Catalysis is the increase in rate of a chemical reaction due to an added substance known as a catalyst. Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly,very small amounts of catalyst often suffice;mixing,surface area,and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product,in the process of regenerating the catalyst.
Organometallic chemistry is the study of organometallic compounds,chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal,including alkali,alkaline earth,and transition metals,and sometimes broadened to include metalloids like boron,silicon,and selenium,as well. Aside from bonds to organyl fragments or molecules,bonds to 'inorganic' carbon,like carbon monoxide,cyanide,or carbide,are generally considered to be organometallic as well. Some related compounds such as transition metal hydrides and metal phosphine complexes are often included in discussions of organometallic compounds,though strictly speaking,they are not necessarily organometallic. The related but distinct term "metalorganic compound" refers to metal-containing compounds lacking direct metal-carbon bonds but which contain organic ligands. Metal β-diketonates,alkoxides,dialkylamides,and metal phosphine complexes are representative members of this class. The field of organometallic chemistry combines aspects of traditional inorganic and organic chemistry.
Surface science is the study of physical and chemical phenomena that occur at the interface of two phases,including solid–liquid interfaces,solid–gas interfaces,solid–vacuum interfaces,and liquid–gas interfaces. It includes the fields of surface chemistry and surface physics. Some related practical applications are classed as surface engineering. The science encompasses concepts such as heterogeneous catalysis,semiconductor device fabrication,fuel cells,self-assembled monolayers,and adhesives. Surface science is closely related to interface and colloid science. Interfacial chemistry and physics are common subjects for both. The methods are different. In addition,interface and colloid science studies macroscopic phenomena that occur in heterogeneous systems due to peculiarities of interfaces.
Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element,usually in the presence of a catalyst such as nickel,palladium or platinum. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically constitutes the addition of pairs of hydrogen atoms to a molecule,often an alkene. Catalysts are required for the reaction to be usable;non-catalytic hydrogenation takes place only at very high temperatures. Hydrogenation reduces double and triple bonds in hydrocarbons.
In organic chemistry,hydroformylation,also known as oxo synthesis or oxo process,is an industrial process for the production of aldehydes from alkenes. This chemical reaction entails the net addition of a formyl group and a hydrogen atom to a carbon-carbon double bond. This process has undergone continuous growth since its invention:production capacity reached 6.6×106 tons in 1995. It is important because aldehydes are easily converted into many secondary products. For example,the resultant aldehydes are hydrogenated to alcohols that are converted to detergents. Hydroformylation is also used in speciality chemicals,relevant to the organic synthesis of fragrances and pharmaceuticals. The development of hydroformylation is one of the premier achievements of 20th-century industrial chemistry.
The Fischer–Tropsch process (FT) is a collection of chemical reactions that converts a mixture of carbon monoxide and hydrogen,known as syngas,into liquid hydrocarbons. These reactions occur in the presence of metal catalysts,typically at temperatures of 150–300 °C (302–572 °F) and pressures of one to several tens of atmospheres. The Fischer–Tropsch process is an important reaction in both coal liquefaction and gas to liquids technology for producing liquid hydrocarbons.
Heterogeneous catalysis is catalysis where the phase of catalysts differs from that of the reactants or products. The process contrasts with homogeneous catalysis where the reactants,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.
The water–gas shift reaction (WGSR) describes the reaction of carbon monoxide and water vapor to form carbon dioxide and hydrogen:
A transition metal carbene complex is an organometallic compound featuring a divalent carbon ligand,itself also called a carbene. Carbene complexes have been synthesized from most transition metals and f-block metals,using many different synthetic routes such as nucleophilic addition and alpha-hydrogen abstraction. The term carbene ligand is a formalism since many are not directly derived from carbenes and most are much less reactive than lone carbenes. Described often as =CR2,carbene ligands are intermediate between alkyls (−CR3) and carbynes (≡CR). Many different carbene-based reagents such as Tebbe's reagent are used in synthesis. They also feature in catalytic reactions,especially alkene metathesis,and are of value in both industrial heterogeneous and in homogeneous catalysis for laboratory- and industrial-scale preparation of fine chemicals.
