摘要
分别以硅酸乙酯为硅源、P123为模板剂,采用直接水热合成法将不同量的硅钨杂多酸(HSiW)直接固载于六方相介孔分子筛SBA-15中,利用XRD、N_2 adsorption-desorption、FT-IR、DR UV-Vis、TEM、Py-IR等手段对材料进行了表征,并且以油酸甲酯合成反应为探针反应,评价其催化性能.结果表明:所制备的HSiWSBA-15催化剂中HSiW呈高分散状态,并具有SBA-15的介孔结构和HSiW的Keggin型结构特征;同时,随着HSiW固载量的增加,所制催化剂中SBA-15的介孔长程有序性减弱;对油酸与甲醇酯化反应呈现出较好的催化性能,其中25%HSiW-SBA-15催化活性最佳,并显示出较好的循环使用性能.
A series of SBA-15 materials functionalized with 12-silicotungstic acid(HSiW-SBA-15) were onepot hydrothermally synthesized with Pluronic PI 23 as template and tetraethylorthosilicate as the silica source.The materials were characterized by various techniques,such as XRD.N_2 adsorption-desorption.FT-IR,DR UV-Vis.TEM and Py-TR.Their catalytic activities for the synthesis of biodiesel were investigated comparatively with the esterification of oleic acid with methanol as the probe reaction.The results showed that the HSiW was highly dispersed and resulting materials maintained the ordered mesoporous structure of SBA-15 and the Keggin structure of HSiW.On the other hand,the functionality of HSiW influenced the long range order of SBA-15 to some extent,which decreased with the increase of HSiW dosage.Furthermore,the HSiW-SBA-15 was efficient for oleic acid esterification and 25%HSiW-SBA-15 with excellent durability was found to be more active than the others.
引文
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