Abstract: A two-step method for producing monolithic alumina aerogels having porosities of greater than 80 percent. Very strong, very low density alumina aerogel monoliths are prepared using the two-step sol-gel process. The method of preparing pure alumina aerogel modifies the prior known sol method by combining the use of substoichiometric water for hydrolysis, the use of acetic acid to control hydrolysis/condensation, and high temperature supercritical drying, all of which contribute to the formation of a polycrystalline aerogel microstructure. This structure provides exceptional mechanical properties of the alumina aerogel, as well as enhanced thermal resistance and high temperature stability.

Abstract: A lean NOx catalyst and method of preparing the same is disclosed. The lean NOx catalyst includes a substrate, an oxide support material, preferably &ggr;-alumina deposited on the substrate and a metal or metal oxide promoter or dopant introduced into the oxide support material. The metal promoters or dopants are selected from the group consisting of indium, gallium, tin, silver, germanium, gold, nickel, cobalt, copper, iron, manganese, molybdenum, chromium, cerium, and vanadium, and oxides thereof, and any combinations thereof. The &ggr;-alumina preferably has a pore volume of from about 0.5 to about 2.0 cc/g; a surface area of between 80 and 350 m2/g; an average pore size diameter of between about 3 to 30 nm; and an impurity level of less than or equal to about 0.2 weight percent. In a preferred embodiment the &ggr;-alumina is prepared by a sol-gel method, with the metal doping of the &ggr;-alumina preferably accomplished using an incipient wetness impregnation technique.

Abstract: Catalysts made from a newly discovered phase of aluminum trihydroxide and processes for making such catalysts. This invention also relates to a method for improving the activity of and for regenerating catalysts having a silica-alumina support.

Abstract: A method for making alumina having a pore structure characterized by the absence of macropores, no more than 5% of the total pore volume in pores greater than 350 Å, a high pore volume (greater than 0.8 cc/g measured by mercury intrusion) and a bi-modal pore volume distribution character, where the two modes are separated by 10 to 200 Å, and the primary pore mode is larger than the median pore diameter (MPD), calculated either by volume or by surface area, the MPD by volume being itself larger than the MPD by surface area. Alumina made by such process and catalyst made therefrom.

Abstract: An activated alumina formed by complexing a dehydrated alumina with an agglomerate blocking agent and then hydrating the activated alumina.

Abstract: Disclosed is a hydrogen generation process for use with fuel cells which includes a preferential oxidation step to reduce the concentration of carbon monoxide. The preferential oxidation step includes contacting a fuel stream comprising hydrogen and carbon monoxide in the presence of an oxygen at a preferential oxidation temperature of between about 70° and about 160° C. with preferential oxidation catalyst for reducing the concentration of carbon monoxide to produce a treated fuel gas stream comprising less than about 50 ppm-vol carbon monoxide. The preferential oxidation catalyst comprises ruthenium metal disposed on an alumina carrier having a low density and a high porosity. Superior performance at low preferential oxidation temperatures below 130° C. was observed when the alumina carrier contained a bimodal pore distribution with an average pore distribution of from about 20 to about 3000 angstroms.

Abstract: This invention relates to a method of producing an alumina porous material using a mixed powder of alumina powder and aluminum hydroxide represented by the chemical formula Al(OH)3 at different percentages as the starting material, comprising the steps of heating this mixed powder to decompose the aluminum hydroxide and further heat treating it within a temperature range of 1,000 to 1,600° C., and to the alumina porous material produced by the above-mentioned method with a porosity exceeding 40 volume % and its specific surface area of 8 to 40 m2/g, and further to a filter and catalyst carrier that are obtained using this alumina porous material.

Abstract: A microcrystalline boehmite containing additive in a homogeneously dispersed state. Suitable additives are compounds containing elements selected from the group consisting of alkaline earth metals, alkaline metals, rare earth metals, transition metals, actinides, silicon, gallium, boron, titanium, and phosphorus. The microcrystalline boehmite according to the invention may be prepared in several ways. In general, a microcrystalline boehmite precursor and an additive are converted to a microcrystalline boehmite containing the additive in a homogeneously dispersed state. The additive does not contain zirconia or magnesia.

