PST-29: A Missing Member of the RHO family of Embedded Isoreticular Zeolites
PST-29: A Missing Member of the RHO family of Embedded Isoreticular Zeolites
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PST-29：嵌入式等孔沸石 RHO 系列中缺失的成员
DOI：
10.1021/acs.chemmater.8b03311
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发表时间：
2018
影响因子：
8.6
通讯作者：
S. Hong
中科院分区：
文献类型：
--
作者：
Hwajun Lee;Jiho Shin;Wanuk Choi;Hyun June Choi;Taimin Yang;X. Zou;S. Hong
沸石是结晶微孔铝硅酸盐，具有良好表征和均匀的孔结构，具有广泛的商业应用，包括催化、离子交换、气体吸附和分离。 1 我们最近发现了一种新型沸石家族，其复杂性不断扩大，并具有嵌入式等网状结构，称为 RHO 家族（图 1）。 2− 4 该沸石家族始于 rho 沸石（骨架类型 RHO），由 10 面体 ([4882]) 双 8 环 (d8r) 和 26 面体 ([4126886]) lta 笼组成。通过沿着每个晶胞边缘在 lta 笼之间插入一对额外的 d8r 和 18 面体 ([41286]) pau 笼来扩展其支架，这将每代等网状尺寸增加约 10 Å。支架之间的空间由嵌入的笼子填充，形成完全四面体连接的框架。天然沸石泡沸石（PAU）和合成沸石ZSM-25（MWF）分别是RHO家族的第三代（RHO-G3）和第四代（RHO-G4）。通过扩展这种方法，我们预测了几个更复杂的成员（即PST-20（RHO-G5）、PST-25（RHOG6）、PST-26（RHO-G7）和PST-28 (RHO-G8))并通过理性的方法合成它们。 2, 3 然而，尽管每个单元细胞边缘有一个 pau 和两个 d8r 笼的第二代 (RHO-G2) 是由 Gordon 等人首先提出的。 1966年5月至今，它仍然是RHO家族中失踪的成员。应该指出的是，RHO-G2仅包含两种不同类型的嵌入式笼（即14面体（[466286]）tplg和8面体（[4583]）t-oto笼），而所有更高版本都包含四种不同类型的嵌入式笼，即10面体（[4684]）t-gsm和12面体([4785]) t-phi 笼子除了上面提到的两个之外。在本通讯中，我们报告了使用 N,N'-二甲基-1, 4-二氮杂双环合成这一代缺失的 RHO 家族，表示为 PST-29 [2.2。 2] 辛烷 (Me2-DABCO) 二氢氧化物在 Na+ 和 K+ 存在下作为有机结构导向剂 (SDA)。 Me2-DABCO 以前已被用作合成各种沸石的有机 SDA，例如 ZK-5 (KFI)、ZSM-10 (MOZ)、SSZ-98 (ERI)、SSZ-102 (ESV) 和高硅 levyne (LEV)。 6− 10 PST-29 的结构已通过同步加速器单晶 X 射线衍射 (XRD)、同步加速器粉末 XRD 和 Rietveld 分析解析。我们还表明PST-29表现出CO2吸附能力大、吸附速度快
Zeolites are crystalline microporous aluminosilicates with well-characterized and uniform pore structures that are finding a wide variety of commercial applications including catalysis, ion exchange, gas adsorption, and separations. 1 We have recently discovered a novel zeolite family with expanding complexity and embedded isoreticular structures, denoted the RHO family (Figure 1). 2− 4 This zeolite family starts from zeolite rho (framework type RHO) consisting of 10-hedral ([4882]) double 8-ring (d8r) and 26-hedral ([4126886]) lta cages. Its scaffolds are extended by inserting an extra pair of d8r and 18-hedral ([41286]) pau cages between the lta cages along each unit-cell edge, which increases the isoreticular dimension by approximately 10 Å per generation. The space between the scaffolds is filled by embedded cages to form fully tetrahedrally connected frameworks. The natural zeolite paulingite (PAU) and the synthetic zeolite ZSM-25 (MWF) are the third (RHO-G3) and fourth (RHO-G4) generations of the RHO family, respectively.By extending this approach, we have predicted several more complex members (ie, PST-20 (RHO-G5), PST-25 (RHOG6), PST-26 (RHO-G7), and PST-28 (RHO-G8)) and synthesized them via a rational approach. 2, 3 However, although the second generation (RHO-G2) with one pau and two d8r cages per unit-cell edge was first proposed by Gordon et al. in 1966, 5 it has remained a missing member of the RHO family so far. It should be noted that RHO-G2 contains only two different types of embedded cages (ie, 14-hedral ([466286]) tplg and 8-hedral ([4583]) t-oto cages), whereas all the higher generations include four different types of embedded cages, ie, 10-hedral ([4684]) t-gsm and 12-hedral ([4785]) t-phi cages in addition to the two mentioned above. In the present Communication, we report the synthesis of this missing generation of the RHO family, denoted PST-29, using N, N′-dimethyl-1, 4-diazabicyclo [2.2. 2] octane (Me2-DABCO) dihydroxide as an oragnic structure-directing agent (SDA) in the presence of both Na+ and K+. Me2-DABCO has been previously used as an organic SDA in synthesizing various zeolites, eg, ZK-5 (KFI), ZSM-10 (MOZ), SSZ-98 (ERI), SSZ-102 (ESV), and high-silica levyne (LEV). 6− 10 The structure of PST-29 has been solved by synchrotron singlecrystal X-ray diffraction (XRD), as well as by synchrotron powder XRD and Rietveld analyses. We also show that PST-29 exhibits a large CO2 adsorption capacity, fast adsorption