Heterogeneous catalysis is catalysis where the phase of catalysts differs from that of the reagents or products. The process contrasts with homogeneous catalysis where the reagents, products and catalyst exist in the same phase. Phase distinguishes between not only solid, liquid, and gas components, but also immiscible mixtures, or anywhere an interface is present.
Metal–organic frameworks (MOFs) are a class of porous polymers consisting of metal clusters coordinated to organic ligands to form one-, two- or three-dimensional structures. The organic ligands included are sometimes referred to as "struts" or "linkers", one example being 1,4-benzenedicarboxylic acid (BDC).
A carbon dioxide scrubber is a piece of equipment that absorbs carbon dioxide (CO2). It is used to treat exhaust gases from industrial plants or from exhaled air in life support systems such as rebreathers or in spacecraft, submersible craft or airtight chambers. Carbon dioxide scrubbers are also used in controlled atmosphere (CA) storage and carbon capture and storage processes.
Zeolitic imidazolate frameworks (ZIFs) are a class of metal-organic frameworks (MOFs) that are topologically isomorphic with zeolites. ZIFs are composed of tetrahedrally-coordinated transition metal ions connected by imidazolate linkers. Since the metal-imidazole-metal angle is similar to the 145° Si-O-Si angle in zeolites, ZIFs have zeolite-like topologies. As of 2010, 105 ZIF topologies have been reported in the literature. Due to their robust porosity, resistance to thermal changes, and chemical stability, ZIFs are being investigated for applications such as carbon dioxide capture.
Omar M. Yaghi is the James and Neeltje Tretter Chair Professor of Chemistry at the University of California, Berkeley, an affiliate scientist at Lawrence Berkeley National Laboratory, the founding director of the Berkeley Global Science Institute, and an elected member of the US National Academy of Sciences as well as the German National Academy of Sciences Leopoldina.
Covalent organic frameworks (COFs) are a class of porous polymers that form two- or three-dimensional structures through reactions between organic precursors resulting in strong, covalent bonds to afford porous, stable, and crystalline materials. COFs emerged as a field from the overarching domain of organic materials as researchers optimized both synthetic control and precursor selection. These improvements to coordination chemistry enabled non-porous and amorphous organic materials such as organic polymers to advance into the construction of porous, crystalline materials with rigid structures that granted exceptional material stability in a wide range of solvents and conditions. Through the development of reticular chemistry, precise synthetic control was achieved and resulted in ordered, nano-porous structures with highly preferential structural orientation and properties which could be synergistically enhanced and amplified. With judicious selection of COF secondary building units (SBUs), or precursors, the final structure could be predetermined, and modified with exceptional control enabling fine-tuning of emergent properties. This level of control facilitates the COF material to be designed, synthesized, and utilized in various applications, many times with metrics on scale or surpassing that of the current state-of-the-art approaches.
NOTT-202 is a two-part chemical compound that is capable of selectively absorbing carbon dioxide. It is a metal–organic framework (MOF) that functions like a sponge, adsorbing selected gases at high pressures. Its creation was announced by scientists in 2012. The researchers claimed this structure was an entirely new class of porous material.
A two-dimensional polymer (2DP) is a sheet-like monomolecular macromolecule consisting of laterally connected repeat units with end groups along all edges. This recent definition of 2DP is based on Hermann Staudinger's polymer concept from the 1920s. According to this, covalent long chain molecules ("Makromoleküle") do exist and are composed of a sequence of linearly connected repeat units and end groups at both termini.
Solid sorbents for carbon capture include a diverse range of porous, solid-phase materials, including mesoporous silicas, zeolites, and metal-organic frameworks. These have the potential to function as more efficient alternatives to amine gas treating processes for selectively removing CO2 from large, stationary sources including power stations. While the technology readiness level of solid adsorbents for carbon capture varies between the research and demonstration levels, solid adsorbents have been demonstrated to be commercially viable for life-support and cryogenic distillation applications. While solid adsorbents suitable for carbon capture and storage are an active area of research within materials science, significant technological and policy obstacles limit the availability of such technologies.
Some metal-organic frameworks (MOF) display large structural changes as a response to external stimuli, and such modifications of their structure can, in turn, lead to drastic changes in their physical and chemical properties. Such stimuli-responsive MOFs are generally referred to as a flexible metal-organic frameworks. They can also be called dynamic metal-organic framework, stimuli-responsive MOFs, multi-functional MOFs, or soft porous crystals.
