Process for improving the activity of used supported silver catalysts

Abstract From the Canadian patent

In this process a supported silver catalyst used for the manufacture of ethylene oxide by reaction of ethylene with molecular oxygen or air is impregnated with a solution consisting of water, a water-miscible organic solvent and at least one sesame and/or rubidium compound in an amount of from 50 to 1,000 mg of cesium and/or rubidium per kg of solution; the impregnation temperature being from 60 to 200°C, the impregnation time being at least 0.3 hour and, the water content of the impregnating solution being from 5 to 50 weight % relative to the weight of the solution. After impregnation the excess impregnating solution is, separated and after drying of the still moist catalyst it is ready …