Characterization of H2 binding sites in prototypical metal-organic frameworks by inelastic neutron scattering

The hindered rotor transitions of H(2) adsorbed in the chemically related and prototypical porous metal-organic frameworks IRMOF-1, IRMOF-8, IRMOF-11, and MOF-177 were studied by inelastic neutron scattering to gain information on the specifics of H(2) binding in this class of adsorbents. Remarkably sharp and complex spectra of these materials signify a diversity of well-defined binding sites. Similarities in the spectral features as a function of H(2) loading and correlations with recent crystallographic studies were used to assign transitions ranging in rotational barrier from <0.04 to 0.6 kcal/mol as corresponding to localized adsorption sites on the organic and inorganic components of these frameworks. We find that binding of H(2) at the inorganic cluster sites is affected by the nature of the organic link and is strongest in IRMOF-11 in accord with our adsorption isotherm data. The sites on the organic link have lower binding energies, but a much greater capacity for increases in H(2) loading, which demonstrates their importance for hydrogen uptake by these materials.     

Systematic functionalization of a metal-organic framework via a postsynthetic modification approach

The pendant amino groups in isoreticular metal-organic framework-3 (IRMOF-3) were subjected to postsynthetic modification with 10 linear alkyl anhydrides (O(CO(CH2)nCH3)2 (where n = 1 to 18) and the extent of conversion, thermal and structural stability, and Brunauer-Emmett-Teller (BET) surface areas of the resulting materials were probed. (1)H NMR of digested samples showed that longer alkyl chain anhydrides resulted in lower conversions of IRMOF-3 to the corresponding amide framework (designated as IRMOF-3-AM2 to IRMOF-3-AM19). Percent conversions ranged from essentially quantitative (approximately 99%, -AM2) to approximately 7% (-AM19) with IRMOF-3 samples. Modified samples were thermally stable up to approximately 430 degrees C and remained crystalline based on powder X-ray diffraction (PXRD) measurements. Under specific reaction conditions, significant conversions were obtained with complete retention of crystallinity, as verified by single-crystal X-ray diffraction experiments. Single crystals of modified IRMOF-3 samples all showed that the F-centered cubic framework was preserved. All single crystals used for X-ray diffraction were analyzed by electrospray ionization mass spectrometry (ESI-MS) to confirm that these frameworks contained the modified 1,4-benzenedicarboxylate ligand. Single crystals of each modified IRMOF-3 were further characterized by measuring the dinitrogen gas sorption of each framework to determine the effects of modification on the porosity of the MOF. BET surface areas (m(2)/g) confirmed that all modified IRMOF-3 samples maintained microporosity regardless of the extent of modification. The surface area of modified MOFs was found to correlate to the size and number of substituents added to the framework.     

Density functional theory study of interactions of cyclotrimethylene trinitramine (RDX) and triacetone triperoxide (TATP) with metal–organic framework (IRMOF-1(Be))

We performed a density functional study of the interactions of 1,3,5-trinitro-s-triazine (RDX) and triacetone triperoxide (TATP) with small fragments of isoreticular crystalline metal?Corganic frameworks having beryllium as connector metal center (IRMOF-1(Be)). The influence of different metal centers of the connector was evaluated. For particular IRMOF-1 clusters, used small IRMOF-1(Zn) fragments are reported to have higher binding affinity than such components of IRMOF-1(Be), and their interactions with TATP are favored compared with the RDX systems. The binding efficiency is also influenced by the presence of linkers. One benzene linker connected with a Be?CO?CC cluster was found to have the lowest binding energy for the target molecules when compared with larger fragments containing more linkers. Binding with IRMOF-1 fragments leads to polarization of RDX and TATP. The said effect is found to be larger for the TATP systems.     

