Basf Aktiengesellschaft

Karl-Heinz Boehning

Matthias Schwarzmann

Wolf D Mross

Juergen Plueckhan

Heinrich Aichinger

Klaus Herzog

Franz Merger

Ulrich Hammon

Richard Krabetz

Gerd Duembgen

Herbert Vogel

Fritz Thiessen

Hans-Juergen Becker

Klaus-Christian Renner

Wilhelm Ruppel

Hans Martan

Guenter Herrmann

Gert Buerger

Johannes E Schmidt

Hermann Wistuba

Walter Scheidmeir

Rolf Seubert

Heinz Dreyer

Ewald Gallei

Stefan Boeck

A silver catalyst containing one or more alkali metals and also tungsten as promotors for the direct oxidation of ethylene with oxygen to form ethylene oxide, on a porous support substantially consisting of .alpha.-aluminum oxide and having a specific surface area (BET) of from 0.3 to 3 m.sup.2 /g, which contains tungsten in a concentration of from 60 to 330 ppmwt, based on the total catalyst, per m.sup.2 of surface area for each gram of supporting material.

Silver catalyst

A catalyst for decomposing dinitrogen monoxide which is pure or present in gas mixtures comprises metallic silver applied to an alumina carrier with a BET surface area of from 5 to 25 m.sup.2 /g.

Catalytic decomposition of dinitrogen monoxide which is pure or present

Phthalic anhydride is prepared in a multiple tube reactor provided with separate salt baths, the temperature of the salt bath used for cooling the first layer of catalyst, as regarded in the direction of flow of the reaction mixture, being from 2.degree. to 20.degree. C. higher than that of the salt bath(s) associated with the following layer(s).

Preparation of phthalic anhydride from o-xylene

Compositions of the formula Mo.sub.12 P.sub.a V.sub.b X.sup.1 c X.sup.2

Compositions of the formula MO.sub.12 P.sub.a V.sub.b X.sup.1.sub.c

Supported silver catalysts which contain one or more alkali metals are prepared in a two-stage process by doping a basic catalyst which contains silver in metallic form and may also contain lithium with the heavy alkali metal sodium, potassium, rubidium and/or cesium using an impregnating solution which contains the heavy alkali metal and one or more nitrates of the general formula

Preparation of a silver catalyst

A catalytically active composition for the gas phase oxidation of propylene to acrolein and acrylic acid, of the general formula

Preparation of a catalytically active composition for the gas phase

A silver catalyst containing lithium and cesium as promoters for the direct oxidation of ethylene with oxygen to give ethylene oxide is applied to a porous carrier and essentially consists of .alpha.-alumina and contains certain amounts of soluble calcium, aluminum, potassium and sodium salts. The carrier has a BET surface area of from 0.4 to 0.8 m.sup.2 /g, a pore volume of not less than 0.45 ml/g, the pores being equally accessible to cold and warm water, a bulk density of less than 700 kg/m.sup.3 and a shape which, in the reactor, provides a geometrical surface area of not less than 600 m.sup.2 /m.sup.3, on which more than 13% by weight of silver are applied as active component and more than 115 kg of silver are available per m.sup.3 of reactor, and from 100 to 300 ppm by weight of lithium and from 200 to 600 ppm by weight of cesium are present as promoters. A process for the preparation of the silver catalyst and its use for the oxidation of ethylene are described.

Silver catalyst and a process for its preparation

A silver catalyst for the direct oxidation of ethylene with oxygen to give ethylene oxide is applied on a porous carrier and essentially consists of .alpha.-alumina and contains certain amounts of soluble calcium, aluminum, potassium and sodium salts. The carrier has a BET surface area of from 0.2 to 0.8 m.sup.2 /g, a pore volume of not less than 0.5 ml/g, the pores being equally accessible to cold and warm water, and a bulk density of less than 650 kg/m.sup.3, and has a shape which, in the reactor, provides a geometric surface area of not less than 600 m.sup.2 /m.sup.3, on which more than 13% by weight of silver are applied as the active component, more than 110 kg of silver being available per m.sup.3 of reactor.

Silver catalyst and its preparation

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Ludwigshafen, Germany

Karl-Heinz Boehning