurtado, A. J. Fletcher, K. M. Thomas, J. Am. Chem. Soc. 130, 6411 (2008)) .

10. Isosteric Heats of Adsorption for 1-ppz and 1-Li. Gravimetric H2 adsorption data were recorded over the range 0-100 000 Pa (0-1.0 bar) at both 78 K and 88 K for 1-ppz and 1-Li. All data were rigorously corrected for the buoyancy of the system, samples and absorbates. The isosteric heats of adsorption Qst were determined by fitting a virial-type equation to both the 78 K and 88 K H2 adsorption isotherms. The ln(p) values for a given amount adsorbed (n) were calculated from the linear regressions determined using the following virial equation (B. Chen, X. Zhao, A. Putkham, K. Hong, E. B. Lobkovsky, E. J. Hurtado, A. J. Fletcher, K. M. Thomas, J. Am. Chem. Soc. 130, 6411 (2008) ; X. Zhao, B. Xiao, A. J. Fletcher, K. M. Thomas, J. Phys. Chem. B 109, 8880 (2005) ; J. H. Cole, D. H. Everett, C. T. Marshall, A. R. Paniego, J. C. Powl and F. Rodriguez-Reinoso, J. Chem. Soc. Faraday Tran, 70, 2154 (1974) ; I. P. O'Koye, M. Benham, K. M. Thomas, Langmuir 13, 4054 (1997) ; C. R. Reid, I. P. O'Koye, K. M. Thomas, Langmuir 14, 2415 (1998) ; C. R. Reid, K. M. Thomas, Langmuir 15, 3206 (1999) ; C. R. Reid, K. M. Thomas, J. Phys. Chem. B 105, 10619 (2001) ; X. Zhao, S. Villar-Rodil, A. J. Fletcher, K. M. Thomas, J. Phys Chem. B 110, 9947 (2006)) .

Figure imgf000039_0001

Equation (3) where p is pressure, n is amount adsorbed and A0, A1 etc. are virial coefficients. A0 is related to adsorbate-adsorbent interactions, whereas A1 describes adsorbate-adsorbate interactions (J. H. Cole, D. H. Everett, C.

T. Marshall, A. R. Paniego, J. C. Powl and F. Rodriguez-Reinoso, J.

Chem. Soc. Faraday Tran, 70, 2154 (1974)) . Henry's Law constant (AT11) is equal to expC40) , and at low surface coverage A2 and higher terms can be neglected. Therefore, a graph of ln(n/p) versus n should give a straight line at low surface coverage. This approach has been used for analysis of adsorption of a wide range of gases (J. H. Cole, D. H. Everett, C. T. Marshall, A. R. Paniego, J. C. Powl and F. Rodriguez- Reinoso, J. Chem. Soc. Faraday Tran, 70, 2154 (1974) ; L P. O'Koye, M. Benham, K. M. Thomas, Langmuir 13, 4054 (1997) ; C. R. Reid, I. P. O'Koye, K. M. Thomas, Langmuir 14, 2415 (1998) ; C. R. Reid, K. M. Thomas, Langmuir 15, 3206 (1999) ; C. R. Reid, K. M. Thomas, J. Phys. Chem. B 105, 10619 (2001)) , including hydrogen (X. Zhao, B. Xiao, A. J. Fletcher, K. M. Thomas, J. Phys. Chem. B 109, 8880 (2005) ; X. Zhao, S. Villar-Rodil, A. J. Fletcher, K. M. Thomas, J. Phys Chem. B 110, 9947 (2006)) , on a variety of adsorbents.

