以环己胺为有机模板剂,硅溶胶为硅源,采用静态合成法在220oC的水热体系中制得了ZSM-35分子筛纯相.当初始凝胶中含有一定量的K+时,在晶化过程中,K^+与Na^+的共同作用可以很好地抑制混晶丝光沸石的生成,且当n(K^+)/n(K^++Na^+)=0.3时,制得的ZSM-35分子筛晶化度最高.利用X射线衍射和紫外拉曼光谱对分子筛形成的最佳条件以及晶化机理进行了研究.发现合成初期前体中含有五元环和六元环的硅物种构筑单元.通过水热晶化过程,与硅酸盐的五元环或六元环有关的450cm^-1处紫外拉曼谱峰增强,在晶化后期,随着无定形凝胶逐渐被消耗,在421,312和215cm-1处出现新的ZSM-35结构的特征拉曼谱峰,说明这些环物种相互聚集最终形成了ZSM-35分子筛.
The pure ZSM-35 zeolite was synthesized in a static hydrothermal system at 220 oC using cyclohexylamine as the template and silica sol as the Si source.When the initial gel contained a certain amount of K^+,the mutual role of K^+ and Na^+ inhibited the formation of mordenite,and well crystallized product was formed with n(K^+)/n(K^++Na^+) = 0.3.Optimum regions of the synthetic conditions of ZSM-35 zeolite obtained by X-ray diffraction were n(M2O)/n(Al2O3) = 3.2-3.4 and n(SiO2)/n(Al2O3) = 22.The building units in the precursor were identified as five-membered and six-membered silicate rings by UV-Raman spectroscopy.The intensity of the Raman band at 450 cm^-1 increased in the beginning of crystallization,and the new bands at 421,312,and 215 cm^-1 appeared with consuming the amorphous gel,indicating that the ring species were turned out to be aggregate through the hydrothermal treatment,and finally formed ZSM-35 zeolite.The strong Raman band at 421 cm-1 should be assigned to the bending vibration of the five-membered silicate ring,and the Raman band at 312 cm^-1 might correspond to the six-membered silicate ring of ZSM-35 zeolite framework.