Abstract: A catalyst for the manufacture of alkylene oxide, for example ethylene oxide, by the vapor-phase epoxidation of alkene containing impregnated silver and at least one efficiency-enhancing promoter on an inert, refractory solid support, said support incorporating a sufficient amount of zirconium component (present and remaining substantially as zirconium silicate) as to enhance at least one of catalyst activity, efficiency and stability as compared to a similar catalyst which does not contain the zirconium component.

Abstract: An improved process for the manufacture of ethylene oxide through the epoxidation of ethylene using a catalyst comprising silver and at least one efficiency-enhancing salt of a member of a redox-half reaction pair. Added to the epoxidation reaction is a two-component gas-phase promoter system comprising a chlorine-containing component (for example ethyl chloride, methyl chloride, vinyl chloride and ethylene dichloride), and a nitrogen-containing component of nitric oxide and other compounds capable of generating under reaction conditions at least one gaseous efficiency-enhancing member of a redox-half reaction pair comprising NO, NO2, N2O3 or N2O4. The amount of each component of said gaseous promoter is adjusted to maintain the ration of N* to Z* less than or equal to 1 wherein, N* is the nitric oxide equivalent in ppmv, ranging from 1 to 20 ppmv and Z*=ethyl chloride equivalent (ppmv)*100 percent/ethane equivalent (mol percent)*100 ranging from 5 to 40 ppmv.

Abstract: An improved carrier useful for preparing a catalyst having excellent catalytic performance when used in the production of alkylene oxide, such as ethylene oxide. The carrier is obtained by a) impregnating a preformed alpha-alumina carrier with at least one modifier selected from among alkali metal silicates and alkaline earth metal silicates, b) drying said impregnated carrier; and c) calcining said dried carrier. The carrier may optionally be washed, prior to being impregnated by conventional catalytic material and/or promoter material.