Showing papers on "Catalyst support published in 1974"

Structure and properties of microcrystalline catalysts

Abstract: Supported metal catalysts are widely used because it is possible to prepare them in a highly dispersed form, consisting of very small microcrystals, which provide a maximum available surface area for the catalytic reaction [1]. Superficially, one might expect that the effectiveness of the material as a catalyst would be simply proportional to the surface area. In this case the specific catalytic activity would be independent of the size of the microcrystals. Size-independent specific activity is observed in a number of reactions, such as hydrogenation of benzene on alumina-supported platinum [2]. For other reactions, the specific catalytic activity is dependent on the size of the mircrocrystals. It is possible that the surface of a very small microcrystal is either more or less active than that of a larger crystal. Figure 1 shows the specific activity of the catalyst for deuteration of benzene and for hydrogen exchange with benzene on nickel catalysts [3]. Note that the smaller microcrystals are ...

Supports for catalyst materials

Abstract: A self supporting substrate support for a catalyst system is provided by a metal, preferably an aluminium bearing ferritic alloy. The metal carries an electrically insulating surface layer, such as alumina, compatible with catalytic material deposited thereon. The system is particularly suitable for catalyst systems for treating exhaust gases of internal combustion engines.

Fluid catalytic cracking process with substantially complete combustion of carbon monoxide during regeneration of catalyst

Abstract: An improved fluid catalytic cracking process providing improved product yield and selectivity employs a regenerated hydrocarbon conversion catalyst having improved activity and a low level of residual coke, desirably less than 0.05 wt. % on catalyst, obtained by burning coke from spent catalyst under balanced conditions supporting substantially complete combustion of carbon monoxide with provision for recovery of evolved heat by transfer directly to the catalyst particles particularly within a dilutephase zone in the regenerator vessel. Effluent gas from the regenerator may be discharged directly to the atmosphere with no discernible effect upon ambient air quality.

Methanol synthesis catalyst

Abstract: A methanol synthesis catalyst precursor comprises copper oxide and a support comprising spinel-forming metal oxides, spinel being present in crystallites not larger than 120 Angstrom units. Using catalyst prepared from such a precursor by reduction, methanol synthesis can be operated without catalyst changing for longer periods than when using a similar catalyst containing no spinel. A precipitation method for making the precursor is described.

Reactivation of organochromium olefin polymerization catalyst in presence of oxygen

Abstract: A particulate catalyst support containing titanium is heated to calcination temperature and thereafter impregnated with a π bonded organochromium compound. Thereafter the chromium-containing support is reactivated, at least a portion of the reactivation occurring in the presence of oxygen. In one embodiment at least 2 percent solvent is present as the catalyst is reactivated at approximately room temperature. In an alternate embodiment the support is calcined at a temperature within the range of 1450° to 1650°F. Such catalysts are particularly suitable for the production of high melt index polymer from at least one mono-1-olefin containing 2 to 8 carbon atoms per molecule.

Alumina catalyst support

Abstract: In the manufacture of an alumina catalyst support, activated alumina is admixed with a binder such as cellulose ether and a filler material such as wood flour, with sufficient water to form a thick paste, which is extruded and cut into pellets, dried, rehydrated, and finally calcined. A catalyst support is provided having a high degree of macropore content, particularly as regards the proportion of total pore volume contributed by pores larger than 3,000 angstrom units.

Organometallic complexes of molybdenum and tungsten as catalyst precursors in the disproportionation of propene

Abstract: Organometallic complexes of molybdenum and tungsten have been supported on silica or alumina and activated at temperatures at or above 373 K; the activities of the resulting substances as propene-disproportionation catalysts have been determined at ambient temperatures. Catalysts derived from alkyl and acetato-complexes show activities of the same order as catalysts made from supported Mo(CO)6. Tungsten-based catalysts have activities of the same order as molybdenum-derived catalysts, and catalysts derived from less thermally stable complexes are the more active. No propene disproportionation has been observed for chromium-based catalysts.