The simulation data for H2 adsorption at 78 and 88 K for 1-ppz between 70-300 mbar using equation (3) are shown in Figures 28 and 29. The simulation data for H2 adsorption at 78 and 88 K for 1-Li using equation

(3) are shown in Figures 30 and 31. All the regression coefficients were larger than 0.99, confirming that the model fits the data very well. The virial method based on equation (3) is preferred at low pressure because the linearity in the low pressure part of the isotherm provides direct confirmation of the accuracy of the interpolations. Also, the intercept of the graph gives A0, where the Henry's Law constant Kn = expC40) and this is a measure of the H2 to surface interaction. The isosteric heat {ΔH) for H2 adsorption on 1-ppz and 1-Li were calculated as a function of surface coverage by Clausius-Clapeyron equation (4) .

Figure imgf000040_0001

Equation (4) where R is the gas constant. The error in the measured isosteric enthalpies is estimated as 0.1 kJ/mol. Uses of the Invention

Figure 33 shows a cross section of a spherical steel H2 container 2 according to the invention comprising a mechanical valve 2a. Container 2 contains a material 3 according to the invention. In use, H2 can be introduced into material 3 of container 2 via valve 2a under a pressure of for instance 3 x 106 Pa. The hysteretic properties of the material 3 control the release rate of the H2 and allow it to be stored at lower pressure and closer to ambient temperatures than it would ordinarily.

Similarly, Figure 34 shows a cross section of a spherical steel H2 container 2 according to the invention comprising a mechanical valve 2a. Container 2 contains a material 3 according to the invention located adjacent to valve 2a which separates valve 2a from a further storage material 4. In use, H2 can be introduced into material 3 of container 2 via valve 2a under a pressure of for instance 3 x 106 Pa. H2 can also further pass into further storage material 4. In this embodiment further storage material 4 does not possess hysteretic properties. Material 3 essentially acts as a valve, controllably allowing the release of H2 from itself and further storage material 4, which essentially acts as a reservoir for H2.

Figure 35 shows a cross section of a car 5 fitted with a spherical steel H2 container 2 according to the invention connected to an engine 6. The engine 6 comprises a H2 fuel cell which in this instance is a proton exchange membrane fuel cell. The H2 fuel is stored in the container 2 until the engine 6 is used, at which point the H2 is controllably released by the container 2 to the H2 fuel cell as required. The container 2 may be refilled with H2 as and when required.

Figures 36a and 36b together show a substance separation technique according to the invention. First, in Figure 36a, a spherical steel container 2 according to the invention is pressurised with a mixture of two substances 7 and 8 which enter material 3 according to the invention. Second, in Figure 36b, the pressure at the opening of container 2 is reduced to a level where substance 7 is preferentially released over substance 8. Accordingly, substances 7 and 8 can be separated. Depending on the particular circumstances, such as the nature of the material 3, the substances to be separated and the pressures involved, either pure substance 7 or substance 7 containing a small amount of substance 8 may be released. In order to release substance 8 or the remaining substance 8 the pressure at the opening of container 2 is further reduced to an appropriate level.

