GB1021328A - Catalytic process for preparing unsaturated aliphatic nitriles and catalyst therefor - Google Patents

Abstract

Unsaturated nitriles are prepared by reacting an olefine with ammonia and air or oxygen at an elevated temperature in the presence of PbaBibMocOd in which a = 0.08-0.75 c, b = 0.1-0.8 c, d = 3.1-4.5 c such that a + b = 0.55-1.1 c, mounted on silica. The nitriles may be prepared in fixed or fluidized bed processes. Comparative examples describe the synthesis of acrylonitrile from a propylene, ammonia, steam, air 1 : 1 : 1 : 8 mixture at 480 DEG C.ALSO:An oxidation catalyst is made from a homogeneous acid solution of a lead salt, a bismuth salt, a soluble molybdenum compound, a colloidal silicic acid sol and a mineral acid which does not form an insoluble precipitate with lead, in the absence of a combination of ammonium ions and phosphorus-containing compounds, by evaporating the solution in such a manner that segregation of the components does not take place and heating the residue to an elevated temperature for several hours. Evaporation may be effected by spray drying. The catalyst may be deposited on cores of sintered aluminium silicate, corundum, quartz, feldspar, granite, sintered magnesite or silicon carbide so as to form particles 1-8 mm. in diameter and of maximum porosity 10%. The catalyst may be used in a fixed or fluidized bed.