Abstract: A process for the preparation of a catalyst from a catalytic precursor comprising a support based on alumina and/or silica-alumina and/or zeolite and comprising at least one element of group VIB and optionally at least one element of group VIII, by impregnation of said precursor with a solution of a C1-C4 dialkyl succinate. An impregnation step for impregnation of said precursor which is dried, calcined or regenerated, with at least one solution containing at least one carboxylic acid other than acetic acid, then maturing and drying at a temperature less than or equal to 200° C., optionally a heat treatment at a temperature lower than 350° C., followed by an impregnation step with a solution containing at least one C1-C4 dialkyl succinate followed by maturing and drying at a temperature less than 200° C. without subsequent calcination step. The catalyst is used in hydrotreatment and/or hydroconversion.

Abstract: Disclosed is a one pot process for the synthesis of ultra-small uniform-sized (1-3 nm) transition metal nanoparticles with shape tunability. These nanoparticles have uses in various fields, including catalysis and fuel cells.

Abstract: The precursor of a hydroprocessing catalyst is made by impregnating a metal oxide component comprising at least one metal from Group 6 of the Periodic Table and at least one metal from Groups 8-10 of the Periodic Table with an amide formed from a first organic compound containing at least one amine group, and a second organic compound containing at least one carboxylic acid group. Following impregnation heat treatment follows to form in situ generated unsaturation additional to that in the two organic compounds. The catalyst precursor is sulfided to form an active, sulfide hydroprocessing catalyst.

Abstract: Bulk catalysts that include a Group VI metal, a Group VIII metal, and at least 10-60% of an organic compound based component are formed. The bulk catalysts have increased stability through the use of a stabilizer in the organic compound based component, the use of an improved gas phase sulfidation, or a combination thereof. The bulk catalysts are suitable for hydroprocessing of hydrocarbon feeds.

Abstract: The present invention relates to a vehicular air cleaner. A DOR (Direct Ozone Reduction) system for suppressing deterioration of a purifying function of an ozone purifying material is provided. Active oxygen is produced by an ozone purifying function of activated carbon. The probability that the active oxygen contacts with a fin of a radiator on a rear surface side is higher than that on a front surface side of the radiator. Accordingly, the activated carbon on the rear surface side of the radiator is easily oxidized as compared with the activated carbon on the front surface side. Therefore, in the fin, a coating amount of the activated carbon on the front surface side of the radiator is adjusted to be larger than a coating amount of the activated carbon on the rear surface side. Thus, the probability that the active oxygen contacts with the activated carbon can be reduced.

Abstract: Provided are a solid catalyst for propylene polymerization and a method for preparing the same, specifically a solid catalyst for propylene polymerization which does not contain any environmentally harmful material and can produce a polypropylene having excellent stereoregularity with a high production yield, and a method for preparing the catalyst.

Abstract: A liquid catalyst for methanation of carbon dioxide, including an amphiphilic ionic liquid and a metal active component dispersed in the amphiphilic ionic liquid. The metal active component is dispersed in the amphiphilic ionic liquid in the form of stable colloid. The colloid is spherical and has a particle size of between 0.5 and 20 nm. The metal active component includes a first metal active component and a second metal active component. The first metal active component includes nickel. The second metal active component is selected from the group consisting of lanthanum, cerium, molybdenum, ruthenium, ytterbium, rhodium, palladium, platinum, potassium, magnesium, or a mixture thereof. The molar ratio of the first metal active component to the second metal active component is between 10:0.1 and 10:2.

Abstract: The purpose of the present invention is to provide a stable colloidal gold solution and a method for producing the stable colloidal gold solution. A colloidal gold solution which contains, in water, gold nanoparticles having particle diameters of 100 nm or less and anions represented by general formula (a); and a method for producing the colloidal gold solution. R—COO? (a) (In the formula, R represents a linear or branched alkyl group having 1-4 carbon atoms.

Abstract: The invention relates to a method of synthesis of substantially pure nanoparticles in a continuous-flow system, in which a precursor substance solution undergoes reduction reaction using a reducing agent solution and nanoparticles are produced, wherein the reduction reaction is terminated by adding an agent neutralizing the reducing agent and a stable nanoparticle colloid is produced. In the method of the invention a need for using surfactants or other organic molecules for nanoparticle stabilization has been eliminated.

