Abstract: Chemically and thermally stable monolithic catalysts are disclosed having platinum or alkali metal-vanadium active phases for use in the conversion of sulfur dioxide to sulfur trioxide. The platinum catalyst comprises a foraminous ceramic support which has at its wall surfaces a high surface area substrate for an active catalyst phase, and a combination of a platinum active phase and a promoter on the substrate. The substrate preferably comprises silica, provided, for example, by application of a silica washcoat. The promoter is selected from among compounds of zirconium, hafnium and titanium.The alkali-vanadium catalyst comprises a foraminous ceramic support having a porous silica substrate for the active phase at its foraminal wall surfaces. An alkali metal-vanadium active catalyst is in the pores of the porous silica.

Abstract: A method for preparing a multicomponent catalyst including molybdenum, bismuth, iron and cesium or thallium for producing methacrolein and methacrylic acid by the gas-phase catalytic oxidation of isobutylene or tert-butanol with molecular oxygen, wherein an aqueous nitric acid solution containing 0.01 to 0.36 mole of nitric acid per mole of ammonium molybdate, which is a material for the molybdenum component of the catalyst, and at least one material for the bismuth, iron, cesium and thallium components of the catalyst is added to an aqueous solution containing ammonium molybdate and materials for the remaining catalyst components, if any, to obtain a slurry which is then dried and calcined, provided that the nitric acid excludes nitric acid radicals contained in the materials containing the catalyst components. The amount of nitric acid used is controlled in a particular range, so that a highly active catalyst for gas-phase catalytic oxidation is obtained.

Abstract: Preparation of alkali metal/alkaline earth metal oxide catalyst on a refractory metal oxide support by using at least one suitable organic or inorganic acid. Catalysts prepared by this method have and exhibit superior catalytic activity.

Abstract: Catalyst composition comprising an alloy of at least one noble metal of group VIII of the Periodic Table and at least one metal capable of alloying with the group VIII noble metal, admixed with a component comprising at least one of the metals rhenium, tungsten or molybdenum, used for producing an alcohol and/or a carboxylic acid ester by reacting hydrogen with a carboxylic acid or anhydride thereof.

Abstract: The invention relates to ethylene oxide catalysts containing silver, alkali metal promoters, rhenium promoters and optionally rhenium co-promoters selected from sulfur, molybdenum, tungsten, chromium and mixtures thereof supported on a carrier consisting of at least 85 percent by weight of alpha alumina, from about 0.01 to about 6 percent by weight (measured as the oxide) of an added alkaline earth metal in the form of an oxide, from about 0.01 to about 5 percent by weight (measured as the dioxide) of added silicon in the form of an oxide and from zero to about 10 percent by weight (measured as the dioxide) of added zirconium in the form of an oxide. The invention also relates to an ethylene oxide process using the above catalyst.

Abstract: A methed for converting a feedstock alkane containing from 1 to 3 carbon atoms to a higher molecular weight hydrocarbon comprising contacting a feedstock with an oxygen-containing gas in the presence of a catalytic composition is disclosed. The catalytic composition includes a Group IA metal, a Group IIA metal and a third component, the precursor of which is a sol such as an aqueous suspension of a metal such as aluminum, silicon, titanium, zinc, zirconium, cadmium or tin with which the other components of the composition are throughly dispersed.

Abstract: A denitrizing catalyst which comprises:(a) an alkali metal oxide or an alkaline earth metal oxide in amounts of 50-90% by weight as oxides;(b) at least one metal oxide selected from the group consisting of Co.sub.3 O.sub.4, Cu.sub.2 O, Cr.sub.2 O.sub.3, Mn.sub.2 O.sub.3, NiO, PbO, Bi.sub.2 O.sub.3, MoO.sub.2, Al.sub.2 O.sub.3, SiO.sub.2, ZrO.sub.2, Fe.sub.2 O.sub.3, TiO.sub.2, WO.sub.3, MoO.sub.3, SnO.sub.2 and ZnO in amounts of 5-50% by weight as oxides; and(c) at least one metal or at least one oxide of metals selected from the group consisting of Ru, Rh, Pd, Ag, Pt and Au in amounts of 0.01-10% by weight as metals.Nitrogen oxides contained in waste gases are denitrized effectively by putting the gases into contact with the catalysts in the absence or presence of carbon monoxide as a reducing agent.

Abstract: Sulfur oxides are removed from gases by contact with a composition containing 3 wt % potassium and 1 wt % thorium on alumina.