Claims

1. A material for the releasable storage of one or more substances comprising a framework defining one or more pores and one or more guest gate entities associated with the pores wherein one or more of the guest gate entities are capable of reversibly at least hindering the entry into the pores, or release from the pores of said one or more substances.
2. The material according to claim 1 , wherein each of said one or more guest gate entities is associated with a different pore.
3. The material according to claim 1 , wherein two or more guest gate entities are associated with the same pore.
4. The material according to any of the preceding claims, wherein the one or more of the guest gate entities are reversibly attached to the pores via permanent dipole to permanent dipole bonding, hydrogen bonding, instantaneous dipole to induced dipole (van der Waals) bonding, cation-pi interactions and/or pi-pi interactions.
5. The material according to any of the preceding claims, wherein the storage of the one or more substances is achieved via physisorption or chemisorption.
6. The material according to any of the preceding claims, wherein the framework and/or one or more of the guest gate entities are neutral.
7. The material according to any of claims 1 to 5, wherein the framework and/or one or more of the guest gate entities are charged.
8. The material according to claim 7, wherein the framework is anionic.
9. The material according to claim 7 or claim 8, wherein one or more of the guest gate entities are cationic.
10. The material according to claim 7, wherein the framework is cationic.
11. The material according to claim 7 or claim 10, wherein one or more of the guest gate entities are anionic.
12. The material according to any of the preceding claims, wherein the framework is a metal-organic framework.
13. The material according to claim 12, wherein the framework is based upon a d-block transition metal, a p- or s-block block metal or f-block lanthanide or actinide.
14. The material according to claim 12 or 13, as it depends from any of claims 1 to 9 and 11 , wherein the framework is a doubly-interpenetrated anionic framework.
15. The material according to claim 14, wherein the framework is constructed from [In2(L)2]2", wherein L4 is 1 , 1 ' ,4' , 1 " ,4" , 1 " ' - quaterphenyl- 3 ,5, 3 ' " , 5 ' " -tetr acarboxylate .
16. The material according to any of claims 1 to 15, wherein one or more of the guest gate entities are a cationic metal centre, cluster, and/or an organic or inorganic cation.
17. The material according to claim 16, wherein one or more of the guest gate entities are piperazinium (H2ppz2 + ) .
18. The material according to any of claims 1 to 16, wherein one or more of the guest gate entities are Li + , Mg2+ , and/or Al3 + .
19. The material according to claim 17, as it depends from claim 15, wherein the material comprises [H2ppz] [In2(L)2] .
20. The material according to claim 18, as it depends from claim 15, wherein the material comprises Li1 5H0 5[In2(L)2] .
21. The material according to any of the preceding claims, wherein the material is in a solvated form.
22. The material according to any of the preceding claims, wherein the framework provides further storage capacity by defining an extension of the one or more pores via the presence of one or more extended framework portions.
23. The material according to claim 22, wherein said extended framework portions may comprise extended ligands.
24. The material according to any of the preceding claims, wherein the entry of substances into the pores is achieved via pressurisation, a change in temperature, the exchange of one or more stored substances by one or more competitor substances, the use of a supercritical fluid, the use of an ionic liquid and/or chemical modification.
25. The material according to claim 24, wherein the pressurisation is carried out at pressures of from 0 to 2xlO5 Pa.
26. The material according to any of the preceding claims, wherein the material further comprises one or more substances releasably stored by the material.
27. The material according to claim 26, wherein the one or more substances are one or more gas, one or more liquid or a combination of the above.
28. The material according to claim 27, wherein the one or more substances are one or more of H2, N2, CO2, methane, acetylene, NO, NO2, CO, HCN, O2, and volatile organic compounds.