Abstract: The invention relates to a process for producing a protected reduced supported metal catalyst powder, in particular catalysts used in a variety of chemical reactions, such as the hydrogenation of hydrocarbon compounds in petrochemical and oleo-chemical processes; the hydrogenation of unsaturated fats and oils, and unsaturated hydrocarbon resins; and in the Fischer Tropsch process. This invention also relates to a composition comprising said catalyst and a liquid. In accordance with the invention there is provided a process for preparing a protected, reduced metal catalyst on a support, wherein said supported catalyst is in the form of a powder, which process comprises contacting and mixing said supported catalyst with a liquid in an inert atmosphere and wherein the amount of liquid corresponds to up to five times the amount required for incipient wetness.

Abstract: The invention relates to a method for the preparation of composite silica alcogels, aerogels and xerogels, comprising i) providing a reaction mixture comprising at least the following: silane reagent, base catalyst, gelation retarding additive, aqueous/organic solvent mixture, guest particle, ii) agitating the reaction mixture as necessary and sufficient until achieving the viscosity where the spontaneous movement of the guest particles does not occur anymore; and iii) shaping the material obtained to a desired shape during or after step ii); then iv) drying, if desired The method according to the invention is also useful in continuous manufacturing technology, and the invention provides an apparatus for applying the method. The invention further provides novel composite silica alcogels, aerogels or xerogels obtainable by the method according to the invention.

Abstract: A catalyst unit suitable for loading into a tube in a reactor includes a plurality of catalyst particles incorporated within a removable solid matrix, said unit in the form of an elongate body in which the particles are packed together such that the volume shrinkage upon removal of the removable matrix is ?20%. The catalyst particles preferably comprise one or more metals selected from the group consisting of Fe and Co in oxidic or reduced form. The units are particularly suitable for loading catalyst into tubes in a Fischer-Tropsch reactor.

Abstract: The invention relates to the use of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene and its alkyl, aryl, or heteroatom substituted analogs, that act as catalysts in the presence of an alkali metal (Li, K, Na) for the reduction of electron-deficient and electron-rich triaryl phosphines to their corresponding alkali metal diaryl phosphide salts. The process is also useful for the catalysis of triaryl phosphine chalcogen adducts such as the sulfides, oxides, and selenides, diaryl(halo)phosphines, triaryl phosphine-borane adducts, and tetra-aryl bis(phosphines) that can also be reduced to their corresponding alkali metal diaryl phosphide salts. The invention also relates to small molecule PAHs and polymer tethered PAHs naphthenics.

Abstract: A composition that comprises a support material having incorporated therein a metal component and impregnated with both hydrocarbon oil and a polar additive. The composition that is impregnated with both hydrocarbon oil and polar additive is useful in the hydrotreating of hydrocarbon feedstocks, and it is especially useful in applications involving delayed feed introduction whereby the composition is first treated with hot hydrogen, and, optionally, with a sulfur compound, prior to contacting it with a hydrocarbon feedstock under hydrodesulfurization process conditions.

Abstract: Long-lived charge separation is attained with high efficiency by using a supramolecular complex utilizing pi-pi interaction. A supramolecular complex is formed by pi-pi interaction between extended viologen, the extended viologen having heteroaryls coupled together by a linking group with pi-electron conjugated system, and porphyrin. As a result of study of photoelectron transfer reaction, it has been found that within the supramolecular complex, efficient electron transfer occurs from the singlet excited state of porphyrin to the extended viologen, thereby obtaining a charge separation condition of extremely long lifetime exceeding 1 millisecond.

Abstract: Compositions, and methods of making thereof, comprising from about 1% to about 5% of a perfluorinated sulfonic acid ionomer or a hydrocarbon-based ionomer; and from about 95% to about 99% of a solvent, said solvent consisting essentially of a polyol; wherein said composition is substantially free of water and wherein said ionomer is uniformly dispersed in said solvent.

