| 摘要 |
The partial hydrogenation of cycloaliphatic hydrocarbons having at least two olefinic double bonds is effected with hydrogen in the presence of metallic palladium and heavy metal ions (a heavy metal is one having a specific gravity above 5). Suitable starting materials contain 2-4 conjugated or non-conjugated double bonds in a C5-C12 ring which may be substituted by up to three C1-C4 alkyl groups or 1 or 2 double bonds in a C5-C12 ring and additionally 1 or 2 double bonds in a C2-C6 side chain or in a second C5-C8 alicyclic ring which may be fused to the first ring, e.g. cyclopentadiene, 1,3 - cyclohexadiene, 1,3,5-cycloheptatriene, 1,3- or 1,5-cyclooctadiene, cyclooctatetraene, cyclododecadiene, methyl-cyclopentadiene, dimethylcyclooctadiene, 1-vinyl - 1 - cyclohexene, 1 - vinyl - 4 - cyclohexene, limonene, 1,11-dicyclohexenyl, dicyclopentadiene, and bicyclo-[4,2,0]-octatriene-2,4,7. Metallic palladium is deposited on active charcoal, alumina, barium sulphate, calcium carbonate, pumice, silicates, or silica gel or a compound, e.g. oxide, hydroxide, carbonate or silicate, providing heavy metal ions. Suitable heavy metals are Cu, Ag, Zn, Cd, Hg, Tl, Pb, Sn, Sb, Bi, V, Zr and Fe; any salt other than catalyst poisons (e.g. cyanides, thiocyanates, sulphides and arsenites) may be used, the necessary amount varying according to the metal. In a preferred embodiment the supported palladium catalyst is boiled in an aqueous or alcoholic solution of the heavy metal salt for 5-120 minutes. Ammonia, amines, organic sulphides or ethers may also be present as catalyst deactivators. The process is preferably effected in an inert diluent, e.g. a saturated hydrocarbon, alcohol, ester or ketone at - 20 DEG to 150 DEG C.ALSO:A catalyst used in the partial hydrogenation of polyolefinic cyclic hydrocarbons comprises metallic palladium and ions of a heavy metal (i.e. one having a specific gravity above 5), particularly Cu, Ag, Zn, Cd, Hg, Tl, Pb, Sn, Sb, Bi, V, Zr, and Fe. The palladium may be deposited on active charcoal, alumina, barium sulphate, calcium carbonate, pumice, silicates, silica gel, or an oxide, hydroxide, carbonate or silicate of the heavy metal. In a preferred embodiment a supported palladium catalyst is boiled in an aqueous or alcoholic solution of a heavy metal salt for 5-120 minutes, the amount varying with the metal. Any salt other than catalyst poisons (e.g. cyanides, thiocyanides, sulphides and arsenites) may be used. The process is effected in a diluent to which may be added ammonia, amines, organic sulphides or ethers as catalyst deactivators. |
