| 摘要 |
1283235 Olefin oxidation catalysts BP CHEMICALS Ltd 8 Oct 1970 [14 Nov 1969] 55840/69 Heading B1E [Also in Division C2] Catalyst for use in the oxidation of propylene to propylene oxide comprises (a) silver in elemental form, (b) selenium or tellurium in elemental form or in the form of a compound, for example selenide, selenite or selenate, and, optionally, (c) inert support material, for example pumice, silica or silicon carbide. The catalyst may contain from 0.001 to 0.05 parts by weight of selenium or tellurium per 100 parts by weight of silver. The catalyst may be prepared by a process which comprises preparing elemental silver powder by reducing, for example with glucose or dextrose, silver oxide obtained by precipitation from a solution of a silver salt, for example silver nitrate, and thereafter treating the silver powder, optionally after supporting an inert material aforesaid and/or compressing into pellets or discs, either with elemental selenium or tellurium or with an organoselenium or organotellurium compound. Examples relate to unsupported catalyst containing 0.017 or 0.03 atoms of selenium per 100 atoms of silver (Example 1) or 0.024 or 0.035 atoms of tellurium per 100 atoms of silver (Example 2), dimethyl selenide or dimethyl telluride being used in the preparation of the catalyst which is used in the form of 2-3 mm granules obtained by breaking compressed discs of one inch diameter. |