Abstract: The object of this invention is a suspension of metal nanoparticles with a mean size of between 1 and 20 nanometers, in at least one non-aqueous ionic liquid, whereby said suspension also contains at least one nitrogen-containing ligand, in which said metal nanoparticles comprise at least one transition metal in the zero valence state that is selected from among rhodium, ruthenium, iridium, nickel, and platinum by themselves or in a mixture and in which said nitrogen-containing ligand is selected from the group that is formed by the linear compounds that comprise at least one nitrogen atom, whereby the non-aromatic cyclic compounds comprise at least one nitrogen atom, the non-condensed aromatic compounds comprise at least one nitrogen atom, the condensed aromatic compounds comprise at least one group of two aromatic cycles that are condensed two by two, and at least one nitrogen atom, whereby the condensed aromatic compounds comprise at least 3 aromatic cycles and 1 nitrogen atom, and whereby the condensed ar

Abstract: The invention relates to a porous heterogeneous catalyst. In order to prepare a catalyst which catalyzes with a relatively high selectivity the hydrogenation of individual unsaturated bonds of polyunsaturated compounds it is proposed that the inner surface of the catalysts is coated with an ionic liquid.

Abstract: The invention relates to a process for producing a catalyst comprising a metal of the platinum group and a second metal selected from among the metals of the platinum group or the transition metals, in which a catalyst comprising the metal of the platinum group is mixed with a complex comprising the second metal to give a dry powder in a first step and the powder is subsequently heat treated to form a compound between the metal of the platinum group and the second metal. The invention further relates to the use of the catalyst produced according to the invention.

Abstract: A composition that comprises a support material having incorporated therein a metal component and impregnated with both hydrocarbon oil and a polar additive. The composition that is impregnated with both hydrocarbon oil and polar additive is useful in the hydrotreating of hydrocarbon feedstocks, and it is especially useful in applications involving delayed feed introduction whereby the composition is first treated with hot hydrogen, and, optionally, with a sulfur compound, prior to contacting it with a hydrocarbon feedstock under hydrodesulfurization process conditions.

Abstract: An ink composition for forming a fuel cell electrode includes a catalyst composition, a polymeric binder, a polymeric dispersant, and a solvent. The polymeric dispersant includes a perfluorocyclobutyl-containing polymer.

Abstract: Compositions, and methods of making thereof, comprising from about 1% to about 5% of a perfluorinated sulfonic acid ionomer or a hydrocarbon-based ionomer; and from about 95% to about 99% of a solvent, said solvent consisting essentially of a polyol; wherein said composition is substantially free of water and wherein said ionomer is uniformly dispersed in said solvent.

Abstract: The invention is directed to a process for the hydrogenation of unsaturated triglycerides in the presence of a supported precious metal catalyst and hydrogen, in which process a precious metal catalyst is used, comprising an aggregate of solid support, precious metal nano particles and surfactant or polymer.

Abstract: An improved slurry catalyst feed system for heavy oil upgraded is provided. The catalyst feed system comprises a fresh slurry catalyst and a deoiled spent catalyst, with the deoiled spent catalyst being present in an amount of at least 10% the catalyst feed system. The deoiled spent catalyst is a slurry catalyst that has been used in a hydroprocessing operation resulting in than 80% but more than 10% of original catalytic activity, and containing less than 10 wt. % soluble hydrocarbons as unconverted heavy oil feed. The deoiled spent catalyst is slurried in a hydrocarbon medium as dispersed particles prior to being fed to the heavy oil upgrade system.

Abstract: A composition having a substantial or material absence of or no phosphorous and comprising a support material, a metal compound and either a hydrocarbon oil or a polar additive or a combination of both a hydrocarbon oil and polar additive. The polar additive has particularly defined properties including having a dipole moment of at least 0.45. The composition is useful in the hydroprocessing of hydrocarbon feedstocks, and it is especially useful in the hydrotreating of vacuum gas oils and petroleum resid feedstocks.

Abstract: The invention pertains to a process for activating an hydrotreating catalyst comprising a Group VIB metal oxide and a Group VIII metal oxide which process comprises contacting the catalyst with an acid and an organic additive which has a boiling point in the range of 80-500° C. and a solubility in water of at least 5 grams per liter (20° C., atmospheric pressure), optionally followed by drying under such conditions that at least 50% of the additive is maintained in the catalyst. The hydrotreating catalyst may be a fresh hydrotreating catalyst or a used hydrotreating catalyst which has been regenerated.