Abstract: The invention relates to chemical compounds and their use as catalysts in the solvolysis of alkyl halides. The chemical compounds, when dry, have formula (I):(EO.sub.4 M).multidot.(Imp)p (I)wherein E is selected from the group consisting of phosphorus, arsenic, antimony and bismuth, and is preferably phosphorus, and M is a metal or a mixture of metals.Imp corresponds to a basic impregnating compound consisting of alkaline earth metal, or preferably alkali metal, and their mixtures in combination with a counter-anion to ensure electrical neutrality.The coefficient p is between 10.sup.-2 and 1/3.

Abstract: The present invention discloses two polyoxoanion supported metal complexes found to be useful in olefin hydrogenation. The complexes are novel compositions of matter which are soluble in organic solvents. In particular, the compositions of matter comprise A.sub.x [L.sub.n Ir.sup.(I) .multidot.X.sub.2 M.sub.15 M'.sub.3 O.sub.62 ].sup.x- and A.sub.y [L.sub.n Ir.sup.(I) .multidot.X.sub.2 M.sub.9 M'.sub.3 O.sub.40 ].sup.y- where L is a ligand preferably chosen from 1,5-cyclooctadiene (COD), ethylene, cyclooctene, norbornadiene and other olefinic ligands; n=1 or 2 depending upon the number of double bonds present in the ligand L; X is a "hetero" atom chosen from B, Si, Ge, P, As, Se, Te, I, Co, Mn and Cu; M is either W or Mo; M' is preferably Nb or V but Ti, Zr, Ta, Hf are also useful; and A is a countercation preferably selected from tetrabutyl ammonium and alkali metal ions.

Abstract: Catalyst supports, catalyst systems, methods for the preparation thereof, in dimerization processes therewith are provided. Catalyst supports are prepared from alkali metal carbonate, at least one low surface area silica-alumina, and a liquid. Catalyst systems comprised of at least one elemental alkali metal deposited on the catalyst support. Optionally, the catalyst system further comprises of at least one promoter.

Abstract: A high-density and mean-porosity catalyst, supported on a siliceous matrix, based on vanadium, iron, oxygen and alkali metals, wherein the V.sub.2 O.sub.5 content ranges from 6 to 9% by weight, the Me.sub.2 O content ranges from 8.5 to 12% by weight (Me being an alkali metal), the particle density ranges from 1.10 to 1.40 g/cm.sup.3 and furthermore:the pore volume ranges from 0.20 to 0.70 cm.sup.3 /g and the surface area ranges from 0.30 to 5 m.sup.2 /g, the average radius of the pores ranging from 600 to 2200 nanometers;the SiO.sub.2 content is lower than 75% by weight and the Fe.sub.2 O.sub.3 content is higher than 0.90% by weight.

Abstract: Olefins such as propylene and isobutylene are converted to the corresponding unsaturated nitriles, acrylonitrile, and methacrylonitrile, respectively, by reacting a mixture of the olefin, ammonia, and molecular oxygen-containing gas in the presence of a catalyst containing the oxides of bismuth, molybdenum, iron, nickel and magnesium, at least one element selected from the group comprising potassium and cesium, and optionally one element selected from the group comprising cobalt, phosphorus, manganese, tellurium, sodium, cerium, chromium, antimony and tungsten wherein the sum of cesium and potassium is at least 0.1 to 0.4.

Abstract: Catalytic cracking catalysts which comprise molecular sieves/zeolites dispersed in an inorganic oxide matrix that includes pollucite.

Abstract: A silver catalyst for the production of ethylene oxide having 5 to 25% by weight, based on the amount of a finished catalyst, of finely divided metallic silver and 0.001 to 0.05 gram equivalent weight of cesium per kg of the finished catalyst carried on an .alpha.-alumina carrier having the outer surface thereof and the surface of pores in said carrier coated with amorphous silica, and a method for production thereof by supporting finely divided metallic silver and cesium and then subjecting the supported carrier to a high temperature heat treatment in an inert gas at a temperature of 400.degree. to 950.degree. C.

Abstract: A process for producing a molybdenum bismuth-containing metal oxide catalyst comprising: mixing(I) a metal element-containing slurry which contains molybdenum and at least one metal element selected from the group consisting of Fe, Ni, Co, Mg, Cr, Mn, Zn, Pb, La and Ce and which has a pH of 6 or above with(II) a bismuth compound, a solution thereof or a slurry thereof; and then drying and calcining the mixture obtained.

