双杂原子Fe-Co-β沸石的合成、表征及催化苯乙烯氧化反应

Synthesis,Characterization of Heteroatomic Fe-Co-β Zeolite and Catalytic Performance on the Oxidation of Phenylethylene

采用水热合成法在Si O2-Fe2O3-Co O-（TEA）2O-H2O-NH4F体系中合成了Fe-Co-β沸石,运用X射线衍射、红外光谱、固体紫外可见漫反射光谱、差重-热重分析和扫描电镜等技术对所合成的沸石进行了表征,探讨了影响Fe-Co-β沸石合成的因素,考察了Fe-Co-β沸石对H2O2氧化苯乙烯反应的催化活性.结果表明,按化学组成（物质的量比）n（Si O2）∶n（Fe2O3）∶n（Co O）∶n[（TEA）2O]∶n（H2O）∶n（NH4F）=60∶（0.25-0.5）∶（1.0-3.0）∶（15-18）∶（650-750）∶（30-45）配制初始反应混合物,晶化温度140℃,晶化时间11 d,可以制备出结晶良好的Fe-Co-β沸石.所得Fe-Co-β[Si/（Fe＋Co）=24]沸石在H2O2氧化苯乙烯的反应中表现出良好的催化活性,在最优反应条件下,苯乙烯的转化率约为92.6%,苯甲醛和苯乙醛的选择性分别约为71.4%和28.6%.

Fe-Co-fl zeolite was hydrothermally synthesized in the SiO2-F2O3-CoO-（TEA）2O-H20-NH4F system. The structure and chemical composition of the products were characterized by X-ray diffraction, infrared spec troscopy, UV-Vis diffuse reflectance spectroscopy, thermogravimetry-differential thermal analysis, and scanning electron microscopy. The factors that affect the synthesis of the Fe-Co43 zeolite were investigated. The results indicate that the well-crystallized Fe-Co-fl zeolite can be synthesized from the precursor with the molar ratios of n（SiO2）： n（re203）： n（CoO）： n[ （TEA）20]： n（H20）： n（NH4F） = 60：（0.25 -0.5）： （1.0 -3.0）： （15 18）： （650 - 750）： （30 - 45 ）. The as-synthesized Fe-Co-β zeolite with the composition of nSi/n （Fe ＋ Co） = 24 shows excellent catalytic activity toward the oxidation of styrene using HE O2 as the oxidant. The phenylethylene conversion reaches 92.63% , whereas the seleetivities for benzaldehyde and phenylacetaldehyde reaeh 71.44% and 28.56%, respectively, under the optimal conditions.