29. The material according to any of claims 26 to 28, wherein the one or more substances releasably stored by the material may be present in an amount of at least 6 wt% of the volume of the material.
30. The material according to any of claims 26 to 29, wherein the release of substances from the pores is achieved via a lowering of the external pressure, chemical modification, a change in temperature, the exchange of one or more stored substances by one or more competitor substances, and/or photochemical activation.
31. A method of manufacturing a material for the releasable storage of one or more substances comprising preparing a framework defining one or more pores in the presence of one or more guest gate entities, wherein the material has one or more of the guest gate entities associated with the pores and one or more of the guest gate entities are capable of reversibly at least hindering the entry into the pores, or release from the pores of said one or more substances.
32. The method according to claim 31 , wherein the method comprises preparing the framework and then incorporating the one or more guest gate entities, or preparing the framework and incorporating the one or more guest gate entities in the same step.
33. The method according to either claim 31 or 32, wherein, following the preparation of the framework defining one or more pores and one or more guest gate entities associated with the pores, the method further comprises exchanging one or more of the guest gate entities with other guest gate entities.
34. Use of a material according to any of claims 1 to 30 to releasably store, one or more substances; or separate two or more different substances by the preferential storage and/or release of at least one of said substances over the remaining substances.
35. The use according to claim 34 in fuel cells, batteries, electronics, chemical storage, sensors or the delivery of pharmaceuticals.
36. A method of manufacturing a material comprising one or more substances releasably stored by the material comprising providing a material according to any of claims 1 to 25 and introducing the one or more substances by pressurisation, a change in temperature, the exchange of one or more stored substances by one or more competitor substances, the use of a supercritical fluid, the use of an ionic liquid and/or chemical modification.
37. A container enclosing a material according to any of claims 1 to 30.
38. Use of a container according to claim 37 to releasably store, one or more substances; or separate two or more different substances by the preferential storage and/or release of at least one of said substances over the remaining substances.
39. A framework for the releasable storage of one or more substances, wherein the framework defines one or more pores, and wherein the framework is suitable to have one or more guest gate entities associated with the pores to reversibly at least hinder the entry into the pores, or release from the pores of said one or more substances.
40. A method of producing H2 comprising storing H2 in a storage container containing a material according to any of claims 1 to 30 and releasing it later, over time, using the one or more guest gate entities and a pressure differential across the container to control the release of H2.
41. A method of separating one or more substances from a mixture of substances comprising storing one or more of said substances in a storage container containing a material according to any of claims 1 to 30 and/or releasing one or more of said substances from a storage container containing a material according to any of claims 1 to 30, wherein the presence of the one or more guest gate entities enables the preferential storage and/or release of at least one of said substances over the remaining substances.
42. A material for the releasable storage of one or more substances comprising a framework defining one or more pores and one or more guest gate entities associated with the pores, wherein one or more of the guest gate entities are capable of enhancing the uptake of one or more substances into the pores of the framework and/or the isosteric heat of adsorption of one or more substances.
PCT/GB2010/050834 2009-05-22 2010-05-21 Storage/separating materials WO2010133891A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB0908839.4 2009-05-22
GB0908839A GB0908839D0 (en) 2009-05-22 2009-05-22 Storage/separating material

