| 摘要 |
<p>are prepd. by catalytic dimerisation of acrylonitrile (I) in a process in which the monomer is brought into contact for 0.1-30 secs. under 1-100 atm. (pref. 2-50) pressure at 260-593 degrees C (pref. 427-538 degrees C) with a catalyst consisting of activated alumina of specific surface 0.5-800 m2/g. (pref. 2-200) contg. inorganic sulphide ions. The catalyst is prepd. by bringing the activated Al2O3 in contact at is not 260 degrees C for 0.1-5 hrs. with a material that liberates S= at thid temp., e.g. H2S, CS2 or an organic S-contg. cpd., esp. H2S. The pref. catalyst contains Al2O3 and the sulphide of one of a wide range of metals, but esp. Na, Sr and Ag. The amt. of sulphide is at least enough to have a catalystic effect on the dimerisation reaction; the metal content is 0.1-50% (pref. 1-10%) of the wt. of the catalyst. The catalyst may also be formed by deposition of metal on alumina to give a prod. which is then contacted at is not 260 degrees C for 0.1-5 hrs. with a source of S= to give at least partial sulphide formation. In previous methods of catalytic dimerisation of acrylonitrile, it was generally necessary to submit the catalyst, before use, to redn. by H2 so that the metallic constituents were essentially in the elemental metal form. In other cases, the metallic catalysts were in the form of Cl-, SO42-, NO3-, CH3COO- or other organic salt form. In the preset method no special redn. treatment is needed.</p> |
