Abstract: A photo-catalyst containing titanium fluoride nitride comprising, Ti(IV)OaNbFc or a compound represented by MeTi(IV)OaNbFc prepared by doping at least one metal Me selected from the group consisting of alkali or alkaline earth metals on Ti(IV)OaNbFc. (wherein, b is 0.1 to 1, c is 0.1 to 1 and a is a value to maintain Ti(IV) and is decided in relation to b and c.). The photo-catalyst containing titanium fluoride nitride is especially characterized by loading at least one promoter selected from the group consisting of Pt, Ni and Pd.

Abstract: A carbonylation catalyst useful for producing esters and carboxylic acids in a vapor phase carbonylation process, wherein the catalyst includes a solid component having a catalytically effective amount of platinum and tin associated with a solid catalyst support material and a vaporous halide promoter component.

Abstract: This invention provides catalyst compositions that are useful for polymerizing at least one monomer to produce a polymer. This invention also provides catalyst compositions that are useful for polymerizing at least one monomer to produce a polymer, wherein said catalyst composition comprises contacting an organometal compound, an organoaluminum compound, and a solid, wherein said solid is selected from the group consisting of titanium tetrafluoride, zirconium tetrafluoride, and a treated solid oxide compound.

Abstract: A catalyst composition comprising an inorganic support material, a palladium component, a silver component, and a promotor component having the formula XYFn, wherein X is an alkaline metal, Y is an element selected from the group consisting of antimony, phosphorus, boron, aluminum, gallium, indium, thallium, and arsenic, and n is an integer which makes YFn a monovalent anion. The above-described catalyst is employed as a catalyst in the selective hydrogenation of acetylene. The above-described catalyst is made by incorporating a palladium component, a silver component, and a promotor component into an inorganic support material.

Abstract: A novel catalyst and the use thereof in a reforming process are disclosed. The catalyst comprises a refractory inorganic oxide, uniform platinum-group metal, uniform Group IVA (IUPAC 14) metal and surface-layer lanthanide-series metal. The catalyst is particularly suitable for the reforming of a hydrocarbon feedstock to obtain an aromatics-rich product.

Abstract: To provide a rust inhibitor which is a fired composition excellent in corrosion resisting properties almost as same as or even better than lead compounds and which is also good in stability of electrodeposition bath. The fired composition is a fired matter of a zinc compound and a tin compound, wherein zinc oxide Wz and tin oxide Ws are in the relation of Wz≧Ws in weight %. The ratio of the zinc oxide Wz and the tin oxide Ws is in the range of 99/1 to 70/30 in weight %, and preferably in the range of 95/5 to 85/15. Such a fired matter has not only a rust resisting function but also a curing catalyst function, so that such a curing catalyst as dibutyl tin oxide, which has heretofore been used, can be eliminated.

Abstract: An orthorhombic phase mixed metal oxide is produced selectively in quantitative yield.

Abstract: A multimetallic reforming catalyst and the preparation process thereof are disclosed. Said catalyst comprises the following components on the basis of mass percent: 0.01-2.0 of a Group VIII metal, 0.01-5.0 of a Group IVA metal, 0.01-10.0 of Eu, 0.01-10.0 of Ce, 0.10-10.0 of a halogen, and 63.00-99.86 of a refractory inorganic oxide. This catalyst has relatively high activity and selectivity, low carbon deposition rate and long lifetime for reformation of naphthas.

Abstract: The invention relates to a process for the preparation of an epoxidation catalyst, which process involves impregnating a silicon containing carrier with a gas stream consisting of titanium halide. The invention also relates to a process for the preparation of alkylene oxide using such catalyst.

Abstract: A process for the production of acetylopyridines of the formula (1): 1

Abstract: Hydrothermally synthesized catalysts comprising a mixed metal oxide are utilized to produce unsaturated carboxylic acids by the vapor phase oxidation of an alkane, or a mixture of an alkane and an alkene, in the presence thereof; or to produce unsaturated nitrites by the vapor phase oxidation of an alkane, or a mixture of an alkane and an alkene, and ammonia in the presence thereof.