Publications (1)

Publication Number Publication Date
WO2010133891A1 true WO2010133891A1 (en) 2010-11-25

Family

ID=40862828

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB2010/050834 WO2010133891A1 (en) 2009-05-22 2010-05-21 Storage/separating materials

Country Status (2)

Country Link
GB (1) GB0908839D0 (en)
WO (1) WO2010133891A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014015383A1 (en) * 2012-07-26 2014-01-30 Commonwealth Scientific And Industrial Research Organisation Gas separation processes
WO2014071351A1 (en) * 2012-11-05 2014-05-08 The Regents Of The University Of California Metal-organic framework for the separation of alkane isomers

Non-Patent Citations (58)

* Cited by examiner, † Cited by third party
Title
A. J. FLETCHER; E. J. CUSSEN; D. BRADSHAW; M. J. ROSSEINSKY; K. M. THOMAS, J. AM. CHEM. SOC., vol. 126, 2004, pages 9750
A. L. SPEK, J. APPL. CRYSTALLOGR., vol. 36, 2003, pages 7
A. V. ANIL KUMAR; H. JOBIC; S. K. BHATIA, ADSORPTION, vol. 13, 2007, pages 501
A. WITKOWSKI, J. CHEM. PHYS., vol. 47, 1967, pages 3645
AHUJA, R.: "Li-decorated metal-organic framework 5: a route to achieving a suitable hydrogen storage medium", PROC. NATL. ACAD. SCI. U.S.A., vol. 104, 2007, pages 20173 - 20176
B. CHEN; X. ZHAO; A. PUTKHAM; K. HONG; E. B. LOBKOVSKY; E. J. HURTADO; A. J. FLETCHER; K. M. THOMAS, J. AM. CHEM. SOC., vol. 130, 2008, pages 6411
BHATIA, S. K.; MYERS, A. L.: "Optimum conditions for adsorptive storage", LANGMUIR, vol. 22, 2006, pages 1688 - 1700, XP028757459, DOI: doi:10.1016/j.colsurfa.2012.11.008
BLOMQVIST, A.; ARAUJO, C. M.; SREPUSHARAWOOT, P.; AHUJA, R.: "Li-decorated metal-organic framework 5: a route to achieving a suitable hydrogen storage medium", PROC. NATL. ACAD. SCI. U.S.A., vol. 104, 2007, pages 20173 - 20176
C. R. REID; I. P. O'KOYE; K. M. THOMAS, LANGMUIR, vol. 14, 1998, pages 2415
C. R. REID; K. M. THOMAS, J. PHYS. CHEM. B, vol. 105, 2001, pages 10619
C. R. REID; K. M. THOMAS, LANGMUIR, vol. 15, 1999, pages 3206
CHEN, B. ET AL.: "Surface interactions and quantum kinetic molecular sieving for H2 and D2 adsorption on a mixed metal-organic framework material", J. AM. CHEM. SOC., vol. 130, 2008, pages 6411 - 6423
CHOI, H. J.; DINCA, M.; LONG, J. R.: "Broadly hysteretic H2 adsorption in the microporous metal-organic framework Co(1,4-benzenedipyrazolate)", J. AM. CHEM. SOC., vol. 130, 2008, pages 7848 - 7850
CHOI, H. J.; DINCA, M.; LONG, J. R.: "Broadly hysteretic Hz adsorption in the microporous metal-organic framework Co(1,4-benzenedipyrazolate)", J. AM. CHEM. SOC., vol. 130, 2008, pages 7848 - 7850
CHUN, H.; DYBTSEV, D. N.; KIM, H.; KIM, K.: "Synthesis, X-ray crystal structures, and gas sorption properties of pillared square grid nets based on paddle-wheel motifs: Implications for hydrogen storage in porous materials", CHEM. EURO. J., vol. 11, 2005, pages 3521 - 3529, XP055059986, DOI: doi:10.1002/chem.200401201
COLE, J. H. ET AL.: "Thermodynamics of high temperature adsorption of some permanent gases by porous carbons", J. CHEM. SOC. FARADAY TRANS., vol. 70, 1974, pages 2154 - 2169
DALACH, P.; FROST, H.; SNURR, R. Q.; ELLIS, D. E.: "Enhanced hydrogen uptake and the electronic structure of lithium-doped metal-organic frameworks", J. PHYS. CHEM. C., vol. 112, 2008, pages 9278 - 9284