Adsorption of RDX and TATP on IRMOF-1: an ab initio study

The adsorption of 1,3,5-trinitro-s-triazine (RDX) and triacetone triperoxide (TATP) on representative fragments of metal organic framework (IRMOF-1) was studied at the B3LYP/6-31G(d) level of theory. For examined adsorbates several possible adsorption positions toward the IRMOF-1 fragments were found. The adsorption strength of the adsorbate on IRMOF-1 is largely affected by the geometry of the active site of IRMOF-1 which controls the orientation of the target molecule with respect to the IRMOF-1 fragment. The calculations show that the adsorption on these fragments occurs due to the formation of hydrogen bonds between the molecular C–H groups and the oxygen atoms of IRMOF-1. The RDX and TATP molecules are the most strongly adsorbed on the linker fragment of IRMOF-1. This type of adsorption results in the polarization of RDX and TATP on the IRMOF-1 fragments. The interaction energy of two most stable RDX-, and TATP-IRMOF-1 adsorption systems are ?9.8 and ?12.8 kcal/mol, respectively. It can be concluded that the 1,4-benzenedicarboxylate site of IRMOF-1 shows the stronger molecular adsorption of RDX and TATP than the site containing [Zn₄O(CO₂)₆] and also it is characterized by higher reactivity than the other considered sites. The binding of studied explosive molecules to IRMOF-1 consists of interplay between attractive interactions between the target molecule and MOF as well as the shielding by the IRMOF-1 fragment induced by the molecular adsorption. The relative importance of these effects depends on the chemical nature, the size, and the shape of the molecule and MOF. Small-size molecules require smaller space for the adsorption and also they are less shielded by the sizeable adsorbent. So they interact better when adsorbed on larger IRMOF-1 fragment. On the other side, larger molecules show higher adsorption strength with small fragments of IRMOF-1.     

Metal-organic framework supported ionic liquid membranes for CO2 capture: anion effects

IRMOF-1 supported ionic liquid (IL) membranes are investigated for CO(2) capture by atomistic simulation. The ILs consist of identical cation 1-n-butyl-3-methylimidazolium [BMIM](+), but four different anions, namely hexafluorophosphate [PF(6)](-), tetrafluoroborate [BF(4)](-), bis(trifluoromethylsulfonyl)imide [Tf(2)N](-), and thiocyanate [SCN](-). As compared with the cation, the anion has a stronger interaction with IRMOF-1 and a more ordered structure in IRMOF-1. The small anions [PF(6)](-), [BF(4)](-), and [SCN](-) prefer to locate near to the metal-cluster, particularly the quasi-spherical [PF(6)](-) and [BF(4)](-). In contrast, the bulky and chain-like [BMIM](+) and [Tf(2)N](-) reside near the phenyl ring. Among the four anions, [Tf(2)N](-) has the weakest interaction with IRMOF-1 and thus the strongest interaction with [BMIM](+). With increasing the weight ratio of IL to IRMOF-1 (W(IL/IRMOF-1)), the selectivity of CO(2)/N(2) at infinite dilution is enhanced. At a given W(IL/IRMOF-1), the selectivity increases as [Tf(2)N](-) < [PF(6)](-) < [BF(4)](-) < [SCN](-). This hierarchy is predicted by the COSMO-RS method, and largely follows the order of binding energy between CO(2) and anion estimated by ab initio calculation. In the [BMIM][SCN]/IRMOF-1 membrane with W(IL/IRMOF-1) = 1, [SCN](-) is identified to be the most favorable site for CO(2) adsorption. [BMIM][SCN]/IRMOF-1 outperforms polymer membranes and polymer-supported ILs in CO(2) permeability, and its performance surpasses Robeson's upper bound. This simulation study reveals that the anion has strong effects on the microscopic properties of ILs and suggests that MOF-supported ILs are potentially intriguing for CO(2) capture.     

Binding energies of hydrogen molecules to isoreticular metal-organic framework materials

Recently, several novel isoreticular metal-organic framework (IRMOF) structures have been fabricated and tested for hydrogen storage applications. To improve our understanding of these materials, and to promote quantitative calculations and simulations, the binding energies of hydrogen molecules to the MOF have been studied. High-quality second-order Moller-Plesset (MP2) calculations using the resolution of the identity approximation and the quadruple zeta QZVPP basis set were used. These calculations use terminated molecular fragments from the MOF materials. For H2 on the zinc oxide corners, the MP2 binding energy using Zn4O(HCO2)6 molecule is 6.28 kJ/mol. For H2 on the linkers, the binding energy is calculated using lithium-terminated molecular fragments. The MP2 results with coupled-cluster singles and doubles and noniterative triples method corrections and charge-transfer corrections are 4.16 kJ/mol for IRMOF-1, 4.72 kJ/mol for IRMOF-3, 4.86 kJ/mol for IRMOF-6, 4.54 kJ/mol for IRMOF-8, 5.50 and 4.90 kJ/mol for IRMOF-12, 4.87 and 4.84 kJ/mol for IRMOF-14, 5.42 kJ/mol for IRMOF-18, and 4.97 and 4.66 kJ/mol for IRMOF-993. The larger linkers are all able to bind multiple hydrogen molecules per side. The linkers of IRMOF-12, IRMOF-993, and IRMOF-14 can bind two to three, three, and four hydrogen molecules per side, respectively. In general, the larger linkers have the largest binding energies, and, together with the enhanced surface area available for binding, will provide increased hydrogen storage. We also find that adding up NH2 or CH3 groups to each linker can provide up to a 33% increase in the binding energy.     

