在MFI化纳米晶体框架中包含单个原子的直接证据
Florent Dubray1, Simona Moldovan2, Cassandre Kouvatas1
1Normandie Université , ENSICAEN, UNICAEN, CNRS, Laboratoire Catalyse et Spectrochimie (LCS), 14000 Caen , France.
Journal of the American Chemical Society
|May 24, 2019
概括
原子分散的原子成功地集成到纳米尺寸的MFI石中,产生一种新型的疏水催化剂. 这种突破性的材料为各种应用中的催化剂设计提供了新的可能性.
科学领域:
- 材料科学
- 催化剂
- 纳米技术
背景情况:
- 石是催化过程中重要的多孔材料.
- 在石框架内控制金属原子的分散是具有挑战性的.
- 国际货币基金组织的热石被广泛使用,但可能存在缺陷.
研究的目的:
- 为了证明原子分散的 (Mo) 融入纳米尺寸的MFI石的直接证据.
- 在MFI框架内描述Mo的分布,酸度和结构影响.
- 探索这种新材料在催化剂设计中的潜力.
主要方法:
- 扫描传输电子显微镜高角度环状暗场成像 (STEM-HAADF) 用于Mo分布.
- 用探针分子 (TMPO,化) 探测酸度和Mo物种的P魔角旋转核磁共振 (MAS NMR) 和富里埃变换红外 (FT-IR) 光谱.
- 2D P-P MAS无线电频率驱动复合NMR用于Mo物种的表征.
- 用于结构分析的X射线衍射 (XRD) (对称性和单元体积).
主要成果:
- 在纳米尺寸的MFI热岩框架中直接证明了原子分散的Mo (0.05nm) 的均分布.
- 在框架内与分离的Mo原子相关的易斯酸度的识别.
- 证明了醇缺陷含量降低,导致高度疏水的焦石.
- 在Mo结合时,对称性从正方体降低到单临床和单细胞扩张的观察.
结论:
- 在MFI纳米石中成功合成和表征原子分散的Mo.
- 这种新型的Mo-MFI材料具有独特的特性,如易斯酸性和疏水性.
- 这种材料为设计各种应用的先进催化剂提供了重要的机会.
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