Stacked bed catalyst system for deep hydrodesulfurization

A hydrodesulfurization process for producing a low sulfur content liquid product comprising contacting a sulfur containing feedstock with a stacked bed catalyst system comprising a first catalyst bed comprising a hydrodesulfufization catalyst, followed by a second catalyst bed comprising a ruthenium sulfide catalyst, at a temperature of about 150.degree. C. to about 400.degree. C. and a pressure of about 50 psig (344.74 kPa) to about 2500 psig (17236.89 kPa), wherein said ruthenium sulfide catalyst has a surface area of at least about 30 m.sup.2 /g and wherein said hydrodesulfurization catalyst of said first catalyst bed is comprised of an active metal sulfide component and an inorganic refractory oxide, said active metal of said active metal sulfide selected from the group consisting of at least one Group VI B metal and at least one promoter metal and wherein said inorganic refractory oxide is selected from the group consisting of refractory oxides of elements of Groups II to IV of the Periodic Table.