Storage and separation of CO2 and CH4 in silicalite, C168 schwarzite, and IRMOF-1: a comparative study from Monte Carlo simulation

Storage of pure CO2 and CH4 and separation of their binary mixture in three different classes of nanostructured adsorbents--silicalite, C168 schwarzite, and IRMOF-1--have been compared at room temperature using atomistic simulation. CH4 is represented as a spherical Lennard-Jones molecule, and CO2 is represented as a rigid linear molecule with a quadrupole moment. For pure component adsorption, CO2 is preferentially adsorbed than CH4 in all the three adsorbents over the pressure range under this study, except in C168 schwarzite at high pressures. The simulated adsorption isotherms and isosteric heats match closely with available experimental data. A dual-site Langmuir-Freundlich equation is used to fit the isotherms satisfactorily. Compared to silicalite and C168 schwarzite, the gravimetric adsorption capacity of pure CH4 and CO2 separately in IRMOF-1 is substantially larger. This implies that IRMOF-1 might be a potential storage medium for CH4 and CO2. For adsorption from an equimolar binary mixture, CO2 is preferentially adsorbed in all three adsorbents. Predictions of mixture adsorption with the ideal-adsorbed solution theory on the basis of only pure component adsorption agree well with simulation results. Though IRMOF-1 has a significantly higher adsorption capacity than silicalite and C168 schwarzite, the adsorption selectivity of CO2 over CH4 is found to be similar in all three adsorbents.     

Insitu growth of IRMOF-3 combined with ionic liquids to prepare solid-phase microextraction fibers

A superior solid-phase microextraction (SPME) fiber-coating material, IRMOF-3@ILs/PDMS, was prepared by the in situ growth of IRMOF-3 onto stainless-steel wires and protection with ionic liquids (ILs) and polydimethylsiloxane (PDMS). The ILs can efficiently prevent the substantial cracking of IRMOF-3 caused by moisture, and a thin PDMS film can protect the IRMOF-3@ILs material to achieve a much better extraction efficiency as well as excellent resistance to high temperature and high humidity. This IRMOF-3@ILs/PDMS coating possessed a porous structure, a rough surface and an increased lifespan (by at least 100 times) compared with that of IRMOF-3. The coating was evaluated by analyzing four polycyclic aromatic hydrocarbons (PAHs) in water, and good precision (<7.7%), low detection limits (12.0–15.4 ng L⁻¹), and wide linearity (50–20,000 ng L⁻¹) were achieved under the optimized conditions. The fiber was successfully applied to the sensitive analysis of PAHs in rainwater by coupling it with gas chromatography–mass spectrometry (GC–MS).     

Hierarchical modeling of ammonia adsorption in functionalized metal-organic frameworks

The adsorption of ammonia in four metal-organic frameworks modified with different functional groups (-OH, -C=O, -Cl, -COOH) was investigated using a hierarchical molecular modeling approach. To describe the hydrogen bonding and other strong interactions between NH(3) and the surface functional groups, a set of Morse potential parameters were obtained by fitting to energies from quantum chemical calculations at the MP2 level of theory. We describe a systematic force field parameterization process, in which the Morse parameters were fitted using simulated annealing to match a large number of single-point MP2 energies at various distances and angles. The fitted potentials were then used in grand canonical Monte Carlo simulations to predict ammonia adsorption isotherms and heats of adsorption in functionalized MIL-47, IRMOF-1, IRMOF-10, and IRMOF-16. The results show that ammonia adsorption can be significantly enhanced by using materials with appropriate pore size, strongly interacting functional groups, and high density of functional groups.     

