Magnetic Metal–Organic Framework Composites: Solvent-Free Synthesis and Regeneration Driven by Localized Magnetic Induction Heat

Driven by the magnetic induction heat, a versatile solvent-free Magnetic Induction Framework Synthesis (sMIFS) route has been developed to synthesize magnetic metal–organic framework composites (MFCs). The MFC yield can be effectively enhanced through increasing the reaction time, magnetic nanoparticle content in the powder reaction mixture, and the applied magnetic field strength. Compared with the same reactions carried out in solvent, sMIFS exhibits better MFC yield at the cost of well-defined morphologies. The resulting MFCs exhibit highly efficient CO2 capture capacity. Upon exposing to an alternating magnetic field, MFCs also can be highly efficiently regenerated triggered by localized magnetic induction heat through a magnetic induction swing adsorption process

Metal−Organic Frameworks Impregnated with Magnesium-Decorated Fullerenes for Methane and Hydrogen Storage

A new concept is described for methane and hydrogen storage materials involving the incorporation of magnesium-decorated fullerenes within metal−organic frameworks (MOFs). The system is modeled using a novel approach underpinned by surface potential energies developed from Lennard-Jones parameters. Impregnation of MOF pores with magnesium-decorated Mg10C60 fullerenes, denoted as Mg−C60@MOF, places exposed metal sites with high heats of gas adsorption into intimate contact with large surface area MOF structures. Perhaps surprisingly, given the void space occupied by C60, this impregnation delivers remarkable gas uptake, according to our modeling, which predicts exceptional performance for the Mg−C60@MOF family of materials. These predictions include a volumetric methane uptake of 265 v/v, the highest reported value for any material, which significantly exceeds the U.S. Department of Energy target of 180 v/v. We also predict a very high hydrogen adsorption enthalpy of 11 kJ mol−1 with relatively little decrease as a function of H2 filling. This value is close to the calculated optimum value of 15.1 kJ mol−1 and is achieved concurrently with saturation hydrogen uptake in large amounts at pressures under 10 atm

Synthesis and Hydrogen Storage Properties of Be₁₂(OH)₁₂(1,3,5-benzenetribenzoate)₄

Synthesis and Hydrogen Storage Properties of Be12(OH)12(1,3,5-benzenetribenzoate)4</sub

Interpenetrated Zirconium–Organic Frameworks: Small Cavities versus Functionalization for CO₂ Capture

Porous interpenetrated zirconium–organic frameworks (PIZOFs) with various functional groups are explored for CO₂ capture using molecular simulation and experiment. Functionalization enhances the CO₂ uptake and selectivity over other gases, but small cavities play an even more important role. Particularly at low pressures, small cavities enhance the CO₂ adsorption density nearly 5 times greater than the functionalization. PIZOF-2 outperforms the other PIZOF structures for CO₂ separation from methane and nitrogen (related to raw natural gas and postcombustion of coal mixtures) due to the combination of small cavities around 5 Å in diameter and functionalized linkers with methoxy groups attached to the central ligand. The small cavities within the interpenetrated structures are crucial for achieving high selectivities, especially for cavities surrounded by a combination of 6 benzene rings, 2 metal clusters, and 4 methoxy groups that offer a tight overlapping potential energy field, ideal for “catching” CO₂

Synthesis and Hydrogen Storage Properties of Be₁₂(OH)₁₂(1,3,5-benzenetribenzoate)₄

Synthesis and Hydrogen Storage Properties of Be12(OH)12(1,3,5-benzenetribenzoate)4</sub

Interpenetrated Zirconium–Organic Frameworks: Small Cavities versus Functionalization for CO₂ Capture

Porous interpenetrated zirconium–organic frameworks (PIZOFs) with various functional groups are explored for CO₂ capture using molecular simulation and experiment. Functionalization enhances the CO₂ uptake and selectivity over other gases, but small cavities play an even more important role. Particularly at low pressures, small cavities enhance the CO₂ adsorption density nearly 5 times greater than the functionalization. PIZOF-2 outperforms the other PIZOF structures for CO₂ separation from methane and nitrogen (related to raw natural gas and postcombustion of coal mixtures) due to the combination of small cavities around 5 Å in diameter and functionalized linkers with methoxy groups attached to the central ligand. The small cavities within the interpenetrated structures are crucial for achieving high selectivities, especially for cavities surrounded by a combination of 6 benzene rings, 2 metal clusters, and 4 methoxy groups that offer a tight overlapping potential energy field, ideal for “catching” CO₂

