Synthesis Of POM-based Mesoporous Materials For Oxidative Desulfurization In Fuel

With the improvement of environmental protection consciousness,every country was strictly for automobile exhaust emissions of sulfur standard.In order to meet the standards of environmental regulations,it was found that the traditional hydrodesulfurization technology already cannot satisfy the requirement of removing high boiling point aromatic sulfide in gasoline and diesel benzothiophene,dibenzothiophene,3-methyl-benzothiophene,4,6-dimethyl-benzothiophene.Other new desulfurization methods come into being at the moment,such as oxidation desulfurization（ODS）,biological desulfurization（BDS）and adsorption desulfurization（ADS）,etc.In this work,I will select oxidation desulfurization as the research object,and simulated oil are octane with adding sulfur material benzothiophene,dibenzothiophene,3-methyl-benzothiophene,4,6-dimethylbenzothiopheneto to explore the effect of ultra-deep desulfurization.In this paper,the investigation of preparation the mesoporous catalyst of loading multifunction ionic liquid and that used for oxidation desulfurization activity.The research work mainly includes the following three parts:（1）Seven mesoporous catalysts were synthesized by hydrothermal and calcination method that active tungsten species were successfully introduced into the meso-ceria: CeO₂-400,0.125W-CeO₂-400,0.25W-CeO₂-400,0.5W-CeO₂-400,0.25W-CeO₂-300,0.25W-CeO₂-500,0.25W-CeO₂-600.Among the seven catalysts0.25W-CeO₂-400 was the best by adjusting the W/Ce mole ratio and calcination temperature.Its structure is characterized by FI-IR,UV,Raman,The small and wide angle XRD、XPS、BET、TEM to prove the catalysts were successful synthesis.Taken0.25W-CeO₂-400 as the research object to investigate remove DBT in oxidative desulfurization,the optimum reaction conditions were suggested: m（catal）= 0.03 g,O/S = 5,T = 30 oC,t = 50 min,99.2% of DBT could be removed.For different sulfur compounds,the desulfurization activity decreased according to the following order:DBT > BT > 4,6-DMDBT.The effective of desulfurization almost no reduce after three times circulation.（2）Six kinds of dendritic and mesoporous silica ball were synthesized through the oil-water two phase interface reaction: Mo/SiO₂-550-1:5,Mo/SiO₂-550-1:10,Mo/SiO₂-550-1:15,Mo/SiO₂-550-1:20,Mo/SiO₂-450-1:10,Mo/SiO₂-650-1:10.By adjusting the different Mo/Si and different calcination temperature found Mo/SiO₂-550-1:10 equipped with best desulfurization effect.The FT-IR,small/wide-angle XRD,N2 adsorption–desorption,XPS.etc characterizations show that the mesoporous catalysts with high specific surface area,and structure stability after loaded.Five different substrate sulfur compounds oxidation activity order:4,6-DMDBT > DBT > 4-MDBT > 3-MBT > BT.And the optimum reaction conditions of 4,6-DMDBT are found: O/S = 3,T = 60 oC,t = 40 min,and the catalyst dosage was resduced to 0.01 g which can achieve complete removal.Moreover,the catalyst circulation for four times that desulfurization effect can still reach 94.7%.（3）The six kinds catalysts of dendritic mesoporous silica balls were successfully synthesized with ionic liquid [C₁₆mim]₄W₁₀O₃₂ and TEOS through the oil-water two phase interface reaction.On the basis of previous studies by changing the CTAC and TEOS concentration to change the specific surface areas and pore size of mesoporous silica balls in the synthesis processes（SiO₂-15-5,W/SiO₂-15-5,W/SiO₂-15-10,W/SiO₂-15-20,W/SiO₂-25-5,W/SiO₂-35-5）.And different characterization such as Raman,small/wide-angle XRD,N2 adsorption–desorption,XPS which were demonstrated the [C₁₆mim]₄W₁₀O₃₂ evenly dispersed in surface of mesoporous silica carrier,and these catalysts have high specific surface area,and the structure stability after loaded.The oxidation activity of catalyst on the four different substrate order:DBT > 4,6-DMDBT > 3-MBT > BT.It was found that W/SiO₂-15-5 works best by active data.The optimized conditions were: O/S = 3,T = 60 oC,t = 30 min,the catalyst dosage was reduced to 0.005 g,DBT can achieve the purpose of the depth desulfurization,and catalyst circled for six times.The mesoporous catalyst was synthesized successfully and the first application on simulated oil desulfurization experiment.The catalysts achieved good desulfurization effects,and which enrich and develop the experimental research in the field of mesoporous catalyst in oxidative desulfurization.It possessed a certain actual application value.