Ethylene oxide catalyst and process

A process for preparing a catalyst for the vapor phase production of ethylene oxide from ethylene and molecular oxygen which process comprises impregnating a porous refractory oxide with a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium and a rhenium co-promoter selected from phosphorus, boron and mixtures thereof supported on a porous, refractory support.

A process for preparing a catalyst for the vapor phase production of ethylene oxide from ethylene and molecular oxygen which comprising impregnating a porous refractory support with one or more solutions comprising silver, alkali metal, rhenium and a rhenium co-promoter selected from the group consisting of phosphorus, boron and mixtures thereof, wherein the concentration of the silver (expressed as the metal) in the solution ranges from about 1 gram/liter to the solubility limit of silver in the solution, the concentration of alkali metal (expressed as the metal) in the solution ranges from about 1.times.10-3 grams/liter to about 12 grams/liter, the concentration of the rhenium (expressed as the metal) in the solution ranges from about 5.times.10.sup.-3 grams/liter to about 20 grams/liter and the concentration of the rhenium co-promoter (expressed as the element) in the solution ranges from about 1.times.10.sup.-3 grams/liter to about 20 grams/liter to provide the catalyst with a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium, and a promoting amount of rhenium co-promoter.

A process for preparing a catalyst for the vapor phase production of ethylene oxide from ethylene and molecular oxygen which comprising impregnating a porous refractory support comprising alpha alumina with one or more solutions comprising solvent having silver compound(s) dissolved therein, alkali metal compound(s) dissolved therein, rhenium compound(s) dissolved therein, and rhenium co-promoter compound(s) wherein the rhenium co-promoter is selected from compounds of phosphorus, boron and mixtures thereof, dissolved therein, sufficient to deposit on the support from about 1 percent by weight to about 25 percent by weight of the total catalyst of the silver compound(s), expressed as the metal, from about 10 parts per million to about 3000 parts per million by weight of alkali metal compound(s), expressed as the metal, by weight of the total catalyst, from about 0.1 micromoles to about 10 micromoles per gram of total catalyst of rhenium compound(s), expressed as the metal, and from about 0.1 micromoles to about 10 micromoles per gram of total catalyst of rhenium co-promoter compound(s), expressed as the element, to provide the catalyst with a catalytically effective amount of silver, a promoting amount of alkali metal, a promoting amount of rhenium and a promoting amount of rhenium co-promoter.