Abstract: There is provided a method for pillaring a layered silicate, such as kenyaite, with polymeric oxide by using a single step treatment with a mixture of swelling agent and pillar precursor. The swelling agent may be an organic cation, such as a cetyltrimethylammonium cation, and the pillar precursor may be a compound which is capable of hydrolyzing to form a polymeric oxide. Tetraethylorthosilicate is an example of such a pillar precursor.

Abstract: The invention relates to catalytic compositions for the hydrogenation of 1,1,2-trichloro-1,2,2-trifluoroethane to chlorotrifluoroethylene and trifluoroethylene comprising a porous oxygenated support impregnated with a metal of group VIII of the periodic table of the elements and one or more compounds chosen from the salts of an alkali or alkaline-earth metal.The invention also relates to a process for obtaining these catalytic compositions and a process of hydrogenation by means of these catalytic compositions.

Abstract: A multifunctional catalyst, a method of preparing the catalyst and the use of the catalyst in treating exhaust fumes from internal combustion engines are described. The catalyst includes a porous layer containing (weight %, dry):about 50 to about 99.7% of at least one refractory inorganic oxide,about 0.1 to about 25% of at least one uranium oxide,about 0.1 to about 35% of at least one oxide of at least one metal P selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, lanthanum, praseodymium, neodymium, gadolinium, and yttrium andabout 0.1 to 20% of a metal A selected from the group consisting of platinum, rhodium, palladium, ruthenium, iridium, and mixtures thereof.

Abstract: A catalytic process for gas phase oxidative coupling of aliphatic and alicyclic hydrocarbon compounds to produce higher molecular weight hydrocarbon compounds, the catalyst being a mixed basic metal oxide or sulfide catalyst. One preferred mixed basic metal oxide catalyst is boron/alkali metal promoted metal oxide.

Abstract: Methyl chloride is produced by contacting methanol and hydrogen chloride in the vapor phase in the presence of KZnCl.sub.3 supported on silica. The process produces methyl chloride in good yield with minimal formation of dimethyl ether as a by-product.

Abstract: A catalytic composition effective in the catalytic conversion of a feedstock alkane, such as methane, to a higher molecular weight hydrocarbon is disclosed. The composition includes a first component comprising a Group IA metal, a second component comprising a Group IIA metal, a third component, the precursor of which comprises a sol (an aqueous suspension of aluminum, silicon, titanium, zinc, zirconium, cadmium or tin) and a fourth component including a Group VIII metal, silver or a combination thereof, present in an amount effective to substantially increase the catalytic activity of the composition.In addition, methods of preparing such catalytic compositions and catalytic compositions prepared by such methods are disclosed.

Abstract: Catalyst particles of an active material of the general formula[Mo,V,W].sub.12 Bi.sub.a [Fe,Ce].sub.b [Ni,Co,Zn].sub.C [Alkali].sub.d [P,As,Sb,B].sub.e [Si,Al,Ti].sub.f O.sub.xwherea is from 0.1 to 5,b is from 0.1 to 10,c is from 1 to 15,d is from 0.01 to 2,e is from 0 to 2,f is from 0 to 30 andx is the number of oxygen atoms required to saturate the valences of the other components,have the shape of a 3-spoked to 5-spoked wheel or of a rosette which have wall thicknesses of from 0.5 to 4 mm and a diameter of from 3 to 20 mm.

Abstract: Normal methods of impregnating silicalite with noble metals leads either to metal loadings under 8% at high (greater than 60%) dispersion or loading of over 8% noble metal at low dispersion. To obtain silicalite impregnated with a noble metal at more than 8 weight percent loading and with at least 60% dispersion it has been found necessary to pretreat the silicalite with a base and to impregnate the base treated silicalite with a noble metal compound in two stages separated by calcination. Platinized silicalite so prepared may be dispersed in a poly(tetrafluoroethylene) matrix and used as a fixed bed to catalyze isotopic exchange gaseous hydrogen and water vapor arising from a mass of liquid water flowing over the fixed catalyst bed.

Abstract: Disclosed are catalyst compositions comprised of chemically-mixed, copper-titanium oxides and the use of such catalyst compositions in the hydrogenation of certain esters to obtain the alcohol corresponding to the acid residue of the ester.