Abstract: A solid titanium catalyst component (I) comprising titanium, magnesium, halogen, a specific cyclic ester compound (a) and a specific cyclic ester compound (b), an olefin polymerization catalyst containing this catalyst component (I), and an olefin polymerization process using this olefin polymerization catalyst are disclosed. According to the solid titanium catalyst component, the olefin polymerization catalyst and the process for preparing an olefin polymer of the invention, an olefin polymer having high stereoregularity and a wide molecular weight distribution can be prepared with high activity, preparation of an olefin polymer excellent not only in molding properties such as high-speed streatchability and high-speed moldability but also in rigidity becomes possible, and besides, production cost can be reduced.

Abstract: The invention relates to the use of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene and its alkyl, aryl, or heteroatom substituted analogs, that act as catalysts in the presence of an alkali metal (Li, K, Na) for the reduction of electron-deficient and electron-rich triaryl phosphines to their corresponding alkali metal diaryl phosphide salts. The process is also useful for the catalysis of triaryl phosphine chalcogen adducts such as the sulfides, oxides, and selenides, diaryl(halo)phosphines, triaryl phosphine-borane adducts, and tetra-aryl bis(phosphines) that can also be reduced to their corresponding alkali metal diaryl phosphide salts. The invention also relates to small molecule PAHs and polymer tethered PAHs naphthenics.

Abstract: The present invention discloses 1) a catalyst composition consisting of a crosslinked organic polymer compound and a palladium catalyst, wherein said catalyst is physically carried on said crosslinked organic polymer compound, 2) a manufacturing method of the above catalyst composition 1), characterized by homogenizing a straight chain organic polymer compound, having a crosslinkable functional group, and a palladium catalyst in a solvent dissolving said straight chain organic polymer compound, then depositing a composition thus formed and subjecting the crosslinkable functional group in said deposit to a crosslinking reaction, 3) a method for substitution reaction at an allyl position, characterized by reacting an allyl carbonate and a neucleophilic agent in the presence of the above catalyst composition 1), and 4) a method for oxidizing an alcohol, characterized by subjecting the above catalyst composition 1) to reaction with an alcohol.

Abstract: Multicomponent nanoparticles include two or more dissimilar components selected from different members of the group of noble metals, base transition metals, alkali earth metals, and rare earth metals and/or different groups of the periodic table of elements. The two or more dissimilar components are dispersed using a polyfunctional dispersing agent such that the multicomponent nanoparticles have a substantially uniform distribution of the two or more dissimilar components. The polyfunctional dispersing agent may include organic molecules, polymers, oligomers, or salts of these. The molecules of the dispersing agent bind to the dissimilar components to overcome same-component attraction, thereby allowing the dissimilar components to form multicomponent nanoparticles. Dissimilar components such as iron and platinum can be alloyed together using the dispersing agent to form substantially uniform multicomponent nanoparticles, which can be used alone or with a support.

Abstract: This invention relates to the preparations of noble metal catalysts, i.e., platinum and platinum alloys, on suitable supports with nanonetwork structures and high catalytic efficiencies. A compact structure of a monolayer or a few layers is formed by self-assembly of organic polymer, e.g., polystyrene (PS), nanospheres or inorganic, i.e., silicon dioxide (SiO2), nanospheres on a support surface. In the void spaces of such a compact arrangement, catalyst is formed by filling with catalyst metal ion-containing aqueous solution and reduced by chemical reduction, or formed by vacuum sputtering. When using organic polymer nanospheres as the starting or structure-directing material, the polymer particles are removed by burning at a high temperature and the catalyst having a nanonetwork structure is obtained.

Abstract: An electrocatalyst ink composition comprising a liquid vehicle, particles comprising at least one electrocatalyst metal, and at least one copolymer dispersant comprising at least one polyalkylene oxide segment.

Abstract: The present invention provides a method for producing a catalyst comprising the steps of: producing a metal salt solution containing salts of one or more metals; dispersing the metal salt solution, an organic matter and a porous carrier made of one or more metal oxides in a solvent to form a composite complex comprising one or more metal ions having 10 to 50,000 atoms, the organic matter bonded to the metal ions, and simultaneously make the composite complex carried on the porous carrier; and calcining the carrier having the composite complex carried thereon. The method may further comprise a step of reducing the metal ions on the porous carrier by reducing the carrier, after the step of making the composite complex carried on the carrier.

