Abstract: Catalysts comprising a catalytically active composition, the catalytically active composition comprising vanadium, phosphorus, iron and oxygen, wherein the catalytically active composition has an iron:vanadium atomic ratio of 0.005 to <0.05, and wherein iron in the catalytically active composition is derived from an iron starting material comprising Fe(III) phosphate; and processes for making such catalysts as well as uses therefor to prepare maleic anhydride are described.

Abstract: A process for preparing a coated catalyst in which a finely divided mixture of a multielement oxide comprising the elements Mo and V and a molybdenum oxide or a molybdenum oxide former is applied to the surface of a support body as an active composition.

Abstract: Processes comprising providing a catalyst precursor, and heating the catalyst precursor to a temperature of at least 350° C. in an atmosphere comprising air, wherein air is fed into the atmosphere at a rate of 0.05 to 4.0 standard m3/h, and wherein the catalyst precursor is activated at a temperature of at least 350° C. for more than 9 hours are described along with catalysts formed thereby and uses for such catalysts.

Abstract: A process for preparing shaped catalyst bodies whose active composition is a multielement oxide, in which a finely divided precursor mixture with addition of graphite having a specific particle size is shaped to the desired geometry and then treated thermally.

Abstract: A reactor for testing catalyst systems which has a plurality of catalyst tubes (2) which are arranged parallel to one another in the interior space of the reactor and whose ends are welded into tube plates and also has caps (3) at each end of the reactor which each bound a cap space (4), with a fluid reaction medium (5) being fed via one cap space (4) into the catalyst tubes (2), flowing through the catalyst tubes (2) and being discharged via the other cap space (4), and is also provided with a heat exchange medium circuit in which the heat exchange medium (6) is fed in at one end of the reactor, flows through the intermediate space between the catalyst tubes (2) and flows out at the other end of the reactor, wherein the catalyst tubes (2) are arranged in two or more catalyst tube regions (7) which are thermally separate from one another, is proposed.

Abstract: The invention relates to a process for preparing phthalic anhydride, in which the catalytic gas-phase oxidation of o-xylene and/or naphthalene is carried out over at least three zones of catalysts of increasing activity, with only the last zone of the catalyst system containing phosphorus and the last zone also comprising at least 10% by weight of vanadium (calculated as V2O5) based on the active composition of the catalyst and having a ratio of vanadium (calculated as V2O5) to phosphorus of greater than 35.

Abstract: The invention relates to a process for preparing nitrogen-containing catalysts, comprising: a) preparation of an oxidic species comprising the following components: at least one metal M selected from groups Ib to VIIb and VIII of the Periodic Table of the Elements, it being possible for the same metal to be present in different oxidation states; if appropriate one or more promoters P selected from groups Ib to VIIb and VIII of the Periodic Table of the Elements, the lanthanides, and from groups IIIa to VIa of the Periodic Table of the Elements, excluding oxygen and sulfur; if appropriate one or more elements R selected from hydrogen, alkali metals and alkaline earth metals; if appropriate one or more elements Q selected from chloride and sulfate; oxygen, the molar proportion of oxygen being determined by the valency and frequency of the elements in the oxidic species other than other oxygen; b) reaction of the oxidic species with an amine component selected from ammonia, primary and secondary amines and

Abstract: A description is given of a process for preparing aldehydes, carboxylic acids and/or carboxylic anhydrides, in particular phthalic anhydride, in which a gaseous stream comprising an aromatic hydrocarbon and molecular oxygen is passed at elevated temperature over a bed of a first catalyst and a bed which is made up of a second catalyst having a higher activity than the first catalyst and is located downstream of the first catalyst in the flow direction of the gaseous stream, wherein the catalytically active composition of the first catalyst comprises at least vanadium oxide, titanium dioxide and antimony oxide and the ratio of vanadium, calculated as V2O5, to antimony, calculated as Sb2O3, in the first catalyst is from 3.5:1 to 5:1. The source of antimony oxide used for the first catalyst is preferably particulate antimony trioxide having a mean particle size of from 0.5 to 5 ?m. The process allows the desired oxidation products to be obtained in high yield over longer periods of time.

Abstract: Catalytic titanium dioxide mixtures comprising: a first anatase titanium dioxide having a BET surface area greater than 15 m2/g and a hydrogen uptake for the reduction of Ti4+ to Ti of from 5 to 20 ?mol/m2; and a second anatase titanium dioxide having a BET surface area less than or equal to 15 m2/g and a hydrogen uptake for the reduction of Ti4+ to Ti3+ of from 0.6 to 7 ?mol/m2, processes for preparing catalysts containing the same, catalysts containing active compositions including such titanium dioxide mixtures on support materials, and catalyst systems using the same.

Abstract: A catalyst is described which has a catalytically active composition which contains a phase A and a phase B in the form of three-dimensional delimited regions, wherein phase A is a silver-vanadium oxide bronze and phase B a mixed oxide phase based on titanium dioxide and vanadium pentoxide. The catalyst serves to prepare aldehydes, carboxylic acids and/or carboxylic anhydrides from aromatic or heteroaromatic hydrocarbons by gas phase oxidation.

Abstract: Multimetal oxides corresponding to the general formula (I), processes for their preparation, precatalysts containing such oxides and catalysts made therefrom for gas phase partial oxidation of hydrocarbons: Aga-cQbMcV12Od.eH2O??(I) wherein a represents a number having a value of 5 to 9; Q represents an element selected from the group consisting of P, As, Sb, Bi and mixtures thereof; b represents a number having a value of 0.

