Search

Metal-organic frameworks (MOFs) are excellent candidates for water harvesting from desert air. MOF-303 (Al(OH)(PZDC), where PZDC is 1-H-pyrazole-3,5-dicarboxylate), a robust and water-stable MOF, is a particularly promising water-harvesting sorbent that can take up water at low relative humidity and release it under mild heating. Accordingly, development of a facile, high-yield synthesis method for its production at scale is highly desirable. Here we report detailed protocols for the green, water-based preparation of MOF-303 on both gram and kilogram scales. Specifically, four synthetic methods (solvothermal, reflux, vessel and microwave), involving different equipment requirements, are presented to guarantee general accessibility. Typically, the solvothermal method takes ~24 h to synthesize MOF-303, while the reflux and vessel methods can reduce the time to 4-8 h. With the microwave-assisted method, the reaction time can be further reduced to just 5 min. In addition, we provide guidance on the characterization of MOF-303, as well as water-harvesting MOFs in general, to ensure high quality of the product in terms of its purity, crystallinity, porosity and water uptake. Furthermore, to address the need for future commercialization of this material, we demonstrate that our protocol can be employed to produce 3.5 kg per batch with a yield of 91%. MOF-303 synthesized at this large scale shows similar crystallinity and water uptake capacity compared to the respective material produced at a small scale. Our synthetic procedure is green and water-based, and can produce the MOF within hours., (© 2022. Springer Nature Limited.)

Mammalian cells are promising agents for cell therapy, diagnostics, and drug delivery. For full utilization of the cells, development of an exoskeleton may be beneficial to protecting the cells against the environmental stresses and cytotoxins to which they are susceptible. We report here a rapid single-step method for growing metal-organic framework (MOF) exoskeletons on a mammalian cell surface under cytocompatible conditions. The MOF exoskeleton coating on the mammalian cells was developed via a one-pot biomimetic mineralization process. With the exoskeleton on, the individual cells were successfully protected against cell protease (i.e., Proteinase K), whereas smaller-sized nutrient transport across the exoskeleton was maintained. Moreover, vital cellular activities mediated by transmembrane GLUT transporter proteins were also unaffected by the MOF exoskeleton formation on the cell surfaces. Altogether, this ability to control the access of specific molecules to a single cell through the porous exoskeleton, along with the cytoprotection provided, should be valuable for biomedical applications of mammalian cells.

Two major issues in cell-mediated drug delivery systems (c-DDS) are the availability of free cell surfaces for the binding of the cells to the target or to their microenvironment and internalization of the cytotoxic drug. In this study, the Janus structure, MOF nanoparticles, and tannic acid (TA) are utilized to address these issues. Janus carrier cells coated with metal-organic frameworks (MOFs) are produced by asymmetrically immobilizing the nanoparticles of a MOF based on zinc with cytotoxic enzymes that are internally encapsulated on the surface of carrier cells. By maintaining the biological and structural features of regular living cells, the MOF-coated Janus cells developed in the present study preserve the intrinsic binding capacity of the cells to their microenvironment. Interconnected MOFs loaded onto the other face of the Janus cells cannot penetrate the cell. Therefore, the carrier cells are protected from the cytotoxic drug contained in MOFs. These MOF-Janus carrier cells are demonstrated to successfully eliminate three-dimensional (3D) tumor spheroids when a chemotherapeutic protein of proteinase K is released from the MOF nanoparticles in an acid environment. The ease with which the MOF-Janus carrier cells are prepared (in 15 min), and the ability to carry a variety of enzymes and even multiple ones should make the developed system attractive as a general platform for drug delivery in various applications, including combination therapy.