Abstract: Catalytic systems and methods for oxidizing materials in the presence of metal catalysts (preferably manganese-containing catalysts) complexed with selected macropolycyclic rigid ligands, preferably cross-bridged macropolycyclic ligands. Included are using these metal catalysts in such processes as: synthetic organic oxidation reactions such as oxidation of organic functional groups, hydrocarbons, and heteroatoms, including enantiomeric epoxidation of alkenes, enynes, sulfides to sulfones and the like; oxidation of oxidizable compounds (e.g., stains) on surfaces such as fabrics, dishes, countertops, dentures and the like; oxidation of oxidizable compounds in solution, dye transfer inhibition in the laundering of fabrics; and further in the bleaching of pulp and paper products.

Abstract: Naphtha is selectively hydrodesulfurized with retention of olefin content. More particularly, a CoMo metal hydrogenation component is loaded on a silica or modified silica support in the presence of an organic additive to produce a catalyst which is then used for hydrodesulfurizing naphtha while retaining olefins.

Abstract: Supported catalysts include an inorganic solid support such as silica that is functionalized to have inorganic acid functional groups attached thereto. The functionalization of the support material is optimized by (i) limiting the amount of water present during the functionalization reaction, (ii) using a concentrated mineral acid or derivative thereof, and/or (iii) increasing the reaction temperature and/or reaction pressure. The acid-functionalized support material serves as a support for a metal nanoparticle catalyst. The nanocatalyst particles are preferably bonded to the support material through an organic molecule, oligomer, or polymer having functional groups that can bind to both the nanocatalyst particles and to the support material. The supported catalysts can advantageously be used for the direct synthesis of hydrogen peroxide from hydrogen and oxygen feed streams.

Abstract: Disclosed are nanoparticles formed from a plurality of two or more different components. The two or more components are dispersed using a dispersing agent such that the nanoparticles have a substantially uniform distribution of the two or more components. The dispersing agents can be poly functional small organic molecules, polymers, or oligomers, or salts of these. The molecules of the dispersing agent bind to the particle atoms to overcome like-component attractions, thereby allowing different and/or dissimilar components to form heterogeneous nanoparticles. In one embodiment, dissimilar components such as iron and platinum are complexed using the dispersing agent to form substantially uniform heterogeneous nanoparticles. Methods are also disclosed for making the multicomponent nanoparticles. The methods include forming suspensions of two or more components complexed with the dispersing agent molecules. The suspensions can also be deposited on a support material and/or anchored to the support.

Abstract: A process for synthesis of a catalyst is provided. The process includes providing a carbon precursor material, oxidizing the carbon precursor material whereby an oxygen functional group is introduced into the carbon precursor material, and adding a nitrogen functional group into the oxidized carbon precursor material.

Abstract: A method of producing a composite carbon catalyst is generally disclosed. The method includes oxidizing a carbon precursor (e.g., carbon black). Optionally, nitrogen functional groups can be added to the oxidized carbon precursor. Then, the oxidized carbon precursor is refluxed with a non-platinum transitional metal precursor in a solution. Finally, the solution is pyrolyzed at a temperature of at least about 500° C.

Abstract: Supported metallic catalysts comprised of a Group VIII metal, a Group VIB metal, and an organic additive, and methods for synthesizing supported metallic catalysts are provided. The catalysts are prepared by a method wherein precursors of both metals are mixed and interacted with at least one organic additive, dried, calcined, and sulfided. The catalysts are used for hydroprocessing, particularly hydrodesulfurization and hydrodenitrogenation, of hydrocarbon feedstocks.

Abstract: Alkadienes may be telomerized in the presence of a heterogeneous catalyst comprising an alumina or titania support which is modified with one or more ionic complexes of Pd or Pt and activated at a temperature from 450° C. to 850° C. for a time not less than two hours. The resulting telomere may be useful in a number of applications.

Abstract: A Process for hydroconverting of a heavy hydrocarbonaceous feedstock comprising a catalyst to produce lower boiling hydrocarbon products. The method can be used for the high- boiling point residues of oil refining (asphaltene, the residues of vacuum and under pressure distillation of oil, and the useless and heavy materials of thermo catalytic processes), heavy oil, natural bitumen, and bitumen-containing sands. It can also be used in oil refinery industries for the production of gas, gasoline fractions, distillation gas oil, concentrate of ash containing metals and chemical fertilizers.