DINCA, M. ET AL.: "Observation of Cu2+-H2 interactions in a fully desolvated sodalite-type metal-organic framework", ANGEW. CHEM. INT. ED., vol. 46, 2007, pages 1419 - 1422
E. S. STOYANOV; Y. A. CHESALOV, J. CHEM. SOC. FARADAY TRANS., vol. 92, 1996, pages 1725
FEREY, G. ET AL.: "A chromium terephthalate-based solid with unusually large pore volumes and surface area", SCIENCE, vol. 309, 2005, pages 2040 - 2042
FEREY, G. ET AL.: "Hydrogen adsorption in the nanoporous metal- benzenedicarboxylate M(OH) (O2C-C6H4- CO2) (M = A13+, Cr3+), MIL-53", CHEM. COMMUN., 2003, pages 2976 - 2977
FEREY, G. ET AL.: "Hydrogen adsorption in the nanoporous metal- benzenedicarboxylate M(OH)(O2C-C6H4- CO2) (M = Al3+, Cr3+), MIL-53", CHEM. COMMUN., 2003, pages 2976 - 2977
FÉREY, G., SCIENCE, vol. 310, 2005, pages 1119
FUENTES-CABRERA, M.; NICHOLSON, D. M.; SUMPTER, B. G.: "Electronic structure and properties of isoreticular metal-organic frameworks: the case of M-IRMOF1 (M=Zn, Cd, Be, Mg, and Ca)", J. CHEM. PHYS., vol. 123, 2005, pages 124713 - 124718
G. M. SHELDRICK, ACTA CRYSTALLOGR. SECTION, vol. A 64, 2008, pages 112
H. J. CHOI; M. DINCA; J. R. LONG, J. AM. CHEM. SOC., vol. 130, 2008, pages 7840
HAILIAN LI, ET.AL.: "An Open-Framework Germanate with Polycubane-Like Topology", ANGEWANDTE CHEMIE INTERNATIONAL EDITION, vol. 38, 1999, Wiley-VCH, pages 653 - 655, XP002596671 *
HAN, S. S.; GODDARD, W. A.: "High H2 storage of hexagonal metal-organic frameworks from first-principles-based grand canonical monte carlo simulations", J. PHYS CHEM. C., vol. 112, 2008, pages 13431 - 13436
HAN, S. S.; GODDARD, W. A.: "Lithium-doped metal-organic frameworks for reversible H2 storage at ambient temperature", J. AM. CHEM. SOC., vol. 129, 2007, pages 8422 - 8423
I. P. O'KOYE; M. BENHAM; K. M. THOMAS, LANGMUIR, vol. 13, 1997, pages 4054
J. H. COLE; D. H. EVERETT; C. T. MARSHALL; A. R. PANIEGO; J. C. POWL; F. RODRIGUEZ-REINOSO, J. CHEM. SOC. FARADAY TRAN, vol. 70, 1974, pages 2154
J. W. WARD, J. PHYS CHEM., vol. 72, 1968, pages 4211
KLONTZAS, E.; MAVRANDONAKIS, A.; TYLIANAKIS, E.; FROUDAKIS, G. E.: "Improving hydrogen storage capacity of MOF by functionalization of the organic linker with lithium atoms", NANO LETTERS, vol. 8, 2008, pages 1572 - 1576, XP055007616, DOI: doi:10.1021/nl072941g
LIN, X. ET AL.: "High capacity hydrogen adsorption in Cu(II) tetracarboxylate framework materials: the role of pore size, ligand functionalization, and exposed metal sites", J. AM. CHEM. SOC., vol. 131, 2009, pages 2159 - 2171
LIN, X. ET AL.: "High H2 adsorption by coordination-framework materials", ANGEW. CHEM. INT. ED., vol. 45, 2006, pages 7358 - 7364, XP002552658, DOI: doi:10.1002/anie.200601991
LIN, X. ET AL.: "High Hz adsorption by coordination-framework materials", ANGEW. CHEM. INT. ED., vol. 45, 2006, pages 7358 - 7364, XP002552658, DOI: doi:10.1002/anie.200601991
LIN, X.; JIA, J.; HUBBERSTEY, P.; SCHRODER, M.; CHAMPNESS, N. R.: "Hydrogen storage in metal-organic frameworks", CRYSTENGCOMM., vol. 9, 2007, pages 438 - 448
M. CADENE, J. MOLECULAR STRUCTURE, vol. 2, 1968, pages 193
M. CADENE; A. M. VERGNOUX, SPECTROCHIMICA ACTA, PART A: MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, vol. 28, 1972, pages 1663
