CoCrAPO-5分子筛及分子筛膜的合成与应用

发布时间：2018-06-11 16:27

本文选题：CrCoAPO-5 + 片状　；参考：《天津大学》2014年硕士论文

【摘要】：首次在传统水热条件下采用快速晶化法,得到了高晶化产量、较小尺寸的薄片状CrCoAPO-5分子筛。合成过程中通过控制凝胶制备温度、晶化温度以及晶种加入等因素,调节分子筛颗粒的形貌以及大小。合成的CrCoAPO-5分子筛采用SEM、XRD、IR、UV-Vis、TG等进行表征。同时我们将此方法应用于AlPO4-5、CoAPO-5分子筛的合成,同样获得了低轴径比且具有AFI结构的片状分子筛,从而说明此方法适用于AFI型片状分子筛的合成,为分子筛形貌的控制提供了一种新的思路。在合成的分子筛样品性能表征中,小尺寸的薄片状CrCoAPO-5分子筛由于扩散通道较短,有助于客体分子在分子筛孔道内的吸附和扩散,表现出模板剂易于脱除、高吸水性能及高的环己烷催化氧化活性。在环己烷的液相催化体系中反应温度、溶剂丙酮的量、催化剂的尺寸、反应装置的选择等均对催化反应的活性产生一定的影响。使用二次生长法在α-Al_2O_3载体上合成CrCoAPO-5分子筛膜。在晶种层上先后进行二次生长有助于提高分子筛膜的交联性,且通过调控一次生长液的凝胶组成及一次生长时间使得在晶种层上获得c轴垂直于载体表面的不交联的片状CoCrAPO-5分子筛层,有助于在其基础上通过外延生长获得具有高度择优c轴取向的致密分子筛膜,且提高了分子筛膜的稳定性。在分子筛膜的合成过程中,通过调节合成凝胶的模板剂及水的含量可以有效地控制分子筛膜中晶体的生长方向,降低合成凝胶的配制温度及合成凝胶的水含量可在一定程度上促进分子筛膜的交联性生长。
[Abstract]:The CrCoAPO-5 molecular sieve with high crystallization yield and smaller size was obtained by rapid crystallization under traditional hydrothermal conditions for the first time. The morphology and size of molecular sieve particles were adjusted by controlling the gel preparation temperature, crystallization temperature and seed addition. The synthesized CrCoAPO-5 molecular sieve was characterized by SEMN XRDX IR IR UV VisC TG and so on. At the same time, we have applied this method to the synthesis of AlPO4-5 CoAPO-5 molecular sieve, and obtained the flake molecular sieve with low axis to diameter ratio and AFI structure, which shows that this method is suitable for the synthesis of AFI flake molecular sieve. It provides a new way to control the morphology of molecular sieve. In the characterization of the properties of the synthesized molecular sieve samples, the small size wafer CrCoAPO-5 molecular sieve is helpful for the adsorption and diffusion of guest molecules in the pore channels of molecular sieve because of the short diffusion channel, which shows that the template agent is easy to be removed. High water absorption and high catalytic oxidation activity of cyclohexane. In the liquid-phase catalytic system of cyclohexane, the reaction temperature, the amount of solvent acetone, the size of catalyst and the selection of reaction device have certain influence on the catalytic activity. CrCoAPO-5 molecular sieve membrane was synthesized by secondary growth method on 伪 -Al _ S _ 2o _ 3 carrier. The secondary growth on the seed layer is helpful to improve the crosslinking property of molecular sieve membrane. By adjusting the gel composition and the growth time of the primary growth solution, the uncrosslinked and uncrosslinked CoCrAPO-5 molecular sieve layer with c axis perpendicular to the surface of the carrier was obtained on the seed layer. It is helpful to obtain dense molecular sieve membrane with highly preferential c-axis orientation on the basis of epitaxial growth and improve the stability of zeolite membrane. In the process of synthesis of molecular sieve membrane, the crystal growth direction of molecular sieve membrane can be effectively controlled by adjusting the templating agent and the content of water in the synthetic gel. To a certain extent, the crosslinking growth of molecular sieve membrane can be promoted by lowering the preparation temperature of synthetic gel and the water content of synthetic gel.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TQ424.25;TB383.2

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