Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing, China.
Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, Suzhou, China.
Nature. 2022 Jul;607(7920):703-707. doi: 10.1038/s41586-022-04876-x. Epub 2022 Jul 13.
Single-molecule imaging with atomic resolution is a notable method to study various molecular behaviours and interactions. Although low-dose electron microscopy has been proved effective in observing small molecules, it has not yet helped us achieve an atomic understanding of the basic physics and chemistry of single molecules in porous materials, such as zeolites. The configurations of small molecules interacting with acid sites determine the wide applications of zeolites in catalysis, adsorption, gas separation and energy storage. Here we report the atomic imaging of single pyridine and thiophene confined in the channel of zeolite ZSM-5 (ref. ). On the basis of integrated differential phase contrast scanning transmission electron microscopy (iDPC-STEM), we directly observe the adsorption and desorption behaviours of pyridines in ZSM-5 under the in situ atmosphere. The adsorption configuration of single pyridine is atomically resolved and the S atoms in thiophenes are located after comparing imaging results with calculations. The strong interactions between molecules and acid sites can be visually studied in real-space images. This work provides a general strategy to directly observe these molecular structures and interactions in both the static image and the in situ experiment, expanding the applications of electron microscopy to the further study of various single-molecule behaviours with high resolution.
单分子原子分辨率成像技术是研究各种分子行为和相互作用的一种重要方法。尽管低剂量电子显微镜已被证明在观察小分子方面非常有效，但它尚未帮助我们实现对多孔材料（如沸石）中单个分子的基本物理和化学的原子理解。与酸位相互作用的小分子的构型决定了沸石在催化、吸附、气体分离和储能等方面的广泛应用。在这里，我们报告了在沸石 ZSM-5 的通道中限制的单个吡啶和噻吩的原子成像（参考文献）。基于集成微分相衬扫描透射电子显微镜（iDPC-STEM），我们直接观察了吡啶在 ZSM-5 中在原位气氛下的吸附和解吸行为。通过比较成像结果与计算结果，单吡啶的吸附构型得到了原子分辨率的解析，噻吩中的 S 原子也得到了定位。在实空间图像中可以直观地研究分子和酸位之间的强相互作用。这项工作提供了一种通用策略，可以直接观察这些分子结构和相互作用在静态图像和原位实验中的情况，从而将电子显微镜的应用扩展到进一步研究具有高分辨率的各种单分子行为。