The intracellular delivery of biofunctional enzymes or therapeutic proteins through systemic administration is of great importance in therapeutic intervention of various diseases. However, current strategies face substantial challenges owing to various biological barriers, including susceptibility to protein degradation and denaturation, poor cellular uptake, and low transduction efficiency into the cytosol. Here, we developed a biomimetic nanoparticle platform for systemic and intracellular delivery of proteins. Through a biocompatible strategy, guest proteins are caged in the matrix of metal-organic frameworks (MOFs) with high efficiency (up to ∼94%) and high loading content up to ∼50 times those achieved by surface conjunction, and the nanoparticles were further decorated with the extracellular vesicle (EV) membrane with an efficiency as high as ∼97%. In vitro and in vivo study manifests that the EV-like nanoparticles can not only protect proteins against protease digestion and evade the immune system clearance but also selectively target homotypic tumor sites and promote tumor cell uptake and autonomous release of the guest protein after internalization. Assisted by biomimetic nanoparticles, intracellular delivery of the bioactive therapeutic protein gelonin significantly inhibits the tumor growth in vivo and increased 14-fold the therapeutic efficacy. Together, our work not only proposes a new concept to construct a biomimetic nanoplatform but also provides a new solution for systemic and intracellular delivery of protein.

A variety of nanomaterials have been developed specifically for biomedical applications, such as drug delivery in cancer treatment. These materials involve both synthetic and natural nanoparticles and nanofibers of varying dimensions. The efficacy of a drug delivery system (DDS) depends on its biocompatibility, intrinsic high surface area, high interconnected porosity, and chemical functionality. Recent advances in metal-organic framework (MOF) nanostructures have led to the achievement of these desirable features. MOFs consist of metal ions and organic linkers that are assembled in different geometries and can be produced in 0, 1, 2, or 3 dimensions. The defining features of MOFs are their outstanding surface area, interconnected porosity, and variable chemical functionality, which enable an endless range of modalities for loading drugs into their hierarchical structures. MOFs, coupled with biocompatibility requisites, are now regarded as highly successful DDSs for the treatment of diverse diseases. This review aims to present the development and applications of DDSs based on chemically-functionalized MOF nanostructures in the context of cancer treatment. A concise overview of the structure, synthesis, and mode of action of MOF-DDS is provided.

A variety of nanomaterials have been developed specifically for biomedical applications, such as drug delivery in cancer treatment. These materials involve both synthetic and natural nanoparticles and nanofibers of varying dimensions. The efficacy of a drug delivery system (DDS) depends on its biocompatibility, intrinsic high surface area, high interconnected porosity, and chemical functionality. Recent advances in metal-organic framework (MOF) nanostructures have led to the achievement of these desirable features. MOFs consist of metal ions and organic linkers that are assembled in different geometries and can be produced in 0, 1, 2, or 3 dimensions. The defining features of MOFs are their outstanding surface area, interconnected porosity, and variable chemical functionality, which enable an endless range of modalities for loading drugs into their hierarchical structures. MOFs, coupled with biocompatibility requisites, are now regarded as highly successful DDSs for the treatment of diverse diseases. This review aims to present the development and applications of DDSs based on chemically-functionalized MOF nanostructures in the context of cancer treatment. A concise overview of the structure, synthesis, and mode of action of MOF-DDS is provided. [ABSTRACT FROM AUTHOR]

CO2, emitted mainly from fossil fuel combustion, is one of the major greenhouse gases. CO2 could be converted into more valuable chemical feedstocks including CO, HCOOH, HCHO, CH3OH, or CH4. To reduce CO2, catalysts were designed and their unique characteristics were utilized based on types of reaction processes, including catalytic hydrogenation, complex metal hydrides, photocatalysis, biological reduction, and electrochemical reduction. Indeed, the electroreduction method has received much consideration lately due to the simple operation, as well as environmentally friendly procedures that need to be optimized by both of the catalysts and the electrochemical process. In the past few decades, we have witnessed an explosion in development in materials science—especially in regards to the porous crystalline materials based on the strong covalent bond of the organic linkers containing light elements (Covalent organic frameworks, COFs), as well as the hybrid materials that possess organic backbones and inorganic metal-oxo clusters (Metal-organic frameworks, MOFs). Owing to the large surface area and high active site density that belong to these tailorable structures, MOFs and COFs can be applied to many practical applications, such as gas storage and separation, drug release, sensing, and catalysis. Beyond those applications, which have been abundantly studied since the 1990s, CO2 reduction catalyzed by reticular and extended structures of MOFs or COFs has been more recently turned to the next step of state-of-the-art application. In this perspective, we highlight the achievement of homogeneous catalysts used for CO2 electrochemical conversion and contrast it with the advances in new porous catalyst-based reticular chemistry. We then discuss the role of new catalytic systems designed in light of reticular chemistry in the heterogeneous-catalyzed reduction of CO2.

