双杂原子Fe-V-β沸石的合成、表征及催化性能

Synthesis,Characterization,and Catalytic Behavior of Biheteroatomic Fe-V-β Zeolite

采用水热合成法在SiO2-Fe2O3-V2O5-(TEA)2O-H2O-NH4F体系中合成了Fe-V-β沸石,并用X射线衍射、红外光谱、固体漫反射光谱、热重-差热分析、扫描电镜-能量色散谱仪和等离子体发射光谱等技术对沸石样品进行了表征,探讨了影响Fe-V-β沸石合成的因素.结果表明,按摩尔比组成SiO2:Fe2O3:V2O5:(TEA)2O:H2O:NH4F=60:(0.1～0.75):(0.1～0.75):(17～18):(550～650):(30～50)配制初始反应混合物,可以制备出结晶良好的Fe-V-β沸石,且Fe和V原子进入到沸石骨架.所得Fe-V-β(Si/(Fe+V)=30)沸石在H2O2氧化苯乙烯反应中表现出最高的催化活性,苯乙烯转化率为25.4%,苯甲醛、苯乙醛和苯乙酮的选择性分别为69.1%,22.5%和4.1%.

The Fe-V-β zeolite was hydrothermally synthesized in a SiO2-Fe2O3-V2O5-（TEA）2O-H2O-NH4F system.The structure and chemical composition of the zeolite samples were characterized by X-ray diffraction,infrared spectroscopy,thermogravimetry-differential thermal analysis,inductively coupled plasma-atomic emission spetrometry,scanning electron microscopy-energy dispersive spectrometry,and ultraviolet-visual diffuse reflection spectroscopy.The factors that affected the synthesis of Fe-V-β zeolite were investigated.The results indicated that the well-crystallized Fe-V-β zeolite could be synthesized from the precursor with SiO2：Fe2O3：V2O5：（TEA）2O：H2O：NH4F molar ratio of 60：（0.1–0.75）：（0.1–0.75）：（17–18）：（550–650）：（30–50）,and the Fe and V atoms entered the framework of the zeolite.The as-synthesized Fe-V-β zeolite with Si/（Fe＋V）=30 showed higher catalytic activity in the oxidation of styrene using H2O2 as the oxidant.The styrene conversion was 25.4%,and the selectivity was 69.1% for PhCHO,22.5% for PhCH2CHO,and 4.1% for PhCOMe,respectively.