Abstract: Supported catalysts containing silver and alkali metals, for the preparation of ethylene oxide from ethylene and oxygen in the gas phase, are prepared or regenerated by modifying, respectively, a new or spent supported catalyst which already contains metallic silver and may or may not contain the light alkali metals lithium and/or sodium and, where a spent catalyst is concerned, also contains the heavy alkali metals potassium, rubidium and/or cesium, with a solution containing the heavy alkali metals, the modifier solution used containing(a) a surfactant and/or a reducing agent, in the case of the preparation of a new catalyst or(b) a surfactant, in the case of the regeneration of a spent catalyst.

Abstract: A catalyst for the manufacture of ethylene oxide, giving improved yield and having a long life, based on an alkali metal-modified silver catalyst on an oxide carrier is obtained by providing the silver-containing catalyst, in the reduced state, with the alkali metal by applying an alcoholic alkali metal salt solution which also contains an organic oxygen compound or nitrogen compound which forms complexes with silver ions.

Abstract: This invention concerns a new carrier catalyst, the active mass of which contains silver, a process for its manufacture and a process for the manufacture of ethylene oxide by reacting oxygen-containing gases with ethylene by using this catalyst. This carrier catalyst comprising a carrier material and a catalyst, the active mass of which is 20 to 90 percent by weight of silver, 0.005 to 5 percent by weight of lithium, and 3 to 70 percent by weight of SiO.sub.2 in free form or in the form of silicates, is extremely well suited for the manufacture of ethylene oxide by adding oxygen to ethylene.

Abstract: A novel catalyst for the manufacture of ethylene oxide from ethylene by means of oxygen or air, comprising from 2 to 12% of silver on a conventional carrier, together with from 0.1 to 2 atom% (based on silver) of lithium and from 0.05 to 0.35 atom% of potassium or 0.003 to 0.25 atom% of rubidium or 0.0005 to 0.2 atom% of cesium or mixtures of potassium, rubidium and/or cesium in amounts exhibiting corresponding catalytic activity. The catalyst is advantageously obtained by heating a carrier which is impregnated with a silver complex compound.