Catalyst composition and method for the preparation thereof

Abstract: Supported catalyst compositions made by incorporating preformed materials comprising the reaction product of organophosphorus compounds such as the organophosphates and organophosphites with chromium trioxide, wherein the organic moiety is a hydrocarbon radical, e.g., alkyl, aralkyl, aryl, cycloalkyl, or the like or combinations thereof. Typical supports constitute an inorganic material of high surface area, especially a high pore volume (>1.96 cc/g) silica xerogel. The catalysts are activated by heating in a dry, oxygen containing atmosphere. The catalysts are utilized alone or in conjunction with other catalytic ingredients such as organometallic and/or organo non-metallic reducing agents. Polymerizations of 1-olefins promoted with the subject catalysts proceed efficiently to products of specially adapted utility for molding, particularly to resins useful for the production of blow molded articles.

Fixed bed catalyst

Abstract: An improved fixed bed catalyst is disclosed and comprises the active catalyst material supported on a particular type of porous silica xerogel which has been treated with steam under particular temperature conditions.

Stabilized automotive exhaust gas catalyst

Abstract: A process for preparing an ultra stable catalyst capable of converting the noxious components in exhaust gases to innocuous entities is described. The catalyst is made by applying a solution of a salt of a noble metal such as palladium or platinum to a specially prepared support followed by activation at 1,800 DEG -2,100 DEG F. The special support is prepared by activating and stabilizing common support materials such as alumina with cerium oxide at high temperatures prior to application of the noble metal. The catalyst is stable to 2,100 DEG F.

Chromocene‐based catalysts for ethylene polymerization: Thermal removal of the cyclopentadienyl ligand

Abstract: Thermal aging of a chromocene catalyst, (C5H5)2Cr/SiO2, in an inert atmosphere leads to a modified catalyst which shows poor response to hydrogen as a transfer agent. Polyethylenes prepared at a polymerization temperature of 90°C with this modified catalyst have a low melt index and high vinyl unsaturation level. By thermogravimetry the weight loss of the catalyst, relative to dehydrated silica, was equivalent to loss of one cyclopentadienyl ligand per chromium site. Pyrolytic gas chromatography showed cyclopentadiene was liberated in the thermal process. These overall studies provide strong evidence that loss of a cyclopentadienyl ligand in supported chromium catalysts has a profound effect on overall polymerization behavior.

Solid catalyst for heterogeneous reactions

Abstract: Catalyst for carrying out heterogeneous catalytic chemical reactions. The catalyst is a composite comprising a solid carrier and at least one member of the group of carboxymethane sulfonic acid and products resulting from the thermal treatment thereof at a temperature not exceeding 350°C. The catalyst is prepared by impregnating the carrier carboxymethane sulfonic acid or a precursor or precursors thereof, drying the impregnated carrier at a temperature not exceeding 170°C and baking the so dried product at 170° to 330°. Examples of catalytic reactions that are successfully carried out with such a catalyst are production of alcohols by hydration of olefins, production of esters from acids and olefins, production of esters from alcohols and alkylation of aromatic hydrocarbons.

Catalyst for polymerization of olefins and process for preparing the same

Abstract: A process for preparing a solid catalyst for the polymerization of olefins which comprises the steps of (1) reducing titanium tetrachloride with an organoaluminum compound, (2) treating the resulting β-type titanium trichloride with a complexing agent, (3) treating the solid catalyst thus obtained with an organoaluminum compound, and (4) treating the resulting solid catalyst with a complexing agent, and a solid catalyst for the polymerization of olefins prepared by the above process.

Catalyst support formed by adding acidic material to silica containing titanium

Abstract: Olefin polymers are made using a chromium oxide catalyst on a support formed by adding an acidic material to a silicate solution containing titanium. This catalyst is capable of producing a polymer of an olefin having a high melt index and is of particular utility in the production of such polymer in a particle-form process.

Multi-component catalyst

Abstract: A catalyst support body is impregnated selectively, to provide a central core portion containing a catalytically active component and a surrounding peripheral portion integral with and laterally enclosing said core, the peripheral portion being selectively impregnated with a catalyst component differing from that in the core. In the preferred embodiment the core contains catalyst active for NOx reduction and the peripheral portion contains catalyst active for CO oxidation. The catalyst is designed particularly for use in two stage treatment of I.C. engine exhaust gases.

