| 摘要 |
Acyclic olefins are disproportionated in the presence of a catalyst made by subliming rhenium heptoxide, Re2O7, on to Al2O3. Specified alkenes are propylene, butenes 1-2, pentenes 1-2, hexenes-1, -2, -3, heptenes-1, -2, -3 and octenes-1, -2. In examples propylene is disproportionated at 40 DEG C. and G.H.S.V. 1600 or 2000 to yield ethylene and butene-2.ALSO:Disproportionation catalysts consisting of rhenium heptoxide, Re2O7, on Al2O3 are made by heating Re2O7 in a stream of carrier gas whereby it is sublimed onto Al2O3 located downstream. In an embodiment, ammonium perhenate located in the lower portion of a vertical tube is thermally decomposed in an ascending stream of carrier gas and deposited onto particles of Al2O3 which are located in a fluidised bed in an upper portion of the tube. The support may be g -Al2O3 of specified pore size, volume and surface area. The catalyst may be activated by heating in an inert gas and/or air. Comparative examples describe the preparation of catalysts and their use for disproportionating propylene. |
