Abstract: In accordance with the process of this invention, an improved catalyst for molecular oxidation of a hydrocarbon to form the corresponding carboxylic anhydrides is prepared by the steps of (a) forming a catalyst precursor by depositing on titanium dioxide solids in the anatase form a discontinuous monolayer amount of at least one source of a Group VIB metal oxide; (b) calcining the thus-formed catalyst precursor under conditions sufficient to convert the Group VIB metal oxide source into the corresponding group VIB metal oxide; (c) depositing upon amount of at least one vanadium oxide source which is calcining the vanadium-deposited solids under conditions sufficient to convert the vanadium compound into vanadium oxide.

Abstract: The present invention relates to a process for the regeneration and stabilization of certain phosphorus-vanadium-oxygen complex catalysts or phosphorus-vanadium-oxygen co-metal complex catalysts, with halogen-containing components and subsequently treating the catalyst with phosphorus compounds. These catalysts are useful for the manufacture of maleic anhydride from butane feedstock.

Abstract: Maleic anhydride is produced by the catalytic vapor phase partial oxidation of a nonaromatic hydrocarbon having at least four carbon atoms in a straight chain with molecular oxygen or a molecular oxygen-containing gas in the presence of phosphorus-vanadium mixed oxide oxidation catalyst. The catalyst is diluted with an inert solid material in an amount sufficient to form a catalyst-inert solid material composition effective to stabilize the maleic anhydride yield such that the average yield decay is less than 0.30% of the established initial maleic anhydride yield per month over an extended period of sustained operations.

Abstract: In accordance with the process of this invention, an improved catalyst for molecular oxidation of a hydrocarbon to form the corresponding carboxylic anhydrides is prepared by the steps of (a) forming a catalyst precursor by depositing on titanium dioxide solids in the anatase form at least a monolayer amount of at least one vanadium oxide source which is convertible to vanadium oxide upon calcining; (b) calcining the thus-formed catalyst precursor under conditions sufficient to convert the tantalum oxide source into the oxide form; (c) depositing upon the calcined catalyst precursor a catalytically effective amount of at least one vanadium oxide source which is convertible into vanadium oxide upon heating and at least one metal oxide source selected from the group consisting of oxides of Sb, Ga, Ge, In, T.sub.1, Pb, Se, Te, P and Bi, which is convertible into the corresponding metal oxide upon heating and which is reactive with V.sub.2 O.sub.

Abstract: A catalyst for the oxidation of butane to produce maleic anhydride comprising a substrate containing phosphorus and vanadium or alternatively phosphorus, vanadium and a co-metal characterized by the presence of post deposited vanadium. A process for the manufacture of maleic anhydride from butane feedstock using the novel catalyst is also described. Maleic anhydride is useful in the manufacture of alkyd resins.

Abstract: A catalyst for the oxidation of butane to produce maleic anhydride comprising a substrate containing phosphorus and vanadium or alternatively phosphorus, vanadium and a co-metal characterized by the presence of post deposited vanadium. A process for the manufacture of maleic anhydride from butane feedstock using the novel catalyst is also described. Maleic anhydride is useful in the manufacture of alkyd resins.

Abstract: A process is disclosed for the improvement of a vanadium-phosphorus-oxygen catalyst or a vanadium-phosphorus-oxygen-co-metal catalyst suitable for use in the manufacture of maleic anhydride from butane, which process comprises applying in situ water and a phosphorus compound in an amount to partially deactivate a portion of the catalyst in a catalyst bed containing an exotherm of reaction which was present in the catalyst bed prior to the addition of the phosphorus compound, thereby moving the exotherm downstream into the catalyst bed and thus improving the catalyst.These catalysts are useful for the manufacture of maleic anhydride from butane feedstock.

Abstract: A method of optimizing the yield of a vanadium-phosphorus catalyst during the oxidation of butane to maleic anhydride, which comprises establishing the temperature at which the catalyst provides the desired percentage conversion and yield of maleic anhydride with the established feed composition and then maintaining that temperature by continuously introducing an amount of a suitable phosphorus compound necessary to prevent a decline in selectivity to maleic anhydride without significantly increasing the temperature.

