Abstract: Catalysts deposited on a support are described. The catalyst itself is formed by combining (i) a metallocene of a transition, lanthanide or actinide metal and (ii) a siloxy-aluminoxane composition which comprises an aluminoxane which contains hydrocarbyl-siloxane moieties which are free of Si-OH groups, wherein the molar ratio of aluminum to hydrocarbylsiloxane is from about 1:1 to 1000:1. The siloxy-aluminoxane composition used is free of Si-OH groups, and the aluminoxane of the siloxy-aluminoxane composition was formed by partial hydrolysis of trialkylaluminum. Supports for the catalysts are particulate inorganic oxides, preferably silica, alumina, silica-alumina, or a mixture thereof, or resinous polyolefin support materials.

Abstract: The present invention provides a methanol reforming catalyst having the following general formula on a dry basis:X.sub.a Y.sub.b Z.sub.c O.sub.d, whereinX is a metal selected from the group consisting of zinc, cadmium, mercury, rubidium, cesium, silver, and combinations thereof, Y is a metal selected from the group consisting of beryllium, magnesium, calcium, strontium, barium, and combinations thereof, Z is a material selected from the group consisting of boron, silicon, aluminum, silicoaluminate, zirconium, titanium, hafnium, gallium, lanthanum, scandium, and yttrium, and combinations thereof, and O is the element of oxygen. The claimed methanol reforming catalyst contains neither copper oxide nor chromium oxide.

Abstract: A catalyst system comprising a nitrided silicoaluminophosphate, and a method of preparing such catalyst system which comprises nitriding a silicoaluminophosphate, are disclosed. The thus-obtained catalyst system is employed as a catalyst in the conversion of a hydrocarbon feedstock comprising oxygenated hydrocarbons to olefins.

Abstract: A catalyst system comprising a silylated silicoaluminophosphate composition, and methods of preparing such catalyst system, are disclosed. The thus-obtained catalyst system is employed as a catalyst in the conversion of a hydrocarbon feedstock comprising oxygenated hydrocarbons to olefins.

Abstract: The invention concerns a hydrotreated catalyst comprising a support, at least one group VI metal, silicon, boron, optionally at least one metal from group VIII of the periodic table, optionally phosphorus, and optionally a halogen, also a particular preparation of this catalyst. The invention also concerns the use of the catalyst for hydrotreating hydrocarbon feeds.

Abstract: A composition comprises silicon, aluminum, zirconium, and boron. A process for producing the composition comprises contacting a silicon compound, an aluminum compound, a zirconium compound, and a boron compound under a condition sufficient to effect the production of a composition comprising silicon, aluminum, zirconium, and boron. Also disclosed is a process for catalytically cracking a hydrocarbon-containing fluid which comprises contacting said hydrocarbon-containing fluid with a catalyst composition which comprises silicon, aluminum, zirconium, and boron.

Abstract: A method is provided for making a platinum hydrosilylation catalyst by equilibrating a mixture of an alkenylpolysiloxane and a cycloalkylpolysiloxane in the presence of a haloplatinic acid and thereafter treating the resulting equilibrate with a base. Improved rate of cure and a reduction in ppm levels of platinum required to effect hydrosilylation are achieved.

Abstract: A process is provided for the production of a catalyst useful for removing nitrogen oxides out of exhaust gases from internal combustion engines operated under lean burn conditions. The catalyst is produced by supporting at least one catalytic metal, such as platinum, iridium, rhodium, other transition metals and alkaline earth metals, as the active component on a support, such as a zeolite, by either wash-coating a solution of the catalytic metal components onto the support; evaporating off solvent from a mixture of solvent, catalyst material and support, or rapidly drying droplets of support and catalyst material containing slurry with a hot gas. The supported catalyst is activated by heating to a temperature of 150 to 300.degree. C. for a period of time sufficient to desorb catalytic material components, such as water, chlorine and ammonia, out of the pores of the catalyst that adversely affect the activity and heat resistance of the catalyst.

Abstract: A process of modifying the porosity of an aluminosilicate or silica whose porosity is not amenable to modification by acid extraction. The process involves contacting said aluminosilicate or silica with an alkali aluminate, and then extracting the aluminate-treated material with an extraction agent so as to form the porosity-modified aluminosilicate or silica. The process is applicable to zeolites which are unreactive under acid extraction conditions, e.g. ferrierite, and applicable to zeolites which are structurally unstable under acid extraction conditions, such as the mineral bikitaite. Mesoporous compositions are disclosed, including a mesoporous ferrierite and a mesoporous zeolite DCM-3.