Abstract: Collections of particles are described that include crystalline aluminum oxide selected from the group consisting of delta-Al2O3 and theta-Al2O3. The particles have an average diameter less than about 100 nm. The particles generally have correspondingly large BET surface areas. In certain embodiments, the particle collections are very uniform. In some embodiments, collections of particles include doped aluminum oxides particles with an average diameter less than about 500 nm. The collections of particles can be deposited as coatings. Methods are described for producing desired aluminum oxide particles.

Abstract: A modified alumina is useful as metals passivator in fluidizable catalytic cracking catalysts. The modified alumina is prepared from a hydrated alumina, e.g., gibbsite, which is reacted with a low-molecular weight organic acid, e.g., acetic acid, forming aluminum salts. Calcination of the modified alumina results in decomposition of the aluminum salt.

Abstract: Disclosed is a process for preparing nanoscale metal-based powders from a metal salt and an amphiphilic copolymer containing ethylene oxide. The copolymer and metal salt are mixed to form a metal salt/copolymer paste which is then calcined at a temperature sufficient to remove water and organics and to form a metal oxide.

Abstract: A catalyst for hydrofining fraction oils, comprises an alumina carrier and at least one metal and/or thereof oxide of Group VIB and at least one metal and/or thereof oxide of Group VIII supported on said alumina carrier. The pore volume of said alumina carrier is not less than 0.35 ml/g, in which the pore volume of the pores having a diameter of 40-100 angstrom accounts for more than 80% of the total pore volume, the alumina carrier is prepared by a special process. The catalyst possesses relatively high hydrogenation activity.

Abstract: Disclosed are a porous material comprising particles without substantial fibrous structure and having pores, the pores having a mean pore diameter in a meso-pore region, sharp pore size distribution, and at least a part of the pores being connected three-dimensionally to form a three-dimensional network structure with random passages, the porous material preferably being of alumina and having a spongy structure or the porous material preferably being an aggregate of particles having an aspect ratio of 3 or less; a process of producing the porous material which includes a step of aging a system capable of becoming an oxide on thermal decomposition; a catalyst for exhaust gas purification having excellent NOx removal performance, high resistance against sulfur poisoning, and satisfactory high-temperature durability which comprises the porous material as a carrier having supported thereon a noble metal and an NOx storage component; and a method of exhaust gas purification using the catalyst.

Abstract: The present invention pertains to an improved process for the preparation of quasi-crystalline boehmite. In this improved process a quasi-crystalline boehmite precursor is aged at a pH below 7, prefereably under hydrothermal conditions. It was found that when conducting the preparation processes for quasi-crystalline aluminas described in the prior art at a pH below 7 and under hydrothermal conditions instead of the high pH and thermal aging used in the prior art, QCBs with higher crystallinity are obtained. In the process according to the invention additives may be added to the quasi-crystalline boehmite precursor. This results in a high quality QCB with additives in a homogeneously dispersed state. Suitable additives are compounds containing elements selected from the group of rare earth metals alkaline earth metals, transition metals, actinides, silicon, gallium, boron, and phosphorus.

Abstract: An integrated circuit chip carrier assembly is provided by joining a substrate having electrically conductive regions on at least one major surface thereof to a stiffener by a bonding film. The bonding film comprises a dielectric substrate having a thermoset adhesive on both of its major surfaces. The thermoset adhesive prior to the bonding is a B-stage adhesive, is tack-free at normal room temperatures and is solvent free.

Abstract: The present invention pertains to a quasi-crystalline boehmite containing additive in a homogeneously dispersed state. Suitable additives are compounds containing elements selected from the group of alkaline earth metals, alkaline metals, transition metals, actinides, silicon, gallium, boron, titanium, and phosphorus. Said QCBs according to the invention may be prepared in several ways. In general, a quasi-crystalline boehmite precursor and an additive are converted to a quasi-crystalline boehmite containing the additive in a homogeneously dispersed state.

