采用Li-LSX, Ca-LSX为起始物进行离子交换分别制备了Li+、Ca2+混合型LSX, 通过ICP-AES, 7Li MAS NMR, 23Na MAS NMR及静态吸附等检测方法, 考察了起始物不同对离子交换限度, 离子定位与产品吸附性能的影响. 实验结果表明, 以Ca-LSX为起始物进行Li交换得到的Li-Ca-LSX最大交换率为31.5%, 此时吸附性能最优, 氮氧吸附量分别为36.4和5.0mL/g, 选择性系数为12.4, 且节约了Li的用量. 借助NMR结果发现, 对吸附性能有直接影响的Li+, 除公认SIII位置外, 尚有少量SI’亦有较显著作用.
Mixed ion exchanged Li-Ca-LSX were prepared respectively from the starting materials Li-LSX and Ca-LSX and effects of the difference on ion exchanging degree, ion location and adsorption properties were investigated via the measurements of ICP-AES, 7Li MAS NMR, 23Na MAS NMR and static adsorption method. The results show that the Li-Ca-LSX prepared from Ca-LSX as the starting material reaches the exchange maximum by 31.5% and the best properties, namely the specific adsorption capacity at 36.4mL/g for N2 and 5.0mL/g for O2; and the N2/O2 adsorption selectivity at 12.4. From the results of NMR, it is found that excepting the well-known site SIII, some Li+ locating at the site SI’ can also affect significantly on the adsorption properties of LSX.
参考文献
| [1] | Yang R T. Recent advances and new horizons in gas adsorption with a focus on new sorbents. Topical Conference on Seperation Technology, New York, 1997.14. [2] Mckee D W. Sepration of an Oxygen-Nitrogen Mixture. US 3 140 933. 1964. [3] Chao C C. Process for Separating Nitrogen from Mixture Thereof with Less Polar Substances US 4 859 217. 1989. [4] Kirner J F. Nitrogen adsorption with highly Li exchanged X-zeolites with low Si/Al ratio. US 5 268 023. 1993. [5] 关莉莉, 段连运, 谢有畅(GUAN Li-Li, et al). 无机材料学报(Journal of Inorganic Materials), 2005, 20 (2): 503--507. [6] Huston N D, Regee S U, Yang R T. AIChE, 1999, 45 (4): 724--734. [7] Coe C G, Kirner J F, Pierantozzi R R, et al. Nitrogen Adsorption with a Ca and or Sr Exchanged Lithium X Zeolite. US 5 152 813.1992. [8] Kuhl G H. Zeolites, 1987, 7 (5): 451--457. [9] Mortier W J, Bosmams H J, Uytterhoeven J B. J. Phys. Chem., 1972, 76 (5): 650--656. [10] Feuerstein M, Lobo R F. Chem. Mater., 1995, 2 (1): 43--51. [11] Feurestein M, Engelhardt G, McDaniel P L. Microp. Mesop. Mater., 1998, 26: 27--35. [12] Jasra R V, Choudary N V, Bhat S G T. India. J. Chem., 1995, 34 (1): 15--21. [13] Sherry H S. Cation Exchange on Zeolites. Proceedings of the 2nd International Conference on Zeolite. Worcester, 1970. 350. [14] 崔邑诚, 张爱民, 董家禄, 等. 化学学报, 2003, 61 (3): 350--353. |
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