Abstract: A method for converting a feedstock alkane containing from 1 to 3 carbon atoms to a higher molecular weight hydrocarbon comprising contacting a feedstock with an oxygen-containing gas in the presence of a catalytic composition is disclosed. The catalytic composition includes a Group IA metal, a Group IIA metal and a third component, the precursor of which is a sol such as an aqueous suspension of a metal such as aluminum, silicon, titanium, zinc, zirconium, cadmium or tin with which the other components of the composition are thoroughly dispersed.

Abstract: A process for preparing a high-density and, low-silica catalyst, supported on a siliceous matrix, based on vanadium, oxygen and alkali metals, wherein the V.sub.2 O.sub.5 content ranges from 6 to 9% by weight, the K.sub.2 O content ranges from 8.5 to 12% by weight and the particle density ranges from 0.90 to 1.40 g/cm.sup.3 and wherein furthermore:the volume of the pores is from 0.30 to 0.70 cm.sup.3 /g and the surface area is from 0.30 to 3 m.sup.2 /g, the average radius of the pores being from 650 to 2200 nanometers;the SiO.sub.2 content is equal to or lower than 75% by weight and the Fe.sub.2 O.sub.3 content is equal to or greater than 0.90% by weight.

Abstract: A catalyst suitable for use as a three-way catalyst having low H.sub.2 S emissions for emission control and with substantially no ceria present is made with a refractory oxide particle or powder support having deposited thereon about 0.5-20% by weight of a non-rate earth oxide stabilizer, at least 0.5 to about 5% by weight of an alkali metal oxide as a promoter, and a catalytically-effective amount of one or more platinum group metals. The preferred refractory oxide is alumina and the non-rare earth oxide stabilizer can be an oxide such as ZrO.sub.2, MgO, CaO, SnO, CaO, Y.sub.2 O.sub.3, TiO.sub.2, ZnO, B.sub.2 O.sub.3, P.sub.2 O.sub.5, SnO.sub.2, Bi.sub.2 O.sub.3, or SiO.sub.2 with the preferred oxide being zirconia.

Abstract: In a method for producing a catalyst for oxidizing sulfurous acid gas which uses vanadium pentaoxide as a main catalyst, potassium salts as subsidiary catalysts and diatomaceous earth as a carrier; disclosed is a method for producing a parallel gas flow type catalyst for oxidizing sulfurous acid gas, characterized in that after an ingredient mixture of a solution containing vanadium pentaoxide and potassium salts, diatom earth, water and a binder containing sodium polyacrylate is knead, said ingredient mixture is extrusion molded into a shape in which gas passage holes have a honeycomb or grid structure.

Abstract: Catalytic materials are modified by adding one or more electropositive and/or electronegative elements thereto in amounts sufficient to adjust the resultant geometric mean electronegativity to a value within a desired or predetermined range. The invention is particularly suited to the preparation of hydrocarbon hydroprocessing catalysts, particularly with respect to hydrodesulfurization catalysts comprising a support material containing a porous refractory oxide. With such catalysts, not only is the geometric mean electronegativity adjusted to a desired value, but if the electropositive or electronegative element added to the catalyst has pore growth promotion properties, the average pore size of the resultant catalyst is increased while its surface area, and usually also its total pore volume, is decreased.

Abstract: The invention relates to a process for the preparation of a glyoxylic acid ester by oxydehydrogenation of the corresponding glycolic acid ester in the gas phase over a supported catalyst in a tubular reactor. The catalyst support consists of at least one cylindrical monolith which essentially has the same diameter as the reactor tube and contains channels with a diameter of 1 to 10 mm leading from the inlet to the outlet of the reactor tube. 60 to 90% of the monolith volume is formed by hollow spaces.

Abstract: Polyoxoanions are converted to the corresponding heteropolyacids by conversion to their tetrabutylammonium salt followed by pyrolysis.

Abstract: Diphenylamine which is unsubstituted or substituted by alkyl or alkoxy groups can be prepared by treating appropriately substituted dicyclohexylamine with 1-10 bar of H.sub.2 over catalysts containing 0.05-5% by weight of rhodium at 250.degree.-450.degree. C. In addition to rhodium, the catalysts contain at least one other platinum metal from the group consisting of palladium, platinum and iridium on a support containing the noble metals in a total amount of 0.05-5% by weight, the percentage by weight of rodium with respect to all noble metals being 10-90%, and furthermore containing additives of 1-6% by weight of an alkali metal hydroxide and 1-6% by weight of an alkali metal sulphate. All percentages are based on the total weight of the catalyst.