Abstract: A catalyst for the oxidation of an alkane to an oxygenated hydrocarbon in the presence of oxygen as a first oxidant, comprising a redox active metal centre that can be present in an oxidised and in a reduced form, an acid, a second oxidant for oxidising the reduced form of the redox active metal centre, and a source of nitrous oxide.

Abstract: The present invention relates to metallic catalysts containing nanoparticles of transition metals in particular of Co, Ru, Fe, Pd and Rh, disposed in pure ionic liquids or impregnated on supports that comprise zeolites, silicas, aluminas and oxides, forming catalytic systems, and to a method for preparation thereof.

Abstract: Reforming nanocatalysts are formed using a dispersing agent to increase the activity, selectivity and longevity of the catalyst when used in a reforming process. The nanocatalyst particles are formed using a dispersing agent having at least one functional group selected from the group of a hydroxyl, a carboxyl, a carbonyl, an amide, an amine, a thiol, a sulfonic acid, sulfonyl halide, an acyl halide, an organometallic complex, and combinations of these. The dispersing agent is particularly useful for forming multicomponent catalysts comprising an alloy, combination, mixture, decoration, or interspersion of platinum and one or more of tin, rhenium or iridium. The formation of the nanoparticles may include a heat treating process performed in an inert or oxidative environment to maintain the catalyst atoms in a non-zero oxidation state to thereby maintain a stronger bond between the dispersing agent and the catalyst atoms.

Abstract: Methods for manufacturing supported catalysts and the use of these catalysts in, e.g., the direct synthesis of hydrogen peroxide. The nanocatalyst particles are manufactured from catalyst atoms complexed with organic agent molecules (e.g., polyacrylic acid). The complexed catalyst atoms are heated to cause formation of the nanocatalyst particles. The temperature used to cause formation of the particles is typically greater than 30° C., preferably greater than 50° C, and more preferably greater than 70° C.

Abstract: Catalytic compositions for conversion of substituted aromatic feed materials to oxidized products comprising aromatic carboxylic acid derivatives of the substituted aromatic feed materials comprise a combination comprising a palladium component, an antimony component and/or a bismuth component, and one or more Group 4, 5, 6 or 14 metal or metalloid components. A process for oxidizing substituted aromatic feed materials comprises contacting the feed material with oxygen in the presence of such a catalytic composition in a liquid reaction mixture.

Abstract: A microencapsulated Group VIII metal catalyst which is stable even in air, easy to recover, and reusable is disclosed. It comprises a polymer with side chains containing an aromatic substituent, and a metal catalyst comprising a Group VIII metal encapsulated in to this polymer.

Abstract: The objective is to incarcerate a Lewis acid metal in a polymer and to make this catalyst recoverable while maintaining its function as a Lewis acid metal catalyst. The present invention is a polymer-incarcerated Lewis acid metal catalyst in which a Lewis acid metal is incarcerated in a crosslinked polymer and the crosslinked polymer is crosslinked using the crosslinking groups contained in a crosslinkable polymer. The polymer incarcerated Lewis acid metal catalyst is characterized by the crosslinkable polymer containing at least one type of monomer unit containing hydrophobic substituents and hydrophilic substituents containing crosslinking groups, and the hydrophobic substituents contain aromatic substituents. This crosslinkable polymer preferably comprises at least one type of monomer unit containing hydrophobic substituents and hydrophilic substituents containing crosslinking groups and a monomer unit containing hydrophobic substituents.

Abstract: A catalyst manufacturing process includes heat treating an intermediate catalyst composition that includes catalyst nanoparticles having catalyst atoms in a non-zero oxidation state bonded to a dispersing/anchoring agent. The catalyst nanoparticles are formed using a dispersing agent having at least one functional group selected from the group of a hydroxyl, a carboxyl, a carbonyl, an amide, an amine, a thiol, a sulfonic acid, sulfonyl halide, an acyl halide, an organometallic complex, and combinations of these. The dispersing agent can be used to form single- or multicomponent supported nanocatalysts. The dispersing agent also acts as an anchoring agent to firmly bond the nanocatalyst to a support. Performing the heat treating process in an inert or oxidative environment to maintain the catalyst atoms in a non-zero oxidation helps maintains a stronger bonding interaction between the dispersing agent and the catalyst atoms.