摘要 |
This invention relates to ethylene oxide catalyst for the vapor phase production of ethylene oxide from ethylene and oxygen prepared by impregnating a porous, refractory support having a surface area ranging from about 0.05 to about 10 m2/g with a solubilized catalytically effective amount of silver, a solubilized promoting amount of alkali metal, a solubilized promoting amount of rhenium, and a solubilized promoting amount of hafnium metal, wherein the Group IVB metal is provided in the form of Group IVB oxo salts. The catalyst provide substantial initial activity improvement as well as long term selectivity and activity stability improvement over prior art rhenium promoted catalyst, without any loss of initial selectivity advantage. |