The Preparation Of Polyoxometalates Catalysts And Catalytic Oxidative Desulfurization

As the environment seriously polluted, more and more stringent regulation has been made in order to minimize the pollution to the environment. Deep desulfurization of fuel oils has been paid widely attention. The conventional method for sulfur removal is hydrodesulfurization (HDS). This process is highly efficient in removing sulfides and disulfides, however, it is difficult to reduce refractory sulfur-containing compounds such as dibenzothiophene (DBT) and its derivatives. Extreme operating conditions is needed which leads to high instrumental cost in order to deeply desulfurization. Therefore, it is highly desirable to develop a method which can achieve deep desulfurization to produce clean diesel. Oxidative desulfurization (ODS) combined with extraction is considered to be one of the most promising process due to its highly efficient for desulfurization under mild conditions. In the oxidative desulfurization process, hydrogen peroxide is considered to be easily prepared, non-polluting, no corrosive oxidant. Therefore, the oxidation of DBT by hydrogen peroxide as the oxidant under mild conditions would be of great significance in industry.The membrane catalyst has attracted considerable attention since they are easily removed from the reaction mixture, allow mild reaction conditions and do not cause corrosion to equipment and pollution to the environment. Therefore, to develop a membrane catalyst which is high efficient for sulfur removal will be of great significance.This paper synthesized two membrane catalysts and had successfully oxidized DBT by hydrogen peroxide as the oxidant under mild conditions. Furthermore, the catalyst can repeat six times.1. We prepared polyoxometalates membrane catalyst [C16H33N(CH3)3]3[PO4{MoO(O2)2}4]/agarose(C16PMo(O2)2/agarose)[C16H33N(CH3)3]3[PO4{MoO(O2)2}4]/poly(N-isopropylacrylamide)(C16PMo(O2)2/PNI PAAm) and characterized them by IR、UV-vis、SEM、EDS、XPS measurements.2. To investigate the catalytic activity of C16PMo(O2)2/agarose on oxidation of DBT, we studied the effect of H2O2/sulfer molar ratio (O/S), reaction time, the loading amount of C16PMo(O2)2on agarose, the amount of catalyst, the concentration of DBT and the reuse of catalyst.3. To investigate the catalytic activity of C16PMo(O2)2/PNIPAAm on oxidation of DBT, we studied the catalytic performance of different systems, H2O2/sulfer molar ratio (O/S), reaction time, the amount of catalyst, the concentration of DBT and the reuse of catalyst. 4. According the references, the mechanism of the oxidation of DBT to sulfone with H2O2is speculated.