Two lanthanide metal–organic frameworks [Ln-MOFs, Ln = Eu(III), Tb(III)] composed of oxalic acid and Ln building units were hydrothermally synthesized and fully characterized by powder X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscope, and energy-dispersive X-ray spectroscopy. Furthermore, their magnetic susceptibility measurements were obtained using SQUID based vibrating sample magnetometer (MPMS 3, Quantum Design). Both Ln-MOFs exhibited highly efficient luminescent property. Solid-state photoluminescence (PL) measurements revealed phosphorescence emission bands of Eu-MOF and Tb-MOF centered at 618 nm (red emission) and 550 nm (green emission) upon excitation at 396 nm and 285 nm, respectively. Eu-MOF and Tb-MOF displayed a phosphorescence quantum yield of 53% and 40%, respectively. Time-resolved PL analyses showed very long lifetime values, at 600 and 1065 ± 1 µs for Eu-MOF and Tb-MOF, respectively. Calculations performed by density functional theory indicated a charge transfer form metal centres to the ligand which was in good agreement with the experimental studies. Therefore, this new mode of highly photoluminescent MOF materials is studied for the first time which paves the way for better understanding of these systems for potential applications. [ABSTRACT FROM AUTHOR]

Nanomaterials have been widely used as a class of antibacterial drugs. However, the bottlenecks of this class of materials are their significant aggregation and accumulation, as well as toxicity resulting from excessive metal leaching. Metal–organic frameworks (MOFs) have inspired researchers owing to their distinct characteristics of robust architecture and tunable pore structures, which may help overcome the above challenges. We, herein, synthesize UiO-66-NH2 and use it as a solid support for loading quinazoline derivatives that are specifically designed and active against Gram-negative bacteria. The quinazoline derivatives were adsorbed on UiO-66-NH2 nanoparticles to form new UiO-66-NH2-quinazoline formulations which have a large inhibitory zone against Gram-negative bacteria, compared to that of free quinazoline compounds. This work has the potential for increasing antibacterial activity while also broadening the antibacterial range, and thus opens a pathway for new medical applications using MOFs. [ABSTRACT FROM AUTHOR]

Various photocatalysts have been developed for photocatalytic water splitting—one of the most important processes that produces dihydrogen as clean energy for fuel cells. The successful achievements for this application are based mainly on transition metal oxides and some metal sulfides/nitrides. Recently, metal–organic frameworks (MOFs), a class of hybrid functional materials comprising organic backbone tethered infinitively in limitless way by metal‐oxide clusters, both of which can be customized accurately at the molecular level for targeted applications, have been able to photocatalytically degrade water. Herein, it is first aimed to comprehensively review fundamentals of water splitting catalyzed by semiconductor photocatalysts, which casts light on understanding of challenges in this area, thus providing strategies for development, if not rational design, of visible‐light‐driven MOFs that are capable of degrading water to hydrogen and oxygen. The recent advancements of using MOF photocatalysts for water splitting are further described in a way that benchmark achievements and limitations are considered so that the readers can imagine the big picture in this field and pay considerable attention to future solutions. [ABSTRACT FROM AUTHOR]

Because of the energy crisis facing the planet, reducing fossil fuel reliance is an urgent scientific task. Alternative fuels have recently been in high demand. Taking into account the enormous amount of CO2 released from combustion, converting CO2 into high value‐added products using photochemistry—the catalytic transformation is activated by the ubiquitous sunlight mimicking the photosynthesis of natural plants—is of paramount importance. Scientists have developed various photocatalysts for the CO2 photoreduction. Among them, reticular materials including metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) have been employed for many applications during the past decade and have emerged as advanced catalytic platforms for the photoreduction of CO2. This Progress Report aims to provide the fundamentals, mechanism, and methods of characterization to gain insight into the process of CO2 photoreduction. In addition, this Progress Report highlights the achievements in using reticular materials as advanced catalysts for the photoreduction of CO2 and discusses the relationship between structural features of MOFs/COFs with their photocatalytic performance. Based on the comprehension of advancements, opportunities, and challenges of reticular materials for the CO2 photoreduction, the future prospects of this technology are discussed to direct the exciting research in designing better CO2 reduction photocatalysts. [ABSTRACT FROM AUTHOR]