Abstract: A high-strength &agr;-alumina formed body with a low soda content, of which pore distribution is controlled, can be provided in an easy and inexpensive manner. The &agr;-alumina formed body can be produced by a method comprising calcining a gibbsite-phase aluminum hydroxide to obtain rehydratable alumina powder; forming the rehydratable alumina powder in the presence of water to obtain a formed body; maintaining the formed body in the presence of water at about 110-200 ° C., to rehydrate the formed body; and calcining the rehydrated formed body at about 1200° C. or higher. The &agr;-alumina formed body is useful as a carrier for catalysts, chemicals, microbes for food leftover disposal and the like.

Abstract: An activated alumina formed body with a high bulk density and a large macro-pore volume is provided. The activated alumina formed body can be produced by a method comprising the steps of calcining a gibbsite-phase aluminum hydroxide having a median particle size of from about 10 &mgr;m to about 35 &mgr;m and a packed bulk density of from about 1.05 g/cm3 to about 1.3 g/cm3 to obtain an at least partially rehydratable alumina powder; forming the rehydratable alumina powder in the presence of water; maintaining the formed body in the presence of water to rehydrate the formed body; and calcining the rehydrated formed body to obtain an activated alumina formed body. The activated alumina formed body is usable as an adsorbent, a catalyst supporting precious metal or the like.

Abstract: Thermally stable transitional alumina particulates retaining high specific surface area after calcination at 1000° C. suitable for the use as catalysts or catalysts supports are produced by treating an aqueous solution containing Al3+ and optionally a doping amount of La3+ (e.g., 0.3 mol. %) with an anion-exchange resin to give a stable hydroxide sol followed by freeze drying of the sol and further thermal dehydration. The resultant stabilized transitional alumina retains high specific surface area at 1000° C., and additionally stabilization is achieved at very low levels of added La.

Abstract: There is provided macrostructures of porous inorganic material which can have controlled size, shape, and/or porosity and a process for preparing the macrostructures. The macrostructures comprise a three-dimension network of particles of porous inorganic materials. The process for preparing the macrostructures involves forming an admixture containing a porous organic ion exchanger and a synthesis mixture capable of forming the porous inorganic material and then converting the synthesis mixture to the porous inorganic material. After formation of the composite material, the porous organic ion exchanger can be removed from the composite material to obtain the macrostructures.

Abstract: A precursor for forming an aluminum oxide film comprises a liquid solution of an aluminum organic precursor compound in an organic solvent. In a second embodiment, the precursor comprises a suspension of aluminum oxide powder in a solution of an aluminum organic precursor compound. A precursor according to the invention is deposited on a substrate by dipping, rolling, spraying, misted deposition, spin on deposition, or chemical vapor deposition then heated to fabricate transparent aluminum oxide films. The electronic properties of the aluminum oxide films may be improved by depositing a plurality of layers of the precursor and annealing the precursor between layers.

Abstract: Pseudo-boehmite, which is a raw material for a catalyst carrier for hydrogenation refining, is produced by mixing, under a predetermined condition, an aluminate aqueous solution produced from an alkaline etching step for aluminum in an alumite treatment and an acidic aluminum aqueous solution produced from an anodization step for aluminum in the alumite treatment. Pseudo-boehmite can be also produced by maturing, with an alkaline solution, an aluminum hydroxide sludge produced from a washing step for aluminum in the alumite treatment. It is possible to establish a method for producing pseudo-boehmite, which makes it possible to reutilize a resource at extremely low cost by utilizing a treatment waste liquid and a sludge in an alumite treatment site.

Abstract: The present invention relates to a porous aluminum oxide structure comprising Al2O3 and Zr, the structure having an open porosity greater than about 30% and an average pore size from about 20 nm to about 1000 nm, wherein the Zr, expressed as ZrO2, has a concentration less than about 5 weight % of the weight of the Al2O3.

