Local structure of xenon adsorbed in the nanospaces of zeolites as studied by high-pressure 129Xe NMR.
Local structure of xenon adsorbed in the nanospaces of zeolites as studied by high-pressure 129Xe NMR.
复制标题
通过高压 129Xe NMR 研究了吸附在沸石纳米空间中的氙的局部结构。
DOI：
10.1039/b604633a
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
T. Eguchi
中科院分区：
文献类型：
--
作者：
H. Omi;T. Ueda;N. Kato;K. Miyakubo;T. Eguchi
用原位高压探针研究了不同微孔材料中氙的~（129）H NMR化学位移随压力（0-10 MPa）和局域密度的变化关系。化学位移的密度依赖性进行了分析，使用氙密度的化学位移的维里展开。结果表明，第二维里系数取决于孔的尺寸和形状，并且孔隙空间影响微孔和中孔材料中的氙-氙相互作用。此外，为了根据吸附氙的局部结构来解释维里系数的大小，我们使用Xe（n）簇分析了分子筛5A中吸附氙的局部结构，从而允许描述化学位移的密度依赖性。通过对13 X和ZSM-5分子筛的计算，验证了该模型的有效性。后者表明，被吸附的氙作为氙单体存在，直到约0.6填充在微孔中。随着氙填充量的增加，已生长出n = 4的较大氙团簇。根据氙（n）团簇模型的分析，第二维里系数与氙团簇的尺寸密切相关，对低载区的化学位移贡献很大。
Pressure (0-10 MPa) and local density dependence of 129Xe NMR chemical shift of xenon in various microporous materials was investigated using an in situ high-pressure probe. The density dependence of the chemical shift was analyzed using virial expansion of the chemical shift by xenon density. Results indicate that the second virial coefficient depends on the pore size and shape, and that the void space affects xenon-xenon interaction in both microporous and mesoporous materials. Furthermore, to interpret the magnitude of the virial coefficient in terms of the local structure of the adsorbed xenon, we analyzed the local structure of adsorbed xenon in molecular sieve 5A using Xe(n) clusters, thereby allowing description of the density dependence of the chemical shift. We also demonstrated the cluster model's validity by applying it to molecular sieves 13X and ZSM-5. The latter showed that the adsorbed xenon exists as a xenon monomer up to the filling of about 0.6 in micropores. Larger xenon clusters up to n = 4 have been grown with increasing filling of xenon. According to analyses using the Xe(n) cluster model, the second virial coefficient is related closely with the xenon cluster size, which contributes greatly to the chemical shift in the low loading region.
活性炭纤维（ACM）中氙气分子间相互作用的高压129Xe NMR研究
DOI：
--
发表时间：
2006
期刊：
Bull. Chem. Soc. Jpn 79(2)
影响因子：
--
作者：
T.;Ueda;H.;Omi;T.;Yukioka;T.;Eguchi
通讯作者：
Eguchi