A facile synthesis of mesoporous Mo–Al oxides for desulfurization of dibenzothiophene in the extractive catalytic oxidative desulfurization system

In order to obtain the deep desulfurization in the extractive catalytic oxidative desulfurization (ECODS) system, the evaporation-induced self-assembly (EISA) assisted by cash (combined assembly by soft and hard chemistry) method was applied to prepare mesoporous Mo–Al oxides with the stable catalytic performance when the acetonitrile as the extractant and H2O2 as the oxidant. Their physical chemical properties were also characterized by XRD, N2 sorption, FT-IR, SEM–EDX, H2-TPR, and Raman techniques. The characterization results indicated that tetrahedral molybdenum species can be highly dispersed into the meso-structure of γ-Al2O3, and the stronger interactions would be formed for 25Mo–Al catalyst than the 25Mo–Al–C catalyst prepared by impregnation method resulting in their superior physical chemical properties although the molybdenum species is the same. The 25Mo–Al catalyst showed higher desulfurization ratio than other xMo–Al catalysts and its value can be reached up to 100% at the molar ratio of H2O2 to dibenzothiophene (DBT) 2.3, volume ratio of oil phase to acetonitrile 3, catalyst dosage 0.012 g/mL, reaction temperature 60 °C and reaction time 30 min. The 25Mo–Al catalyst also showed good stability even after reaction for 10 recycles.