多孔金属有机骨架材料储氢性能分子模拟

采用优化的DREIDING力场参数, 通过巨正则系综蒙特卡洛(GCMC)模拟方法对H₂在IRMOF-1、IRMOF-61和IRMOF-62共3种金属有机骨架(MOFs)材料中的吸附平衡性能进行了比较研究. 结果表明, 该力场能够在全压力范围内很好地复制H₂在IRMOF-62材料中的等温吸附曲线; 但对低压下H₂在IRMOF-61中的等温吸附曲线预测出现低估. 与IRMOF-1相比, 具有互穿骨架结构的IRMOF-61和IRMOF-62材料在常温下的储氢能力并无明显提高. 进一步比较77 K时100 kPa、3.0 MPa下H₂在上述MOFs材料中达到吸附平衡时的几率密度分布发现, H₂会优先吸附在Zn₄O骨架附近靠近苯环的位置;对具有互穿结构的MOFs材料而言,由于其孔腔尺寸缩小, 使得H₂优先吸附位区域零散化. 适当长度的有机配体形成的互穿骨架结构能增强与H₂分子之间的相互作用, 具备较高的储氢能力; 而有机配体尺寸过长则会增加骨架结构中H₂吸附死角, 对H₂的吸附能力反而出现下降.     

Diffusion and separation of CO2 and CH4 in silicalite, C168 schwarzite, and IRMOF-1: a comparative study from molecular dynamics simulation

Recently we have investigated the storage and adsorption selectivity of CO(2) and CH(4) in three different classes of nanoporous materialssilicalite, IRMOF-1, and C(168) schwarzite through Monte Carlo simulation (Babarao, R.; Hu, Z.; Jiang, J. Langmuir, 2007, 23, 659). In this work, the self-, corrected, and transport diffusivities of CO(2) and CH(4) in these materials are examined using molecular dynamics simulation. The activation energies at infinite dilution are evaluated from the Arrhenius fits to the diffusivities at various temperatures. As loading increases, the self-diffusivities in the three frameworks decrease as a result of the steric hindrance; the corrected diffusivities remain nearly constant or decrease approximately linearly depending on the adsorbate and framework; and the transport diffusivities generally increase except for CO(2) in IRMOF-1. The correlation effects are identified to reduce from MFI, C(168) to IRMOF-1, in accordance with the porosity increasing in the three frameworks. Predictions of self-, corrected, and transport diffusivities for pure CO(2) and CH(4) from the Maxwell-Stefan formulation match the simulation results well. In a CO(2)/CH(4) mixture, the self-diffusivities decreases with loading, and good agreement is found between simulated and predicted results. On the basis of the adsorption and self-diffusivity in the mixture, the permselectivity is found to be marginal in IRMOF-1, slightly enhanced in MFI, and greatest in C(168) schwarzite. Although IRMOF-1 has the largest storage capacity for CH(4) and CO(2), its selectivity is not satisfactory.     

Saturation of hydrogen sorption in Zn benzenedicarboxylate and Zn naphthalenedicarboxylate

We report excess hydrogen saturation values from high-pressure isotherms of metal organic framework structures taken at 77 K. Zn benzendicarboxylate (IRMOF-1) and Zn naphthalendicarboxylate (IRMOF-8) linker structures show identical saturation values of 137 hydrogen molecules on a per unit cell basis, despite the higher sorption potential of IRMOF-8 of 6.1 kJ/mol over that of IRMOF-1 of 4.1 kJ/mol. Charge transfer between linker and vertex, as well as surface area, appear to dominate the sorption behavior, over that of linker length in these two systems.     

A DFT study of IRMOF-3 catalysed Knoevenagel condensation

It has been recently reported that IRMOF-3 [Gascon et al., J. Catal, 2009, 261, 75] may behave as a basic catalyst, active in the Knoevenagel condensation. In particular, it has been shown that the basicity of aniline-like amino moieties is enhanced, along with the catalytic activity, when incorporated into MOF structures. The computational study here was aimed at finding possible atomistic explanations of the increased basicity and catalytic activity of the IRMOF-3 embedded aniline groups, experimentally claimed. It was, moreover, aimed at guessing a reaction mechanism for the IRMOF-3 catalysed Knoevenagel condensation of benzaldehyde and ethyl-cyanoacetate. Within the DFT framework we have studied structure and basicity properties of IRMOF-3 and we have analysed the energetics of the catalytic cycle as well as of possible deactivation paths, including it. The increased basicity of IRMOF-3 over other amminic catalysts has been explained via the formation of protonated conjugate derivatives, involving hydrogen-bonds and originating quasi-planar 6-term rings. Several plausible reaction steps have been moreover taken into account and a mechanism for the Knoevenagel condensation, including catalyst deactivation, has been proposed for aniline molecules and embedded aniline moieties. This allowed us to suggest that the increased IRMOF-3 activity, as a basic catalyst, should be mostly related to its water adsorption ability, preserving the properties of the catalytically active amino moieties.     