Abstract: Ceramic honeycombs incorporating cell walls of a sintered alumina material providing controlled pore size distribution in combination with high BET surface area and flexural (MOR) strength are formed by the extrusion, drying and firing of plasticized alumina powder batches containing major proportions of anhydrous, high-surface-area gamma alumina powders dispersed with selected acids; low combined drying and firing shrinkages provide strong, crack-free bodies of high surface area and strength.

Abstract: A modified alumina is useful as metals passivator in fluidizable catalytic cracking catalysts. The modified alumina is prepared from a hydrated alumina, e.g., gibbsite, which is reacted with a low-molecular weight organic acid, e.g., acetic acid, forming aluminum salts. Calcination of the modified alumina results in decomposition of the aluminum salt.

Abstract: Alumina particles obtained from aluminum chloride by a gas phase method, the particles being amorphous or transition alumina particles and having an amorphous, &ggr;-, &dgr;- or &thgr;-crystalline form or a mixed form thereof, with primary particles thereof having an average particle diameter of 5 to 100 nm, and secondary particles, resulting from the aggregation of primary particles, having an average particle diameter of 50 to 800 nm.

Abstract: The present invention relates to a method of containing nickel into the alumina aerogel prepared by sol-gel method and supercritical drying and of preparing the nickel-alumina hybrid aerogel catalyst. The nickel-alumina catalyst prepared in the present invention has an excellent reactivity with a prolonged lifetime.

Abstract: Stable highly active supported copper based catalysts are comprised of copper oxide or elemental copper crystallites supported on mechanically stable aluminum oxide and are characterized by high surface area, small copper crystallite size, and high metal loading. The average crystallite size of the copper compound is from about 20 to about 300 Å, the copper loading is from about 10 to about 35 weight percent, the average particle diameter is from about 0.1 mm to about 10 mm, and the total surface area is from about 20 to about 400 square meters per gram. The catalysts are useful for hydration of nitriles to amides, especially hydration of acrylonitrile to acrylamide. The catalysts are distinguished by high mechanical stability, extended lifetime, and excellent resistance to hydration and copper leaching.

Abstract: The present invention concerns a moulded microcrystalline spherical Al2O3- sintered body, process for its production as well as its use.

Abstract: A material with high surface area can be obtained through the partial or total removal of CaO and MgO by acid leaching of blast furnace slag. This is accomplished by an improved process for selective leaching of blast furnace slag and other solid solution materials by control of temperature during leaching, rate of addition of acid, type of the acid, concentration of the acid, and concentration of the slag in the slurry. When these variables are controlled as disclosed a hierarchy of dissolution occurs. The hierarchy begins with MgO, progresses to CaO, and is followed by A12O3, and the rate of acid addition is slow and controlled so that alumina does not dissolve (thereby depriving the remaining silica has no acid sites or catalytic activity). By invoking the hierarchy one gains selectivity, and this can be used to convert blast furnace slag to a material with high surface area which may have applications as an absorbent could be economically feasible.

Abstract: The present invention concerns a moulded microcrystalline spherical Al2O3- sintered body, process for its production as well as use.

Abstract: A process for the production of an aluminum oxide composition which includes subjecting an aluminoxane with a basic structural element of —Al—O—Al— or a basic oligomeric structural element of —Al—O—Al—O—Al—O—Al— to mild hydrolysis with at least one inert gas moistened below its dew point to produce a composition and subjecting the composition to thermolysis at temperatures from about 300 to about 900° C.

