【摘要】 以凹凸棒石黏土为原料,在水热条件下原位晶化制备了NaY沸石,随后利用二次晶化法制备ZSM-5/NaY复合沸石。结果表明,导向剂是合成NaY沸石的关键,在导向剂作用下,仅以凹凸棒石黏土为原料即可合成NaY沸石,铝源NaAlO₂的加入可以有效提高沸石的结晶度。随后在ZSM-5沸石合成体系中,添加的NaY沸石溶解为第一阶段形成的ZSM-5沸石提供营养,最后形成ZSM-5/NaY复合沸石,该复合沸石的性质不同于机械混合物的性质,形成了新的酸中心,其酸中心主要为中等程度的酸中心。更多还原

【Abstract】 NaY zeolites were synthesized from palygorskite via in situ hydrothermal method. ZSM-5/NaY composite zeolites were subsequently prepared from palygorskite using a secondary crystallization method. The results indicated that the guiding agent was the key factor controlling the synthesis of NaY zeolites. NaY zeolites could prepared from palygorskite without adding NaAlO₂ at the presence of the guiding agent and the intensity of NaY zeolites increased with NaAlO₂. The added NaY zeolites were dissolved and provided the nutriment needed in the growth process of ZSM-5 zeolite crystals obtained the first crystallization stage under the ZSM-5 zeolite synthesis system and then ZSM-5/NaY composite zeolites were synthesized. The properties of the composite zeolites were different with that of the mechanical mixture of ZSM-5 zeolites and NaY zeolites. New acid sites mainly attributed to medium acid sites were formed in the composite zeolites.更多还原