水热体系下新型层状UZM-8沸石的合成

Synthesis of UZM-8 Zeolite in Hydrothermal System

水热体系下合成了新型层状UZM-8沸石,采用~13C交叉极化魔角旋转核磁共振(~13C CP MAS NMR)谱研究了该体系下二甲基二乙基氢氧化铵(DEDMAOH)的模板导向作用。研究结果表明,DEDMA^+与沸石发生较强的相互作用,处于沸石的不同化学环境中,起到了较强的模板导向作用。采用XRD和SEM方法对合成的UZM-8沸石进行了表征,考察了晶种和Na^+对UZM-8沸石的形成及结构的影响。实验结果表明,当n(DEDMA^+)∶n(SiO_2)<0.3时,合成体系中UZM-8沸石无法自发结晶,而当体系中存在Na^+和晶种时,n(DEDMA^+)∶n(SiO_2)=0.1时仍可合成出UZM-8沸石,且合成产物UZM-8沸石的结晶度提高,晶化时间缩短。

Novel layered UZM-8 zeolites were hydrothermally synthesized using diethyldimethylammonium hydroxide （DEDMAOH） as a template. The strong interactions between the DEDMA ^＋ and the zeolites were found by means of 13C CP MAS NMR, which indicated the structure-directing function of the template for forming the UZM-8 zeolites. The resultant UZM-8 zeolites were characterized by means of XRD and SEM. Effects of the crystal seeds and Na^＋ on formations and structures of the UZM-8 zeolites were investigated. The results indicated that the UZM-8 zeolites could not be crystallized spontaneously when n （ DEDMA ^＋ ） ： n （ SiO2 ） 〈 0.3. As both Na^＋ and the crystal seeds existed in the synthesis system, the UZM-8 zeolites could be obtained even when n （DEDMA ^＋ ） ： n（ SiO2 ） = 0. 1. Meanwhile, the crystallinities of the resultant UZM-8 zeolites rose and their crystallization periods shortened.