Construction of bifunctional 3-D ordered mesoporous catalyst for oxidative desulfurization

Abstract

The development of catalysts with the functions of catalyzing the oxidation of organosulfur and separating the products from reaction mixturesis facilitates to achieve high-efficiency oxidative desulfurization (ODS) of fuel. Herein, the MoO3 nanoparticles (mean diameter = 1.33 nm) confined in Ti-doped KIT-6 could be synthesized by triblock copolymer (EO20PO70EO20)-assisted in-situ synthesis method combined with stepwise pyrolysis. The prepared catalyst (Mo/KIT-6-Ti) exhibited excellent ODS performance. When cumene hydroperoxide (CHP) was used as the oxidant, Mo/KIT-6-Ti not only could completely remove dibenzothiophene (DBT) in the model gasoline at room temperature in 40 min but also had the excellent ability to adsorb and separate the sulfone product from the model gasoline. After five reaction-regeneration cycles, the DBT conversion over Mo/KIT-6-Ti still reached above 99% in 60 min. Furthermore, kinetic studies revealed that the oxidation reaction of DBT on Mo/KIT-6-Ti had extremely low activation energy (34.9 kJ/mol). Data from radical scavenger experiments suggested that hydroxyl radicals play a dominant role in the ODS. This catalyst has the potential to negate the need for a solvent extraction step in fuel desulfurization and produce ultralow sulfur fuel.