Indium-based Metal-organic Framework Research Articles

Indium-Based Metal-Organic Framework for High-Performance Electroreduction of CO2 to Formate.

It is urgent to find a catalyst with high selectivity and efficiency for the reduction of CO2 by renewable electric energy, which is the important means to reduce the greenhouse effect. In this work, we report that the metal-organic framework (MOF) indium-based 1,4-benzenedicarboxylate (In-BDC) catalyzes CO2 to formate with a Faradaic efficiency (FEHCOO-) of more than 80% in a wide voltage range between -0.419 and -0.769 V (vs. reversible hydrogen electrode, RHE). In-BDC performs at a maximum FEHCOO- of 88% at -0.669 V (vs. RHE) and a turnover frequency of up to 4798 h-1 at -1.069 V (vs. RHE). The long-term durability of 21 h and reusability of the electrocatalyst are clearly demonstrated. It opens up a new opportunity to utilize MOF with novel metal motifs for the efficient electroreduction of CO2.

Encapsulation of Single Iron Sites in a Metal-Porphyrin Framework for High-Performance Photocatalytic CO2 Reduction.

Efficient CO2 reduction with earth-abundant photocatalysts is a highly attractive but very challenging process for chemists. Herein, we synthesized an indium-porphyrin framework, In(H2TCPP)(1-n)[Fe(TCPP)(H2O)](1-n)[DEA](1-n) (In-FenTCPP-MOF; H2TCPP = tetrakis(4-benzoic acid)porphyrine; DEA = diethylamine), with a porphyrin ring supporting the single-site iron for the high-performance visible-light-driven conversion of CO2 to CO. A high CO yield of 3469 μmol g-1 can be achieved by a 24 h photocatalytic reaction with a high CO selectivity (ca. 99.5%). This activity was much higher than that of its cobalt analogues or the Fe-free indium-based metal-organic framework (MOF). Systematic experimental and theoretical studies indicate that the porphyrin-supported iron centers in the MOF matrix serve as efficient active sites, which can accept electrons from the photoexcited MOFs in order to mediate CO2 reduction.

Enhancement in electrical conductivity of a porous indium based metal–organic framework upon I2 uptake: combined experimental and theoretical investigations

Combined experimental and theoretical calculations shed light on the enhancement of conductivity through I2 incorporation in an indium metal–organic framework.

Thermally stable indium based metal–organic frameworks with high dielectric permittivity

Two thermally stable In-based MOFs exhibit high dielectric behavior with wide bandgaps.

Post-synthetic metal-ion metathesis in a single-crystal-to-single-crystal process: improving the gas adsorption and separation capacity of an indium-based metal–organic framework

By means of post-synthetic metal-ion metathesis, Cu ions selectively substitute In ions in the paddlewheel of JLU-Liu40-In to construct JLU-Liu40-In/Cu, which has significant improved the ability of thermal stability and gas sorption and separation.

Dual-emitting CsPbX3@ZJU-28 (X = Cl, Br, I) composites with enhanced stability and unique optical properties for multifunctional applications

Abstract Currently, all-inorganic CsPbX3 (X = Cl, Br, and I) perovskite quantum dots (QDs) receive great attention due to their spectacular characteristics and optical properties. However, the stability problem greatly restricts the applicability of CsPbX3 QDs. Herein, a novel protection strategy is reported by in-situ growth of CsPbX3 QDs in the mesoporous blue-emitting indium-based metal organic frameworks (ZJU-28). Accordingly, the CsPbX3@ZJU-28 composites possess dual-emission with broad band blue light emission ascribed to π-π* transitions of organic ligands in ZJU-28 and a distinctive narrow peak attributed to the excitonic emission of CsPbX3 QDs. Intriguingly, the CsPbX3@ZJU-28 exhibited both excitation-wavelength dependent and temperature dependent luminescence properties, which make the composites promising for potential application in anti-counterfeiting and temperature sensing. In addition, the ZJU-28 matrix encapsulation give CsPbX3 QDs greatly improved stability, which makes them attractive in LED applications. Therefore, this work will broaden the applicability of CsPbX3 QDs in multifunctional applications, such as anti-counterfeiting, temperature sensing and LEDs.

Chiral Phosphoric Acids in Metal-Organic Frameworks with Enhanced Acidity and Tunable Catalytic Selectivity.

Chiral phosphoric acids are incorporated into indium-based metal-organic frameworks (In-MOFs) by sterically preventing them from coordination. This concept leads to the synthesis of three chiral porous 3D In-MOFs with different network topologies constructed from three enantiopure 1,1'-biphenol-phosphoric acid derived tetracarboxylate linkers. More importantly, all the uncoordinated phosphoric acid groups are periodically aligned within the channels and display significantly enhanced acidity compared to the non-immobilized acids. This facilitates the Brønsted acid catalysis of asymmetric condensation/amine addition and imine reduction. The enantioselectivities can be tuned (up to >99 % ee) by varying the substituents to achieve a nearly linear correlation with the concentrations of steric bulky groups in the MOFs. DFT calculations suggest that the framework provides a chiral confined microenvironment that dictates both selectivity and reactivity of chiral MOFs.