Abstract: In a process for preparing N-alkenylcarboxamides by dehydration of N-(2-hydroxyalkyl)carboxamides and/or diethers thereof in the presence of a catalyst, molecular sieves, in particular zeolites, are used as catalyst.

Abstract: Provided is a mesopore material and the manufacturing method thereof characterized by having uniform diameter of each pore as well as a high crystallographic regularity, comprising primary particles having a small axe with uniformity, allowing for synthesizing the primary particles with the size freely controlled, and allowing for simple manufacturing at a reduced cost. The mesopore material comprising: pores having a diameter in a range of 2 to 10 nm; and a primary particle having a major axe in a range of 10 nm to 1 .mu.m. The diameter range is defined at a maximum peak in a pore distribution curve, and 75% or more of the pores is in a diameter range of -40% to +40% of the pore diameter at the maximum peak. Further provided is a laminar silicic acid composed of the uninvertible tetrahedral sheet and has a uniform shape and size. Also provided is a laminar silicic acid salt composed of the uninvertible tetrahedral sheet and has a uniform shape and size.

Abstract: A coating composition which is excellent in water resistance, weatherability and durability and can maintain its appearance for a prolonged period of time can be provided. A coating composition comprising a coating component and a photocatalyst containing calcium phosphate and titanium oxide is disclosed. As the photocatalyst, use is made of titanium oxide particles partially covered thereon with calcium phosphate, or porous body coated thereon with a film of titanium oxide, the film of titanium oxide being further covered partially thereon with calcium phosphate. The crystal form of titanium oxide is preferably anatase. The organic coating includes vinyl-type synthetic resin emulsions, and the inorganic coating is e.g. a solution containing a metal alkoxide for forming a film by a sol-gel method.

Abstract: This invention relates to a hydrotreating catalyst for a hydrocarbon oil and also to a process for hydrotreating the hydrocarbon oil by using the catalyst. More specifically, the present invention is concerned with a hydrotreating catalyst formed by having a hydrogenation-active component supported on a silica-alumina carrier and having a specific pore distribution and also with a hydrotreating process making use of the catalyst for the removal of sulfur compounds and nitrogen compounds from a hydrocarbon oil.

Abstract: Monomodal or polymodal catalyst supports or catalysts having a BET specific surface area of from 0.01 to 250 m.sup.2 /g and a monomodal or polymodal pore size distribution having a mean pore diameter of from 50 to 300,000 nm measured by the mercury pressure porosimetry method, whereina) from 10 to 95% of the pore volume is at from 0.1 to 3 times the mean pore diameter and/orb) from 10 to 80% of the pore volume is at from 0.4 to 3 times the mean pore diameter and/orc) from 50 to 95% of the pore volume is at from 0.1 to 1 times the mean pore diameter and/ord) from 50 to 80% of the pore volume is at from 0.4 to 1 times the mean pore diameter ande) the width at half height of the pore size distribution is less than 0.

Abstract: Monomodal or polymodal catalyst supports or catalysts having a BET specific surface area of from 0.01 to 250 m.sup.2 /g and a monomodal or polymodal pore size distribution having a mean pore diameter of from 50 to 300,000 nm measured by the mercury pressure porosimetry method, whereina) from 10 to 95% of the pore volume is at from 0.2 to 100 times the mean pore diameter and/orb) from 10 to 80% of the pore volume is at from 0.8 to 100 times the mean pore diameter and/orc) from 50 to 95% of the pore volume is at from 0.2 to 1 times the mean pore diameter and/ord) from 50 to 80% of the pore volume is at from 0.8 to 1 times the mean pore diameter ande) the width at half height of the pore size distribution is less than 0.

Abstract: A method for fluorinating molecular sieve catalysts to increase selectivity to ethylene during conversion of oxygenates to olefins, fluorinated catalysts produced by such method, and methods of using the fluorinated molecular sieve catalysts to increase selectivity to ethylene during conversion of oxygenates to olefins.

Abstract: Process for the manufacture of a support for olefin polymerization catalysts comprising silica, aluminium phosphate and optionally alumina, according to which a source of silica, chosen from alkaline aqueous silica sols and alkaline aqueous solutions of inorganic silicate, is added, in a first step, to an aqueous solution of a source of phosphate ions which has a pH of less than 5, the pH of the medium being maintained below 5 throughout the first step, an aluminium compound is added, in a second step, to the medium obtained from the first step and a precipitate is formed, in a third step, by adding a precipitation agent to the medium obtained from the second step, the pH of the precipitation medium being maintained above or equal to 5.

