Patent ID: 8088706

Claim:
A process for the preparation of a catalyst composition having the general formula, on an oxide basis, (X) b (M) c (Z) d (O) e (I) wherein X represents at least one non-noble Group VIII metal; M represents at least one Group VIB metal; Z represents one or more elements selected from the group consisting of aluminum, silicon, magnesium, titanium, zirconium, boron and zinc; O represents oxygen; one of b and c is the integer 1; and d, e, and the other of b and c each are a number greater than 0 such that the molar ratio of b:c is in the range of from 0.5:1 to 5:1, the molar ratio of d:c is in the range of from 0.1:1 to 50:1, and the molar ratio of e:c is in the range of from 3.6:1 to 108:1; said process comprises heating a composition of the general formula (NH 4 ) a (X) b (M) c (Z) d (O) e (II) in which a is a number greater than 0 and X, M, Z, O, b, c, d and e are as defined above, at a temperature in the range of from 100 to 600° C., wherein the composition of general formula II is in the form of, or is recovered from, a slurry optionally after ageing at a temperature in the range of from 20 to 95° C. for a minimum of 10 minutes, said slurry being obtained by coprecipitating, at a temperature and for a time sufficient to produce the composition II, at least one non-noble Group VIII metal compound, at least one Group VIB metal compound, at least one refractory oxide material and an alkali compound, in a protic liquid, at least one of the metal compounds being partly in solid state and partly in dissolved state.