Silver catalyst.

摘要

Silver catalyst with lithium and caesium as promoter for the direct oxidation of ethylene with oxygen to ethylene oxide on a porous support, which essentially consists of alpha -alumina and contains defined quantities of calcium, aluminium, potassium and sodium compounds soluble in nitric acid, with a silver content of at least 14% by weight, a caesium and/or rubidium content of 0.05-0.2% by weight and a lithium content of 0.025-0.4% by weight, each relative to the total catalyst, its support having a BET surface area of 1-2 m<2>/g and a pore volume of 0.40-0.55 ml/g and containing at most 400 ppm by weight of aluminium, 300 ppm by weight of calcium, 150 ppm by weight of potassium and 150 ppm by weight of sodium as compounds soluble in nitric acid, and a process for the preparation thereof and the use of this catalyst for the production of ethylene oxide from ethylene and oxygen in the gas phase.