Synthesis Of Oxide Supported Metal-based Ionic Liquids And Study On Catalytic Oxidative Desulfurization In Fuel

With the continuous development of the automobile industry, people’s demand for fuel is increasing day by day. However, a series of sulfur compounds in the fuel converted into sulfur oxides(SOx) after combustion, which seriously pollute environment and threaten human’s health. Therefore, fuel desulfurization is imperative to have both theoretical and applied value. In this paper, a series of supported ionic liquid catalysts were designed, synthesized and applied in the extractive and catalytic oxidative desulfurization(ECODS) system. The desulfurization effect of various catalysts on the fuel was studied, also, the corresponding catalytic oxidation desulfurization reaction mechanism was further discussed. The main conclusions are listed as follows:1. [Bmim]FeCl4/SiO2, as a type of supported ionic liquid catalyst, is synthesized through the sol-gel method. Serials of charization methods, such as FT-IR, DRS, Raman and TG-DSC, are used to study the structure and property of the as-prepared catalyst. Different reaction conditions are investigated when the as-prepared catalytic is used in the ECODS reaction system. Here, 30% [Bmim]FeCl4/SiO2 is chossen as its outstanding catalytic performance. The experiment conditions are optimized as followings: m(catalyst) = 0.05 g,n(O/S) = 4,T = 30°C,t = 1 h,V([Omim]BF4) = 1 mL. Deep desulfurization(sulfur removal of 97.3%) is achieved under the above experiment conditions. Sulfur removal of different substrates are also investigated, and their reaction actives are decresed as: DBT > BT > 4,6-DMDBT. Sulfur removal could still reach up to 90% after 5 times recycling of the as-prapred catalysts.2. [Bmim]FeCl4/Am TiO2, as another type of supported ionic liquid catalyst, is synthesized with using Am TiO2 as a carrier. Serials of charization methods, such as TG, wide angle XRD, FT-IR, XPS, etc., are used to study the structure and property of the as-prepared catalyst. Different reaction conditions are investigated when the as-prepared catalytic is used in the ECODS reaction system. Here, the catalyst calcined under 250°C is chossen as its outstanding catalytic performance. The experiment conditions are optimized as followings: m(catalyst) = 5 mg,n(O/S) = 4,T = 60oC,t = 1 h, V([Omim]BF4) = 1 mL. The sulfur removal could reach up to 99.6% under the above reaction conditions. Sulfur removal of different substrates are decresed as following: DBT > BT > 4,6-DMDBT. DBTO2, as the oxidization product of DBT, is found with help of GC-MS measurements. After been recycled for 25 times, the sulfur removal of the as-prepared catalysts could still reach up to 100%, indicating is outstanding recycling ability.3. [C16mim]3PMo12O40/Am TiO2, as a type of supported polyacid ionic liquids, is synthesized by one-pot method. Different charicatrization methods, such as FT-IR, DRS, wide angle XRD, N2 adsorption-desorption and XPS, are used to analyzed the properties and structure of the as-prepared catalyts. Its cataltic ability is evalutated by the cataltic oxidation of DBT existed in model oil. Reaction conditions, which might influence the sulfur removal are investigated. The optimized reaction conditions are listed as following: m(catalyst) = 0.01 g,n(O/S) = 3,T = 50℃,t = 1 h,V([Bmim]BF4) = 1 m L. The DBT existed in model oil could be removed totally under the above reaction conditions. Sufur removal of different substrates is decreased as: DBT > 3-MBT > BT > 4-MDBT. Sulfur removal could still reach up to 92.9%, when the as-prepared catalyst is been recycled for 10 times, indicating its superior catalytic ability. Mo(O)2, produced by the reaction between H2O2 and catalyst, is considered to be the active species which could oxidize DBT to DBTO2.4. C16SiW-TiO2 is synthesized by one-pot method. Kinds of characterization methods, such as FT-IR, Raman, N2 adsorption-desorption, XPS, SEM, etc., are used to investigate the structure and composition of the as-prepared catalysts. The best sulfur removal is obtained when 0.1-C16SiW-TiO2 is used in the ECODS reaction system. High sulfur removal, 95.3%, is obtained, when the O/S ratio is only 2. Deep desulfurization(100%) is, then, obtained with a tiny increasment of the using amount of H2O2. The reaction mechanism is proposed based on the GC-MS analyze of oil phase and ionic phase. Sulfur removal of different substrates are decreased as: DBT > 3-MBT > BT > 4-MDBT. Sulfur removal decreased little after the as-prepared catalyst(0.1-C16SiW-TiO2) is been recycled for 8 times, indicating its outstanding recycling abilities.5. Serials of supported SiW12O40-based ionic liquid catalyst with high catalytic activity are synthesized by the sol-gel method. Then, the properties and component of the as-prepared catalysts are evaluated by FT-IR, DRS, wide angle XRD, XPS, SEM, TEM, etc. Here, the amphiphilic property of 0.2-C16SiW-SiO2 is found with the experiment data from surface tension measuring instrument. Here, sulfur removal(99.9%) could realized in a solvent-free reaction condition. The oxidized product(DBTO2) is detected with the help of GC-MS measurement. DBTO2 is consider to be formated by the oxidization of DBT by the active species [W(O)2], which is generated by the reaction of H2O2 and as-prepared catalyst. Sulfur removal of different substrates are investigated by 0.2-C16SiW-SiO2, and the sulfur removal is decreased as: DBT > 4-MDBT > 4, 6-DMDBT > BT. Sulfur removal could still reach up to 96.2% after 7 times recycling of the as-prepared catalyst.