Kinetics for Oxidation of Dibenzothiophene Catalyzed by Keggin-based Heteropoly Acids/H_2O_2 in [bmim]BF_4

摘要

Extraction and catalytic oxidative desulfurization (ECODS) could success-fully integrate phosphomolybdic acid (H_3PM0_(12)O_(40)26H_2O, PM0_(12)), hydrogen peroxide (H_2O_2), and 1 -butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) into a single efficient system that was manipulated to facilitate the separation and oxidation of sulfur compounds. The peroxometal complex was formed rapidly as PM0_(12) was oxidized by H_2O_2 and it could be solubilized in hydrophilic ionic liquid. The experimental results showed high sulfur removal up to 99.4% under the optimized desulfurization system. Kinetics of the ECODS system of dibenzothiophene was pseudo first order with the apparent activation energy of 53.8 kJ-mol~(-1). The catalytic reaction system could be recycled eight times without a significant decrease in reaction activity.