Abstract: The invention relates to a catalyst which contains a catalytically active quantity of at least one oxygen-containing molybdenum and/or wolfram compound on an oxidic support material and which has been calcinated at temperatures of 400 to 900° C. after the precursor compound of the catalytically active compounds have been applied to the support material or to a support material precursor. The transport pores for this catalyst each have a diameter of >25 nm and a volume of at least 50 mm3/g. The catalyst contains x ?mol (wolfram and/or molybdenum)/m2 molybdenum and/or wolfram, with 10.1<x<20.9 in relation to the finished catalyst, with the oxidic support material having a BET surface area of 135 to 220 m2/g. Catalysts of this type are characterized by an acidity of at least 70 ?mol/g at pKs<?3 in the dry state and are therfore very active. The invention also relates to a method for producing a catalyst of this type and to the preferred use thereof.

Abstract: The invention relates to a catalyst which contains a catalytically active quantity of at least one oxygen-containing molybdenum and/or wolfram compound on an oxidic support material and which has been calcinated at temperatures of 400 to 900° C. after the precursor compound of the catalytically active compounds have been applied to the support material or to a support material precursor. The transport pores for this catalyst each have a diameter of >25 nm and a volume of at least 50 mm3/g. The catalyst contains x &mgr;mol (wolfram and/or molybdenum)/m2 molybdenum and/or wolfram, with 10.1<x<20.9 in relation to the finished catalyst, with the oxidic support material having a BET surface area of 135 to 220 m2/g. Catalysts of this type are characterized by an acidity of at least 70 &mgr;mol/g at pKs<−3 in the dry state and are therfore very active. The invention also relates to a method for producing a catalyst of this type and to the preferred use thereof.

Abstract: A coated catalyst for the catalytic gas-phase oxidation of aromatic hydrocarbons comprises, on an inert nonporous support, a catalytically active composition comprising a defined amount of vanadium oxide, titanium dioxide, a cesium compound, a phosphorus compound, and antimony oxide, wherein the catalytically active composition is applied in two or more layers and where relative to the inner layer or inner layers the outer layer has an antimony oxide content which is from 50 to 100% lower and wherein the amount of catalytically active composition of the inner layer or layers is from 10 to 90% by weight of the amount of catalytically active composition, and can be used for preparing carboxylic acids and/or anhydrides, in particular phthalic anhydride; also specified is a production process for such catalysts.

Abstract: The invention relates to a method for producing shell catalysts for the catalytic vapor-phase oxidation of aromatic carboxylic acids and/or carboxylic acid anhydrides comprised of a supporting core and of catalytically active metal oxides which are deposited in a shell-shaped manner on said supporting core. The inventive catalysts are obtained by spraying an aqueous active mass suspension, said suspension containing the active metal oxides, at higher temperatures onto the hot supporting material which has a temperature ranging from 50 to 450° C. The aqueous active mass suspension contains 1 to 10 wt. %, with regard to the solid content of the active mass suspension, a binding agent comprised of A) a polymerizate obtained by radical polymerization, containing 5 to 100 wt. % of monomers (a) in the form of ethylenically unsaturated acid anhydrides or ethylenically unsaturated dicarboxylic acids whose carboxyl groups can form an anhydride and containing 0 to 95 wt.

Abstract: A catalyst comprising at least one metal of the 10th group of the Periodic Table of the Elements and at least one metal of the 11th group of the Periodic Table of the Elements on an aluminum oxide support, wherein the metal or metals of the 10th group is or are essentially concentrated in an outer layer close to the surface of the catalyst particle, the metal or metals of the 11th group is or are distributed essentially uniformly over the volume of the catalyst particle and the weight ratio of the metal or metals of the 11th group to the metal or metals of the 10th group is not more than 1.95.

Abstract: A coated catalyst which consists of a hollow cylindrical carrier and a catalytically active oxide material applied to the outer surface of the carrier, the applied catalytically active oxide material being applied in a coat thickness of from 10 to 1000 &mgr;m, and having a specific catalytic surface area of from 20 to 30 m2/g and an abrasion of <10, preferably <5, particularly preferably <0.5, % by weight in the turntable abrasion test.

Abstract: A coated catalyst which consists of a hollow cylindrical carrier and a catalytically active oxide material applied to the outer surface of the carrier, the applied catalytically active oxide material being applied in a coat thickness of from 10 to 1000 .mu.m, and having a specific catalytic surface area of from 20 to 30 m.sup.2 /g and an abrasion of <10, preferably <5, particularly preferably <0,5, % by weight in the turntable abrasion test. The catalyst is useful in the preparation of acrylic acid by the gas phase oxidation of acroleins.

Abstract: Cobalt catalysts whose catalytically active composition comprises from 55 to 98% by weight of cobalt, from 0.2 to 15% by weight of phosphorus, from 0.2 to 15% by weight of manganese and from 0.05 to 5% by weight of alkali metal, calculated as oxide, are prepared by calcining the catalyst composition, reducing it at final temperatures of from 200.degree. to 400.degree. C. in a stream of hydrogen and subsequently surface-oxidizing it by treatment in a stream of air at final temperatures of from 20.degree. to 60.degree. C. and can be used in a process for hydrogenating organic nitriles and/or imines.

Abstract: A catalyst which consists of a carrier and a catalytically active oxide material applied to the surface of the carrier is prepared by a process in which the carrier is first moistened with, as an adhesive liquid, an aqueous solution of an organic substance boiling at above 100.degree. C. at atmospheric pressure and a layer of active oxide material is then bonded to the surface of the moistened carrier by bringing it into contact with dry, finely divided active oxide material and the adhesive liquid is then removed from the moistened carrier coated with active oxide material.

Abstract: Cobalt catalysts whose catalytically active material comprises from 55 to 98 wt % of cobalt, from 0.2 to 15 wt % of phosphorus, from 0.2 to 15 wt % of manganese, and from 0.2 to 15 wt % of alkali metal, calculated as oxide, in which the catalyst material is calcined in a first step at final temperatures of from 550.degree. to 750.degree. C. and in a second step at final temperatures of from 800.degree. to 1000.degree. C., and a process for the hydrogenation of organic nitriles and/or imines, in which the novel cobalt catalyst is used.

Abstract: Heat-curable bismaleimide resins contain a bismaleimide and a heterocyclic comonomer having terminal alkenyl or alkenyloxy groups. A preferred comonomer is 2,6-bis-(2-propenylphenoxy)-pyridine. The bismaleimide resins are suitable for the production of high performance composites.