Abstract: The invention concerns a homogeneous bed of particles of a catalyst, said catalyst comprising at least one amorphous matrix, at least one noble metal, at least one additional metal M and at least one halogen, and in which, for a catalyst particle,

Abstract: A mixed metal oxide, which may be an orthorhombic phase material, is improved as a catalyst for the production of unsaturated carboxylic acids, or unsaturated nitrites, from alkanes, or mixtures of alkanes and alkenes, by contact with a liquid contacting member selected from the group consisting of organic acids, alcohols, inorganic acids and hydrogen peroxide.

Abstract: A catalyst composition, suitable for polymerization of low-density and high-molecular weight polyolefin, comprising unsymmetrical unabridged metallocene compound and an aluminoxane is disclosed, wherein the metallocene compound and the aluminoxane are uniformly deposited on a porous support by using an oscillatory wave having the frequency of 20 to 500 kHz, and the activity of the catalyst composition increases when hydrogen is introduced in the polymerization of olefin.

Abstract: A novel catalyst for use in dehydrogenation of saturated hydrocarbons to unsaturated hydrocarbons and a method for its preparation is disclosed. Said catalyst comprises a composite incorporated within its spatial geometry on a percentage by weight basis, with a uniform concentration gradient, the following active elements: from 0.1 to 5.0% of a noble metal; from 0.1 to 5.0% of a metal of Group IV A; from 0.1 to 6.0% of a metal Group III A; from 0.1 to 10.0% of an alkali or alkaline earth metal element; from 0.01 to 10.0% of a halogen; and from 0.1 to 5.0% of a metal Group VIII selected from Fe, Co and Ni provided on a high surface area meso or macroporous support. The the high surface mesoporous support comprises a spheroidal gamma alumina support with a diameter of 1.4 to 2.0 mm, a surface area in the range of from 150 to 220 m2/g, with bimodal narrow pore size distribution, water adsorption capacity in the range of from 1.4 to 2.

Abstract: A process for producing a Ziegler-Natta catalyst, the process comprising reacting an organo magnesium compound with a halogenated compound to produce crystalline magnesium halide having an intense diffraction line in an x-ray spectrum thereof at lattice distance within the range of from 2.56 to 3.20 Angstroms and titanating the magnesium halide by mixing the magnesium halide with a titanium compound whereby the titanated magnesium halide hasp in an x-ray spectrum thereof, a halo appearing at a lattice distance within the range from 2.56 to 3.30 Angstroms.

Abstract: Supported metal halides and metal halide solid acids are used as catalysts for the polymerization of a feed stream containing at least one of pure monomer, C5 monomers, and C9 monomers to produce hydrocarbon resins. Freely-associated water may be removed from the solid acid catalyst prior to use. Resins with softening points (Ring and Ball) in the range of about 5° C. to 170° C. can be prepared. These catalysts offer advantages over the traditional Friedel-Crafts polymerization catalysts since the acid sites are an integral part of the solid. The solid acid catalysts are relatively nonhazardous, reusable catalysts which eliminate or at least reduce contamination of the resulting resin products with acid residues or by-products.

Abstract: A polyester having a good color tone, an excellent forming property and a high resistance to cohesion of foreign substance around a melt-spinning orifice when the polyester is melt-spun, is produced by polymerizing an aromatic difunctional carboxylic acid—alkyleneglycol ester and/or oligomer thereof in the presence of a catalyst including a reaction product of (A) a Ti compound component including a Ti compound (1) of formula (I) or a Ti compound (2) produced by reacting the Ti compound (1) with an aromatic difunctional carboxylic acid of the formula (III) or anhydride thereof, with (B) a P compound component selected from P compound (3) of the formula (III). [R1=C2-C10alkyl group; p=1-3, n=2-4, R2=substituted or unsubstituted C6-C20aryl or C1-C20 alkyl group, m=1 or 2, q=0 or 1, and m+q=1 or 2].

Abstract: This invention provides a process for producing a catalyst composition comprising contacting at least one group 4 metallocene, at least one organoaluminum compound, and at least one solid. The solid is selected from the group consisting of titanium tetrafluoride, zirconium tetrafluoride, and a treated solid oxide compound. The treated solid oxide compound comprises a solid oxide compound having titanium tetrafluoride or zirconium tetrafluoride deposited on the surface of the solid oxide compound. The solid oxide compound comprises oxygen and at least one element selected from the group consisting of groups 2-9 and 11-17 of the Periodic Table of Elements, including lanthanides and actinides. This invention also provides the catalyst composition produced by this process.