Abstract: A process for the reactivation of vanadium-phosphorus-oxygen catalyst with alkyl esters of phosphoric acid and water is disclosed. The catalysts are useful for the manufacture of maleic anhydride from C.sub.4 hydrocarbon benzene feedstock.

Abstract: This invention relates to highly attrition resistant catalysts, catalyst precursors and catalyst supports and to processes for making and using them.

Abstract: A process for activating fluid bed catalysts useful for producing maleic anhydride from 4 carbon atom hydrocarbons is provided including contacting the fluidized catalyst containing the mixed oxides of vanadium and phosphorus with oxygen and a reducing gas at least partially combustible with oxygen at elevated temperatures sufficient to cause such combustion, wherein the molar ratio of reducing gas to oxygen is greater than the stoichiometric ratio required for complete combustion of the reducing gas. Also provided are catalysts activated by the process of the invention, as well as a process for producing maleic anhydride utilizing the catalysts thus activated.

Abstract: Catalyst containing a vanadium/phosphorus complex oxide, for the oxidation of hydrocarbons to maleic anhydride. The catalyst contains 1 to 1.3 atoms of phosphorus per atom of vanadium. The pore volume of those pores which have a radius of 100 to 1,000 .ANG. is at least 30 percent of the total pore volume of the pores which have a radius of less than 10,000 .ANG.. The method for preparing the catalyst involves introducing a phosphorus-containing compound into an organic solvent, and continuously adding a vanadium-containing compound over the course of 0.5 to 4 hours. 1 to 1.3 atoms of phosphous is employed per atom of vanadium. The water formed during the reaction is removed continuously and directly from the reaction mixture. Thereafter the reaction mixture is separated. The V-P-O complex oxide is isolated as a solid, dried at a temperature of 90.degree. to 150.degree. C. and activated at a temperature of 200.degree. to 300.degree. C. to provide the catalyst.

Abstract: Improved supported, mixed-metal oxide oxidation catalysts are prepared by conditioning a devolatilized catalyst precursor with an alcohol prior to calacining the precursor to a finished catalyst. For example, a promoted bismuth phosphomolybdate oxidation catalyst useful for converting propylene to acrolein demonstrates enhanced performance characteristics when the devolatilized catalyst precursor is subjected to boiling ethanol prior to calcining it to a finished catalyst.

Abstract: A process is disclosed for the improvement of a vanadium-phosphorus-oxygen catalyst or a vanadium-phosphorus-oxygen-co-metal catalyst suitable for use in the manufacture of maleic anhydride from butane, which process comprises applying in situ water and a phosphorus compound in an amount to partially deactivate a portion of the catalyst in a catalyst bed containing an exotherm of reaction which was present in the catalyst bed prior to the addition of the phosphorus compound, thereby moving the exotherm downstream into the catalyst bed and thus improving the catalyst.These catalysts are useful for the manufacture of maleic anhydride from butane feedstock.

Abstract: An improved vanadium/phosphorus catalyst for the oxidation of n-butane to maleic anhydride is disclosed. Preferably, the catalyst contains a promoter. A process for the oxidation of n-butane to maleic anhydride using the improved catalyst is also disclosed.

Abstract: A process for the manufacture of a phosphorus-vanadium and phosphorus-vanadium co-metal catalysts suitable for use in the manufacture of maleic anhydride from benzene, butane, and other C.sub.4 hydrocarbons which process comprises reacting at a temperature of about 0.degree. C. to about 200.degree. C. a vanadium compound in an organic ether solvent having about 2 to about 10 carbon atoms with a phosphoryl halide in the presence of water or an aliphatic alcohol having from about 1 to about 8 carbon atoms, eliminating the solvent and activating the catalyst by the addition of the hydrocarbon feedstock and water and a phosphorus compound at a temperature of about 300.degree. C. to about 500.degree. C. wherein the amount of water added is about 1000 parts per million to about 40,000 parts per million by weight of the reactor feed gas stream is disclosed. The catalysts are useful for the manufacture of maleic anhydride from butane, benzene, and other C.sub.4 hydrocarbon feedstocks.