Understanding adsorption and interactions of alkane isomer mixtures in isoreticular metal-organic frameworks

Novel metal-organic frameworks (MOFs) may lead to advances in adsorption and catalysis owing to their superior properties compared to traditional nanoporous materials. A combination of the grand canonical Monte Carlo method and configurational-bias Monte Carlo simulation was used to evaluate the adsorption isotherms of C4-C6 alkane isomer mixtures in IRMOF-1 and IRMOF-6. The amounts of adsorbed linear and branched alkanes increase with increasing pressure, and the amount of branched alkanes is larger than that of the linear ones. The locations of the alkane isomer reveal that the Zn4O clusters of the IRMOFs are the preferential adsorption sites for the adsorbate molecules. The interaction energy between the Zn4O cluster and the adsorbate is larger than that between the organic linker and the adsorbate. It was further confirmed that the Zn4O cluster plays a much more important role in adsorption by pushing a probe molecule into the pore at positions closer to the Zn4O cluster. It is difficult for branched alkane molecules to approach the Zn4O cluster of IRMOF-6 closely owing to strong spatial hindrance. In addition, the adsorption selectivity is discussed from the viewpoints of thermodynamics and kinetics, and the diffusion behavior of n-butane and 2-methylpropane were investigated to illustrate the relationship between diffusion and adsorption.     

Early stages in the degradation of metal-organic frameworks in liquid water from first-principles molecular dynamics

IRMOF-1 structures are known to suffer lattice break-up when exposed to water-rich environments, a limiting factor in their everyday use. To shed light on the underlying mechanism of disruption, the role of the metal in the secondary building unit (SBU) has been systematically investigated, and the global behaviour of IRMOF-1-type structures with the three metals Zn, Mg, and Be studied by Born-Oppenheimer Molecular Dynamics in liquid water. Results show that fully hydrated Be based compounds are stable up to 500 K while the equivalent structures with Mg or Zn break down already at 300 K. The reasons behind this instability are in the tendency of the metal atom to form penta- and hexa-coordination spheres and in the strength of the M-O bond. These are the key factors that generate unique breaking patterns for Mg and Zn IRMOF-1 analogues, as well as the reason for the high hydrothermal stability of the Be-IRMOF-1.     

Bifunctional, chemically patterned flat stamps for microcontact printing of polar inks

Different methods to create chemically patterned, flat PDMS stamps with two different chemical functionalities were compared. The best method for making such stamps, functionalized with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (PFDTS) and 3-(aminopropyl)triethoxysilane (APTS), appeared to be full functionalization of a freshly oxidized flat PDMS stamp with either adsorbate, followed by renewed oxidation through a mask and attachment of the other adsorbate. These stamps were used to transfer polar inks (a thioether-functionalized dendrimer and a fluorescent dye) by microcontact printing. The PFDTS monolayer was used as a barrier against ink transfer, while the APTS SAM areas functioned as an ink reservoir for polar inks. The printing results confirmed the excellent transfer of hydrophilic inks with these stamps to gold and glass substrates, even from aqueous solutions. Attachment of a fluorescent dye on the amino-functionalized regions shows the possibility of the further modification of the chemically patterned stamps for tailoring of the stamps' properties.     

