Abstract: Compacts based on pyrogenically produced silicon dioxide and having the following physical and chemical characteristics: Outer diameter 0.8-20 mm BET surface area 30-400 m2/g Pore volume 0.5-1.3 ml/g Breaking strength 10-250N Composition >99.8 wt. % SiO2 Other constituents <0.2 wt. % Abrasion <5 wt. % Apparent weight 350-750 g/l are produced in that pyrogenically produced silicon dioxide is homogenized with methyl cellulose, microwax and polyethylene glycol with addition of water, dried at a temperature of 80-150° C. and comminuted to a powder, optionally the powder is compressed into compacts, and heat-treated at a temperature of 400 to 1200° C. for a time of 0.5 to 8 hours. These compacts can be used as catalysts or catalyst carriers in vinyl acetate monomer production and ethylene hydration.

Abstract: The use of modified silicon dioxide as a catalyst support in catalytic reactions under hydrothermal conditions is described. The pore structure of the supports may be stabilized against hydrothermal reaction conditions by impregnating the catalyst supports with elements of Group IVB of the Periodic Tube of Elements.

Abstract: Compacts produced from a pyrogenically produced oxide, magnesium stearate, methyl cellulose and urea are mixed together in the presence of water, compacted, dried, comminuted to a powder, and the powder is pressed with an isostatic press to compacts and the compacts tempered. The resulting compacts have an outside diameter of 16 to 100 mm.

Abstract: A process for producing 3-aminomethyl-3,5,5-trimethylcyclohexyl amine (isophorone diamine) from isophorone nitrile. Isophorone nitrile is iminated in a first stage and then the reaction mixture is subjected to aminating hydrogenation in a second stage in the presence of a fixed bed hydrogenation catalyst based on Raney cobalt. The fixed bed hydrogenation catalyst is produced in a special manner by mixing a powdery Co--containing Raney alloy with powdery cobalt, sintering the powdery mixture to shaped moldings and then activating by leaching with alkali hydroxide solution. The yield and/or space-time yield in isophorone diamine production can be increased.

Abstract: Shaped, activated Raney metal fixed-bed catalysts are obtained by molding a powder of at least one catalyst alloy, comprising at least one Raney process metal as catalytically active component and a leachable alloy component, and a powder of pure Raney process metal as binder with the addition of a shaping aid and pore-producer and subsequent calcination at temperatures below 850.degree. C. During calcination the shaping aid and pore-producer are burned away. Catalyst alloy powder and binder powder thereby sinter together to give a mechanically stable and porous molded item. This molded item thus consists of particles of catalyst alloys which are bonded by the powder of pure Raney process metal. It has no catalytically inactive, ceramic or glassy binder. The surface layer of the molded item is activated by leaching the leachable alloy component contained in the catalyst alloys with caustic soda solution.

Abstract: A process for uniform and reproducible impregnation of fixed bed catalyst supports in the form of loose particles with a desired shell volume, by applying atomized impregnating solutions of precursors of the catalytically active components onto the heap of catalyst supports circulated in a tank. By suitable selection of the spraying parameters, in particular the droplet size range, the quantity of solvent and the quantity of impregnating solution sprayed per rotation of the tank, the catalyst supports may be provided with shells with an excellent degree of uniformity.

Abstract: A process is described for preparing hydrogenation catalysts which contain noble metals, having at least one catalytically active component and optionally promoters and/or modifiers on a support consisting of activated carbon washed with nitric acid. The activated carbon is subjected to an oxidative pretreatment with an oxidizing agent before applying the catalytically active components, promoters and modifiers.

Abstract: A catalyst containing platinum on carbon as carrier for the catalytic oxidation of glyoxal to glyoxalic acid. Activity and selectivity of the catalyst can be considerably improved by modification with molybdenum and/or cerium.