Abstract: Iron/lithium promoted phosphorus-vanadium-oxygen catalysts for the production of maleic anhydride are prepared by contacting a substantially tetravalent vanadium-containing compound and a phosphorus-containing compound and a promoter component containing each of iron and lithium in a substantially anhydrous alcohol medium in the presence of anhydrous hydrogen chloride to form an iron/lithium promoted phosphorus-vanadium-oxygen catalyst precursor. The catalyst precursor is recovered, dried, roasted, formed into structures if structures are desired, and calcined.

Abstract: Oxidation of butane to maleic anhydride using a vanadium-phosphorus oxide catalyst, in oxidized form, wherein the resulting reduced catalyst is separately regenerated. A recirculating solids reactor can be employed. Less than the stoichiometric amount of oxygen, based on the total amount of butane converted, can be employed.

Abstract: A mixed oxide catalyst precursor comprising vanadium and phosphorus treated in finely divided form with phosphoric acid and water soluble compound of aluminum and/or boron to improve resistance to attrition.

Abstract: A process for the manufacture of novel phosphorus-vanadium and phosphorus-vanadium co-metal catalysts having a characteristic X-ray diffraction pattern suitable for use in the manufacture of maleic anhydride from benzene, butane and other C.sub.4 hydrocarbons which process comprises reacting at a temperature of about 0.degree. C. to about 200.degree. C. a vanadium compound in an organic ether solvent having about 2 to about 10 carbon atoms with a phosphoryl halide in the presence of water or an aliphatic alcohol having from about 1 to about 8 carbon atoms, eliminating the solvent and activating the catalyst by the addition of the hydrocarbon feedstock and water and a phosphorus compound at a temperature of about 300.degree. C. to about 500.degree. C. wherein the amount of water added is about 1000 parts per million to about 40,000 parts per million by weight of the reactor feed gas stream is disclosed. The catalysts are useful for the manufacture of maleic anhydride from benzene, butane and other C.sub.

Abstract: A process for the reactivation of a vanadium-phosphorus-oxygen catalyst promoted by metals selected from the group consisting of zinc, molybdenum, niobium, tungsten, uranium, cobalt and tin with alkyl esters of phosphoric acid and water is disclosed. The catalysts are useful for the manufacture of maleic anhydride from butane, butene, butadiene or benzene feedstock.

Abstract: A process is provided for the preparation of attrition resistant, microspheroidal fluid bed catalysts comprising the mixed oxides of vanadium and phosphorus in which a vanadium phosphorus mixed oxided catalyst precursor is densified, comminuted, formed into fluidizable particles and calcined under fluidization-type conditions. The present invention further provides the attrition resistant fluidizable catalysts prepared by the inventive process, and further provides a process for utilizing such attrition resistant catalysts in the production of maleic anhydride in the vapor phase by the oxidation of 4 carbon atom hydrocarbons.

Abstract: An oxidation catalyst of large surface area for converting C.sub.4 to C.sub.10 hydrocarbons to maleic anhydride comprises the oxides of vanadium, phosphorus and, optionally and preferably, tin, in combination with a microporous crystalline silica or a crystalline zeolite having a silica-to-alumina ratio of at least 6.0.

Abstract: The useful life of vanadium-phosphorus-oxygen (PVO) catalyst in fixed bed reactors can be substantially extended by treatment with a phosphorus compound followed by steam treatment. The PVO catalysts may be treated with steam after long periods (months) of only phosphorus compound treatment and the benefit of the present invention obtained or the phosphorus and steam treatments may be of only a few hours duration and sequential. In extending the useful life of the PVO catalyst according to the present invention, the temperature profile in the catalyst bed is restored to substantially the same profile as the fresh catalyst.

Abstract: A process for oxidizing a hydrocarbon to maleic anhydride using a mixed oxide catalyst of vanadium and phosphorous prepared by a procedure including pretreating the dried catalyst precursor of the said mixed oxides in finely divided form with an acid solution.

Abstract: A process for the production of maleic anhydride by catalytic air oxidation of hydrocarbons capable of being so oxidized at a temperature in the range of 300.degree.-450.degree. C.

Abstract: A process for preparing a vanadium, phosphorus oxygen containing catalyst composition capable of partially oxidizing hydrocarbons (e.g., n-butane) to form a carboxylic anhydride (e.g., maleic anhydride), and a process for using this catalyst to form such anhydrides is disclosed. The catalyst composition is prepared by an organic solution technique followed by activation in an air-hydrocarbon atmosphere.