Abstract: The invention concerns a catalyst comprising a porous organic or inorganic support and at least one active phase comprising at least one acid selected from acids with formula R--SO.sub.3 H, where R is fluorine or an alkyl group or a fluorinated alkyl group, and at least one weakly basic aprotic organic solvent, the support having been impregnated with the active phase, the catalyst being such that it is essentially constituted by particles with an average diameter in the range 0.1 .mu.m to 150 .mu.m, and being such that before impregnation with the active phase, the support has a total pore volume in the range 0.5 cm.sup.3 /g to 6 cm.sup.3 /g. The invention also concerns the use of the catalyst for aliphatic alkylation.

Abstract: A transition metal containing catalyst having a silica-support is provided for the production of polyolefins from .alpha.-olefins that can be converted to polymer films, preferably thin films of polyolefin, which have lower defects resulting from a decreased presence of silica-containing residues from the catalyst. The catalyst has a porous silica support component and a catalytic component which may include, but is not limited to, such materials as chromium, magnesium-titanium (Ziegler-Natta type) or metallocene compounds (Metallocene catalyst type). The porous silica component of the catalyst has an average pore volume of from about 2.5 to about 3.5 ml/g and a surface area of 200 to 400 m.sup.2 /g and preferably 250 to 350 m.sup.2 /g. The average pore diameter ranges from about 285 to about 700 Angstroms and preferably 500-700 Angstroms for porous silica components having surface areas of 200 m.sup.2 /g and preferably 285-400 Angstroms for porous silica components having surface areas of 350 m.sup.2 /g.

Abstract: Chiral stationary phases perform well when the underlying support for the chiral organic material is coated onto a silica pore widened by a hydrothermal treatment. The resulting silica is amorphous with a unimodal distribution of large pores. A variety of chiral stationary phases perform well and are distinguished, inter alia, by the treatment, if any, prior to coating the chiral organic material.

Abstract: Processes for the living polymerization of olefin monomers with terminal carbon-carbon double bonds are disclosed. The processes employ initiators that include a metal atom and a ligand having two group 15 atoms and a group 16 atom or three group 15 atoms. The ligand is bonded to the metal atom through two anionic or covalent bonds and a dative bond. The initiators are particularly stable under reaction conditions in the absence of olefin monomer. The processes provide polymers having low polydispersities, especially block copolymers having low polydispersities. It is an additional advantage of these processes that, during block copolymer synthesis, a relatively small amount of homopolymer is formed.

Abstract: Rhenium oxide catalysts carried on aluminium silicates, if required with added boric oxide, tungsten oxide, molybdenum oxide or vanadium oxide for the metathesis of olefins and functionalised olefins, in particular of carboxylic acid esters, are provided, whereby the carrier material was hydrothermally treated.

Abstract: Compacts produced from a pyrogenically produced oxide, magnesium stearate, methyl cellulose and urea are mixed together in the presence of water, compacted, dried, comminuted to a powder, and the powder is pressed with an isostatic press to compacts and the compacts tempered. The resulting compacts have an outside diameter of 16 to 100 mm.

Abstract: The invention relates to cobalt carbonyl catalysts of the formula (I) ##STR1## where R is --CH(CH.sub.2 OCH.sub.2 CH.sub.3).sub.2 or --C.sub.2 H.sub.4 (OCH.sub.2 CH.sub.2).sub.n OY, with n=1 to 12 and Y=H or CH.sub.3, and also a process for their preparation and their use as hydroformylation catalysts.

Abstract: Catalyst for controlling emissions of the present invention is comprised of at least one kind of transition metal atoms and at least one of Al or Si, wherein said transition metal atoms form a part of the surface of the catalyst for purifying exhaust gas. Accordingly, the catalyst for purifying exhaust gas has both high performance for purifying NO.sub.x and high heat resistance, because monoatomic active metal disperses in the catalyst structure, active metal is taken firmly in the structure, and said transition metal forms a part of the surface of the surface.

Abstract: This invention relates to new crystalline organic compositions having unique combinations of framework-confined uniform mesopores and textural mesopores and to a method for their preparation. The compositions typically possess a framework wall thickness of at least about 17 .ANG., small elementary particle size of less than about 400 .ANG., and ratio of textural to framework-confined mesoporosity of greater than about 0.2. The formation of the mesoporous structure is accomplished by a novel self-assembly mechanism involving hydrogen bonding between neutral amine surfactant (S.degree.) and neutral inorganic oxide precursor (I.degree.). This S.degree.I.degree. templating approach allows for facile and environmentally benign recycling of the cost-intensive template by simple solvent extraction methods.