Abstract: A method and catalyst system for economically producing aromatic carbonates from aromatic hydroxy compounds is disclosed. In one embodiment, the present invention provides a method of carbonylating aromatic hydroxy compounds by contacting at least one aromatic hydroxy compound with oxygen and carbon monoxide in the presence of a carbonylation catalyst system that includes an effective amount of at least one Group 8, 9, or 10 metal source; an effective amount of at least one bromide composition; an effective amount of at least one activating organic solvent; an effective amount of a combination of inorganic co-catalysts comprising at least one titanium source and at least one copper source; and an effective amount of at least one base.

Abstract: A carbonylation catalyst useful for producing esters and carboxylic acids from reactants including lower alkyl alcohols, lower alkyl alcohol generating compounds, such as ether and ester derivatives of the alcohols, and mixtures thereof in a vapor phase carbonylation process. The catalyst includes a solid component having a catalytically effective amount of iridium and tin which are associated with a solid catalyst support material and a vaporous halide component.

Abstract: Applicants have developed a novel catalyst composition comprising a crystalline metal oxide having the empirical formula: AvBt+wNixD(Gu−)yOz, where A is an alkali metal (e.g. Na), B is a basic metal (e.g. Ca), D is a framework component (e.g. P), and G is an anionic species (e.g. OH−). Nickel may be present in the framework of the crystalline metal oxide, dispersed thereon, or both. Preferably, the metal oxide component has an apatite or hydroxyapatite crystal structure. These crystalline metal oxide components have been found to have improved performance in partial oxidation and light hydrocarbon (e.g. methane) reforming to produce synthesis gas. A new process for synthesizing these metal oxides is also disclosed.

Abstract: A carbonylation catalyst useful for producing esters and carboxylic acids from reactants including lower alkyl alcohols, lower alkyl alcohol generating compounds, such as ether and ester derivatives of the alcohols, and mixtures thereof in a vapor phase carbonylation process. The catalyst includes a solid component having a catalytically effective amount of iridium and tin which are associated with a solid catalyst support material and a vaporous halide component.

Abstract: Active fluoride catalysts that are useful in producing electrophilic fluorination agents; especially useful in producing BDM from the reaction of fluorine with carbon dioxide and FTM from the reaction of fluorine with carbonyl fluoride. The fluoride catalyst comprises a mixture of two or more fluorides selected from a transition metal fluoride, an alkali metal fluoride and/or an alkaline earth metal fluoride. Alternately, the fluoride catalyst is one or more fluorides, such as alkali metal fluorides, alkaline earth metal fluorides, and/or transition metal fluorides, deposited on an inert support.

Abstract: A carbonylation catalyst useful for producing esters and carboxylic acids from reactants including lower alkyl alcohols, lower alkyl alcohol generating compositions such as ether and ester derivatives of the alcohols, and mixtures thereof in a vapor phase carbonylation process, said catalyst includes a solid component having a catalytically effective amount of platinum and tin associated with a solid catalyst support material and a vaporous halide promoter component.

Abstract: A method and catalyst system for economically producing aromatic carbonates from aromatic hydroxy compounds. In one embodiment, the present invention provides a method of carbonylating aromatic hydroxy compounds by contacting at least one aromatic hydroxy compound with oxygen and carbon monoxide in the presence of a carbonylation catalyst system that includes a catalytic amount of an inorganic co-catalyst containing titanium. In various alternative embodiments, the carbonylation catalyst system can include an effective amount of a palladium source and an effective amount of a halide composition. Further alternative embodiments can include catalytic amounts of various inorganic co-catalyst combinations.

Abstract: The invention relates to a homogeneous bed of catalyst particles comprising at least one amorphous matrix, at least one noble metal, at least one additional metal M and at least one halogen, and in which, for a catalyst particle: CPt is the local concentration of noble metal; CM is the local concentration of additional metal M; Cx is the local concentration of halogen; in which catalyst particle bed the local dispersion of the value of CPt/CM or CPt/Cx is termed homogeneous along the diameter of the particle, which corresponds to at least 70% of the values CPt/CM or CPt/Cx deviating by a maximum of 30% from the local average ratio. The invention also relates to a process for transforming hydrocarbons into aromatic compounds with the catalyst, such as a gasoline reforming process and a process for producing aromatic compounds.