<i>In Situ</i> Investigation of Multicomponent MOF Crystallization during Rapid Continuous Flow Synthesis

Access to the potential applications of metal–organic frameworks (MOFs) depends on rapid fabrication. While there have been advances in the large-scale production of single-component MOFs, rapid synthesis of multicomponent MOFs presents greater challenges. Multicomponent systems subjected to rapid synthesis conditions have the opportunity to form separate kinetic phases that are each built up using just one linker. We sought to investigate whether continuous flow chemistry could be adapted to the rapid formation of multicomponent MOFs, exploring the UMCM-1 and MUF-77 series. Surprisingly, phase pure, highly crystalline multicomponent materials emerge under these conditions. To explore this, in situ WAXS was undertaken to gain an understanding of the formation mechanisms at play during flow synthesis. Key differences were found between the ternary UMCM-1 and the quaternary MUF-7, and key details about how the MOFs form were then uncovered. Counterintuitively, despite consisting of just two ligands UMCM-1 proceeds via MOF-5, whereas MUF-7 consists of three ligands but is generated directly from the reaction mixture. By taking advantage of the scalable high-quality materials produced, C6 separations were achieved in breakthrough settings

Magnetic Framework Composites for Low Concentration Methane Capture

This study proposes a simple and energy efficient technique for methane (CH₄) capture from low concentration emission sources. An extrusion-based process was used to fabricate magnetic framework composites (MFCs) from a metal organic framework (MOF), aluminum fumarate, and MgFe₂O₄ magnetic nanoparticles (MNP). Methane uptake for MFCs with different MNP loading at 1 bar and 300 K revealed a high methane uptake of up to 18.2 cm³ g^–1. To regenerate the MFCs, a magnetic induction swing adsorption (MISA) process was applied. A working capacity of 100% was achieved for the MFC over 10 adsorption–desorption cycles with an average of 6 min per cycle for the regeneration step. The ability to access 100% of the adsorbed CH₄ in the MFC with rapid and localized heating achieved with the MISA process potentially provides an energy efficient technique for CH₄ capture and reuse from low concentration sources

Sulfonated Metal–Organic Framework Mixed-Matrix Membrane toward Direct Lithium Extraction

Lithium supply has been limited by time-consuming and energy-intensive processing. Membranes are an attractive alternative as a low energy, timely, and continuous process to facilitate ion–ion separations. However, recent metal–organic framework (MOF) membranes are difficult to prepare and scale. Here, we realize an electrochemical LiCl/NaCl selectivity of 1.21 by use of a flexible, low-cost, and simple solution cast mixed-matrix membrane comprised of cellulose triacetate and UiO-66-SO3H MOF. Compatible chemical interactions between the MOF and polymer allowed for high loadings of up to 100% (mMOF/mpolymer) consistently, minimizing interfacial defects and aggregation. Single salt transport measurements confirmed that the selectivity of the membrane arises from high lithium diffusion (1.6 cf sodium diffusion) across the membrane overcoming high sodium solubility (1.3 cf lithium solubility). Incorporating a combination of confined sub-nanoporous (6.3 and 9.5 Å) pore windows in UiO-66-SO3H and chemically compatible high diffusivity SO3– groups achieve flexible, low-cost, and scalable membranes with desirable selectivity towards refining lithium

High Performance Hydrogen Storage from Be-BTB Metal–Organic Framework at Room Temperature

The metal–organic framework beryllium benzene tribenzoate (Be-BTB) has recently been reported to have one of the highest gravimetric hydrogen uptakes at room temperature. Storage at room temperature is one of the key requirements for the practical viability of hydrogen-powered vehicles. Be-BTB has an exceptional 298 K storage capacity of 2.3 wt % hydrogen. This result is surprising given that the low adsorption enthalpy of 5.5 kJ mol^–1. In this work, a combination of atomistic simulation and continuum modeling reveals that the beryllium rings contribute strongly to the hydrogen interaction with the framework. These simulations are extended with a thermodynamic energy optimization (TEO) model to compare the performance of Be-BTB to a compressed H₂ tank and benchmark materials MOF-5 and MOF-177 in a MOF-based fuel cell. Our investigation shows that none of the MOF-filled tanks satisfy the United States Department of Energy (DOE) storage targets within the required operating temperatures and pressures. However, the Be-BTB tank delivers the most energy per volume and mass compared to the other material-based storage tanks. The pore size and the framework mass are shown to be contributing factors responsible for the superior room temperature hydrogen adsorption of Be-BTB