Abstract: A process for producing spherical catalyst carrier of silica, silica-alumina composition, zirconia-alumina composition, titania-alumina composition, boria-alumina composition, or boria-silica-alumina composition which has almost the same pore characteristics as alumina hydrate gel, silica-alumina hydrate gel, zirconia-alumina hydrate gel, or titania-alumina hydrate gel (or alumina hydrate paste, boria-alumina hydrate paste, or boria-silica-alumina hydrate paste) as the major raw material, having uniform sphericity and smooth surface and homogeneity, and has a macropore volume that can be controlled includes adding a polysaccharide solution to any of alumina, silica-alumina, zirconia-alumina, or titania-alumina in the form of hydrate gel, or alumina, boria-alumina, or boria-silica-alumina in the form of hydrate paste, mixing them to form a slurry with a controlled concentration, dropping the slurry into a solution containing multivalent metal ions, thereby forming spherical hydrogel, and performing the additio

Abstract: A porous spinel type oxide shows a large surface area and a uniform micro-porous structure. The oxide is expressed by general formula MO—Al2O3 and shows a surface area per unit weight of not less than 80 m2/g. Such a porous spinel type compound oxide is obtained by impregnating a specific &ggr;-alumina carrier with a solution of a compound of metal element M capable of taking a valence of 2, drying the impregnated carrier and calcining it at a temperature of 600° C. or higher. The specific &ggr;-alumina carrier shows a surface area per unit weight of not less than 150 m2/g, a micro-pore volume per unit weight of not less than 0.55 cm3/g and an average micro-pore diameter between 90 and 200 angstroms. The micro-pores with a diameter between 90 and 200 angstroms occupy not less than 60% of the total micro-pore volume of the carrier.

Abstract: The invention concerns a process for synthesising aluminas with a controlled porosity in which the pore diameter is in the range 0.6 nm to 80 nm. This process is carried out in a plurality of steps including at least one step a) in which an alumina precursor is prepared by hydrolysis of at least one anionic inorganic source of aluminium in the presence of at least one surfactant. Step a) of the process is carried out in an essentially aqueous medium the pH of which is generally higher than the isoelectric point of the alumina. The process of the invention also comprises at least one step b) in which the precipitate obtained is dried in air at a temperature of about 40° C. to 110° C. for a period of about 2 to 30 hours, and at least one step c) in which the dried precipitate is calcined at a temperature which is sufficient to eliminate the molecules of surfactant present in the precursor.

Abstract: A catalyst for hydrodemetalization of heavy oil, especially residuum oil, and a process for preparing the same, wherein said catalyst comprises the metal elements of Groups VIII and/or VIB as active components supported on an alumina carrier having large pores. The total pore volume of said carrier is in the range of 0.80˜1.20 ml/g (by mercury porosimetry method), the specific surface area in the range of 110˜200 m2/g, the peak pore diameter in the range of 15˜20 nm, and the bulk density in the range of 0.50˜0.60 g/ml. In the process of the invention, a physical pore-enlarging agent and a chemical pore-enlarging agent are added simultaneously during the mixing of the pseudoboehmite to a plastic mass, then extruding, drying, calcining, the carrier is obtained, then impregnating with active components by spraying onto the carrier, after drying and calcining, the catalyst is obtained.

Abstract: Hydrated aluminium compounds of the present invention are represented by the general formula nS, mM, Al2O3, xH2O where S is a surfactant or a group of surfactants, n is the number of moles of S, M is an alkaline cation, preferably selected from the group formed by Na+, K+, NH4+, m is the number of moles of M and x is the number of moles of water. The hydrated compounds are obtained from inorganic aluminium sources which are in the form of cation-monomers and/or cation-oligomers. The surfactants are anionic and/or non-ionic surfactants. When the group of surfactants comprises at least one anionic surfactant, at least one cationic surfactant can optionally be added.

Abstract: In order to produce aluminium oxide beads, an acid aluminium oxide sol or an acid aluminium oxide suspension is converted into droplets by a vibrating nozzle plate and pre-solidified after the formation of a bead shape by laterally blowing gaseous ammonia and then coagulated in an ammonia solution.

