Method for producing an epoxidation catalyst

The invention relates to a method for producing a stabilised catalyst system. According to said method, a salt of a metal from the first, second or eighth subgroup is reduced to colloidal metal in an essentially water-free, oxidation resistant, organic solvent; with a reduction agent and in the presence of a stabiliser, said salt being soluble in said solvent. Alternatively, the metal salt can be hydrolysed to colloidal metal oxide with water, in the presence of a stabiliser. The solvent is selected from aliphatic, aromatic, nitrated aliphatic and nitrated aromatic, halogenated aliphatic and halogenated aromatic hydrocarbons and a hydrophobic stabiliser that is soluble therein is used as the stabiliser. By selecting the solvent in this way, it is possible to avoid unwanted secondary reactions such as the formation of secondary products such as glycols and glycol monoalkylethers to a large extent. The inventive catalyst system or the catalyst that can be isolated from the same can be used for the epoxidation of alkenes in solution. In a particularly preferred embodiment of the invention, a catalyst system containing colloidal silver is used for the epoxidation of ethylene.