Abstract: A catalyst used for producing, by catalytic gas phase oxidation of a C.sub.3 -C.sub.5 oelfin or tertiary alcohol, the corresponding unsaturated aldehyde and unsaturated carboxylic acid, said catalyst characterized by comprising molybdenum, iron and bismuth and having a specific surface area in the range from 1 to 20 m.sup.2 /gr, a pore volume in the range from 0.1 to 1.0 cc/gr and a pore diameter distribution in which the pore diameters are collectively distributed in the range of each of from 1 to 10 microns and from 0.1 to less than 1 micron; and a process for preparing said catalyst by charging an unfired material power into a centrifugal flow coating device to form particles having the average particle diameter of 2 to 10 mm and then firing the particles.

Abstract: Catalytic compositions which comprise alumina bound spinel and/or spinel-mullite mixtures having an alkali metal content of below about 0.50 weight percent, preferably below about 0.10. The compositions are obtained by calcining a caustic leaching preformed particulate composites of clay and alumina sol, preferably chlorhydrol. The catalysts are particularly useful for the catalytic cracking of heavy hydrocarbon feedstocks to obtain gasoline and light cycle oil. When used for cracking feedstocks high in vanadium content these compositions may contain added alkaline earth oxide in order to passivate the vanadium.

Abstract: A process of oxidizing an olefin having at least three carbon atoms directly to the corresponding epoxide comprising contacting the olefin with oxygen in the presence of a catalyst comprising a mixed silver-promoter metal (+2 or +3) silicate. In the direct oxidation of propylene the process yields a high selectivity to propylene oxide.

Abstract: A particulate catalyst, especially suitable for condensation of an alpha, beta-ethylenically unsaturated monocarboxylic acid with formaldehyde, is disclosed. The catalyst comprises a catalyst support constituted by porous silica gel, and cesium ions in the +1 oxidation state on the catalyst support surface. The catalyst support has a surface area of about 50 to about 150 m.sup.2 /gram, a porosity of less than about 1 cm.sup.3 /gram, and a pore-size distribution such that less than about 10 percent of the pores present in the catalyst have a pore diameter greater than about 750 Angstroms. The cesium ions are present in an amount of about 4 to about 10 percent by weight, based on the weight of the catalyst. Also disclosed are methods of making the catalyst. One method contemplates combining, with agitation, a silica sol and a cesium compound able to provide cesium in the +1 oxidation state on the catalyst support surface. The silica sol has a silica particle diameter of about 50 to about 200 Angstroms.

Abstract: Catalytic vapor phase intramolecular dehydration reaction of an alkanolamine represented by the general formula ##STR1## wherein each of R and R' is selected from hydrogen, a methyl group and an ethyl group, and n is an integer of 2 to 5, to convert it into a cyclic amine represented by the general formula ##STR2## wherein R, R' and n are as defined above. The catalyst is an oxide composition represented by the following formulaSi.sub.a X.sub.x Y.sub.y O.sub.bwherein Si is silicon, X is at least one element selected from alkali metals and alkaline earth metals, Y is at least one element selected from B, Al, Ti, Zr, Sn, Zn and Ce, and O is oxygen; and the suffixes a, x, y and b represent the atomic ratios of the elements Si, X, Y and O respectively, and when a=1, x=0.0005-1 and y=0-1, and b is a value determined by a, x and y.

Abstract: A composite having ultra-fine gold particles uniformly and strongly immobilized in a deposited state on a metal oxide is obtained by preparing a solution containing the metal oxide as a carrier and a gold compound, adjusting the pH value of the solution to a specific level thereby inducing precipitation and deposition of gold hydroxide or gold on the carrier and, when the precipitate is in the form of gold hydroxide, further, firing the precipitate. The ultra-fine gold particles immobilized on metal oxides are useful as a catalyst for reduction and oxidation, in sensor elements for flammable gases, and as an electrode catalyst.

Abstract: Acrolein and acrylic acid are produced by vapor-phase catalytic oxidation of propylene in a multi-tubular, fixed-bed reaction vessel with the use of a composite oxide catalyst represented by the formula Mo.sub.a Bi.sub.b Fe.sub.c A.sub.d B.sub.e C.sub.f D.sub.g Si.sub.h O.sub.x, wherein A, B, C, and D represent components selectable from respective groups of elements, and the subscripts a through h and x are specific numbers of atoms of respective elements and groups of elements. This catalyst is adapted and packed in each reaction tube in a manner such that its activity is controlled to increase from the inlet toward the outlet of the tube.