Abstract: Alumina particles having high dispersibility and plasticity, at least on the surface of which a phosphoric acid or phosphate is present and suitable for use as a material for pigments for paints, precision abrasives or ceramics. The alumina particles are produced by adding a crystallization inhibitor containing at least phosphate ion to aluminum hydroxide or alumina hydrate and then conducting a hydrothermal synthesis treatment. The amount of the phosphate ion to be added is in the range of 3.0×10−3 to 2.5×10−2 mol per mol of aluminum hydroxide or alumina hydrate. The particle size of aluminum hydroxide or alumina hydrate is 0.1 to 5.0 &mgr;m. The hydrothermal synthesis is preferably conducted at 350° C. or above under a pressure of 50 to 200 atm and at a temperature elevation rate of 5° C./min to 0.3° C./min. The thus obtained alumina is &agr;-alumina in the form of hexagonal plate single crystal having a particle size of 0.

Abstract: An aluminum salt solution and an alkali aluminate solution are subjected to a neutralization reaction to precipitate and form a pseudo-boehmite powder. The neutralization reaction is performed under a condition in which the reaction temperature is within a range of 55 to 71° C., pH is within a range of 8.5 to 9.5, and the solution feed time is within a range of 7 to 25 minutes. The obtained pseudo-boehmite is as follows. That is, the pore volume concerning pores having a pore diameter ranging from 20 to 600 Å is within a range of 0.8 to 1.8 cc/g as measured by the nitrogen adsorption method, and the maximum value of variation ratio dV/dD of the pore volume with respect to the pore diameter as measured by the BJH method is not more than 0.018 cc/g•Å. When the pseudo-boehmite is used, it is possible to produce a catalyst carrier for hydrogenation refining, which has a sharp pore diameter distribution and which suffers less decrease in strength upon impregnation with a catalyst solution.

Abstract: An alumina sol, containing a small amount of water of crystallization inside the crystal lattice of boehmite, having high mechanical strength, properties suitable for use as an alumina adsorbent or carrier, and the ability to be formed without additional concentration. The alumina sol comprises a fibrous boehmite having the molecular formula Al2O3.1.05-1.30 H2O with the weight average diameter and the weight average length being respectively in the range of 3 to 50 nm and in the range of 30 to 3000 nm, and has an alumina concentration of 15 to 60% by weight.

Abstract: A fire-retardant plastic mixture contains 55%-75% by weight of boehmite which has an orthorhombic crystal structure and has the general formula AlO.sub.x (OH).sub.3-2x with x-values ranging between 0.8 and 0.99, and has a mean grain diameter d.sub.50 ranging between 0.4 and 0.7 .mu.m, a d.sub.10 value ranging between 0.7 and 1.2 .mu.m and a d.sub.90 value ranging between 0.2 and 0.4 .mu.m. The filler material is used in the form of a finely-crystallized hydrargillite which is obtained during a precipitation process according to Bayer with a grain diameter of 0.5 to 3 .mu.m, which is suspended and which, without any mechanical working, is transformed directly in a hydro-thermal process at temperatures ranging between 220.degree. C. and 240.degree. C. under turbulent conditions into a boehmite of the general formula AlO.sub.x (OH).sub.3-2x with x-values ranging between 0.8 and 0.99.

Abstract: An aluminum oxide mass characterized by a specific surface area greater than or equal to 70 m.sup.2 /g and a narrow pore radius distribution, with at least 90% of the pore radii being approximately 0.5 to 2.5 nm, preferably approximately 1.7 to 2.2 nm.

Abstract: A novel catalytic material is prepared by dispersing a catalytically active species, e.g., one or more platinum group metals, on a support phase that contains a high porosity, meso-pores high surface area (HPMPHSA) material. The HPMPHSA material has a porosity, measured in milliliters per gram of material, that is typically at least about 30 percent greater than that of a corresponding conventional material, preferably at least 50 percent greater. In a particular embodiment, the support phase of the catalytic material contains a HPMPHSA alumina having a porosity of about 0.9 ml/g, whereas a conventional alumina typically has a porosity of about 0.45 ml/g. The surface area is above 90, preferably above 100, more preferably equal or above 150 to 160 m.sup.2 /g. The support phase may be wholly composed of the HPMPHSA material or it may be composed of a mixture of the HPMPHSA material and a conventional material. Such a mixture preferably contains at least about 20 percent HPMPHSA material, by weight, e.g.

