Framework Fe Ions in Fe-ZSM-5 Zeolite Studied by UV Resonance Raman Spectroscopy and Density Functional Theory Calculations
Framework Fe Ions in Fe-ZSM-5 Zeolite Studied by UV Resonance Raman Spectroscopy and Density Functional Theory Calculations
复制标题
通过紫外共振拉曼光谱和密度泛函理论计算研究 Fe-ZSM-5 沸石中的骨架 Fe 离子
DOI：
10.1021/jp802955s
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发表时间：
2008-10-16
影响因子：
3.7
通讯作者：
Li, Can
中科院分区：
文献类型：
--
作者：
Sun, Keju;Fan, Fengtao;Li, Can
含过渡金属的沸石在温和条件下的许多催化反应中显示出高的选择性和活性;然而，过渡金属位点离子的详细表征和活性位点的性质仍然难以捉摸。在这里，我们通过244和532 nm激光线激发的共振拉曼光谱和密度泛函理论（DFT）计算之间的相互作用来研究Fe-ZSM-5沸石中的骨架Fe离子。在Fe-ZSM-5的骨架中观察到来自骨架铁离子的1165、1115、1005和516 cm-1处的拉曼谱带。基于DFT计算，在1165、1115和516 cm-1处的谱带归因于Fe-ZSM-5中具有FeO 4四面体的全对称振动的ν0（A1）、ν1（A1）和ν2（A1）模，其源自共振增强拉曼散射，而ν6（T2）在1005 cm-1处的谱带被识别为来自正常拉曼散射的FeO 4四面体的非完全对称振动。本文的工作表明，共振拉曼带。
The transition metal containing zeolites show high selectivity and activity in many catalytic reactions under mild conditions; however, detailed characterization of transition metal site ions and the nature of the active sites remain elusive. Here, we present a study of the framework Fe ions in Fe-ZSM-5 zeolite via interplay between resonance Raman spectroscopy excited by 244 and 532 nm laser lines and density functional theory (DFT) calculations. Raman bands at 1165, 1115, 1005, and 516 cm−1 from the framework iron ions in the framework of Fe-ZSM-5 were observed. On the basis of the DFT calculations, the bands at 1165, 1115, and 516 cm−1 were attributed to ν0(A1), ν1(A1), and ν2(A1) modes with totally symmetric vibration of FeO4 tetrahedron in Fe-ZSM-5, originating from resonant enhanced Raman scattering, while the band at 1005 cm−1 for ν6(T2) was identified as a nontotally symmetric vibration of the FeO4 tetrahedron from normal Raman scattering. The present work indicates that the resonance Raman bands ...