Abstract: Phosphorus-vanadium mixed oxide oxidation catalysts are prepared by introducing a substantially pentavalent vanadium-containing compound and a pentavalent phosphorus-containing compound into an alcohol medium capable of reducing the vanadium to a valence state less than +5 in the presence of an alcohol-modifying agent to form a phosphorus-vanadium mixed oxide catalyst precursor. The catalyst precursor is recovered, dried, formed into desired structures, and calcined at temperatures from about 250.degree. C. to about 600.degree. C. The catalysts are highly effective in that they exhibit a weight/weight productivity of at least 70 grams of maleic anhydride per kilogram of catalyst per hour.

Abstract: A process for the manufacture of a phosphorus-vanadium oxide and a phosphorus-vanadium-co-metal catalyst suitable for the oxidation of butane to maleic anhydride is disclosed. The catalyst is prepared by reacting, in an aqueous medium, a vanadium compound, inorganic acid and, if used, a metal oxide. Ortho-phosphoric acid is then added to form a soluble vanadium-phosphorus or a vanadium-phosphorus-metal catalyst. The acidified water is removed and aliphatic alcohols and either aromatic acids or aromatic anhydrides, or a mixture of these, are added and the alcohols are removed. The solid phosphorus-vanadium, or phosphorus-vanadium-metal oxide is recovered under vacuum.

Abstract: Large surface area oxidation catalysts suitable for converting C.sub.4 to C.sub.10 hydrocarbons to maleic anhydride are disclosed, comprising the oxides of vanadium, phosphorus and tin in combination with a crystalline silica having a surface area between 100 M.sup.2 /g to 450 M.sup.2 /g and wherein the vanadium has an average valence in the range of from 3.5 to 4.9.

Abstract: Maleic anhydride is produced by the oxidation of a non-aromatic hydrocarbon having at least four carbon atoms in a straight chain with molecular oxygen or a molecular oxygen-containing gas in the vapor phase in the presence of a phosphorus-vanadium mixed oxide oxidation catalyst. Such catalysts are prepared by introducing a substantially pentavalent vanadium-containing compound and a pentavalent phosphorus-containing compound into an alcohol medium capable of reducing the vanadium to a valence state less than +5 in the presence of an alcohol-modifying agent to form a phosphorus-vanadium mixed oxide catalyst precursor. The catalyst precursor is recovered, dried, formed into desired structures, and calcined at temperatures from about 250.degree. C. to about 600.degree. C. The catalysts are highly effective in that they exhibit a weight/weight productivity of at least 70 grams of maleic anhydride per kilogram of catalyst per hour.

Abstract: Catalysts useful for the partial oxidation of non-aromatic hydrocarbons, particularly n-butane, with molecular oxygen or a molecular oxygen-containing gas in the vapor phase to produce maleic anhydride are provided which comprise mixed oxides of phosphorus and vanadium. The catalysts are highly effective in that they exhibit a weight/weight productivity of at least 70 grams of maleic anhydride per kilogram of catalyst per hour.

Abstract: Phosphorus-vanadium mixed oxide catalysts are prepared by contacting a tetravalent vanadium compound, dissolved in an aqueous, non-oxidizing acid medium, with crystalline diphosphoric acid to form a phosphorus-vanadium mixed oxide catalyst precursor. The resulting catalyst precursor-containing solution is subjected to a series of concentration/dilution cycles to induce crystallization of the catalyst precursor. The crystals are collected, dried, formed into desired structures, and calcined at temperatures from about 300.degree. C. to about 600.degree. C.

Abstract: An oxidation catalyst composition produced by comprising mixing at least one crystalline composite oxide, as the first component, selected from the group consisting of (i) a crystalline composite oxide containing vanadium and phosphorus and showing the characteristic X-ray diffraction peaks as identified in the following Table A and (ii) a crystalline composite oxide containing vanadium and phosphorus and showing the characteristic X-ray diffraction peaks as identified in the following Table B, an aqueous solution, as the second component, containing vanadium and phosphorus, and silica sol, as the third component, to form an aqueous slurry, spray-drying the slurry, and calcining the solid particles thereby obtained:TABLE A ______________________________________ X-ray diffraction peaks (Anticathode: Cu--K.sub..alpha.) 2.theta. (.+-.0.2.degree.) ______________________________________ 15.7.degree. 19.6.degree. 24.2.degree. 27.1.degree. 28.8.degree. 30.4.degree.

