MESOPOROUS AND MACROPOROUS CATALYST FOR HYDROTREATING PETROLEUM RESIDUE AND PREPARATION METHOD THEREOF

The present invention concerns a method for preparing a hydroconversion catalyst comprising: - a predominantly calcined aluminium oxide support; - a hydro-dehydrogenating active phase comprising at least one metal from group VIB of the periodic table, optionally at least one metal from group VIII, optionally phosphorus, said catalyst having: - a specific surface area Sbet greater than or equal to 100 m2/g, - a total porous volume greater than or equal to 0.75 ml/g, - a mesoporous volume median diameter greater than or equal to 18 nm, - a mesoporous volume greater than or equal to 0.65 ml/g, - a macroporous volume of between 15 and 40 % of the total porous volume; said method comprising at least the following steps: a) Dissolving an acid precursor of aluminium; b) Adjusting the pH by means of a basic precursor; c) Co-precipitating an acid precursor and a basic precursor, at least one of the two containing aluminium in order to form an alumina gel suspension with a targeted alumina concentration; d) Filtering; e) Drying to obtain a powder; f) Shaping; g) Heat treatment to obtain an aluminium oxide support; h) Impregnating the hydro-dehydrogenating active phase on said aluminium oxide support. The invention also concerns the catalyst likely to be prepared by the described preparation method and the use of said catalyst in methods for the hydrotreatment or hydroconversion of heavy hydrocarbon feedstocks.