Abstract: A method of depositing catalytically active components on high-surface carrier materials is disclosed by dispersing the carrier materials in water and mixing this dispersion with an aqueous solution of soluble precursors of the catalytically active components. The pH of the dispersion is adjusted to a value between 6 and 8 before the aqueous solution of the precursors is supplied by capillary injection under constant agitation of the dispersion and thereafter, if necessary, the precursors of the catalytically active components are precipitated on the carrier material by capillary injection of a dilute base.

Abstract: Pelletized adsorbent compositions and methods of adsorbing toxic target compounds are provided for the destructive adsorption or chemisorption of toxic or undesired compounds. The pelletized adsorbents are formed by pressing together powder nanocrystalline particles comprising a metal hydroxide or a metal oxide at pressures of from about 50 psi to about 6000 psi to form discrete self-sustaining bodies. The pelletized bodies should retain at least about 25% of the surface area/unit mass and total pore volume of the starting metal particles.

Abstract: A noble metal hydrocracking catalyst which has high selectivity for naphtha range products is provided. The hydrocracking catalyst comprises:a) from about 70 to about 90 weight percent of a Y zeolite, based on the catalyst having a silica to alumina mole ratio of from about 4.8 to less than 6.0, a unit cell constant within the range of about 24.50 to about 24.57, a Na.sub.2 O level of less than or equal to about 0.2 weight percent;b) from about 10 to about 30 weight percent, based on the catalyst of an alumina having a mercury intrusion pore volume within the range from about 0.55 to about 0.85 cc/g; andc) from about 0.5 to 1 weight percent, based on the catalyst of a noble metal; wherein said hydrocracking catalyst have a dispersivity of the noble metal of equal or greater than about 50% by hydrogen chemisorption measurement, a surface area of greater than or equal to 700 m.sup.2 /g by BET surface area measurement, a compacted bulk density within the range of from about 0.40 to 0.

Abstract: An exhaust gas purifying catalyst in which catalytic activation particles 3 composed of a catalytic element or its compound are carried on a carrier 1. The catalytic activation particles 3, as carried on the carrier 1 and exposed to the outside of the carrier 1, are coated with the carrier 1 by 20 to 90% of their whole surface area. Also disclosed is a process for producing the exhaust gas purifying catalyst.

Abstract: Provided is a process for preparing alumina agglomerates which comprises:(i) treating agglomerates of active alumina with an aqueous medium comprising at least one acid making it possible to dissolve at least part of the alumina and at least one compound providing an anion capable of combining with aluminum ions in solution,(ii) subjecting the agglomerates to a hydrothermal treatment at a temperature in the range of from about 80.degree. C. to about 250.degree. C., and then(iii) thermally activating the agglomerates at a temperature in the range of about 500.degree. C. to about 1100.degree. C.The resulting alumina agglomerates possess exceptional mechanical strength, heat resistance and hydrothermal resistance and are useful as catalysts or catalyst supports.

Abstract: A process for producing alumina and other aluminia products where the formation of a Schiff base imine by reaction of a orgaonaluminum amide or imide oligomer with a carbonyl compound is promoted by the Lewis acid character of the oligomer. The water byproduct of the Schiff base serves as an in situ reagent for subsequent hydrolysis and sol-gel condensation of the aluminum species with concomitant production of alkane. The imine then is washed from the alumina with a suitable solvent. Any of a number of primary amines and aldehydes or ketones may be reagents. Calcining of the sol-gels yields high surface area alumina as characterized by scanning electron microscopy, and gas physisorption measurements. Microporous and/or mesoporous alumina is obtained depending on synthesis conditions. Alumina microspheres are obtained under certain conditions.