Abstract: The present invention relates to a process for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of a hydrocarbon, which comprises feeding a hydrocarbon-comprising stream and a stream comprising oxygen or an oxygen source into a microchannel reactor and carrying out the reaction to form maleic anhydride in the explosive range in the microchannel reactor comprising the catalyst.

Abstract: The invention relates to a process for preparing unsaturated nitrites from the corresponding alkanes which comprises the steps: a) feeding an alkane into a dehydrogenation zone and catalytically dehydrogenating the alkane to the corresponding alkene to obtain a product gas stream A which comprises the alkene, unconverted alkane and possibly one or more further gas components selected from the group consisting of steam, hydrogen, carbon oxides, hydrocarbons having a lower boiling point than the alkane or the alkene (low-boilers), nitrogen and noble gases, b) at least partially removing further gas components from the product gas stream A to give a feed gas stream B which comprises the alkane and the alkene, c) feeding the feed gas stream B, ammonia, an oxygen-containing gas and, if desired, steam into an oxidation zone and catalytically ammoxidizing the alkene to the corresponding unsaturated nitrile to give a product gas stream C which comprises the unsaturated nitrile, ammoxidation by-products, unconverte

Abstract: A catalyst is described which has a catalytically active composition which contains a phase A and a phase B in the form of three-dimensional delimited regions, wherein phase A is a silver-vanadium oxide bronze and phase B a mixed oxide phase based on titanium dioxide and vanadium pentoxide. The catalyst serves to prepare aldehydes, carboxylic acids and/or carboxylic anhydrides from aromatic or heteroaromatic hydrocarbons by gas phase oxidation.

Abstract: A process for preparing (meth)acrylic acid by heterogeneously catalyzed gas phase partial oxidation of a saturated hydrocarbon precursor compound, in which the charging gas mixture contains from 5 to 25% by volume of steam and the molar ratio of molecular oxygen present in the charging gas mixture to saturated hydrocarbon precursor compound present in the charging gas mixture is from 1.5:1 to 2.5:1.

Abstract: The invention relates to a process for producing a catalyst for gas-phase oxidations, which comprises weighing a particulate inert support having a total mass of Msupport into a fluidized-bed apparatus, providing an aqueous suspension of a catalytically active material or sources therefor and a binder having a binder content of Bsusp, fluidizing the inert support by introduction of a gas stream heated to a temperature of Tgas at a flow rate of Qgas, and spraying the suspension at a rate of Qsusp onto the fluidized inert support. When Qgas, Qsusp, Bsusp, Msupport and Tgas are selected within the ranges 3000?Qgas [m3/h]?9000, 1000?Qsusp [g/min]?3500, 2?Bsusp [% by weight]?18, 60?Msupport [kg]?240. 75?Tgas [° C.]?120 so that a parameter K defined as K=0.020 Qgas?0.055 Qsusp+7.500 Bsusp?0.667 Msupport+2.069 Tgas?7 satisfies the relationship 127.5?K?202, high-quality coatings can be produced and the formation of twins made up of support particles adhering to one another can be avoided.

Abstract: A process is described for producing a catalyst for gas-phase oxidations, in which a suspension of TiO2 and V2O5 particles is applied to a fluidized inert support, wherein at least 90% by volume of the V2O5 particles have a diameter of 20 ?m or less and at least 95% by volume of the V2O5 particles have a diameter of 30 ?m or less. The defined particle size distribution of the V2O5 allows a high coating efficiency.

Abstract: The invention relates to a process for preparing phthalic anhydride, in which the catalytic gas-phase oxidation of o-xylene and/or naphthalene is carried out over at least three zones of catalysts of increasing activity, with only the last zone of the catalyst system containing phosphorus and the last zone also comprising at least 10% by weight of vanadium (calculated as V2O5) based on the active composition of the catalyst and having a ratio of vanadium (calculated as V2O5) to phosphorus of greater than 35.

Abstract: A description is given of a process for preparing aldehydes, carboxylic acids and/or carboxylic anhydrides, in particular phthalic anhydride, in which a gaseous stream comprising an aromatic hydrocarbon and molecular oxygen is passed at elevated temperature over a bed of a first catalyst and a bed which is made up of a second catalyst having a higher activity than the first catalyst and is located downstream of the first catalyst in the flow direction of the gaseous stream, wherein the catalytically active composition of the first catalyst comprises at least vanadium oxide, titanium dioxide and antimony oxide and the ratio of vanadium, calculated as V2O5, to antimony, calculated as Sb2O3, in the first catalyst is from 3.5:1 to 5:1. The source of antimony oxide used for the first catalyst is preferably particulate antimony trioxide having a mean particle size of from 0.5 to 5 ?m. The process allows the desired oxidation products to be obtained in high yield over longer periods of time.

Abstract: The invention relates to an apparatus for mixing, drying and coating pulverulent, granular or shaped loose material in a fluidized bed, in particular for use in a process for producing supported catalysts for gas-phase oxidations, which comprises a container (10) for accommodating the loose material, with a bowl-like depression (17) being provided in a lower region (13) of the container (10), a central tube (27) for introducing a gas, with the central tube entering the container in an upper region (12) of the container (10), extending essentially axially downward in the container (10) and opening into the depression (17), an essentially annular deflection shield (29) which is fixed to the central tube (27) in the upper region (12) of the container (10), a guide ring (31) which is located in the lower region (13) of the container (10) and surrounds the central tube (27) essentially concentrically at a distance (L) for part of its length so that a first opening (34) is formed between the wall of the container (