Cobalt-manganese spinel structure catalysts for aerobic oxidative desulfurization

For the first time cobalt-manganese spinel structure catalysts were effectively applied for aerobic oxidation of sulfur-containing compounds. High activity of obtained catalysts is achieved due to the existence of the redox couples Co2+/Co3+ and Mn3+/Mn4+ in the spinel structure. It has been shown that the high mobility of oxygen in the spinel structure contributes to the efficient oxidation of sulfur-containing compounds. The CoMn2O4 and MnCo2O4 spinel-type catalysts were obtained by the hydrothermal method and characterized by a complex of physicochemical methods: XRD, FTIR, nitrogen adsorption–desorption, SEM, TEM, TPR-H2, and XPS. Under optimal conditions (130 °C, ω(cat.) = 0.034 wt%, 2 h), the complete DBT oxidation was achieved in the presence of CoMn2O4. High stability of catalyst over 5 cycles of oxidation was demonstrated. A possible reaction mechanism has been proposed based on EPR data and catalysts characterization results.