VTS-2分子筛的合成、表征与催化氧化性能

Synthesis,characterization and catalytic oxidation performance of VTS-2 molecular sieves

分别以TBOT、VOSO4.3H2O、TEOS为钛源、钒源和硅源,TBAOH为模板剂,异丙醇为溶剂,采用水热晶化法,在Si/(Ti+V)≥33(凝胶中)条件下合成了具有MEL拓扑结构,骨架含两种不同价态过渡金属钛、钒的杂原子分子筛VTS-2。采用XRD、FT-IR、UV-Vis、EDS及催化反应等方法测试了所合成分子筛的晶相结构、波谱性质和催化氧化性能。对苯乙烯催化氧化反应的评价结果显示,在骨架金属含量相近的情况下,骨架含钛、钒两种过渡金属的VTS-2分子筛对烯烃的催化氧化活性分别高于骨架含单一金属的TS-2和VS-2,表明金属钒的引入有助于提高TS-2分子筛的催化氧化活性,调节氧化产物分布。

VTS-2 molecular sieves with MEL morphology and binary transition metal （Ti-V） oxide framework were synthesized by hydrothermal crystallization using tetrabutylorthotitanate（TBOT） as Ti source, tetraethyl orthosilicate（TEOS） as Si source, tetrabutyl ammonium hydroxide（TBAOH） as template, isopropanol as solvent. The crystallinity, spectroscopic properties and catalytic oxidation performance were evaluated by means of XRD, FT-IR, UV-Vis,EDSand catalytic tests respectively. The results of catalytic reaction styrene oxidation showed that VTS-2 molecular sieves with binary transition metal （Ti-V） oxide framework had the higher catalytic activity than TS-2 and VS-2 molecular sieves with single transition metal oxide framework under the condition of closely framework-metal content. , which indicated that the introduction of vanadium into framework of TS-2 molecular sieves helped to improve the catalytic activity of TS-2 and adjust the oxidative products distribution.