| 摘要 |
A process for preparing a modified, activated silver catalyst useful in the vapor phase epoxidation of ethylene with molecular oxygen is disclosed. The improved catalyst comprises an inorganic, porous support containing metallic silver and an effective amount of a higher alkali metal promoter which have been deposited coincidentally on the support. The catalyst is prepared by impregnating a porous inorganic substrate with a solution comprising a silver compound such as a silver carboxylate, an organic amine solubilizing/reducing agent which also serves as a complexing agent for the silver compound, a perchlorate salt of a higher alkali metal, and an aqueous solvent. Optionally, the impregnating solution may contain at least one perhalogenated acid, such as perchloric acid. In a final step the impregnated support is heated at temperatures of from about 50 DEG C. to about 300 DEG C. to evaporate volatiles, decompose the silver compound to metallic silver and activate the catalyst. |
