Aberration-corrected scanning transmission electron microscopy in single-atom catalysis: Probing the catalytically active centers

TY - JOUR

T1 - Aberration-corrected scanning transmission electron microscopy in single-atom catalysis

T2 - Probing the catalytically active centers

AU - Liu, Jingyue

N1 - Funding Information: ?n this perspective, we summarized the capability of ac‐STEM‐HAADF imaging and the application of this powerful technique to characterizing supported single metal atoms. The sub‐angstrom resolution and the atomic number sensitivity of the STEM‐HAADF imaging technique make it possible not only to examine the dispersion of supported single metal atoms but also to obtain their lateral coordinate information with respect to the surface structure of the crystalline support. Such atomic scale data on the coordinates of the supported single metal atoms can be directly used to establish models for DFT calcula‐ tions of the catalytic processes of SACs. The STEM‐HAADF im‐ aging technique has proved to be indispensable for optimizing synthesis protocols, studying the stability of SACs, and probing the nature of catalytically active centers. The major challenge to the broad applications of the STEM associated techniques is that of the electron‐beam induced effects. For TEM imaging, low dose method, coupled with the recently developed highly efficient ultrafast cameras and image processing, has been ef‐ fectively utilized to image electron‐beam sensitive materials such as zeolites and metal organic frameworks [ 砃琂M. Further technical development is needed to alleviate the electron‐beam induced effects in STEM instrument to the degree that localized EDS and EELS spectroscopy techniques can be applied to relia‐ bly analyze the composition and oxidation states of supported single metal atoms. ?nformation on the isolated metal atoms from such localized spectroscopy techniques, especially with monochromated high energy‐resolution EELS, should be ex‐ tremely valuable for understanding the fundamental catalytic processes of supported SACs. The rapid development of gas/liquid sample holders or en‐ vironmental EM chambers, the use of ultra‐stable sample heat‐ ing holders, the use of pulsed electron sources, the develop‐ ment of new electron detectors, and the availability of atomic resolution cryo‐EMs can significantly enhance our capability of characterizing heterogeneous catalysts, especially supported single‐atom catalysts. ?t is expected that the combination of This work was funded by the National Science Foundation under CHE‐ 猃? 砃? ? ? ? and the National Key Basic Research Pro‐ gram of China ( ? 礃?) ( ? 爃? 甀CB ? ? ? ? ? ?). The author acknowl‐ edges the use of the facilities in the John M. Cowley Center for High Resolution Electron Microscopy at Arizona State Univer‐ sity. The author acknowledges his collaborators Dr. Lawrence F. Allard of Oak Ridge National Laboratory, Professors Tao Zhang, Aiqing Wang and Weixue Li of the Dalian ?nstitute of Chemical Physics of the Chinese Academy of Sciences, Professor Jun Li of Tsinghua University, and Drs. Botao ?iao, Yang Lou, Jia Xu, and Sibin Duan as well as Mr. Yafeng Cai.

PY - 2017/9/1

Y1 - 2017/9/1

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U2 - 10.1016/S1872-2067(17)62900-0

DO - 10.1016/S1872-2067(17)62900-0

M3 - Article

AN - SCOPUS:85029434122

SN - 0253-9837

VL - 38

SP - 1460

EP - 1472

JO - Cuihua Xuebao/Chinese Journal of Catalysis

JF - Cuihua Xuebao/Chinese Journal of Catalysis

IS - 9

ER -