Cleaning and regenerating ethylene oxide catalysts

A method of regenerating a supported silver catalyst which has been used for the direct oxidation of ethylene to ethylene oxide which comprises washing the catalyst to remove alkali metal-containing impurities with a composition comprised of an inert organic liquid and about 0.1% to about 10%, by weight, of a solubilizing agent which is selected from the group consisting of aliphatic and aromatic acids, and then applying to the catalyst from 1 to 1000 parts per 1 million parts of catalyst of cesium, rubidium, or a mixture thereof.

In a method for regenerating a supported silver catalyst which has been used for the direct oxidation of ethylene to ethylene oxide which comprises washing the catalyst with an inert organic liquid and then applying to the catalyst from 1 to 1000 parts per 1 million parts of catalyst of cesium, rubidium, or a mixture thereof, the improvement which comprises removing alkali metal-containing impurities by including about 0.1% to about 10% by weight, of a solubilizing agent in the inert organic liquid, said solubilizing agent selected from the group consisting of aliphatic and aromatic acids.