Abstract: This invention relates to transition metal catalyst component chelated by chelate ligand, a catalytic system comprising the transition metal catalyst component in the presence of magnesium halide, and a process for olefin polymerization using the catalytic system. The preparation of chelated transition metal catalyst component[A] are prepared by the unique synthetic method, in which Mg[AlR′(OR)3]2 reacts with chelate ligand to form Mg—Al-chelate ligand complex containing chelate ligand, and this complex reacts with metal halide compound to prepare chelated transition metal compound which is quite soluble in non-polar solvents. The olefin polymerization is performed using a catalytic system comprising the chelated transition metal catalyst component[A], MgCl2 support component[C], and an organoaluminum cocatalyst component[B].

Abstract: A novel catalyst and the use thereof in a reforming process is disclosed. The catalyst comprises a refractory inorganic oxide, platinum-group metal, Group IVA(IUPAC 14) metal, indium and lanthanide-series metal. Utilization of this catalyst in the conversion of hydrocarbons, especially in reforming, results in significantly improved selectivity to the desired gasoline or aromatics product.

Abstract: A process for the halogenation of activated methylene and methine compounds with at least equimolar amounts of an electrophilic halogenation reagent, which comprises reacting said activated methylene and methine compounds in the presence of catalytic amounts of a titanium compound of the formula I or of a titanium compound of the formula II R1TiX1X2X3  (I), R2R3TiX1X2  (II), in which R1 is chlorine, bromine or iodine, a substituted or unsubstituted cyclopentadienyl or indenyl, and X1, X2 and X3 are, independently of one another, chlorine, bromine or iodine, or X1, X2 and X3 are an organic sulfonate group where R1 is a substituted or unsubstituted cyclopentadienyl or indenyl; R2 and R3 are a substituted or unsubstituted cyclopentadienyl or indenyl, R2 and R3 together are a substituted or unsubstituted and bridged or unbridged biscyclopentadienyl or bisindenyl, or R2 and R3 together are a substituted or unsubstituted 1,3-, 1,4- or 1,5-diolate, and X1, and X2 are, independently of one

Abstract: A novel catalyst and the use thereof in a reforming process are disclosed. The catalyst comprises a refractory inorganic oxide, uniform platinum-group metal, uniform Group IVA (IUPAC 14) metal and surface-layer lanthanide-series metal. The catalyst is particularly suitable for the reforming of a hydrocarbon feedstock to obtain an aromatics-rich product.

Abstract: A process for the preparation of a catalyst is described, said catalyst comprising at least one inorganic refractory support, at least one halogen or halogenated compound at a content greater than 0.1% by weight, at least one metal from group VIII of the periodic classification (platinum, palladium, nickel and ruthenium) and at least one additional metal M selected from germanium, tin, lead, iron, titanium and chromium. The process is characterised in that said metal M is introduced in the form of at least one orqanometallic complex. The catalyst prepared in accordance with the invention may be used for dehydrogenation reactions, particularly of paraffinic hydrocarbons and olefinic hydrocarbons.

Abstract: A novel catalyst for use in dehydrogenation of saturated hydrocarbons to unsaturated hydrocarbons and a method for its preparation is disclosed.

Abstract: An aqueous titanium oxide-dispersed sol comprising titanium oxide particles dispersed in water, said sol comprising chloride ions in an amount of 50 to 10,000 ppm by weight as the chlorine element. Titanium tetrachloride is hydrolyzed to form an aqueous titanium oxide-dispersed sol and the chloride ion concentration thereof is controlled. Another aqueous titanium oxide-dispersed sol comprising brookite-type titanium oxide particles dispersed in water, said titanium oxide particles having an average particle size of not more than 0.5 &mgr;m and a specific surface area of not less than 20 m2/g. Addition of titanium tetrachloride to hot water at 75 to 100° C. followed by hydrolysis at 75° C. to the boiling point of the mixture.

Abstract: The invention features a photocatalytic body including: a porous medium 12 formed on a substrate 10; and photocatalytic material 14 supported on the porous medium. Supporting the photocatalytic material 14 on the porous medium 12 enables enhancement of its catalytic activity.