Oxydehydrogenation of alcohols

Abstract: Primary and secondary alcohols are oxidized to aldehydes and ketones, respectively, by passing a gaseous mixture of the alcohol and oxygen (air) over a supported catalyst of Ru, Rh, Pd, Pt, Ir or Os. The catalyst is improved by admixture with a tin compound. The support for the catalyst is preferably alumina, silicon carbide or other inert material having a low surface to weight ratio. Preferred conditions are atmospheric pressure, about 250°-500° C. and a space velocity of 1000-4000/hr. Preferred alcohols are isopropanol, 1-methoxy-2-propanol and ethanol.

Process for preparing a heavy crude conversion catalyst

Abstract: This invention relates to novel catalysts, of two distinct types, useful for the catalytic hydroconversion of the 1050° F.+ hydrocarbon material contained in heavy crudes and residua such that the resulting product will be suitable for further processing in conventional refinery operations allowing maximization of clean liquid products. Catalysts, which include Group VIB and Group VIII metals, preferably in admixture, and preferably including a Group IVA metal, notably germanium, having certain critical ranges of physical characteristics inclusive of large uniform pore sizes, are used for the conversion, these having been shown to possess improved catalytic activity and selectivity for the hydroconversion of the 1050° F.+ materials of the heavy feeds and residua. Novel methods are described for the preparation of such catalysts, as well as for use of such catalysts. One of the catalysts, i.e., one having properties inclusive of a large number of pores in the 100-275A pore size diameter range, is particularly suitable as a first stage catalyst and the other, which has properties inclusive of a large number of pores in the 100-200A pore size diameter, is especially suitable as a second stage catalyst for use in processing the effluent of said first stage.

Regeneration of iridium-containing catalysts

Abstract: The instant invention relates to a process for activating iridium-containing catalysts, said catalysts being inactive because of the presence of the iridium as large crystallites of low activity, and which comprises the step of contacting said catalyst with a halogen-containing gas in the presence of from 0.01 to 10% by volume oxygen, at a temperature of at least 300°C. for a time sufficient to redisperse said large crystallites to crystallites having a substantially smaller particle size. Preferably, the catalyst is a reforming catalyst comprising iridium supported on alumina. In the most preferred embodiment of the instant invention an iridium: platinum on alumina catalyst, which has become deactivated by use in a reforming process wherein carbonaceous materials have deposited on the surface of the catalyst, is regenerated by (1) burning off said carbonaceous deposits by contacting said catalyst with oxygen at a temperature of at least 300°C. for a time sufficient to substantially remove said carbonaceous materials, (2) contacting said catalyst with hydrogen at a temperature and time sufficient to reduce said iridium and platinum substantially to metallic form, and (3) redispersing said metals by contacting said reduced catalyst with oxygen and a halogen-containing gas, e.g., chlorine, the oxygen being present in an amount of less than 10% oxygen by volume, at a temperature of at least 300°C.

Catalyst and catalytic process

Abstract: A process for reacting hydrocarbons of higher molecular weight than methane with steam over a catalyst at low temperatures, ie 200*-650*C, to produce, preferably gases typically containing 5070 percent of methane, can be carried out for long periods without changing the catalyst if the catalyst is the product of reducing a percursor composition containing by weight 25-90 percent of a nickel compound calculated as NiO, alumina, 0.1 to 10 percent of an alkaline earth metal compound calculated as MgO and 0.05 to 3.5 percent of an alkali metal compound calculated as equivalent K2O, the nickel oxide and alumina having been brought together by co-precipitation.

Catalyst for the production of hydrogen and/or methane

Abstract: A cobalt promoted nickel catalyst supported on refractory material and a process employing said catalyst for the production of hydrogen-containing gases, such as synthesis gas, reducing gas or town's gas, or for the production of methane-enriched gases, such as pipe-line gas.

