Seed-assisted, organic structure-directing agent-free synthesis of KFI-type zeolite with enhanced micropore volume and CO2 adsorption capacity
Seed-assisted, organic structure-directing agent-free synthesis of KFI-type zeolite with enhanced micropore volume and CO2 adsorption capacity
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DOI：
10.1007/s10450-019-00113-6
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发表时间：
2019-08-01
影响因子：
3.3
通讯作者：
Endo, Akira
中科院分区：
文献类型：
--
作者：
Kamimura, Yoshihiro;Endo, Akira
ZK-5（KFI型骨架拓扑结构）是一种具有三维通道系统的“小孔”沸石，该系统具有八元环开孔（约100 μ m）。0.39 nm）。最近的一些研究表明，ZK-5具有应用于固体吸附剂或催化剂的潜力，特别是在工业中的CO2捕集和NOx还原。然而，常规ZK-5的质量（例如，嵌段体积）（0.21-0.22 cm（3）g（-1））仍然小于KFI型骨架拓扑结构的理论嵌段体积（0.32-0.34 cm（3）g（-1））。因此，提高ZK-5的体积可以提高其性能。在这项研究中，我们应用种子辅助的方法，以获得KFI型沸石开始通过添加常规合成ZK-5作为种子到有机结构导向剂（OSDA）的K，Sr-铝硅酸盐反应物，然后通过水热处理。对所得到的产物的一系列实验表征表明，在一定的合成条件下，晶种的加入可使KFI型沸石的晶化体积提高到0.26-0.28 cm ~（3）g ~（-1），这比以前报道的ZK-5沸石的晶化体积要大。这种增强的性能导致更高的CO2吸附容量的KFI型沸石相比，传统的ZK-5在宽范围的压力。一系列的实验和与以前文献的比较表明，KFI型沸石的结晶行为不遵循典型的晶种介导生长。相反，种子溶解-重结晶行为被认为发生在种子凝胶系统中。[图形]。
ZK-5 (a KFI-type framework topology) is a "small-pore" zeolite with a three-dimensional channel system with eight-membered ring micropore openings (ca. 0.39 nm). Several recent studies have shown that ZK-5 has the potential to be applied in solid adsorbents or catalysts, particularly in CO2 capture and NOx reduction in industry. However, the quality (e.g. micropore volume) of conventional ZK-5 (0.21-0.22 cm(3) g(-1)) remains smaller than the theoretical micropore volume of the KFI-type framework topology (0.32-0.34 cm(3) g(-1)). Improving the micropore volume of ZK-5 could therefore enhance its performance. In this study, we apply the seed-assisted method to obtain KFI-type zeolite starting by adding conventionally synthesized ZK-5 as a seed into organic structure-directing agent (OSDA)-free K,Sr-aluminosilicate reactants, followed by hydrothermal treatment. The series of experimental characterizations of the obtained products showed that under certain synthesis conditions, the addition of a seed could enhance the micropore volume of KFI-type zeolites to 0.26-0.28 cm(3) g(-1), which is larger than previously reported for ZK-5. Such enhanced properties led to higher CO2 adsorption capacities for the obtained KFI-type zeolites compared with conventional ZK-5 over a wide range of pressures. A series of experiments and comparison with previous literature, indicated that the crystallization behavior of the KFI-type zeolites did not follow typical seed-mediated growth. Instead, seed-dissolution-recrystallization behavior is thought to have occurred in the seeded-gel system.[GRAPHICS].