| 摘要 |
Ethylene is oxidised to ethylene oxide in the presence of a supported silver catalyst, the support comprising spheres or pellets having an inner case with a porosity of less than 10% and an outer margin to the inner core having a porosity of at least 15%. An example describes the conversion at 244 DEG C. of a gas comprising 5.5% CO2, 5.0% C2H4, 0.5% C2H6, 6% O2 and the balance nitrogen.ALSO:A particulate catalyst support comprises an inner core having a porosity of less than 10% and an outer margin bonded to the inner core having a porosity of at least 15%. The thickness of the outer margin may be from 1/32 -/ba1/2 an inch. The core may be Al2O3 and the outer margin may be SiO2, MgO, or Al2O3. Metals are preferentially retained in the outer margin on impregnation due to its greater porosity. The metal specified is Ag. Percentage porosity is defined as the total volume occupied by externally accessible pores. |