Because of the energy crisis facing the planet, reducing fossil fuel reliance is an urgent scientific task. Alternative fuels have recently been in high demand. Taking into account the enormous amount of CO2 released from combustion, converting CO2 into high value‐added products using photochemistry—the catalytic transformation is activated by the ubiquitous sunlight mimicking the photosynthesis of natural plants—is of paramount importance. Scientists have developed various photocatalysts for the CO2 photoreduction. Among them, reticular materials including metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) have been employed for many applications during the past decade and have emerged as advanced catalytic platforms for the photoreduction of CO2. This Progress Report aims to provide the fundamentals, mechanism, and methods of characterization to gain insight into the process of CO2 photoreduction. In addition, this Progress Report highlights the achievements in using reticular materials as advanced catalysts for the photoreduction of CO2 and discusses the relationship between structural features of MOFs/COFs with their photocatalytic performance. Based on the comprehension of advancements, opportunities, and challenges of reticular materials for the CO2 photoreduction, the future prospects of this technology are discussed to direct the exciting research in designing better CO2 reduction photocatalysts. [ABSTRACT FROM AUTHOR]

Due to the many potential applications of metal–organic frameworks (MOFs), research focusing on the design, syntheses, and surface modifications of the new generation of crystalline-based MOF materials has recently received much attention. Among these materials, MOFs based on Ti–oxo clusters are potential candidates for practical applications such as photocatalysis, CO2 reduction, and pollutant degradation because of their high optical responsitivities and photoredox properties. The capabilities of Ti-MOFs in a wide range of applications are inspiring their use as a replacement for TiO2, which has recently been classified as a potential carcinogen. However, the number of tianium–organic framework structures is very limited compared to the many structures of other MOFs. In order to emphasize the importance of discovering new Ti-MOF materials and their related features, this work aims to describe the chemistry of titanium-based MOFs, including their synthetic methods, crystal structures, and topological analysis, as well as further key novel applications, which are desirable for extension to many industrial fields. [ABSTRACT FROM AUTHOR]

Two new series of metal-organic frameworks (MOFs), termed M-VNU-74-I and -II (where M = Mg, Ni, Co; VNU = Vietnam National University) were designed to expand the methanol uptake capacities with polar amide functionalities. The resulting MOFs, isoreticular to MOF-74, exhibited high porosity (up to 3000 m² g-1) as well as the highest reported methanol uptake [>1 g g-1 or >400 cm³ cm-3]. As a representative example, Mg-VNU-74-II was shown to maintain a remarkably high stability and methanol mass transfer capacity for at least 42 ad/desorption cycles (3 days). Indeed, these findings highlight the potential of such materials for practical use in adsorption heat pump applications. [ABSTRACT FROM AUTHOR]

New ZrIV- and HfIV-based metal-organic framework photocatalysts, termed VNU-1 and VNU-2 (where VNU=Vietnam National University), were synthesized and their resulting structures fully characterized. By employing a highly π-conjugated linker, namely 1,4-bis(2-[4-carboxyphenyl]ethynyl) benzene, the optical absorption properties were effectively red-shifted into the visible light region. This strategy, coupled with the high water stability of the materials, led to enhanced MOF-driven photocatalytic degradation, under ultraviolet- visible light, of organic dye pollutants commonly found in wastewater. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) have emerged as promising materials for use in practical applications of renewable energy, water harvesting, and catalytic transformation. Here we report the design of a highly porous MOF, termed MOF-907. Single crystal X-ray diffraction analysis, in combination with topological deconstruction, revealed a MOF based on trigonal prismatic secondary building units linked together by triangular and linear units to form a previously unseen net (nha) with minimal transitivity, which is rational for these constituent building units. The catalytic properties of MOF-907 for the microwave-assisted radical polymerization of methyl methacrylate were demonstrated. MOF-907 produced a poly methyl methacrylate product in a short reaction time (30 min) with high yield (98%), high molecular weight (20,680 g mol−1), and low polydispersity (1.23). Metal-organic frameworks are attractive candidates as catalyst materials. Here, the authors report a highly symmetric hierarchical framework with a rare nha net topology catalyzing microwave-assisted radical polymerization of methyl methacrylate in high yields. [ABSTRACT FROM AUTHOR]