Abstract: A catalyst and a process for oxidative coupling of methane, the catalyst being a mixed basic metal oxide catalyst. One preferred catalyst is boron/alkali metal promoted metal oxide.

Abstract: Catalytic materials are modified by adding one or more electropositive and/or electronegative elements thereto in amounts sufficient to adjust the resultant geometric mean electronegativity to a value within a desired or predetermined range. The invention is particularly suited to the preparation of hydrocarbon hydroprocessing catalysts, particularly with respect to hydrodesulfurization catalysts comprising a support material containing a porous refractory oxide. With such catalysts, not only is the geometric mean electronegativity adjusted to a desired value, but if the electropositive or electronegative element added to the catalyst has pore growth promotion properties, the average pore size of the resultant catalyst is increased while its surface area, and usually also its total pore volume, is decreased.

Abstract: The present invention provides a process for the production of methacrolein and methacrylic acid by the gas phase catalytic oxidation of isobutylene or t-butanol at high temperature using molecular oxygen in the presence of catalyst consisting of molybdenum, tungsten, bismuth, iron, nickel, antimony, and an alkali metal, to which zinc or lead is added, and further phosphorus sulfur, silicon, selenium, germanium or boron, and magnesium, cobalt, manganese or tin are added.

Abstract: A silver-deposited catalyst for production of ethylene oxide by oxidizing ethylene, having high selectivity and long life, is provided by this invention. The catalyst is characterized by a combination of (a) catalyst ingredients comprising silver and a cation component selected at least from sodium, potassium, rubidium and cesium, and (b) a carrier composed mainly of alpha-alumina, said carrier having a surface area of 0.6 to 2 m.sup.2 /g, a water absorption of 20 to 50%, a silica content of 0.5 to 12% by weight, a silica content, per m.sup.2 /g of surface area, of 0.5 to 12, preferably 1 to 8, and a sodium content of 0.08 to 2% by weight.

Abstract: Catalyst supports, catalyst systems, method for the preparation thereof, and dimerization process therewith are provided catalyst supports are prepared from an alkali metal carbonate, water, alcohol, and optionally at least one carbonaceous compound. Catalyst systems comprise at least one elemental alkali metal deposited on the catalyst support. Optionally, the catalyst system further comprises at least one promoter.

Abstract: A catalyst is disclosed which comprises a molybdenum-tungsten-containing complex represented by the formulaMo.sub.a W.sub.b M.sub.c A.sub.d O.sub.

Abstract: A catalyst and process for production of an alpha, beta-ethylenically unsaturated monocarboxylic acid made by condensing formaldehyde with, for example, propionic acid, which catalyst is made from a SiO.sub.2 -SnO.sub.2 mixed-oxide component consisting of porous silica gel and tin (IV) oxide and a cesium ion component.

Abstract: Ammoxidation of C.sub.3 to C.sub.5 acyclic alkanes with NH.sub.3 and O.sub.2 using (1) a mole ratio of alkane:NH.sub.3 in the range from 2 to 16 and a mole ratio of alkane:O.sub.2 in the range 1 to 10 and (2) a mixture of particulate catalyst compositions, the first being especially effective to promote formation of an unsaturated nitrile and an olefin from the paraffin, and the second catalyst composition being especially effective to promote the conversion of the olefin to the unsaturated nitrile. Catalytic compositions useful in the process are disclosed.

Abstract: A process for preparing iron-based catalysts for the synthesis of ammonia by melting of magnetite along with metal oxides as promoters, subsequent cooling of the molten mass and reduction thereof to the desired size, wherein the abovesaid cooling occurs at a rate higher than 25.degree. C./min., preferably ranging from 100.degree. C. to 1600.degree. C./min., at a temperature ranging from 1700.degree. C. to 700.degree. C.The present invention relates to a process for preparing iron-based catalysts having a high activity in the ammonia synthesis, and to the catalyst so obtained.

Abstract: Ammoxidation of C.sub.3 to C.sub.5 acyclic alkanes with NH.sub.3 and O.sub.2 using (1) a mole ratio of alkane:NH.sub.3 in the range from 2 to 16 and a mole ratio of alkane:O.sub.2 in the range 1 to 10 and (2) a mixture of particulate catalyst compositions, the first being especially effective to promote formation of an unsaturated nitrile and an olefin from the paraffin, and the second catalyst composition being especially effective to promote the conversion of the olefin to the unsaturated nitrile. Catalytic compositions useful in the process are disclosed.