Method for preparing catalysts for heterogeneous catalysis by multiple-phase impregnation, catalysts and use of said catalysts

Use of a catalyst for heterogeneous catalysis comprising a β-SiC support and at least one active phase, the said catalyst being obtainable by using a process comprising at least the following steps:

• (a) impregnation of the said support having a specific surface area, determined by the BET nitrogen adsorption method at the temperature of liquid nitrogen according to standard NF X 11-621, equal to at least 2 m2/g and comprising at least one active phase precursor, the said impregnation being done by an impregnation process comprising at least a first impregnation step during which the said support is impregnated at least once by a polar agent A, and a second impregnation step during which the said support is impregnated at least once by an agent B less polar than agent A, knowing that at least agent B comprises at least one active phase precursor,
• (b) thermal breakdown of the said precursor,
• the said use being as a catalyst for chemical reactions selected among oxidation of methane or other hydrocarbons, oxidation of carbon monoxide, or as a catalyst for depollution of exhaust gases of vehicles with internal combustion engines.