Abstract: The present invention relates to silver-containing and optionally promoter-containing supported catalysts and catalyst intermediates, processes for their preparation and their use for preparing alkylene oxides by oxidation of alkenes with oxygen. The catalysts are prepared by treatment of a support with a lactic acid containing silver ions, nitrate ions and optionally promoter metal ions, drying, predecomposition in a virtually oxygen-free atmosphere and subsequent activation by heating in an oxygen-containing atmosphere while precisely controlling the temperature conditions and the feeding-in of oxygen. The catalyst intermediates obtainable by treatment, drying and only predecomposition can be activated in a temporally and physically separate process step to form the actual catalysts. Suitable promoters are alkaline earth metal compounds and/or alkali metal compounds. High activities and high selectivities are achieved when using the catalysts of the invention for preparing alkylene oxides.

Abstract: Silver-containing supported catalyst, catalyst intermediates, processes for their preparation and the use of such catalysts in the preparation of alkaline oxides is described. By the preparatory technique of the invention there is obtained an improved catalyst which is especially useful in the preparation of alkylene oxides by oxidation of alkenes with oxygen-containing gases. The novel catalysts are characterized by a BET specific surface area of about 0.4 to about 0.5 square meters per gram and by a uniform continuous particle structure of spherical silver crystallites on a supported catalyst, which crystallites have an average diameter of 0.3 to 0.4 .mu.m.