纳米片状钼酸铋的制备及其催化氧化脱硫性能研究

Preparation of bismuth molybdate nano flake and study on its catalytic oxidative desulfurization performance

通过水热-退火法和溶剂热-退火法制备了4种钼酸铋样品,采用傅里叶变换红外光谱(FT-IR)、X-射线衍射(XRD)、电子扫描显微图像(SEM)、能量色散光谱(EDS)和N2等温吸附-脱附等分析方法对其结构组成、表面形貌和比表面积进行了表征。在不同反应温度、催化剂(钼酸铋)用量、萃取剂(乙腈)用量、氧化剂(H_(2)O_(2))用量、硫含量等条件下进行模拟油脱硫性能测试。结果表明,制备的钼酸铋均为纳米片状结构,水热-退火法制备的钼酸铋具有最佳脱硫性能;在反应温度为60℃、钼酸铋为0.025 g、乙腈为5 mL、H_(2)O_(2)为0.12 mL、反应时间为75 min时,对硫含量为500、800、1100和1500 mg/L的二苯并噻吩模拟油的脱硫率均可达99.2%以上。动力学分析表明,当反应温度在40~60℃时,拟合的反应速率方程线性关系良好(R^(2)>0.99),推算得到的反应表观活化能为30.82 kJ/mol。

Four kinds of bismuth molybdate samples are prepared through hydrothermal-annealing method and solvothermal-annealing method,respectively.The structural composition,surface morphology and specific surface area of samples are characterized by means of Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and N_(2)isotherm adsorption-desorption analysis methods.The performance of prepared bismuth molybdate samples for desulfurization of oil products are tested under different reaction temperature,catalyst(bismuth molybdate)dosage,extractant(acetonitrile)dosage,oxidant(H_(2)O_(2))dosage and sulfur content.The results suggest that the prepared bismuth molybdate has a nano-flake structure.The sample prepared by hydrothermal-annealing method exhibits the best desulfurization performance.The optimal reaction conditions are as follows:the temperature is at 60℃,bismuth molybdate dosage is 0.025 g,acetonitrile dosage is 5 mL,H_(2)O_(2)dosage is 0.12 mL,and reaction lasts for 75 min.The desulfurization rates exceed 99.2%for dibenzothiophene model oil which contains 500,800,1100,and 1500 mg·L^(-1)of sulfur.It is indicated through kinetic analysis that the fitted reaction rate equation has a good linear relationship(R^(2)>0.99)as the reaction temperature is between 40℃and 60℃.The calculated apparent activation energy of the reaction is 30.82 kJ·mol^(-1).