W-SBA-15的制备及其吸附脱氮性能研究

分别以钨酸钠和钨酸铵为钨源、以正硅酸乙酯为硅源，分别采用直接合成法和后合成法制得W-SBA-15（x）和W/SBA-15（x）（x表示硅钨摩尔比），采用XRD，BET，NH3-TPD等分析手段对样品进行表征，并考察不同制备方法、不同WO3负载量以及焙烧温度、焙烧时间对样品吸附脱氮效果的影响。结果表明：直接合成法制备的W-SBA-15（20）和后合成法制备的W/SBA-15（20）都能很好地保留SBA-15的介孔结构，而直接合成法制备的W-SBA-15（10）使分子筛的有序结晶度明显变差；W-SBA-15（20）相对于W/SBA-15（20）和W-SBA-15（10）具有更好的吸附能力；当焙烧温度为550 ℃、焙烧时间为6h时，所制W-SBA-15（20）吸附剂的吸附脱氮效果最好，在反应温度为140 ℃、反应时间为30min、剂油质量比为1:30的条件下，对喹啉十二烷模拟油的脱氮率为66.32%，饱和吸附量为25.66 mg/g。

STUDY ON W-SBA-15 PREPARATION AND ITS ADSORPTIVE DENITRIFICATION PERFORMANCE

W-SBA-15(x) was synthesized by direct synthesis method using tetraethoxysilane (TEOS) as silica source and Na2WO4 as W source, (x represent the mole ratio of W and Si). The W/SBA-15(x) was prepared by post-synthesis method using prepared SBA-15 and ammonium tungstate solution. The samples were characterized by XRD, BET, and NH3-TPD. Effect of preparation method, WO3 loadings, calcination temperature and time on the performance of adsorptive denitrification was investigated. The results show that the mesoporous structure of SBA-15 can well be remained by both direct synthesis and post-synthesis methods. The ordered crystallinity of W-SBA-15(10) is worse. The denitrification performance of W-SBA-15(20) is better than W/SBA-15(20) and W-SBA-15 (10). The denitrification performance of W-SBA-15(20) is the best when the adsorbent was calcined at 550 ℃ for 6 h. At the adsorption conditions of 140 ℃, 30 min and absorbent/oil ratio of 1:30, the denitrification rate of model oil quinoline solution in dodecane, reaches 66.32% and the saturated absorption capacity is 25.66 mg/g.