Process for reactivating used silver ethylene oxide catalysts

Claim 1

A process for improving the performance of used silver-based catalysts used for the production of ethylene oxide by contacting ethylene in the vapor phase with a molecular oxygen-containing gas at a temperature of from about 150°-300° C. which comprises: (a) washing the used catalyst with 1-10 times its volume of water or a mixture of at least ten percent water with a water-miscible organic solvent, and (b) depositing on the washed catalyst from about 0.00004 to about 0.008 gram equivalent weights per kilogram of total catalyst of alkali metal ions selected from the group consisting of sodium, potassium, rubidium, cesium, or mixtures thereof by impregnating the catalyst with a solution of alkali metal ions dissolved in a solvent selected from the group consisting of alkanols having 1 to 6 carbon atoms, acetone methyl acetate and tetrahydrofuran.