以二甲基二乙基氢氧化铵为模板剂UZM-8沸石的合成与表征

Preparation and Structure Characterization of UZM-8 Zeolite Templated by DEDMAOH

以二甲基二乙基氢氧化铵(DEDMAOH)作为模板剂,通过水热合成方法制备了新型层状沸石材料UZM-8,并考查了DEDMAOH模板剂用量及投料硅铝比对UZM-8沸石结构的影响.采用X衍射(XRD)、扫描电子显微镜(SEM)、傅立叶变换红外(FT-IR)、热重分析(TG,DTG)等方法对所得系列UZM-8沸石进行了表征.该层状沸石具有与MCM-56相似的MWW结构,但层间距及其堆积方式等有所不同.当DEDMAOH/SiO2<0.3时,无法有效合成出UZM-8沸石.随硅铝比的提高,UZM-8在2θ角6.6°和7.1°处的两个衍射峰转变为一个峰,层间沿c轴方向收缩.

Novel layered UZM-8 zeolite was hydrothermally synthesized using diethyldimethyl-ammonium hydroxide （DEDMAOH） as structure-directing agent, and the effects of Si/Al ratio and DEDMAOH dosage on the structures of resultant UZM-8 were also discussed. The UZM-8 zeolite was systematically characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, thermogravimetric analysis （TG, DTG） and infrared （IR） spectrum methods to clarify its framework topology, layer arrangement, and morphology. Its framework topology was similar to ＇that of MWW type MCM-56, but their distinct inter-layer distances and stack patterns were different. UZM-8 could not be fabricated when the DEDMAOH/SiO2 molar ratio was less than 0.3. With the increase of SiO2/Al2O3 molar ratio, the characteristic diffraction peaks indexed as 6.6° and 7.1° contracted into one diffraction peak, which indicated that the interlayer distances were reduced along the c axis.