| 摘要 |
Ethylene oxide is prepared by passing ethylene and an oxygen-containing gas over a heated supported silver catalyst which contains from 160 to 400 parts by weight of lead per million parts by weight of silver calculated as silver oxide. The preferred support is porous alumina. ALSO: An oxidation catalyst comprises silver containing 160-400 parts by weight of lead per million parts of silver calculated as silver oxide. The catalyst is prepared by adding a reducible silver compound containing the required amount of lead to a conventional support and heating the mixture until the silver compound is reduced. A parameter, e.g. a metal oxide or carbonate, may also be present. ALSO: An oxidation catalyst comprises silver and 160-400 parts of lead per million parts by weight of silver calculated as silver oxide. The catalyst is carried on a conventional support, e.g. porous alumina. The catalyst may be prepared by wetting a porous carrier with an aqueous glycol solution, adding a reducible silver compound which contains the required amount of lead and heating the mixture until the silver compound is reduced. Promoters, e.g. alkali metal and alkaline earth metal oxides and carbonates, and noble metal oxides, may be added to the catalyst. |