An indium-based ethane-trapping MOF for efficient selective separation of C2H6/C2H4 mixture

The purification of ethylene (C2H4) from the cracking gas ethane/ethylene mixture (1:15, v/v) is a typical energy-intensive process in the chemical industry. As an alternative, adsorptive separation with much lower energy consumption and operational cost has attracted escalating attention. In this work, we reported an interesting C2H6-trapping adsorbent, In-soc-MOF-1, an indium-based metal-organic framework exhibiting the preferential adsorption of C2H6 over C2H4. Single-component adsorption isotherms showed that the C2H6 adsorption capacities were higher than those of C2H4 under measured temperatures (288, 298 and 308 K). For example, the uptakes of C2H6 and C2H4 were 4.04 and 3.72 mmol/g at 298 K and 100 kPa, respectively. The calculated IAST selectivity of C2H6/C2H4 (1:15) on In-soc-MOF-1 was in the range of 1.4–4.8. Moreover, the dynamic separation performance of In-soc-MOF-1 toward the C2H6/C2H4 binary mixture was evaluated by the breakthrough experiments, the result of which suggests that In-soc-MOF-1 could achieve efficient separation by trapping the impurity C2H6 molecules out of the C2H6/C2H4 binary mixture. Notably, In-soc-MOF-1 not only showed good water and moisture stability but also exhibited excellent recyclability, where negligible decrease in C2H6 adsorption capacity was observed during five cycles of adsorption-desorption tests. These properties suggest that In-soc-MOF-1, as a C2H6-trapping adsorbent, could be considered as a potential candidate in the practical application of separating the cracking gas mixture.

Removal of p-arsanilic acid by an amino-functionalized indium-based metal–organic framework: Adsorption behavior and synergetic mechanism

Organoarsenic compounds are emerging contaminants because of their considerable solubilities in water and the highly toxic inorganic arsenic species formed during their biotic and abiotic degradation in the natural environment. Herein, the adsorption of p-arsanilic acid (p-ASA), a typical organoarsenic compound, was studied by employing an amino-functionalized indium-based metal–organic framework (NH2-MIL-68(In)) and pristine MIL-68(In). Adsorption batch experiments reveal that NH2-MIL-68(In) has a higher adsorption capacity (401.6 mg g−1), affinity (0.0552 L mg−1), and adsorption rate (5.79 × 10−4 g mg−1 min−1) toward p-ASA than those of pristine MIL-68(In). Moreover, the adsorption of p-ASA was spontaneous and exothermic, and obeyed a pseudo-second-order model with intraparticle diffusion. The adsorption mechanism is proposed to involve synergism between π-π stacking and hydrogen-bonding interactions. The NH2 moiety introduced into the MIL-68(In) greatly improves its adsorption performance by enhancing hydrogen bonding. This study provides an important theoretical and experimental basis for the application of MOFs to the removal of organoarsenic compounds such as p-ASA.

A highly stable indium based metal organic framework for efficient arsenic removal from water.

A new porous indium metal organic framework namely (AUBM-1) was successfully synthesized via a solvothermal reaction of pyromellitic acid and indium chloride. Single crystal X-ray analysis revealed the formation of a 3D framework with a pts topology. The resulting MOF structure showed high chemical stability at different pH values. Thus, the activated indium MOF was applied for As removal from water for the first time and showed a high arsenate uptake capacity of 103.1 mg g-1 at neutral pH, which is higher than the commercial adsorbents (usually less than 100 mg g-1 at neutral pH). Finally, the kinetics and thermodynamic studies revealed that the As adsorption was an endothermic process and followed a pseudo-second-order kinetic model.

New Metal-Organic Frameworks for Chemical Fixation of CO2.

A novel series of two zirconium- and one indium-based metal-organic frameworks (MOFs), namely, MOF-892, MOF-893, and MOF-894, constructed from the hexatopic linker, 1',2',3',4',5',6'-hexakis(4-carboxyphenyl)benzene, were synthesized and fully characterized. MOF-892 and MOF-893 are two new exemplars of materials with topologies previously unseen in the important family of zirconium MOFs. MOF-892, MOF-893, and MOF-894 exhibit efficient heterogeneous catalytic activity for the cycloaddition of CO2, resulting in a cyclic organic carbonate formation with high conversion, selectivity, and yield under mild conditions (1 atm CO2, 80 °C, and solvent-free). Because of the structural features provided by their building units, MOF-892 and MOF-893 are replete with accessible Lewis and Brønsted acid sites located at the metal clusters and the non-coordinating carboxylic groups of the linkers, respectively, which is found to promote the catalytic CO2 cycloaddition reaction. As a proof-of-concept, MOF-892 exhibits high catalytic activity in the one-pot synthesis of styrene carbonate from styrene and CO2 without preliminary synthesis and isolation of styrene oxide.

