Preparation Of Supported Heteropoly Acid Catalysts And Application In Oxidative Desulfurization

The supported heteropoly acid catalysts were prepared by three methods as sol-gel method,impregnation and in situ synthesis,which were characterized by XRD,FT-IR,BET,Py-IR and NH₃-TPD for their structure,pore size distribution and acid-stage.According to the characterization results,the best conditions of catalysts prepared by sol-gel method,rare earth type and optimum reaction conditions of catalytic oxidation desulfurization were found.The supported heteropoly acid catalysts H₃PMo₁₂O₄₀/SiO₂-J were prepared by impregnation method.The characterization results show that the active component load on the carrier successfully and without damage the Keggin structure.But the dispersivity of the catalysts were not as good as that which were prepared by sol-gel method.The compositc marerials H₃PMo₁₂O₄₀/SiO₂ were prepared by sol-gel method.The characterization results show that the active component load on the carrier successfully and without damage the Keggin structure.The best synthetic solution of H₃PMo₁₂O₄₀/SiO₂ by sol-gel method were found by orthogonal experiment with oxidative desulfurization as criteria.The experimental results show that the order of the influencing factors of acid catalyst prepared by sol-gel method is H₃PMo₁₂O₄₀>reaction temperature>water and ester mole ratio>alcohol and ester mole ratio.The optimum conditions are as follows:the mass fraction of H₃PMo₁₂O₄₀ 30 wt%,reaction temperature 60?,water and ester molar ratio 10:1,choose to use n-butyl alcohol,alcohol and esters molar ratio 2:1,aging at room temperature for 15 h,calcination at 150?.REPMo₁₂O₄₀/SiO₂ were prepared by sol-gel method.The characterization results show that the active component load on the carrier successfully and without damage the Keggin structure.Screen rare earth elements by orthogonal test with oxidative desulfurization as criteria.The oxidation desulfurization has several factors and the order of effect is ratio O/S>catalyst dosage>type of rare earth>reaction temperature>reaction time.Optimum reaction conditions are as follows:oxygen/sulfur ratio?O/S?,15;the dosage of catalyst,1.5wt%;type of rare earth metal,La;reaction time,90 min;reaction temperature,60?;catalyst loading,30 wt%;the dosage of surface active agent,0.20 wt%.Supported heteropoly acid catalyst H₃PMo₁₂O₄₀/SBA-15 were prepared by in situ synthesis.The characterization results show that the active component load on the carrier successfully and without damage the Keggin structure.The catalysts were mesoporous materials with good dispersion.