Modeling Adsorption and Optical Properties for the Design of CO2 Photocatalytic Metal-Organic Frameworks

Four Metal-Organic Frameworks (MOFs) were modeled (IRMOF-C-BF₂, IRMOF-C-(2)-BF₂, IRMOF-C’-BF₂, and IRMOF-C-CH₂BF₂) based on IRMOF-1. A series of linkers, based on Frustrated Lewis Pairs and coumarin moieties, were attached to IRMOF-1 to obtain MOFs with photocatalytic properties. Four different linkers were used: (a) a BF₂ attached to a coumarin moiety at position 3, (b) two BF₂ attached to a coumarin moiety in positions 3 and 7, (c) a BF₂ attached in the coumarin moiety at position 7, and (d) a CH₂BF₂ attached at position 3. An analysis of the adsorption properties of H₂, CO₂, H₂O and possible CO₂ photocatalytic capabilities was performed by means of computational modeling using Density Functional Theory (DFT), Time-Dependent Density Functional (TD-DFT) methods, and periodic quantum chemical wave function approach. The results show that the proposed linkers are good enough to improve the CO₂ adsorption, to hold better bulk properties, and obtain satisfactory optical properties in comparison with IRMOF-1 by itself.     

IRMOF-1衍生介孔ZnO微球催化合成低聚聚碳酸酯二醇

IRMOF-1是一种最经典的IRMOF系列材料,通过直接在空气中不同温度下热处理IRMOF-1得到三种ZnO催化剂,并采用XRD、SEM、BET、CO_2-TPD等分析技术对所得样品的晶体结构、表观形貌、孔结构、表面碱性进行了表征。结果显示,ZnO为球状结构,是一种典型的介孔材料,BET比表面积和孔径分别为49.7~62.2 m2/g和2.18~2.92 nm。研究了ZnO微球在碳酸二苯酯(DPC)与新戊二醇(NPG)酯交换合成低聚碳酸酯二醇(PCDL)反应中的催化性能。结果表明,500℃下得到的ZnO微球在DPC与NPG酯交换反应中表现出良好的催化活性。     

A novel Ag/Ag3PO4-IRMOF-1 nanocomposite for antibacterial application in the dark and under visible light irradiation

MOF-5 that sometimes called IRMOF-1 has been intensively studied in recent years to develop efficient photocatalyst to degrade refractory organics and inactivate bacteria for wastewater treatment. In the present work, Ag/Ag₃PO₄ nanoparticles incorporated in IRMOF-1 was successfully prepared via hydrothermal approach. The antibacterial activity of synthesized materials (IRMOF-1, Ag/Ag₃PO₄ nanoparticles and Ag/Ag₃PO₄-IRMOF-1 nanocomposite was compared against two types of bacteria (Escherichia coli (E. coil) as Gram negative and Staphylococcus aureus (S. aureus) as Gram-positive bacteria). The deactivation of the bacteria by the prepared material was measured in the dark and under visible light irradiation. The antibacterial activity of synthesized samples was investigated by determining the minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), growth inhibition assay and inhibition zone. The Ag/Ag₃PO₄-IRMOF-1 nanocomposite exhibited stronger antibacterial activities than the Ag/Ag₃PO₄ nanoparticles and IRMOF-1 at all tested bacteria types. Based on inhibition zone, without any light irradiation, Ag/Ag₃PO₄-IRMOF-1 nanocomposite showed activity toward E. coil, but in presence of light nanocomposite depicted activity toward S. aureus. The results demonstrated that antibacterial activity of all synthesized samples in the dark and light against S. aureus bacteria was more than E. coil bacteria. The antibacterial activity mechanism was due to sustained-release of silver ions in the dark and reactive oxygen species (ROS) under visible light. The bioactivity of IRMOF-1 was related to the degradation of the its structure and the release of Zn²⁺ ions into the culture medium that bind to the cell wall and deactivation bacteria.     

Significantly enhanced hydrogen storage in metal-organic frameworks via spillover

The utilization of hydrogen in fuel-cell powered vehicles is limited by the lack of a safe and effective system for hydrogen storage. At the present time, there is no viable storage technology capable of meeting the DOE targets. Porous metal-organic frameworks (MOFs) are novel and potential candidates for hydrogen storage. Until now it is still not possible to achieve any significant hydrogen storage capacity in MOFs at ambient temperature. Here, we report, for the first time, significant amounts of hydrogen storage in MOF-5 and IRMOF-8 at ambient temperature by using a very simple technique via hydrogen dissociation and spillover. Thus, hydrogen uptakes for MOF-5 and IRMOF-8 can be enhanced by a factor of 3.3 and 3.1, respectively (to nearly 2 wt % at 10 MPa and 298 K). Furthermore, the isotherms are totally reversible. These findings suggest that our technique is suitable for hydrogen storage in a variety of MOF materials because of their similar structures as MOF-5 and IRMOF-8.