Preparation of catalyst for selective hydrogenation of hydrogenatable precursors

A reduced metallic catalyst or pre-activated catalyst is formed by contacting a precursor catalyst or a reduced metallic catalyst with a modifier solution in the presence of a source of hydrogen and heat treating the precursor catalyst or the reduced metallic catalyst at super-atmospheric pressure to obtain the reduced metallic catalyst from the precursor catalyst or the pre-activated catalyst from the reduced metallic catalyst. A method of hydrogenating a hydrogenatable precursor includes providing a reduced metallic catalyst or the pre-activated catalyst prepared with modifier buffer and contacting the reduced metallic catalyst or pre-activated catalyst with the hydrogenatable precursor in the presence of hydrogen and, optionally, in the presence of a modifier solution.