use in epoxidation after catalyst formation the catalyst may be optionally thermally treated in a gas such as nitrogen helium vacuum hydrogen oxygen air or the like the thermal treatment temperature is typically from about 20 u00b0 c to about 800 u00b0 c it is preferred to thermally treat the catalyst in the presence of an oxygen containing gas at a temperature from about 200 u00b0 c to 700 u00b0 c and optionally reduce the catalyst in the presence of a hydrogen containing gas at a temperature from about 20 u00b0 c to 600 u00b0 c the epoxidation process of the invention comprises contacting an olefin oxygen and hydrogen in the presence of the catalyst suitable olefins include any olefin having at least one carbon carbon double bond and generally from 2 to 60 carbon atoms preferably the olefin is an acyclic alkene of from 2 to 30 carbon atoms the process of the invention is particularly suitable for epoxidizing c 2 c 6 olefins more than one double bond may be present as in a diene or triene for example the olefin may be a hydrocarbon i e contain only carbon and hydrogen atoms or may contain functional groups such as halide carboxyl hydroxyl ether carbonyl cyano or nitro groups or the like the process of the invention is especially useful for converting propylene to propylene oxide.