^（23）NaMASNMR研究预处理对分子筛晶内结构的影响  

Effect of Pretratment on Structuae of Intrazeolites by ￣(23)Na MASNMR

作　　者：陈彧[1] 戴林森[1] 薛志元[1] 

机构地区：[1]复旦大学化学系,复旦大学分析测试研究中心

出　　处：《分析测试学报》1994年第3期94-97,共4页Journal of Instrumental Analysis

摘　　要：使用固体高分辨２３ＮａＭＡＳＮＭＲ技术研究了ＮａＺＳＭ－５分子筛经不同预处理后晶体内部结构的变化。结果表明，ＮａＺＳＭ－５分子筛中存在着两类钠质点，Ｎａ＋在未处理的样品中与焙烧处理４ｈ后的样品中受到的电场梯度大不相同。Ｚｎ２＋进入了ＮａＺＳＭ－５内孔道并占据了部分阳离子位置；Ｇａ３＋未进入ＮａＺＳＭ－５内孔道，主要位于沸石外表面，并与外表面上Ｎａ＋发生了部分交换。最后讨论了Ｇａ３＋、Ｚｎ２＋离子浸渍量对２３ＮａＭＡＳＮＭＲ谱峰宽的影响。The structure changes of intrazeolites in NaZSM-5 which had subjected to different pret reatments have been studied with high resolution solid-state nuclear magnetic resonance using 23Na as probes It is found that in NaZSM-5 zeolite, there are two main kinds of sodium species, the lines (δ=0 ppm)are attributed to Si-O-Na groups which locate in the surface or defect sites,while δ=-10 ppm line corresponds to(Si-O-Al)Na. Also,there is a great difference in elec tric field gradient between the NaZSM-5 precursor and NaZSM-5 calcined at 500℃ for 4h.Zn2+ Ion enter in the channel and occupy at some sites of the cations, Ga3+ ion exist mainly on the exterior of zeolites and replace a portion of the sodium ions' positions The effect of impr egnation content of Zn2+ ions and Ga3+ on the half peak width (HPW) of 23Na MASNMR spectrum is discussed.

关 键 词：钠 MASNMR 分子筛 结构 前处理 

分 类 号：O647.33[理学—物理化学]