Atom-Selective Analyses Reveal the Structure-Directing Effect of Cs Cation on the Synthesis of Zeolites
Atom-Selective Analyses Reveal the Structure-Directing Effect of Cs Cation on the Synthesis of Zeolites
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原子选择性分析揭示了 Cs 阳离子对沸石合成的结构导向作用
DOI：
10.1021/acs.jpclett.3c00432
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Wakihara Toru
中科院分区：
文献类型：
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作者：
Yamada Hiroki;Horikawa Hirofumi;Anand Chokkalingam;Ohara Koji;Ina Toshiaki;Machida Akihiko;Tominaka Satoshi;Okubo Tatsuya;Liu Zhendong;Iyoki Kenta;Wakihara Toru
为了理解沸石的结晶机理，重要的是澄清结构导向剂的详细作用，其对于沸石的结晶是必不可少的，与无定形铝硅酸盐基质相互作用。在这项研究中，揭示结构导向效应，铝硅酸盐前体的演变，导致沸石成核的综合方法，包括原子选择性的方法进行了分析。总的和原子选择性的对分布函数分析和X射线吸收光谱的结果表明，晶体状的配位环境逐渐形成Cs阳离子周围。这对应于Cs位于RHO结构中d8单元中心的事实，RHO结构的单元在该沸石中是唯一的，并且在ANA系统中也证实了类似的趋势。这些结果共同支持了传统的假设，即在沸石表观成核之前形成晶体状结构。
To understand the crystallization mechanism of zeolites, it is important to clarify the detailed role of the structure-directing agent, which is essential for the crystallization of zeolite, interacting with an amorphous aluminosilicate matrix. In this study, to reveal the structure-directing effect, the evolution of the aluminosilicate precursor which causes the nucleation of zeolite is analyzed by the comprehensive approach including atom-selective methods. The results of total and atom-selective pair distribution function analyses and X-ray absorption spectroscopy indicate that a crystalline-like coordination environment gradually forms around Cs cations. This corresponds to the fact that Cs is located at the center of thed8runits in the RHO structure whose unit is unique in this zeolite, and a similar tendency is also confirmed in the ANA system. The results collectively support the conventional hypothesis that the formation of the crystalline-like structure before the apparent nucleation of the zeolite.