Jeffrey Robert Long is a professor of chemistry at the University of California, Berkeley known for his work in metal−organic frameworks and molecular magnetism. He was elected to the American Academy of Arts and Sciences in 2019 and is the 2019 F. Albert Cotton Award recipient. His research interests include: the synthesis of inorganic clusters and porous materials, investigating the electronic and magnetic properties of inorganic materials; metal-organic frameworks, and gas storage/capture.
MIL-53 belongs to the class of metal-organic framework (MOF) materials. The first synthesis and the name was established by the group of Gérard Férey in 2002. The MIL-53 structure consists of inorganic [M-OH] chains, which are connected to four neighboring inorganic chains by therephthalate-based linker molecules. Each metal center is octahedrally coordinated by six oxygen atoms. Four of these oxygen atoms originate from four different carboxylate groups and the remaining two oxygen atoms belong to two different μ-OH moieties, which bridge neighboring metal centers. The resulting framework structure contains one-dimensional diamond-shaped pores. Many research group have investigated the flexibility of the MIL-53 structure. This flexible behavior, during which the pore cross-section changes reversibly, was termed 'breathing effect' and describes the ability of the MIL-53 framework to respond to external stimuli.
DUT-5 (DUT ⇒ Dresden University of Technology) is a material in the class of metal-organic frameworks (MOFs). Metal-organic frameworks are crystalline materials, in which metals are linked by ligands (linker molecules) to form repeating three-dimensional structures known as coordination entities. The DUT-5 framework is an expanded version of the MIL-53 structure and consists of Al3+ metal centers and biphenyl-4,4'-dicarboxylate (BPDC) linker molecules. It consists of inorganic [M-OH] chains, which are connected by the biphenyl-4,4'-dicarboxylate linkers to four neighboring inorganic chains. The resulting structure contains diamond-shaped micropores extending in one dimension.
David Collison is a British chemist and a Professor in the Department of Chemistry at The University of Manchester. His research in general is based on inorganic chemistry and magnetochemistry, specifically on coordination chemistry, electron paramagnetic resonance spectroscopy and f-block chemistry.
Floriana Tuna is a Romanian chemist and a Senior Research Fellow in the Department of Chemistry at The University of Manchester. Her research in general is based on inorganic chemistry and magnetochemistry, specifically on molecular magnetism, EPR spectroscopy and quantum computing.
Wendy Lee Queen is an American chemist and material scientist. Her research interest focus on development design and production of hybrid organic/inorganic materials at the intersection of chemistry, chemical engineering and material sciences. As of 2020 she is a tenure-track assistant professor at the École polytechnique fédérale de Lausanne (EPFL) in Switzerland, where she directs the Laboratory for Functional Inorganic Materials.
Jorge Gascon is a Professor of Chemical Engineering at King Abdullah University of Science and Technology, director of the KAUST Catalysis Center. and a group leader of Advanced Catalytic Materials group
Xiaodong Zou is a Chinese-Swedish chemist who is a professor at Stockholm University. Her research considers the development of electron diffraction for the three dimensional characterisation of materials. She is a member of the Nobel Committee for Chemistry. She was elected to the Royal Swedish Academy of Sciences and the Royal Swedish Academy of Engineering Sciences.
Carboxylate–based metal–organic frameworks are metal–organic frameworks that are based on organic molecules comprising carboxylate functional groups.
Hydrogen-bonded organic frameworks (HOFs) are a class of porous polymers formed by hydrogen bonds among molecular monomer units to afford porosity and structural flexibility. There are diverse hydrogen bonding pair choices that could be used in HOFs construction, including identical or nonidentical hydrogen bonding donors and acceptors. For organic groups acting as hydrogen bonding units, species like carboxylic acid, amide, 2,4-diaminotriazine, and imidazole, etc., are commonly used for the formation of hydrogen bonding interaction. Compared with other organic frameworks, like COF and MOF, the binding force of HOFs is relatively weaker, and the activation of HOFs is more difficult than other frameworks, while the reversibility of hydrogen bonds guarantees a high crystallinity of the materials. Though the stability and pore size expansion of HOFs has potential problems, HOFs still show strong potential for applications in different areas.
