Catalysts preparation process based on molybden and/or tungsten oxides and oxides of other metals

摘要

the invention relates to a preparation process of catalysts comprising an active phase in response to the general formula:ji also aa bb ox;in which:a represents at least one metal selected from the group consisting of cobalt, nickel, manganese, lead, and b is at least one metal selected from the group consisting of iron, bismuth.chromium, thallium - representing the sum of the indices assigned to each of the metals.is greater than 0 and less than or equal to about 12 (c) and (d) are each equal to or greater than 0 and less than or equal to 12.the sum of c + d is equal to approximately 12 '(representing the sum of the indices assigned to each of the metal b is greater than 0 and less than or equal to about 1.(c + d) - (a - x satisfies the process that induces a type, as a first step, the aqueous phase is mixed metal salts used in the composition of the active phase.molybdenum and tungsten in the form of ammonium salts, and at least one of the metals a and b are in the form of a nitrate or chloride, in a second step.dry pulp is obtained, and in a third step, at least a calcination is eventually deposited on the solid support obtained, process, characterized in that in the first stage.successively, is added to a first aqueous solution containing ammonium salts of molybdenum and tungsten in quantity to achieve the values of c and d,a second aqueous solution containing the salt of a and b in a quantity to achieve the values of a and bby adding to the mixture of ammonia until a ph higher than the ph of the aqueous solution of initial and first in the solution to obtain a filterthe paste.