Hydrothermal synthesis of unsupported MoS₂ as catalyst for hydrodesulfurization of gas oil

Hydrothermal synthesis with ammonium heptamolybdate and thiourea as precursors was used to obtain an unsupported MoS₂ catalyst. The catalyst was obtained in sulfide state directly at mild reaction conditions (i.e., 180°C during 5 h). After catalyst was obtained, it was characterized through nitrogen physisorption, transmission electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Catalytic evaluation was carried out in a batch reactor at 350°C, 55 bar of hydrogen pressure, 750 rpm, and 3 h of reaction time using straight-run gas oil (SRGO) as feedstock. A commercial CoMo/Al₂O₃ catalyst was used for comparison of activity. The synthesized catalyst was slightly more active toward SRGO hydrodesulfurization than commercial one keeping constant the sulfur removal after two runs.