CO2, emitted mainly from fossil fuel combustion, is one of the major greenhouse gases. CO2 could be converted into more valuable chemical feedstocks including CO, HCOOH, HCHO, CH3OH, or CH4. To reduce CO2, catalysts were designed and their unique characteristics were utilized based on types of reaction processes, including catalytic hydrogenation, complex metal hydrides, photocatalysis, biological reduction, and electrochemical reduction. Indeed, the electroreduction method has received much consideration lately due to the simple operation, as well as environmentally friendly procedures that need to be optimized by both of the catalysts and the electrochemical process. In the past few decades, we have witnessed an explosion in development in materials science—especially in regards to the porous crystalline materials based on the strong covalent bond of the organic linkers containing light elements (Covalent organic frameworks, COFs), as well as the hybrid materials that possess organic backbones and inorganic metal-oxo clusters (Metal-organic frameworks, MOFs). Owing to the large surface area and high active site density that belong to these tailorable structures, MOFs and COFs can be applied to many practical applications, such as gas storage and separation, drug release, sensing, and catalysis. Beyond those applications, which have been abundantly studied since the 1990s, CO2 reduction catalyzed by reticular and extended structures of MOFs or COFs has been more recently turned to the next step of state-of-the-art application. In this perspective, we highlight the achievement of homogeneous catalysts used for CO2 electrochemical conversion and contrast it with the advances in new porous catalyst-based reticular chemistry. We then discuss the role of new catalytic systems designed in light of reticular chemistry in the heterogeneous-catalyzed reduction of CO2. [ABSTRACT FROM AUTHOR]

Herein, the NO 2 gas sensing features of SnO 2 nanowires (NWs) and titanium-based metal–organic framework 901 (MOF-901)-coated SnO 2 NWs were investigated. Both gas sensors showed excellent selectivity to NO 2. At 200 °C, the responses of SnO 2 NWs and MOF-901-coated SnO 2 NWs to NO 2 (10 ppm) were 9.7 and 8.2, respectively. However, in a humid atmosphere, the latter nanowires showed better performance, mainly because of their hydrophobic nature and the metal–organic framework layer. At relative humidities (RHs) of 20% and higher, the MOF-901-coated sensor showed higher performance than the pristine sensor. In particular, at 80% RH, responses of 6.6 and 4.0 were obtained for these two sensors to 10 ppm NO 2 , respectively. Furthermore, the MOF-901-coated SnO 2 NWs showed better selectivity than the other sensor. We showed that MOF-901 behaved an important role in reducing the effects of water vapor and that it can be used as a molecular sieve for enhancing the NO 2 gas response of SnO 2 NWs in humid environments. • Synthesis of SnO 2 nanowires (NWs) and MOF-901 coated SnO 2 NWs for NO 2 gas sensing studies. • Superior NO 2 gas sensing of SnO 2 NWs in dry air atmosphere. • Superior NO 2 gas sensing of MOF-901 coated SnO 2 NWs gas sensor in the presence of humidity due to hydrophobic nature. • Excellent selectivity of both gas sensors to NO 2 gas. • Explanation of NO 2 gas sensing mechanism. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are a class of crystalline and porous materials with modular structural features. This modularity has allowed MOFs to be designed and synthesized with adjustable pore sizes and shapes leading to ultrahigh porosity. Among the tens of thousands of known MOF structures, zirconium-based MOFs (Zr-MOFs) have attracted attention not only for their structural properties but also their superior chemical and thermal stabilities, which are critical for a myriad of practical applications. In particular, bipyridine (BPY) functionalized Zr-MOFs have been received recognition for their interesting intrinsic properties, which arise from various post-modification pathways. The fact that post-modification is readily available for such MOFs paves the way towards anchoring specific components (functional groups, metals complexes, and nanoparticles) via the bipyridine docking centers, thus endowing this MOF platform with the capability to chemically alter and enhance the bulk material’s properties. Throughout this review, an emphasis is placed on the preparation of BPY-functionalized Zr-MOFs, their characterization, and subsequent applications, such as electrocatalytic or photocatalytic hydrogen evolution reactions, heterogeneous molecular catalysis, and gas storage for renewable energy. Furthermore, this review highlights the design and applications of materials from the viewpoint of materials design and the necessity and importance of installing complexity to achieve synergistic interactions. Finally, our perspective for future applications is introduced with the expectation of providing useful information to those interested in this specific MOF platform. [ABSTRACT FROM AUTHOR]