Abstract: Disclosed is a high activity solid catalyst for synthesizing low-, medium- and high-density polyethylenes by a slurry phase process, prepared by using commercial powered magnesium as raw material, forming a magnesium halide in the nascent state, followed by successively treating said magnesium halide with an alcohol compound and an alkyl aluminum compound, then reacting the resulting suspension of the spheroidal, porous solid complex carrier with a titanium compound in the presence of an electron donor compound an alkyl aluminum compound to obtain a main catalyst component and finally mixing the catalyst component with an organometallic compound as cocatalyst.

Abstract: Disclosed is a catalyst for synthesizing low-, medium- and high-density polyethylene, prepared by using commercial powdered magnesium as a raw material, forming a magnesium halide in the nascent state, then reacting said magnesium halide with a titanium compound and an alkyl aluminum compound in the presence of an electron donor compound to form a complex, supporting said complex onto silica carrier and drying the resulting mixture by heating to form a solid main catalyst component, and finally mixing said main catalyst component with an organometallic compound as cocatalyst. The catalyst according to the present invention is characterized by a simple preparing procedure, smooth and stable reaction, uniform heat liberation and less agglomerates when used for gas phase polymerizing ethylene, high polymerization activity, high sensitivity to the modification by hydrogen and high copolymerization power, and the products thus obtained have good product morphology.

Abstract: A process for producing high density polyethylene, the process comprising polymerising ethylene, or copolymerising ethylene and an alpha-olefinic comonomer comprising from 3 to 10 carbon atoms, in the presence of a catalyst system comprising first and second chromium-based catalysts, the first chromium-based catalyst having been reduced and reoxidised and the second chromium-based catalysts having been activated, fluoridised before or during the activation step, and reduced, the first and second chromium-based catalysts having a pore volume difference of at least 0.8 cc/g.

Abstract: In a process for preparing a catalyst comprising at least one support, at least one metal from group VIII of the periodic table and at least one additional element M selected from the group formed by germanium, tin, lead, rhenium, gallium, indium and thallium, metal M is introduced in an aqueous solvent in the form of at least one organometalic compound comprising at least one carbon-M bond.

Abstract: It is shown metallocenes with functionalized bridge of formula wherein M represents a transition metal of groups 3, 4, 5 or 6, L represents cyclopentadienyl-type ligands, Y represents a halogen and which can own one or various bridges between unities L. At least one of these bridges is functionalized through a group constituted by the union between a halogen atom and a silicon, germanium or tin atom. It is also shown a method for the synthesis of these metallocene compounds starting from the corresponding metallic halure and a precursor of the ligand which has leaving groups. These metallocene compounds are used as catalyst precursors for the homopolymerization and copolymerization of olefins. It is also shown methods for supporting these metallocenes on inorganic solids in order to obtain solid catalyst systems for olefins polymerization processes in a heterogeneous phase.

Abstract: This invention relates to a composition of matter represented by the formula below, and to a polymerization process comprising combining an olefin in the gas or slurry phase with an activator, a support and a compound represented by the following formula: wherein M is a group 3 to 14 metal, each X is independently an anionic leaving group, n is the oxidation state of M, m is the formal charge of the YZL ligand, Y is a group 15 element, Z is a group 15 element, L is a group 15 or 16 element, R1 and R2 are independently a C1 to C20 hydrocarbon group, a heteroatom containing group, silicon, germanium, tin, lead, phosphorus, a halogen, R1 and R2 may also be interconnected to each other, R3 is absent, or is hydrogen, a group 14 atom containing group, a halogen, a heteroatom containing group, R4 and R5 are independently an aryl group, a substituted aryl group, a cyclic alkyl group, a substituted cyclic alkyl group, or multiple ring system, R6 and R7 are independently absent or hydrogen

Abstract: The present invention provides catalysts and processes for the fluorination of hydrohalomethanes. In particular, the invention provides a process for the fluorination of hydrohalomethanes using hydrogen fluoride and a Lewis Acid catalyst. More specifically, catalysts and a process for the fluorination of dichloromethane are provided.

Abstract: This invention is for a process for the polymerization of propylene to a minimum level of xylene solubles by use of the molar ratio of co-catalyst to external electron donor (selectivity control agent). Using a conventional supported heterogeneous Ziegler-Natta catalyst component with an trialkyl aluminum co-catalyst and an cycloalkylalkyldialkoxysilane external electron nor (selectivity control agent) in a Al/Si molar ratio of about results in the minimum amount of xylene solubles.