Nanomaterial-based catalysts are usually heterogeneous catalysts broken up into metal nanoparticles in order to enhance the catalytic process. Metal nanoparticles have high surface area,which can increase catalytic activity. Nanoparticle catalysts can be easily separated and recycled. They are typically used under mild conditions to prevent decomposition of the nanoparticles.
In organic chemistry and organometallic chemistry,carbon–hydrogen bond activation is a type of organic reaction in which a carbon–hydrogen bond is cleaved and replaced with a C−X bond. Some authors further restrict the term C–H activation to reactions in which a C–H bond,one that is typically considered to be "unreactive",interacts with a transition metal center M,resulting in its cleavage and the generation of an organometallic species with an M–C bond. The intermediate of this step could then undergo subsequent reactions with other reagents,either in situ or in a separate step,to produce the functionalized product.
The Max Planck Institute for Coal Research is an institute located in Mülheim an der Ruhr,Germany specializing in chemical research on catalysis. It is one of the 86 institutes in the Max Planck Society (Max-Planck-Gesellschaft). It was founded in 1912 in Mülheim an der Ruhr as the Kaiser Wilhelm Institute for Coal Research to study the chemistry and uses of coal,and became an independent Max Planck Institute in 1949.
Organochromium chemistry is a branch of organometallic chemistry that deals with organic compounds containing a chromium to carbon bond and their reactions. The field is of some relevance to organic synthesis. The relevant oxidation states for organochromium complexes encompass the entire range of possible oxidation states from –4 (d10) in Na4[Cr–IV(CO)4] to +6 (d0) in oxo-alkyl complexes like Cp*CrVI(=O)2Me.
Organocobalt chemistry is the chemistry of organometallic compounds containing a carbon to cobalt chemical bond. Organocobalt compounds are involved in several organic reactions and the important biomolecule vitamin B12 has a cobalt-carbon bond. Many organocobalt compounds exhibit useful catalytic properties,the preeminent example being dicobalt octacarbonyl.
Carbon nanotube supported catalyst is a novel supported catalyst,using carbon nanotubes as the support instead of the conventional alumina or silicon support. The exceptional physical properties of carbon nanotubes (CNTs) such as large specific surface areas,excellent electron conductivity incorporated with the good chemical inertness,and relatively high oxidation stability makes it a promising support material for heterogeneous catalysis.
A metal-phosphine complex is a coordination complex containing one or more phosphine ligands. Almost always,the phosphine is an organophosphine of the type R3P (R = alkyl,aryl). Metal phosphine complexes are useful in homogeneous catalysis. Prominent examples of metal phosphine complexes include Wilkinson's catalyst (Rh(PPh3)3Cl),Grubbs' catalyst,and tetrakis(triphenylphosphine)palladium(0).
Operando spectroscopy is an analytical methodology wherein the spectroscopic characterization of materials undergoing reaction is coupled simultaneously with measurement of catalytic activity and selectivity. The primary concern of this methodology is to establish structure-reactivity/selectivity relationships of catalysts and thereby yield information about mechanisms. Other uses include those in engineering improvements to existing catalytic materials and processes and in developing new ones.
Alfons Baiker is a Swiss Chemist specializing in Catalysis. Baiker studied chemistry at ETH Zurich. After obtaining his PhD in 1974 he followed several post-doctoral stays at various universities. In 1989 he became a full professor in catalysis and reaction engineering at ETH where he worked until his retirement in 2010.
Alexis Tarassov Bell is an American chemical engineer. He is currently the Dow professor of Sustainable Chemistry in the Department of Chemical and Biomolecular Engineering in UC Berkeley's college of chemistry. He is also the Faculty Senior Scientist at Lawrence Berkeley National Laboratory. He is known for his work with heterogenous catalysts and characterizing the mechanisms of these reactions on a quantum level.
Professor Günther Rupprechter is a distinguished Austrian scientist,full professor and currently Head of the Institute of Materials Chemistry,Technische Universität Wien. He is renowned for his contributions to the fields of physical chemistry,surface science,nanoscience and nanotechnology,particularly in the area of catalytic surface reactions on heterogeneous catalysts,identifying fundamental reaction steps at the atomic level by in situ and operando spectroscopy and microscopy.
