Activation of high selectivity ethylene Oxide catalyst

The invention describes a process for producing a catalyst useful for the epoxidation of an olefin. More particularly, the invention pertains to a catalyst useful for the oxidation of ethylene to ethylene oxide. The catalyst comprises a solid support such as alpha-alumina, which has a catalytically effective amount of silver or a silver-containing compound, and a promoting amount of rhenium or a rhenium-containing compound, and a promoting amount of one or more alkali metals or alkali metal-containing compounds on the surface of the support. To produce a catalyst precursor. The catalyst precursor is contacted with an atmosphere comprising oxygen and steam, which atmosphere is substantially absent of an olefin, to hasten the attainment of peak selectivity in the process of oxidation of ethylene to ethylene oxide.