PROCESS FOR PREPARING MOLYBDENUM AND/OR TUNGSTEN OXIDES CATALYSTS AND OTHER METALS OXIDES CATALYSTS

摘要

the divlulgation).the invention relates to a process for the preparation ofcatalysts comprising an active phase in response to the formulageneral:sa ji coe (also goodwhere a represents at least one metal selected from amongthe group consisting of nickel, manganese, lead.b represents at least one metal selected from the group consisting ofiron, bismuth, chromium, thallium, a representative of thethe sum of the indices assigned to each of the above metals.equal to or less than 0 and less than or equal to 4; (c) and (d) areeach equal to or greater than 0 and less than or equal to 12.the sum of c + d is equal to about 12 m or higherequal to and less than or equal to about 8 to about 12 and (b).when the sum of the indices assigned to each metal bis greater than 0 and less than or equal to about 1.5 (c + d)(a + e); x x x x x x x satisfies the process type components.that, in a first step, mixing in aqueous phasethe metal salts used in the composition of the phase.active, molybdenum and / or tungsten in the form ofammonium salts, and at least one of the metals a and b asthe form of nitrate, in a second step, we dry the pasteis obtained, and in a third step, it is at leastignition of the solid may be deposited on a substrate is obtained.process characterized in that in the first step, weacidified aqueous solution containing a first saltan amount for the molybdenum and tungstento achieve the values of (c) and (d), until a ph ofapproximately 0.5 and 3; separating the precipitate obtainedit is then suspended in the water, so as to obtaina suspension having a ph of between about 1.5 and approximately2.5, is added to the suspension to a second aqueous solutioncontaining metal salts in quantities to a and bto achieve the values of a and b; and, subsequently, theaddition of cobalt carbonate powder quantityin order to achieve the value of e, and it evaporates the solutionfor the paste is obtained. the catalyst obtained bythe process of invention is particularly usable for thepreparation of aldehydes,. alpha. -. beta. oxidation of olefins to unsaturatedin the gas phase.