Abstract: A platinum catalyst containing (A) a platinum complex having a vinyl-containing organosiloxane ligand and (B) a vinyl-containing organopolysiloxane is prepared by mixing components (A) and (B) such that at least 2 mol of vinyl group in component (B) is available per mol of platinum atom in component (A) and heating the mixture at 40.degree.-100.degree. C. for at least 1 hour. When blended in an addition reaction curing type organosiloxane composition, the platinum catalyst has the advantage that even after long-term storage at elevated temperatures, it remains stable and active enough to cause the organosiloxane composition to cure.

Abstract: The present invention provides new catalyst formats which comprise a supported catalyst tethered to a second and different catalyst by a suitable tethering ligand. A preferred system comprises a heterogeneous supported metal catalyst tethered to a homogeneous catalyst. This combination of homogeneous and heterogeneous catalysts has a sufficient lifetime and unusually high catalytic activity in arene hydrogenations, and potentially many other reactions as well, including, but not limited to hydroformylation, hydrosilation, olefin oxidation, isomerization, hydrocyanation, olefin metathesis, olefin polymerization, carbonylation, enantioselective catalysis and photoduplication. These catalysts are easily separated from the products, and can be reused repeatedly, making these systems very economical.

Abstract: This invention relates to new crystalline organic compositions having unique combinations of framework-confined uniform mesopores and textural mesopores and to a method for their preparation. The compositions typically possess a framework wall thickness of at least about 17.ANG., small elementary particle size of less than about 400.ANG., and ratio of textural to framework-confined mesoporosity of greater than about 0.2. The formation of the mesoporous structure is accomplished by a novel self-assembly mechanism involving hydrogen bonding between neutral amine surfactant (S.degree.) and neutral inorganic oxide precursor (I.degree.). This S.degree.I.degree. templating approach allows for facile and environmentally benign recycling of the cost-intensive template by simple solvent extraction methods.

Abstract: The present invention relates to a transesterification process for producing thermoplastic polycarbonates with the use of fixed bed catalysts.

Abstract: A statistically large population of particles of amorphous precipitated silica comprising pigmentary phase particles and glassy phase particles and having a glassy phase fraction in the range of from 0.3 to 30 area percent is useful as an abrasive for dentifrice compositions, especially toothpaste.

Abstract: Disclosed is a supported catalyst which is the reaction product of(a) a silylamine polymer having the general formula ##STR1## where each R is independently selected from alkyl from C.sub.1 to C.sub.6 or aryl from C.sub.6 to C.sub.10, R.sub.1 is a divalent aliphatic or aromatic group from C.sub.2 to C.sub.20, "m" is 1 to about 100, and "n" is 2 to about 500, with(b) an organometallic compound having the general formulaQ--M--(X).sub.3where Q is a stabilizing ligand, each X is independently selected from halogen, alkyl from C.sub.1 to C.sub.6, or dialkylamino from C.sub.1 to C.sub.6, M is zirconium, titanium, or hafnium and M is bonded to a nitrogen in said silylamine polymer, and the ratio nitrogens bondable to M in said silylamine polymer to M atoms is 1:1 to 3:1.

Abstract: Cycloolefin polymers having a high viscosity number are obtained by polymerization of a polycyclic olefin and, if desired, an acyclic olefin and/or a monocyclic olefin in the presence of a catalyst system which comprises an aluminoxane and a metallocene compound of the formula ##STR1## in which R.sup.16 is fluorenyl or indenyl and R.sup.17 is cyclopentadienyl and the bridge R.sup.18 contains silicon.

Abstract: The present invention concerns a catalyst comprising a porous organic or mineral support, preferably silica, and an acidic phase containing B(OSO.sub.2 CF.sub.3).sub.3 and at least one acid selected from the group formed by sulphuric acid (H.sub.2 SO.sub.4) and trifluoromethane sulphonic acid (CF.sub.3 SO.sub.3 H), the support having been impregnated by said acidic phase, said catalyst being such that it is constituted essentially by particles with an average diameter of between 0.1 and 150 .mu.m, such that the support, prior to its impregnation with said acidic phase, has a total pore volume of between 0.5 and 6 cm.sup.3 per gram and said catalyst being characterized in that said acidic phase contains:between 0.1 and 70% by weight of B(OSO.sub.2 CF.sub.3).sub.3 ;between 0 and 90% by weight of H.sub.2 SO.sub.4 ;between 0 and 90% by weight of CF.sub.3 SO.sub.3 H.