Demetallization of high metals feedstocks using regenerated catalyst

Abstract: The demetallization of petroleum feedstocks containing a high percentage of metal impurities, particularly vanadium, by ebullated bed catalytic hydrogenation is improved through an initial pretreatment of particulate activated porous aluminum oxide catalyst in a reaction zone wherein vanadium and carbon are deposited on the catalyst. Following such pretreatment, the used catalyst is removed from the reaction zone at an appropriate rate, regenerated by burnoff of substantially all the carbon, and then returned to the reaction zone. This use of regenerated catalyst results in the average demetallization activity of the catalyst in the reactor being higher for vanadium removal than if the used catalyst were all replaced with fresh catalyst.

Catalysis and surfaces

Abstract: Modern developments in the field of catalysis proceed in various directions to which surface science is directly relevant. Alloy catalysts possess interesting properties. The addition of as little as 5% copper to a nickel catalyst, for example, changes the activity for various reactions by several orders of magnitude and completely modifies the selectivity of the catalyst. Such phenomena raise the question of surface composition and electronic structure of alloys and of the degree of localization of chemisorption forces. Most practical catalysts are prepared in the form of highly dispersed metal onto a high surface-area insulator. Both components possess catalytic activity, which leads to the concept of a bifunctional catalyst. Metal catalysts are responsible mostly for hydrogenation, dehydrogenation, and hydrogenolysis of hydrocarbons, while acid sites on insulators are mostly involved in cracking and isomerization of organic molecules. The high dispersion of metal catalysts represents a novel state of matter, the very small particle, whose properties are different from those of a gas, of a conventional solid, or of a liquid. Little is known about the morphology, structure, thermodynamic properties, and alloying behavior of these particles. In addition to the above problems, we discuss two investigations of surfaces and their connection with the problem of catalyst poisoning and the development of a novel fuel cell.

Oxide catalysts and process for preparation thereof

Abstract: An improved process for preparing an oxide catalyst comprising vanadium oxide and titanium oxide and silica as an optional component, in which more than 50% of the titanium oxide is in the rutile crystalline form, which comprises calcining a mixture of a vanadium compound and amorphous hydrogel of titanium oxide or a mixture further containing silica, in an oxidizing atmosphere at a temperature of 400° to 600°C.; and a catalyst so obtained. This oxide catalyst is very suitable as a fluidized bed catalyst for prepaing acetic acid by gaseous phase oxidation of butenes.

Boria-alumina catalyst base

Abstract: A catalyst support comprised of boria and alumina is prepared by the hydrolysis of a mixture of boron alkoxide and aluminum alkoxide. The boria-alumina composition prepared in accordance with the invention can be readily formed for use as a support for catalysts useful in a number of hydrocarbon conversion processes. For example, the boria-alumina may be used as a support for various combinations of zeolite, nickel oxide and molybdenum oxide to produce a catalyst particularly useful in the hydrocracking of petroleum feedstocks.

Water injection in a dehydrogenation process

Abstract: The activity of a used dehydrogenation catalyst is improved by an increase in the water concentration maintained in the reactants toward the end of the catalyst''s life. Optimum operation results when the water concentration is increased gradually as the temperature of the reactor is increased. The process preferably utilizes a catalyst comprising a platinum component, a germanium component, and an alkali or alkaline earth component on an alumina carrier material.

Support structures for fixed bed flow reactors

Abstract: A catalyst support is described for use in fixed bed flow reactors. The support is a porous, self-supporting structure of multiple layers of a yarn of partially sintered glass-ceramic fibers. The structure has diamond shaped apertures in its walls to provide good fluid permeability. Preferably, it is tubular. Coated with a catalyst, the structures are especially adapted for use in the catalytic conversion of pollutants in the exhaust fumes of internal combustion engines.

Methanol production catalyst and process for preparing the same

Abstract: A copper, zinc, aluminum and boron catalyst is used as a low temperature methanol synthesis catalyst. The proportions of the catalyst components, in terms of metal atoms, are 30-70% of copper, 15-50% of zinc, 1-16% of aluminum and 0.3-5.3% of boron. This catalyst is prepared by adding an alumina sol to the mixture of copper, zinc and boron compounds and firing the total mixture.