磷酸硅锌铝分子筛(ZnAPSO-5)的合成、结构及性能研究

Studies on the Synthesis, Structure and Properties of Zinc Silicoaluminophosphate Molecular Sieve

以二乙氨基乙醇为导向剂,用水热晶化法合成了磷酸硅锌铝分子筛纯相,测定其组成为Zn_(1.12)Si_0.38Al_(10.88)P_(11.62)O_(48),并对其结构和性能进行了研究.实验结果表明,ZnAPSO-5具有AlPO_4-5型分子筛结构,由于锌和硅进入骨架同晶取代了部分铝和磷,致使ZnAPSO-5分子筛有了B酸酸性,而热稳定性也较磷酸锌铝分子筛(ZAPO-5)有所提高.

The pure zinc silicoaluminophosphate molecular sieve (ZnAPSO-5) was synthesized in the presence diethylaminoethanol as a template by hydrothermal crystallization. The chemical composition and parameters of the unit cell of ZnAPSO-5 were determined. The structure of ZnAPSO-5 has been studied by means of X-ray diffraction analysis, scanning electron microscopy, infrared spectra, X-ray photoelectron spectroscopy (XPS). The thermal stability and surface acidity of ZnAPSO-5 were investigated. The results showed that the atoms of zinc and silicon entered into the framework of ZnAP-SO- 5 molecular sieve and that isomorphous replacements of aluminium by zinc and phosphorus by silicon make the framework carry negative charge but it has been balanced by H+. Therefore, ZnAPSO-5 exhibits the property of Bronsted acid.