| 摘要 |
Process for the manufacture of a catalyst containing at least one refractory inorganic oxide, at least one iron oxide and at least one cerium oxide, at least one metal A chosen, for example, from groups VIB, VIIB, VIII and IB of the Periodic Classification and optionally at least one compound of metal B chosen, for example, from groups IA, IIA, the rare-earths group and group IVB of the Periodic Classification, which are deposited in the form of a porous layer ("wash coat") on a ceramic or metal support, the said process being characterised, generally, in that it includes: - a stage (a) in which an aqueous suspension of at least one powder of the said refractory inorganic oxide, containing at least one soluble cerium salt, at least one soluble iron salt, optionally at least a proportion of at least one insoluble compound and/or of at least one soluble salt of the said metal B, optionally at least a proportion of at least one metal A deposited beforehand by impregnation of at least one of its precursors is sprayed in a spraying apparatus onto at least one of the solid constituents present, so that a powder is collected which is optionally calcined; the said process additionally including: - a stage (b) in which the said powder is resuspended while adding the optional remainder or the totality of the said compound of metal B, as well as, optionally, at least one binding agent and optionally at least one inorganic or organic acid; - a stage (c) in which a ceramic or metallic support is coated by means of the suspension obtained in stage (b); - a stage (d) in which the said coated support is calcined; - a stage (e) in which the said coated and calcined support is impregnated with the optional remainder or the totality of the said precursor of the metal A; and - a stage (f) in which the said coated, calcined and impregnated support originating from stage (e) is activated thermally. These catalysts can be used, for example, in the treatment of exhaust gases from internal combustion engines with spark or other ignition, operating with a liquid fuel, a liquefied petroleum gas (LPG) or a compressed natural gas (CNG).
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