Abstract: 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.

Abstract: 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.

Abstract: 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).

Abstract: Compositions of the formula IMo.sub.12 P.sub.a V.sub.b X.sub.c.sup.1 X.sub.d.sup.2 X.sub.e.sup.3 Sb.sub.f Re.sub.g S.sub.h O.sub.n (I),whereX.sup.1 is potassium, rubidium and/or cesium,X.sup.2 is copper and/or silver,X.sup.3 is cerium, boron, zirconium, manganese and/or bismuth,a is from 0.5 to 3.0,b is from 0.01 to 3.0,c is from 0.2 to 3.0,d is from 0.01 to 2.0,e is from 0 to 2.0,f is from 0.01 to 2.0,g is from 0 to 1.0,h is from 0.001 to 0.5 andn is a number determined by the valency and content of the elements different from oxygen in I, are used as catalysts for preparing methacrylic acid by gas-phase oxidation of methacrolein.

Abstract: Compositions of the formula IMO.sub.12 P.sub.a V.sub.b X.sup.1.sub.c X.sup.2.sub.d X.sup.3.sub.e Sb.sub.f Re.sub.g S.sub.h O.sub.n (I)whereX.sup.1 is potassium, rubidium and/or cesium,X.sup.2 is copper and/or silver,X.sup.3 is cerium, boron, zirconium, manganese and/or bismuth,a is from 0.5 to 3.0,b is from 0.01 to 3.0,c is from 0.2 to 3.0,d is from 0.01 to 2.0,e is from 0 to 2.0,f is from 0.01 to 2.0,g is from 0 to 1.0,h is from 0.001 to 0.5 andn is a number determined by the valency and content ofthe elements different from oxygen in I, are used as catalysts for preparing methacrylic acid by gas-phase oxidation of methacrolein.

Abstract: 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 formulaR.sup.+ NO.sub.3.sup.-wherein R.sup.+ is an ammonium, hydrazinium, C.sub.1 -C.sub.12 -monoalkylammonium, C.sub.2 -C.sub.12 -dialkylammonium, C.sub.3 -C.sub.12 -trialkylammonium or C.sub.4 -C.sub.12 -tetraalkylammonium cation.

Abstract: A catalytically active composition for the gas phase oxidation of propylene to acrolein and acrylic acid, of the general formulaMo.sub.12 Bi.sub.0.1-10 Fe.sub.0.8-12 [Co,Ni].sub.0.1-10 P.sub.0-2 A.sub.0-10 B.sub.0.001-1 O.sub.xwhere A is arsenic, antimony, tin, thallium, tungsten, an alkaline earth metal, zinc and/or chromium, B is at least one of the metals sodium, potassium, rubidium, cesium and/or indium and X is the number determined by the atomic valences of the individual elements, is prepared by introducing all or some of the iron and molybdenum in the form of dried pulverulent iron molybdate gel into an aqueous solution or suspension of the other constituents and gelating the mixture by stirring and possibly heating, then comminuting, drying at elevated temperatures and finally calcining.

Abstract: 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.

Abstract: 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.