Insights into Heterogeneous Catalysts under Reaction Conditions by In Situ/Operando Electron Microscopy

Abstract

The advancement of clean energy and environment depends strongly on the development of efficient catalysts in a wide range of heterogeneous catalytic reactions, which has benefited from transmission electron microscopic techniques in determining the atomic‐scale morphologies and structures. However, it is the morphology and structure under the catalytic reaction conditions that determine the performance of the catalyst, which has captured a surge of interest in developing and applying in situ/operando transmission electron microscopic techniques in heterogeneous catalysis. The major theme of this review is to highlight some of the most recent insights into heterogeneous catalysts under the relevant reaction conditions using in situ/operando transmission electron microscopic techniques. Rather than a comprehensive overview of the basic principles of in situ/operando techniques, this review focuses on the insights into the atomic‐scale/nanoscale details of various catalysts ranging from single‐component to multicomponent catalysts under heterogeneous catalytic, electrocatalytic, and photocatalytic reaction conditions involving both gas–solid and liquid–solid interfaces. This focus is coupled with discussions of the correlation of the atomic, molecular, and nanoscale morphology, composition, and structure with the catalytic properties under the reaction conditions, shining light on the challenges and opportunities in design of nanostructured catalysts for clean and sustainable energy applications.

Research progress and prospects on gas-sensitive mechanisms of semiconductor sensors

“…A TEM equipped with an energy dispersive spectrometer (EDS) can analyze the elemental composition of the sample. 131 With the development of ambient TEM, it has been demonstrated that the dynamic morphology change can be captured in solid or gas phases, even at the solid-liquid interface. Using MEMS technique, Wang et al 46 fabricated a gas cell for real-time observation of the microscopic morphology of ZnO nanowires in the reaction with SO 2 (1 bar).…”

Observing the Evolution of Metal Oxides in Liquids

“…This nanobattery worked only for a few cycles, which was unencapsulated, hindering the study of structural evolutions in real batteries. [77,78] Some researchers also revealed the nanoparticle growth and coalescence in ionic liquids at atomic resolution by the open cells. [79,80] They also faced the issue that the ionic liquid electrolyte might polymerize, so chemical reactions were insufficient.…”

Atomic‐Scale Structure Dynamics of Nanocrystals Revealed By In Situ and Environmental Transmission Electron Microscopy

“…[28] There are also a few recent reviews involving different aspects of in situ TEM relating to catalysis and energy conversion. [4,10,[29][30][31][32][33][34][35][36] The nanocrystal's structure and property play a central role in the above aspects but their dynamics under working conditions need to be further contemplated. It is a perfect time to review progress on the dynamic insights into nanocrystals and propose future directions for further investigations.…”