Method for preparing a selective hydrogenation catalyst

A process for the preparation of a catalyst comprising palladium, a porous support comprising at least one refractory oxide selected from the group consisting of silica, alumina and silica-alumina, said porous support having a specific surface area of 140 to 250 m2/g, wherein at least 80% by weight of the palladium is distributed in a crust at the periphery of said support, the thickness of said crust being 20 to 100 μm, said process comprising:

• a) preparing a colloidal solution of palladium oxide or palladium hydroxide in an aqueous phase;
• b) adding said solution obtained from step a) to said porous support at a flow rate of 1 to 20 liter(s)/hour;
• said porous support being contained in a rotary impregnation device functioning at a rotational speed of 10 to 20 rpm;
• c) optionally, submitting the impregnated porous support obtained from step b) to a maturation in order to obtain a catalyst precursor;
• d) drying the catalyst precursor obtained from step b) or c) at a temperature of 70° C. to 200° C.;
• e) calcining the catalyst precursor obtained from step d) at a temperature of 300° C. to 500° C.