Development of Functional Adsorbent for Air Separation by Addition of Metal Cluster Ion into Zeolites

吸附法是空分制氧的有效方法之一。近年来，为了降低成本和能源，强烈需要高性能的吸附剂。本研究以开发高性能的空气分离吸附剂为目的，对沸石吸附剂进行表面改性（光谱分析、热力学分析等）。本论文的主要研究结果如下：1.金属离子簇离子对沸石表面的改性：制备了Li-Cu-LSX和Li-Ag-LSX，以提高N_2选择性吸附位的数量。即在低硅X沸石的方钠石笼和/或D 6 R中形成Ag和Cu离子簇（LSX沸石）以物理地封闭无效阳离子位点（位点I），并且Li^+离子被交换到通过簇离子的还原而产生的新阳离子位点中。2.金属离子簇LSX分子筛的表面分析为了分析Li-CuLSX和Li-Ag-LSX分子筛的表面性质，以CO和CH_4为吸附探针分子，用红外光谱研究了吸附位的特征。Li-CuLSX对CO的吸附量比Li-LSX提高了约3倍。结果表明，采用团簇离子掺杂的方法，Li^+离子被选择性地交换到III位。此外，甲烷吸附表明位点III的静电场比Li-LSX强。这种现象可能是由于D 6 R和/或方钠石笼中存在的铜团簇离子的影响。3. Li-CuLSX对N_2和O_2的吸附和空气分离性能对各种吸附剂的气体吸附和分离性能进行了定量分析。在211 K时，Li-CuLSX的空气分离系数大于Li-LSX。

An adsorption method is one of the effective air separation processes to oxygen produce. Recently, the high-performance adsorbent is strongly required for cost and energy reduction. In this study, to develop a high performance adsorbent for air separation, zeolite adsorbents were modified based on the surface analyses (spectroscopy and thermodynamic analyses etc.). The result obtained in this work is summarized as follows.1.Modification of zeolite surface using metal ion cluster ions.To enhance the amount of N_2 selective adsorption site, Li-CuLSX and Li-Ag-LSX were prepared. Namely, Ag and Cu ion clusters were formed in sodalite cage and/or D6R of low silica X zeolite (LSX zeolite) in order to block ineffective cationic sites (site-I) physically, and Li^+ ions were exchanged into new cation sites created by reduction of the cluster ions, To prepare stable adsorbents with high surface area, the preparing condition were optimized.2.Surface analysis of metal ion cluster included LSX zeolites.In order to analyze surface properties of Li-CuLSX and Li-Ag-LSX, the characteristics of adsorption sites were studied by infrared spectroscopy using CO and CH_4 as adsorption probe molecules. Amount of CO adsorption on Li-CuLSX enhanced to about 3 times than that on Li-LSX. The result showed that Li^+ ions were selectively exchanged to site III using the cluster ion doping method. Furthermore, the methane adsorption showed that the electrostatic field of site III was stronger than that of Li-LSX. This phenomenon may be attributed to an effect of copper cluster ions existed in D6R and/or sodalite cage.3.N_2 and O_2 adsorption and air separation characters of Li-CuLSX.The quantitative analyses of gas absorption and separation characteristics for various adsorbents were carried out. At 211K, air separation factor of Li-CuLSX is larger than that of Li-LSX.