Advances of in situ transmission electron microscopy research on gas phase catalyst particles

Transmission electron microscopy (TEM) has been extensively employed to explore catalytic mechanisms in recent years. Nevertheless, traditional TEM techniques cannot clarify the true active states in the reaction process. In contrast, in situ TEM has made remarkable progress in simulating reactions, allowing the record of dynamic events at the atomic scale. In addition, it provides a wealth of information on the material morphology, microstructure, and dynamics of chemical properties at the micro-nano scale. In this review we introduce the principles, characteristics and research progress in the field of in situ TEM techniques, with particular emphasis on their roles in exploring in the fields of catalysts' synthesis, catalytic behaviors, thermal catalysis, and structure reconstruction of the catalysis process. The challenges and obstacles facing in situ TEM, as well as outlook for emerging research opportunities are discussed in the final part.