A method of preparing hydrodesulfurization catalysts having cobalt and molybdenum sulfide deposited on a support material containing mesoporous silica. The method utilizes a sulfur-containing silane that dually functions as a silica source and a sulfur precursor. The method involves an one-pot strategy for hydrothermal treatment and a single-step calcination and sulfidation procedure. The application of the hydrodesulfurization catalysts in treating a hydrocarbon feedstock containing sulfur compounds to produce a desulfurized hydrocarbon stream is also specified.