Abstract: A process is provided for activating fluidizable catalysts containing the mixed oxides of vanadium and phosphorus useful for the production of maleic anhydride from 4-carbon atom hydrocarbons and oxygen by subjecting the catalyst to fluidization conditions and contacting the fluidized catalyst with oxygen at a temperature at least 20.degree. C. greater than the temperature required to produce about 85 percent conversion of hydrocarbon. A process is also provided for adding make-up fluid bed catalyst to an equilibrated catalyst by introducing a calcined and unequilibrated make-up catalyst into the fluid bed vessel containing equilibrated catalyst, subjecting the mixture to fluidization conditions and contacting the fluidized catalyst mixture with oxygen at a temperature at least 20.degree. C. greater than the temperature required to produce about 85 percent conversion of the hydrocarbon. The catalysts so activated and a process for producing maleic anhydride from 4-carbon atom hydrocarbons is also provided.

Abstract: A vanadium, phosphorus oxygen containing catalyst composition capable of partially oxidizing hydrocarbons (e.g., n-butane) to form a carboxylic anhydride (e.g., maleic anhydride), a process for preparing this catalyst, and a process for using this catalyst to form such anhydrides is disclosed. The catalyst composition is prepared by an organic heterogenous technique followed by a water treatment step and activation.

Abstract: The useful life of vanadium-phosphorus-oxygen (PVO) catalyst in fixed bed reactors can be substantially extended by treatment with a phosphorus compound followed by steam treatment. The PVO catalysts may be treated with steam after long periods (months) of only phosphorus compound treatment and the benefit of the present invention obtained or the phosphorus and steam treatments may be of only a few hours duration and sequential. In extending the useful life of the PVO catalyst according to the present invention, the temperature profile in the catalyst bed is restored to substantially the same profile as the fresh catalyst.

Abstract: Maleic anhydride is produced by the oxidation of a nonaromatic hydrocarbon having at least four carbon atoms in a straight chain with molecular oxygen or a molecular oxygen-containing gas in the vapor phase in the presence of a phosphorus-vanadium mixed oxide catalyst. Such catalysts are prepared by contacting a tetravalent vanadium compound, dissolved in an aqueous, non-oxidizing acid medium, with crystalline diphosphoric acid to form a phosphorus-vanadium mixed oxide catalyst precursor. The resulting catalyst precursor-containing solution is subjected to a series of concentration/dilution cycles to induce crystallization of the catalyst precursor. The crystals are collected, dried, formed into desired structures, and calcined at temperatures from about 300.degree. C. to about 600.degree. C.

Abstract: A mixed oxide catalyst precursor comprising vanadium and phosphorus treated in finely divided form with phosphoric acid and water soluble compound of aluminum and/or boron to improve resistance to attrition.

Abstract: Mixed oxide catalyst of vanadium and phosphorus prepared by a procedure including pretreating the dried catalyst precursor of the said mixed oxides in finely divided form with an acid solution.

Abstract: An improvement in a process for the production of maleic anhydride by the catalytic vapor phase oxidation of a saturated aliphatic hydrocarbon having 4-10 carbon atoms in the presence of a catalyst comprising phosphorus, vanadium and oxygen, wherein long reactor tubes are used in a process employing a high feed concentration and low space velocity so as to minimize air compression.

Abstract: A novel catalyst for the oxidation of butane to produce maleic anhydride comprising a phosphorus and vanadium mixed oxide wherein the catalyst is prepared by using P.sub.2 O.sub.5 in an organic medium wherein the catalyst is not precipitated. The catalyst has a specific phase identified by a characteristic X-ray diffraction pattern. A process for the manufacture of the catalyst and a process for the manufacture of maleic anhydride from butane feedstock utilizing the novel catalyst is disclosed. Maleic anhydride is a well-known industrial chemical used in the manufacture of polyester, and maleic anhydride also has utility as a food stuff.

