Ionic liquid-derived molybdenum oxide encapsulated in 3D ordered meso/macroporous ZrO2 matrix as promising catalyst for the oxidation of dibenzothiophene in fuel oil

Abstract

The removal of thiophene-type sulfides in fuel oil still remains a significant challenge to achieve the production of sulfur-free diesel fuel. Herein, an ionic liquid-derived 3D meso/macroporous Mo/ZrO2 (m/M Mo/ZrO2) composite has been prepared by two steps self-assembling process using 1-hexadecyl-3-methylimidazolium chloride ([C16mim]Cl) and close-packed poly (methyl methacrylate) (PMMA) colloidal crystal as dual-templates. The characterization results demonstrate the existence of interconnected 3D channels, with MoO3 active sites highly dispersed on the tetragonal ZrO2 framework. Moreover, the effects of pore structure, especially mesopores, on the reactivity of as-synthesized m/M Mo/ZrO2 catalyst have been investigated by the addition of different amount of [C16mim]Cl. As-fabricated 3D m/M Mo/ZrO2 catalyst exhibits excellent catalytic activity on dibenzothiophene (DBT) under mild reaction conditions. In addition, the 3D m/M Mo/ZrO2 catalyst demonstrates good cycle stability in the extractive-oxidative desulfurization process with no obvious decrease in activity after 7 cycles, which makes it a promising candidate for deep oxidative desulfurization.