| 摘要 |
Hydrocarbon gas mixtures having a high content of lower olefins, especially the gaseous C2-4 olefins, are prepared by catalytic conversion at a pressure of 1-150 bar, a temperature of 200-600.degree.C and a space velocity of 1,00050,000 Nl synthesis gas per kg catalyst per hour of a gas containing carbon oxides, hydrogen and optionally inert gases, the content of CO being at most 5% vol., in the presence of a catalyst comprising or consisting of at least two intimately mixed heavy metals in free form or as carbides, carbonates and/or oxides, preferably also intimately mixed with an alkali metal carbide, carbonate or oxide, notably potassium carbonate, said catalyst prepared by the reduction and subsequent carburization of a precursor comprising one or more complex cyanides of (a) an alkali metal or ammonium, (b) one or more metals forming difficultly reducible oxides and belonging to group 3 in the Periodical Table, and one one more of the metals having atomic number 24-30, said cyanide(s) having cubic crystal structure with a lattice parameter of about 5-10 .ANG. and a crystallite size below 200 .ANG.. |
