Catalyst comprising an active nickel phase distributed in a shell

A catalyst comprising:

• a nickel-based active phase and an alumina support, wherein said catalyst contains between 1% and 50% by weight of elemental nickel relative to the total weight of the catalyst, wherein:
• said support has a core and a crust at a periphery thereof, and the nickel is distributed in the crust at the periphery of the support, and in the core of the support, wherein the thickness of said crust is between 2% and 15% of the diameter of the catalyst;
• the nickel density ratio between the crust and the core is greater than 3;
• said crust comprises more than 25% by weight of nickel element relative to the total weight of nickel contained in the catalyst, and
• the catalyst contains nickel crystallites in oxide form, and the size of the nickel particles in the catalyst, measured in oxide form, is between 7 and 25 nm, wherein the size of nickel particles in the catalyst, measured in oxide form, means the diameter of the nickel crystallites in oxide form.