关键词: 钼酸钴, 氧化脱硫, 比表面积, 超氧自由基

Abstract: Cobalt molybdate catalyst with large specific surface area was prepared fromcobalt(II) chloride and ammonium molybdate with KIT-6 as hard template and alkali etching process. The morphology and structural of the catalyst were characterizedby X-ray diffractometer, scanning electron microscope,X-ray photoelectron spectroscopy, and N₂ adsorption desorption techniques. Using cobalt molybdate as catalyst and O₂ as oxidant, the catalytic oxidation of dibenzothiophene from simulated oil was studied. The effects of reaction temperature, O₂ flow rate, the amount of catalyst addition and sulfide type on desulfurization efficiency were investigated. The results showed that the optimal reaction conditions were as follows:a simulated oil amount of 20 mL,an amount of catalyst of 0.05 g,an O₂ flow rate of 200 mL/min, a reaction temperature of 110 ℃ and a reaction time of 60 min. Under this condition, the desulfurization rate could reach 96.2%,and the activity of the catalyst had not significantly decreased after 5 times of reuse. Mechanism studies showed that the formation of superoxide radicals in the presence of catalystwas the key to the high desulfurization activity of the catalyst.

Key words: cobalt molybdate, oxidative desulfurization, specific surface area, superoxide radical