Synthesis of porous In2O3/carbon composites derived from metal-organic frameworks for high performance Li-ion batteries

In order to overcome the disadvantages of low electronic conductivity and large volume variation of pure In2O3 anode material, a novel mesoporous In2O3/carbon composite was fabricated by annealing an indium-based metal-organic framework (In-MOF) precursor. SEM and TEM images demonstrated that In2O3/carbon composites were composed of In2O3 nanoparticles embedded in a carbon matrix due to the calcination of the metal organic framework. Galvanostatic charge/discharge test of the In2O3/carbon composite anode electrode showed a high initial discharge capacity of approximately 1410mAhg−1 and remained a reversible discharge capacity of 720mAhg−1 after 150cycles at the current density of 100mAg−1.

Selective Adsorption of Light Alkanes on a Highly Robust Indium Based Metal–Organic Framework

Highly robust indium based InOF-1 was synthesized by the solvothermal method for the separation of C3H8/CH4 and C2H6/CH4. Its adsorption and separation performance was investigated by isotherms (CH4, C2H6, and C3H8) and breakthrough experiments. Results showed that C3H8, C2H6, and CH4 adsorption capacities of InOF-1 were 4.25, 4.14, and 0.64 mmol/g at 298 K and 100 kPa. The adsorption selectivities of C3H8/CH4 and C2H6/CH4 equimolar mixtures were up to 91 and 17 based on ideal adsorbed solution theory (IAST). Importantly, the potential of industrial separation was also confirmed by breakthrough experiments. Furthermore, we employed the configurational-biased grand canonical Monte Carlo (CB-GCMC) method to simulate their adsorption behaviors in InOF-1. It was found that the relatively higher percentages of adsorbate–adsorbate interactions in total energy and the electrostatic interactions of C2H6 and C3H8 made more efficient use of the large free space in the center pores of InOF-1 than that of CH4. Additi...

Indium-based metal–organic frameworks as catalysts: synthesis of 2-nitro-3-arylimidazo[1,2-a]pyridines via oxidative amination under air using MIL-68(In) as an effective heterogeneous catalyst

The metal–organic framework MIL-68(In) has emerged as a productive heterogeneous catalyst for the synthesis of 2-nitro-3-arylimidazo[1,2-a]pyridines via oxidative amination between 2-aminopyridines and nitroalkenes using air as an oxidation agent.

Three-Component Coupling of Aldehyde, Alkyne, and Amine via C–H Bond Activation Using Indium-Based Metal–Organic Framework Mil-68(In) as a Recyclable Heterogeneous Catalyst

A porous indium-based metal–organic framework MIL-68(In) was prepared, and used as a recyclable catalyst for the one-pot three-component coupling of aldehydes, alkynes, and amines to form propargylamines via C–H bond activation. The transformation could proceed readily to produce propargylamines in the presence of a catalytic amount of MIL-68(In). The solvent significantly afftected the reaction, and toluene was the solvent of choice for the coupling transformation using MIL-68(In) catalyst. The reaction could only occur to produce propargylamines in the presence of the solid In-MOF catalyst. The MIL-68(In) catalyst could be reused several times for the synthesis of propargylamines. To our best knowledge, In-MOFs were not previously employed as heterogeneous catalyst for the synthesis of propargylamines from the one-pot three-component coupling of aldehydes, alkynes, and amines via C–H bond activation.

Two metal-organic frameworks with infinite indium hydroxide chains connected through tetradentate carboxylate linkers

Two indium-based metal-organic framework have been hydrothermally synthesized by using 1,2,4,5-benzenetetracarboxylate (pyromellitate) or 3,3′,4,4′-benzophenonetetracarboxylate as linkers. Their structures have been characterized by means of single-crystal X-ray diffraction analysis and reveal closely related networks consisting of identical infinite chains of indium-centered trans-connected octahedra, linked to each other through the tetradentate carboxylate linkers. The structure of the indium pyromellitate (MIL-60) delimits a 3D frameworks with one-dimensional 4.0 × 2.7 Å 2 channels running along [001] encapsulating water. The second compound (MIL-119) is built up from the compact stacking of the 3,3′,4,4′-benzophenonetetracarboxylate molecules connected to four distinct inorganic chains. In the latter, water species are found to be trapped between two indium hydroxide chains or in terminal positions, bonded to the indium cations. Strong hydrogen interactions are observed between these types of water molecules. Both compounds do not exhibit any significant porosity. Crystal data: In 2(OH) 2[C 10O 8H 2]·2H 2O (MIL-60): monoclinic, C2/ m, a = 7.1854(7) Å, b = 17.1940(17) Å, c = 6.5167(7) Å, β = 100.639(2)°, V = 791.27(14) Å 3, Z = 2. In 2(OH) 2(H 2O)[C 17O 9H 6]·H 2O (MIL-119), monoclinic, P2 1/ c, a = 14.2530(11) Å, b = 14.4024(10) Å, c = 11.7027(9) Å, β = 93.018(2)°, V = 2399.0(3) Å 3, Z = 4.