添加剂PVP和MTS对合成Beta分子筛结构与性能的影响

发布时间：2018-03-02 06:34

本文关键词： PVP MTS Beta分子筛催化裂化结构表征水热合成　出处：《燃料化学学报》2017年04期 　论文类型：期刊论文

【摘要】：分别以铝酸钠和硅溶胶为铝源和硅源,四乙基氢氧化铵为模板剂,在水热条件下,考察了添加剂(聚乙烯吡咯烷酮(PVP)和甲基三乙氧基硅烷(MTS))对合成Beta分子筛结构与性能的影响,并通过XRD、TEM、BET、ICP、~(29)Si-NMR和NH_3-TPD等方法对合成样品进行了结构表征和作用机理讨论,同时以催化裂化异丙苯为模型反应评价其催化性能。结果表明,与传统Beta分子筛相比,加入PVP后所得样品具有更高结晶度和较高的硅铝物质的量比(25.68)以及较大的比表面积(772 m~2/g);而加入MTS后尽管具有较大比表面积(657 m~2/g)和较高硅铝物质的量比(25.76),但是结晶度却相对降低,且粒径减小(160-320 nm)。两种添加剂作用下所得样品均具有更多酸量,在催化裂化异丙苯的反应中表现出较高的催化活性。
[Abstract]:The effects of additives (polyvinylpyrrolidone (PVP) and methyl triethoxysilane (MTS)) on the structure and properties of Beta molecular sieve were investigated under hydrothermal conditions using sodium aluminate and silica sol as aluminum and silicon sources and tetraethyl ammonium hydroxide as template. The structure characterization and mechanism of the synthesized samples were discussed by means of XRDD-TEM-BET-ICP-1Si-NMR and NH_3-TPD. The catalytic properties of the synthesized samples were evaluated by catalytic cracking isopropyl benzene as model reaction. The results showed that compared with the traditional Beta molecular sieve, the catalytic properties of the synthesized samples were evaluated. After the addition of PVP, the samples have higher crystallinity and higher volume ratio of Si and Al (25.68) and a larger specific surface area of 772 mm2 / g / g, while after adding MTS, the crystallinity of the sample is relatively low, although it has a larger specific surface area of 657mg / g and a higher volume ratio of Si-Al (25.76g), but the crystallinity of the sample is relatively low. Under the action of the two additives, the samples have more acid content and exhibit higher catalytic activity in the catalytic cracking of cumene.
【作者单位】：北京工业大学化学化工系绿色催化与分离北京市重点实验室;
【基金】：国家自然科学基金(21276005,21576005) 北京市自然科学基金(2152005)资助~~
【分类号】：O643.36

【相似文献】