Abstract: The invention relates to a catalyst comprising: a matrix consisting of 0 and 100% by weight of &lgr; transition alumina, the complement up to 100% by weight of the matrix being in &ggr; transition alumina, and relative to the total weight of the catalyst, from 0.001 to 2% by weight of silicon, from 0.1 to 15% by weight of at least one halogen chosen from the group formed by fluorine, chlorine, bromine and iodine, from 0.01 to 2% by weight of at least one noble metal from the platinum group, from 0.005 to 10% by weight of at least one promoter metal chosen from the group formed by tin, germanium, indium, gallium, thallium, antimony, lead, rhenium, manganese, chromium, molybdenum and tungsten, and if required from 0.001 to 10% by weight of a doping metal.

Abstract: A method and catalyst system for producing aromatic carbonates from aromatic hydroxy compounds. In one embodiment, the method includes the step of contacting at least one aromatic hydroxy compound with oxygen and carbon monoxide in the presence of a carbonylation catalyst system having catalytic amounts of the following components: a Group VIII B metal source; a combination of inorganic co-catalysts including a copper source and at least one of a titanium source or a zirconium source; an onium chloride composition; and a base. Alternative embodiments include inorganic co-catalyst combinations of a lead source and at least one of a titanium source or a manganese source.

Abstract: Fluorine contained within a photocatalyst layer containing titanium oxide and other metallic oxide semiconductors increases the metallic oxide's photocatalytic activity. The described photocatalyst may be in the form of either film, flake, particulate, or fiber. In addition, it can be used for coating the surface of a base material of various forms, such as sheet, film, flake, particulate, bar, or fiber. When using a base material that has an alkaline-containing glass composition, establishing a fluorine-containing layer, such as a layer of fluorine-containing silicon dioxide and other metallic oxide, between the photocatalyst film and the base material can prevent the deterioration of photocatalytic activity of the photocatalyst layer. The fluorine-containing layer functions as an alkaline barrier that controls the diffusion and migration of alkali metallic ions in the glass fibers, such as Na ions, into the photocatalyst layer.

Abstract: The invention relates to a process of activating a supported acid catalyst, and consists in the conversion of Lewis acid-type acid sites which are deposited on a solid substrate into activated acid sites in a non-oxydizing acid medium. The catalyst is exposed to a phase of activation in a medium containing a holohydric acid or a halohydric acid precursor, in the presence of at least one preferably parafinic hydrocarbon or hydrocarbon derivative, at a temperature greater than 20° and preferably between 100° C. and 250° C., and at a pressure of between 105 and 50,106 Pa, for a length of time sufficient to ensure conversion into activated acid sites.

Abstract: A catalyst composition suitable for the conversion of n-butane to butenes. The same catalyst composition that with chlorination is further suitable, when used in the conversion of n-butane, for the production of an increased amount of BTX (benzene-toluene-xylene) and greater selectivity to the production of isobutylenes than attained with the unchlorinated catalyst. A process for the preparation of catalyst compositions suitable for the conversion of n-butane. Use of the catalyst compositions in processes for the conversion of n-butane.

Abstract: The present invention relates to a new process for the preparation of a bimetallic ruthenium/tin catalyst. The process for the preparation of a bimetallic ruthenium/tin catalyst according to the invention is characterised by the fact that it consists in carrying out the reduction of a ruthenium complex having an electrovalency of −4 and a coordination number of 6, the ligands being either a halogen atom or an anion or a tin halide. The catalyst is further employed for the preparation of aldehydes by reduction, in the vapor phase, of carboxylic acids, esters and anhydrides.

Abstract: A supported catalyst and a process for the preparation of the catalyst, the catalyst containing mixed metal oxides or halides deposited on porous catalyst carriers or supports, useful for heterogeneously or solid catalyzed Friedel-Crafts reactions such as alkylation, aralkylation, acylation, or aroylation of aromatic compounds in the preparation of fine chemicals. The supported catalyst has high activity for the Friedel-Crafts reactions when the aromatic ring activating groups are present in the aromatic ring to be aralkylated, acylated or aroylated, and also when the ring activating group is absent or when aromatic ring deactivating groups are present in the aromatic ring to aralkylated, acylated or aroylated, so that the reaction temperature is low and/or the time for completing the reaction is short. The catalyst can be separated and used repeatedly for catalytic reactions.