The Preparation And Characterization And Oxidative Desulfurization Research Of Keggin-type Phosphomolybdate Catalyst

SO_x that generated in combustion of fuels results in acid rain and poisons converted catalysts.All these destroy the environment.Concerning the increasing seriously environmental problems,the world has seen a more and more stringent standard for sulfur content in liquid fuels proposed in many countries,so ultra-deep desulfurization of fuel has become an environmentally urgent subject worldwide due to increasing stringent environmental regulations.Currently,oxidative desulfurization(ODS)was considered one of the promising processes for its mild reaction condition,simple equipment design,and highly efficiency.The heteropoly compound is a kind of compound both have strong acidity and have strong oxidisability,that it not only is easy to dissolve in water and the oxo organic solvent, but also has "pseudo liquid Phase" in solid state,is one kind of ideal catalyst.Oxidative desulfurization(ODS)usually used H₂O₂ as a oxidant,and the operation is in a batch type.Because H₂O₂ is soluble and need for sufficient mixing.The thesis used oxidative desulfurization(ODS)of DBT with cumene hydroperoxide(CHP)as the oxidizing agent over Keggin-type H₃PMo₁₂O₄₀and Na₃PMo₁₂O₄₀were studied by comparing with H₄SiMo₁₂O₄₀and H₃PW₁₂O₄₀.The results indicated that H₃PMo₁₂O₄₀/SiO₂ exhibited much higher ODS activity than H₄SiMo₁₂O₄₀/SiO₂,whereas H₃PW₁₂O₄₀/SiO₂ showed no activity. The ODS activities of SiO₂ supported H₃PMo₁₂O₄₀and Na₃PMo₁₂O₄₀were much higher than their unsupported counter-partners.An induction period was observed during DBT ODS over H₃PMo₁₂O₄₀,Na₃PMo₁₂O₄₀and H₃PMo₁₂O₄₀/SiO₂.Among the catalysts studied in this work, SiO₂ supported Na₃PMo₁₂O₄₀showed the best catalytic performance due to its high ODS activity,long lifetime,and the absence of the induction period.