MAVRANDONAKIS, A.; TYLIANAKIS, E.; STUBOS, A. K.; FROUDAKIS, G. E.: "Why Li doping in MOFs enhances H2 storage capacity? a multi-scale theoretical study", J. PHYS. CHEM. C., vol. 112, 2008, pages 7290 - 7294
MULFORT, K. L.; HUPP, J. T.: "Alkali metal cation effects on hydrogen uptake and binding in metal-organic frameworks", INORG. CHEM., vol. 47, 2008, pages 7936 - 7938
MULFORT, K. L.; HUPP, J. T.: "Chemical reduction of metal-organic framework materials as a method to enhance gas uptake and binding", J. AM. CHEM. SOC., vol. 129, 2007, pages 9604 - 9605
NOUAR, F; ECKERT, J.; EUBANK, J. F.; FORSTER, P.; EDDAOUDI, M.: "Zeolite-like metal-organic frameworks (ZMOFs) as hydrogen storage platform: lithium and magnesium ion-exchange and H2-(rho-ZMOF) interaction studies", J. AM. CHEM. SOC., vol. 131, 2009, pages 2864 - 2870
P. V.D. SLUIS; A. L. SPEK, ACTA CRYSTALLOGR. SECT. A, vol. 46, 1990, pages 194
PLATON, J. APPL. CRYSTALLOGR., vol. 36, 2003, pages 7 - 13
S.-H. JHI, MICROPOROUS MESOPOROUS MATER., vol. 89, 2006, pages 138
SIHAI YANG, ET.AL.: "Cation-induced kinetic trapping and enhanced hydrogen adsorption in a modulated anionic metal-organic framework", NATURE CHEMISTRY, vol. 1, 24 August 2009 (2009-08-24), Nature Publishing Group, pages 487 - 493, XP002596669 *
SIHAI YANG, ET.AL.: "Enhancement of H2 Adsorption in Coordination Framework Materials by Use of Ligand Curvature", CHEMISTRY A EUROPEAN JOURNAL, vol. 15, 23 May 2009 (2009-05-23), Wiley-VCH, pages 4829 - 4835, XP002596670 *
SIHAI YANG, ET.AL.: "Enhancement of H2 adsorption in Li+-exchanged co-ordination framework materials", CHEMICAL COMMUNICATIONS, 14 October 2008 (2008-10-14), RSC, pages 6108 - 6110, XP002596668 *
X. ZHAO; B. XIAO; A. J. FLETCHER; K. M. THOMAS, J. PHYS. CHEM. B, vol. 109, 2005, pages 8880
X. ZHAO; S. VILLAR-RODIL; A. J. FLETCHER; K. M. THOMAS, J. PHYS CHEM. B, vol. 110, 2006, pages 9947
XIANG LIN, ET.AL.: "High H2 Adsorption by Coordination-Framework Materials", ANGEWANDTE CHEMIE INTERANTIONAL EDITION, vol. 45, 2006, pages 7358 - 7364, XP002596672 *
YANG, C.; WANG, X.; OMARY, M. A.: "Fluorous metal-organic frameworks for high-density gas adsorption", J. AM. CHEM. SOC., vol. 129, 2007, pages 15454 - 15455, XP002507981, DOI: doi:10.1021/JA0775265
YANG, C.; WANG, X.; OMARY, M. A: "Fluorous metal-organic frameworks for high-density gas adsorption", J. AM. CHEM. SOC., vol. 129, 2007, pages 15454 - 15455, XP002507981, DOI: doi:10.1021/JA0775265
YANG, S. ET AL.: "Enhancement of H2 adsorption in Li+- exchanged co-ordination framework materials", CHEM. COMMUN., 2008, pages 6108 - 6110, XP002596668, DOI: doi:10.1039/B814155J
YANG, S. ET AL.: "Enhancement of H2 adsorption in Li+-exchanged co-ordination framework materials", CHEM. COMMUN., 2008, pages 6108 - 6110, XP002596668, DOI: doi:10.1039/B814155J
YANG, T.; YANG, S.; LIAO, F.; LIN, J.: "Two isotypic diphosphates LiM2H3(P2O7)2 (M = Ni, Co) containing ferromagnetic zigzag M06 chains", J. SOLID STATE CHEM., vol. 181, 2006, pages 1347 - 1353, XP022708352, DOI: doi:10.1016/j.jssc.2008.03.006
ZHAO, X. ET AL.: "Hysteretic adsorption and desorption of hydrogen by nanoporous metal-organic frameworks", SCIENCE, vol. 306, 2004, pages 1012 - 1015, XP055051859, DOI: doi:10.1126/science.1101982

