| abstract |
This invention relates to an epoxidation catalyst having improved selectivity stability, comprising silver, a promoting amount of alkali metal, a promoting amount of rhenium, a promoting amount of nickel and, optionally, a promoting amount of rhenium co-promoter selected from sulphur, molybdenum, tungsten, chromium and mixtures thereof, on a porous refractory support. Preferably, the nickel has been deposited on the catalyst by post-impregnating the catalyst by a non-aqueous solution of the nickel. |