晶种导向蒸汽辅助晶化法全硅BETA沸石的合成研究

Synthesis of Pure-silica BETA Zeolite by the Method of Seed-direct Steam-assisted Crystallization

全硅BETA沸石在卷烟烟气减害和石油化工领域有较好的应用前景。利用单模板剂合成方法——晶种导向蒸汽辅助晶化法(SAC)合成了全硅的BETA沸石。利用X射线衍射(XRD)、扫描电镜(SEM)、红外(FT-IR)和氮吸附对样品进行了分析。结果表明,晶种量、模板剂四乙基氢氧化铵(TEAOH)和碱度对全硅BETA沸石的合成有着重要的影响。同时还发现,利用SAC法合成的全硅BETA沸石晶体中,四方晶系(A晶型)占有58%~68%,并且原料的配比不影响A晶型的丰富程度。全硅BETA沸石具有一定疏水性,有望用于有机物/水分离体系。

The pure-silica zeolite BETA has a promising prospect in the field of cigarette harm reduction and petrochemical industry. In present work, the single-template method, named as the seed-direct steam-assisted crystallization（SAC）, was used to synthesize the pure-silica zeolite BETA. And then the samples were characterized by powder X-ray diffraction（XRD）, scanning electron microscopy（SEM）, nitrogen adsorption, and Fourier Transform infrared spectroscopy（FT-IR）. The results revealed that BETA seeds, template（TEAOH） and alkalinity exert great effects on the synthesis of pure-silica zeolite BETA. The BETA zeolite with polymorph A enrichments（58%-68%） is synthesized by SAC method, which can not be affected by the change of molar ratio of the raw materials. The pure-silica zeolite BETA possesses the hydrophobic properties, which can be used in the separation of organic/H2 O, and the removal of harmful organic materials in cigarette smoke.