Abstract: A process for preparing an oxidation catalyst composition comprises mixing at least one crystalline composite oxide, as the first component, selected from the group consisting of (i) a crystalline composite oxide containing vanadium and phosphorus and showing the characteristic X-ray diffraction peaks as identified in the following Table A and (ii) a crystalline composite oxide containing vanadium and phosphorus and showing the characteristic X-ray diffraction peaks as identified in the following Table B, an aqueous solution, as the second component, containing vanadium and phosphorus, and silica sol, as the third component, to form an aqueous slurry, spray-drying the slurry, and calcining the solid particles thereby obtained:TABLE A ______________________________________ X-ray diffraction peaks (Anticathode: Cu--K.sub..alpha.) 2.theta. (.+-.0.2.degree.) ______________________________________ 15.7.degree. 19.6.degree. 24.2.degree. 27.1.degree. 28.8.degree. 30.4.degree.

Abstract: Vanadium phosphorus mixed oxide containing catalysts are prepared by sequentially forming an alpha-VOPO.sub.4 catalyst precursor in aqueous media, and thereafter partially reducing a portion of the vanadium to a valence state of +4 in an organic liquid reducing media, in the absence of corrosive reducing agents. The catalysts exhibit excellent activity for the production of maleic anhydride from 4 carbon atom hydrocarbons such as n-butane.

Abstract: Catalytic material is provided by a composition comprising the elements vanadium, non-water-contained hydrogen, phosphorus and non-water-contained oxygen. Freshly prepared catalytic material proxides relatively high yields upon its initial use in the catalytic oxidation of hydrocarbon feedstocks, such as n-butane and benzene to maleic anhydride.

Abstract: Process for the manufacture of maleic anhydride which comprises contacting in the vapor phase a mixture of butane and molecular oxygen with a catalyst comprising in chemical combination phosphorus, vanadium, oxygen and a catalyst modifier comprising titanium combined with one or more elements selected from the group consisting of aluminum, cerium, cobalt and iron.

Abstract: A process is provided for preparing supported catalysts by impregnating a pre-formed support with a solution of a metal alkoxide and contacting the impregnated support with a solution of at least one additional catalyst component. This process is particularly suitable for forming attrition resistant fluidizable catalysts. Catalysts prepared by this method are useful in various reaction processes, and may be utilized in oxidation processes such as the production of maleic anhydride from 4 carbon atom hydrocarbons.

Abstract: In conventional procedures for the preparation of phosphorus-vanadium-oxygen catalysts, with or without promoting elements or carriers, the phosphorus compounds and vanadium compounds are mixed under conditions to form precursors. These precursors are then heated to temperatures up to 600.degree. C. to form phosphorus-vanadium-oxygen catalysts suitable for the conversion of saturated hydrocarbons, such as butane, to maleic anhydride. The present invention employs a new phosphorus-vanadium-oxygen hydrogen intermediate composition which can be converted to the precursor. Catalysts formed from the intermediate are used, according to this invention, for the conversion of saturated hydrocarbons to maleic anhydride.

Abstract: The present invention provides a process for the preparation of oxidation catalysts containing mixed oxides of vanadium and phosphorus, which catalysts are particularly effective in the oxidation of n-butane, n-butenes, 1,3-butadiene or a mixture thereof with molecular oxygen or an oxygen-containing gas in the vapor phase to produce high yields of maleic anhydride with good selectivity. A vanadium compound is introduced into a liquid medium, a mixed phosphorus component comprising orthophosphoric acid and pyrophosphoric acid is added to the liquid medium, reduction of at least a portion of the vanadium to a +4 valence state is effected either prior to or subsequent to the addition of the mixed phosphorus component, and the resulting vanadium-phosphorus oxide catalyst precursor is recovered, dried and calcined.

Abstract: A novel catalyst for the oxidation of butane to produce maleic anhydride comprising a phosphorus and vanadium mixed oxide wherein the catalyst is prepared by using P.sub.2 O.sub.5 in an organic medium wherein the catalyst is not precipitated. The catalyst has a specific phase identified by a characteristic X-ray diffraction pattern. A process for the manufacture of the catalyst and a process for the manufacture of maleic anhydride from butane feedstock utilizing the novel catalyst is disclosed. Maleic anhydride is a well-known industrial chemical used in the manufacture of polyester, and maleic anhydride also has utility as a food stuff.