Abstract: Siloxy-aluminoxane compositions which are the reaction products of hydrocarbylsiloxanes substantially-free of Si--OH groups, and aluminoxanes and which have improved solubility and stability in solution even at up to 60 weight percent when compared to the original aluminoxane. The compositions in combination with metallocenes of transition lanithanide and actinide metals form catalysts which can be used in the polymerization of olefins such as ethylene.

Abstract: A process of producing supported olefin polymerization catalysts in which the support is a porous silica material containing specified amounts of alkali and alkaline metal cations, and olefin polymerization catalysts produced thereby.

Abstract: Process for the production of a microspheroidal powder of low dispersity, according to which a hydrogel is prepared, an aqueous suspension of the ground hydrogel is subjected to atomisation in a stream of gas, gelled particles containing moisture are collected from the atomisation, the particles are brought into contact with an organic liquid in order to remove at least some of the moisture and the particles are then subjected to drying.The process applies to the production of silica powders intended to serve as support for chromium oxide catalysts which may contain titanium oxide and are suitable for the polymerisation of ethylene.

Abstract: This invention relates to a novel catalyst composition comprising a heteropolyacid and a siliceous support which is in the form of extrudates or pellets and to a process for hydrating olefins to the corresponding alcohols in the vapour phase in the presence of such a catalyst composition. By using the specific catalyst composition described herein it is possible not only to increase the space-time-yield of a process but also to prolong the life thereof thereby reducing the frequency with which the catalyst is changed or replaced on a plant, especially in an olefin hydration process.

Abstract: A fixed-bed catalyst is used for treating waste plastics to produce hydrocarbon fractions, gasoline and diesel oil. The catalyst comprises a silica carrier and active components having the formula of A.sub.a B.sub.b Al.sub.c M.sub.d Na.sub.e Ca.sub.f Fe.sub.g O.sub.x. In the formula, A represents potassium, barium, phosphorus, vanadium, chromium, rare earth elements or their mixture. B represents elements of tungsten, molybdenum, nickel, germanium and platinum series. This catalyst has very high selectivity and activity and can be used for reaction at a relatively low temperature, thereby reducing energy consumption, and ensuring good yield of product. The mixed hydrocarbons generated by catalytic reaction using this catalyst may comprise more than 30 percent of aromatics and cyclanes in content.

Abstract: The present invention is directed to a process for the carbonylation of an arylene to an arylaldehyde (e.g., toluene to tolualdehyde) in the presence of a solid acid catalyst. The process for making tolualdehyde comprises carbonylating toluene in the presence of either carbon monoxide or a source of carbon monoxide and in contact with a solid acid catalyst. The reaction is carried out at a temperature ranging from -40.degree. to 200.degree. C., and at a pressure ranging from 20-4000 psig.

Abstract: Provided is a novel polysaccharide derivative having a main structure of the following formula (1) in which a polysaccharide or its derivative has been chemically bonded to the inner and outer surfaces of the pores of a porous carrier at the reducing terminal of the polysaccharide or polysaccharide derivative: ##STR1## Also provided are a method of producing the novel polysaccharide derivative in which a silane agent is chemically bonded to a porous carrier and thereafter a polysaccharide having a degree of polymerization from 11 to 500 or its derivative is further chemically bonded to surface treated carrier at the reducing terminal of the polysaccharide or its derivative, and a method of producing the novel polysaccharide derivative in which a polysaccharide having a degree of polymerization from 11 to 500 or its derivative is chemically bonded to a silane agent at the reducing terminal of the polysaccharide or its derivative and thereafter the polysaccharide derivative is further chemically bonded to a por

Abstract: A catalyst support includes substantially spherical particles of a substantially homogeneous mixture of at least two compounds selected from the group consisting of refractory inorganic oxides, refractory inorganic carbides, refractory inorganic nitrides and mixtures thereof, wherein said particles have a surface area of at least about 30 m.sup.2 /g, an average pore diameter of at least about 150 .ANG., and a particle size of at least about 0.1 mm. The support may be used in a catalyst system to support a Group IVb and a Group VIII metal in a catalyst system useful for hydrogenation of carbon monoxide into C.sub.2 + hydrocarbons. A method is also provided for preparing the catalyst support and system.