This work presents the design and synthesis of MOF catalysts adopting high catalytic active sites through either designed MOFs or postsynthetic modification for heterogeneous catalysis of α-olefin oligomerization and polymerization. [Display omitted] • A new application of metal–organic frameworks (MOFs), i.e., α-olefin oligomerization and polymerization, is reviewed. • MOFs offer advantages for the heterogeneous oligomerization and polymerization of αolefins. • Strategies to postsynthetic modification of MOFs for the α-olefin oligomerization and polymerization are highlighted in detail. • Performance and selectivity of MOFs in catalyzing the oligomerization and polymerization of α-olefins are compared to conventional catalysts. • Mechanistic aspects of the α-olefin oligomerization and polymerization catalyzed by MOFs are discussed. In the industry of petrochemicals, oligomerization of α-olefins, mainly ethylene and propylene, is an important process that produces linear α-olefins (LAOs). Industrial processes for selective LAOs rely on various homogenous catalysts in the presence of alkyl aluminum activators. Recently, heterogeneous catalysts have largely been applied for α-olefin oligomerization and polymerization due to their high selectivity, stability, and reusability. In this context, metal-organic frameworks (MOFs), adopting high surface area, tunable pore structures, and enhanced physicochemical properties achieved through postsynthetic modification, have emerged as promising catalytic systems for this purpose. In this review, we provide a comprehensive overview (124 references) of using designed MOFs, MOFs with postsynthetic modification through linker metalation and mixed-metal clusters for selective oligomerization of α-olefins. We subsequently highlight the use of MOFs as non-selective catalysts for α-olefin oligomerization. Additionally, MOFs that catalyze α-olefin polymerization are also presented. Selective ethylene oligomerization conceptually proceeds through metallacycle mechanism, on the other hand, linear chain growth is the accepted mechanism for ethylene oligomerization and polymerization; accordingly, such mechanistic hypotheses using MOFs are described in detail. We, finally, point out challenges and perspectives for the future research of using MOFs as catalysts for α-olefin oligomerization and polymerization. [ABSTRACT FROM AUTHOR]

• A subclass of metal–organic frameworks (MOFs), i.e., rare-earth MOFs, are reviewed. • RE-MOFs offer advantages for heterogeneous catalysis of various organic reactions. • The metal clusters of RE-MOFs provide diverse and high coordination numbers. • The performance and selectivity of RE-MOFs and conventional catalysts are compared. • The metal oxidation state, site proximity, and ligand functionalization are examined. Metal–organic frameworks (MOFs) have emerged as a new class of crystalline porous hybrid functional materials. The exceptional features of MOFs include their ultrahigh porosity, confined pore structures, configurations of active sites obtained by either the originally designed synthesis or post-synthetic modification, and tailorable chemical structures, all of which make them suitable candidates for many applications including gas storage, separation, catalysis, sensing, and many more. The advantages of MOFs for application to catalysis lie in features such as (1) their high internal surface area, which provides space for reactions; (2) catalytic activity toward organic reactions stemming from both metal and organic active functionalities; (3) selectivity originating from the well-defined pore environment; and (4) architectural and chemical stability endowed by the robust linkages made up of organic units and metal-based clusters, which enables recycling them as catalysts. Rare-earth metal–organic frameworks (RE-MOFs) are a subclass of MOFs that encompass the unique features of MOF chemistry but are notable for their intriguing architectural structures caused by the diverse coordination numbers of their metal clusters, thus distinguishing them from other MOFs for the purposes of catalysis. This review presents recent advances in using heterogeneous catalysts derived from RE-MOFs for various organic transformations. Key features of RE-MOFs are discussed including structural aspects, the nature of the active sites, and their relationships with the catalytic performance of the targeted MOFs. Special emphasis is placed on the effects of the metal oxidation state, site proximity, and ligand functionalization on catalytic performance and selectivity. We further include our perspectives, including several open questions that must be studied to help understand the fundamental chemistry of heterogeneous catalysis using RE-MOFs. [ABSTRACT FROM AUTHOR]