三聚甲醛存在下EMT分子筛的合成及表征  

Synthesis and Characterization of EMT Molecular Sieves in the Presence of Trioxymethylene

作　　者：周晶[1] 邱俊[1] 李鑫[1] 

机构地区：[1]吉林化工学院化学与制药工程学院,吉林132022

出　　处：《人工晶体学报》2017年第6期1099-1105,共7页Journal of Synthetic Crystals

摘　　要：以硅酸钠为硅源、铝酸钠为铝源,以三聚甲醛(TOX)为有机添加剂,室温下悬浮聚集陈化合成了EMT分子筛。考察了凝胶组成、晶化温度、晶化时间等因素对EMT分子筛合成的影响。采用XRD、FT-IR、SEM、BET、ICP等手段对EMT分子筛进行了表征。结果表明,合成EMT分子筛适宜的条件为:凝胶摩尔组成n_(Na_2O)∶n_(Al_2O_3)∶n_(SiO_2)∶n_(H_2O)∶n_(TOX)=18.5∶1∶5∶240∶0.5,晶化温度30℃,晶化时间72 h,此条件下合成的EMT分子筛,XRD特征峰较强,与典型的EMT分子筛的特征衍射峰相吻合,相对结晶度为80.1%,经ICP分析计算Si/Al=2.01,BET比表面积为80.57 m^2/g,孔容和孔径分别为0.03 cm^3/g和2.07 nm,SEM照片显示EMT为球形晶体颗粒团聚状生长,大小均匀,排列紧凑。EMT molecular sieves were synthesized by suspension aggregation aging method at room temperature using trioxymethylene as the organic additive, sodium silicate as the silicon source, and sodium aluminate as the aluminum source. The influence of gel composition, crystallization temperatures and crystallization time on the synthesis of EMT molecular sieves were investigated. The synthesized EMT molecular sieve was characterized by XRD, FT-IR, SEM, BET and ICP. The favorable synthetic conditions for the EMT zeolites are nNa2O： nAl2O3： nSiO2： nH2O： nTOX = 18.5： 1： 5： 240： 0.5, crystallization temperature for 30 ℃, crystallization time for 72 h. EMT molecular sieves were synthesized under above condition, XRD characteristic diffraction peaks are stronger, consisted with typical characteristics of diffraction peaks of the EMT molecular sieve, andtherelative crystallinity is 80.1%, Si/Al is 2.01, BET specific surface area is 80.57 m2/g, pore volume and pore diameter are 0.03 cm3/g and 2.07 nm, respectively. SEM images show the spherical crystal particles grow together, with uniform size and compact arrangement.

关 键 词：三聚甲醛 悬浮聚集陈化法 EMT分子筛 

分 类 号：O643.3[理学—物理化学]