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014015383A1 (en) * 2012-07-26 2014-01-30 Commonwealth Scientific And Industrial Research Organisation Gas separation processes
JP2015529550A (en) * 2012-07-26 2015-10-08 コモンウェルス サイエンティフィック アンド インダストリアル リサーチ オーガナイゼーション Gas separation method
US9533282B2 (en) 2012-07-26 2017-01-03 Commonwealth Scientific And Industrial Research Organisation Gas separation processes
WO2014071351A1 (en) * 2012-11-05 2014-05-08 The Regents Of The University Of California Metal-organic framework for the separation of alkane isomers
US9540294B2 (en) 2012-11-05 2017-01-10 The Regents Of The University Of California Metal-organic framework for the separation of alkane isomers

Also Published As

Publication number Publication date
GB0908839D0 (en) 2009-07-01

Similar Documents

Publication Publication Date Title
Li et al. Recent advances in gas storage and separation using metal–organic frameworks
Jiang et al. Covalent chemistry beyond molecules
Li et al. Governing metal–organic frameworks towards high stability
Zhu et al. BODIPY-based conjugated porous polymers for highly efficient volatile iodine capture
Julien et al. In situ monitoring and mechanism of the mechanochemical formation of a microporous MOF-74 framework
Wang et al. Functionalization of Microporous Lanthanide-Based Metal–Organic Frameworks by Dicarboxylate Ligands with Methyl-Substituted Thieno [2, 3-b] thiophene Groups: Sensing Activities and Magnetic Properties
Elsaidi et al. Flexibility in metal–organic frameworks: a fundamental understanding
Bloch et al. Post-synthetic structural processing in a metal–organic framework material as a mechanism for exceptional CO2/N2 selectivity
Zhao et al. Two (3, 6)-connected porous metal–organic frameworks based on linear trinuclear [Co 3 (COO) 6] and paddlewheel dinuclear [Cu 2 (COO) 4] SBUs: gas adsorption, photocatalytic behaviour, and magnetic properties
Ayati et al. Emerging adsorptive removal of azo dye by metal–organic frameworks
Canivet et al. Water adsorption in MOFs: fundamentals and applications
Chen et al. Applying the power of reticular chemistry to finding the missing alb-MOF platform based on the (6, 12)-coordinated edge-transitive net
Lu et al. Tuning the structure and function of metal–organic frameworks via linker design
Kim et al. A Chemical route to activation of open metal sites in the copper-based metal–organic framework materials HKUST-1 and Cu-MOF-2
Sezginel et al. Tuning the gas separation performance of CuBTC by ionic liquid incorporation
Rieth et al. Kinetic stability of metal–organic frameworks for corrosive and coordinating gas capture
Yan et al. Non-interpenetrated metal–organic frameworks based on copper (II) paddlewheel and oligoparaxylene-isophthalate linkers: synthesis, structure, and gas adsorption
Kapelewski et al. Record high hydrogen storage capacity in the metal–organic framework Ni2 (m-dobdc) at near-ambient temperatures
Peng et al. Methane storage in metal–organic frameworks: current records, surprise findings, and challenges
He et al. A series of metal–organic frameworks with high methane uptake and an empirical equation for predicting methane storage capacity
Wang et al. Applications of metal–organic frameworks for green energy and environment: New advances in adsorptive gas separation, storage and removal
Øien-Ødegaard et al. UiO-67-type metal–organic frameworks with enhanced water stability and methane adsorption capacity
Pettinari et al. Coordination polymers and metal–organic frameworks based on poly (pyrazole)-containing ligands
Li et al. Porous metal–organic frameworks with Lewis basic nitrogen sites for high-capacity methane storage
Zhang et al. “Stereoscopic” 2D super-microporous phosphazene-based covalent organic framework: Design, synthesis and selective sorption towards uranium at high acidic condition

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10722175

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase in:

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10722175

Country of ref document: EP

Kind code of ref document: A1