Abstract: Crystalline silicate compositions having unique combinations of framework-confined uniform mesopores and textural mesopores and to a method for their preparation. The compositions typically possess a small particle size of .ltoreq.400 .ANG., a ratio of textural to framework-confined mesoporosity of 0.2 or greater, and a novel ability to discriminate, to adsorb, and with a metal element in the mesopores, to catalytically transform large organic molecules. The method for the formation of the mesoporous structure is accomplished by hydrogen bonding between a non-ionic amine template and a non-ionic inorganic oxide precursor followed by hydrolysis and crosslinking under mild reaction conditions. The templated products of this invention are preferably obtained using water as a hydrolyzing reagent and an alcohol as a co-solvent. The framework-confined uniform mesopore size can be expanded without the use of an auxiliary organic (pore expanding agent).

Abstract: In the present invention, a class of catalysts is described, to be used in the polycondensation stage in the synthesis of poly(ethylene terephthalate), constituted by a composition of metal derivatives in quantity so that the content of these in the final polymer is below 130 ppm.

Abstract: In order to provide a temperature- and acid-resistant catalyst carrier based on a gas-pervious carrier body and a porous surface layer having a high silica content, while dispensing with a washcoat, the carrier body and the surface layer are designed as a chemically and physically homogeneous structure shaped in a single operation. The SiO.sub.2 content amounts to at least 99% by weight and has a specific surface from 5 m.sup.2 /g to 50 m.sup.2 /g. In a process for producing a catalyst carrier made of synthetic, amorphous silica particles with more than 99% by weight SiO.sub.2, a paste is prepared with the particles, a liquid, and a binder. Plastifying agents are added to the paste and the paste is continuously extruded into a monolithic greenware strand. The alkali and alkaline earth content of the paste is set at no more than 200 ppm and the greenware is cut to length and sintered at a temperature in a range between 800.degree. C. and 1400.degree. C.

Abstract: A supported Lewis acid catalyst system for catalyzing hydrocarbon conversion reactions including cationic polymerization, alkylation, isomerization and cracking reactions is disclosed, wherein the catalyst system comprises an inorganic oxide support having immobilized thereon a least one strong Lewis acid comprising at least one metal salt of a strong Bronsted acid wherein the metal is selected from the group consisting of aluminum, boron gallium, antimony, tantalum, niobium, yttrium, cobalt, nickel, iron, tin, zinc, magnesium barium strontium, calcium, tungsten, molybdenum and the metals of the lanthanide series and wherein the strong Bronsted acid is selected from the group consisting of mineral and organic acids stronger than 100% sulfuric acid.

Abstract: A process for producing a heat-resistant and high-purity porous silicon oxide material having excellent crystallinity and uniformity in pore size. The process includes: a first step of dispersing a substance containing silicon in an aqueous solution of a surfactant and adjusting the pH of the dispersion to a value of 10 or higher; a second step of adjusting the pH thereof to a value lower than 10 and forming a composite of a silicon oxide and a surfactant; and a third step of removing the surfactant from the composite. A water-soluble component is preferably removed from the dispersion between the first and second steps.

Abstract: Dehydroxylated oxide (e.g. silica) particles are obtained by reacting oxide particles, having surface hydroxyl groups, with a dialkylcarbonate or diarylcarbonate. The resulting products have surface alkoxy or aryloxy groups and significantly reduced hydroxyl content. The treated oxide particles are especially suitable for use as catalyst supports, and especially as polyolefin catalyst supports.

Abstract: A process for the alkylation of aliphatic hydrocarbons with olefins catalyzed by a silica-based material, characterised in that the surface Si--OH groups of said silica are esterified with a fluoroalkylsulphonic acid of formula CF.sub.3 (CF.sub.2).sub.n SO.sub.3 H, where n is a whole number between 0 and 11, said material having a Hammett acidity Ho.ltoreq.-11.4.

Abstract: A catalyst, which is active in the oligomerization of olefins is an X-ray-amorphous silica-alumina-nickel oxide gel having an SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio of from 30/1 to 500/1, and NiO/SiO.sub.2 molar ratio of from 0.001/1 to 0.01/1, a superficial area of from 500 m.sup.2 /g to 1.000 m.sup.2 /g, and a porosity of from 0.3 ml/g to 0.6 ml/g, the means pore diameter being 1 nm (10 Angstrom), and devoid of pores having a diameter over 3 nm (30 Angstrom). The catalyst selectively dimerizes isobutene into alpha- and beta-isobutene and oligomerizes propylene into its relative dimers and trimers. A process is described for preparing the silica-alumina-nickel oxide gel.