Recent Progress and Perspective of In Situ TEM Characterization for Catalysis Research

In situ transmission electron microscopy has significantly advanced catalysis research by enabling high-resolution, real-time investigation of catalytic materials under realistic operating conditions, overcoming the fundamental limitations of conventional ex situ characterization. This review systematically summarizes the state of the art in in situ transmission electron microscopy for catalysis. Representative technological innovations in in situ gas and liquid transmission electron microscopy have enabled direct observation of previously elusive dynamic phenomena, including surface reconstruction, metal-support interaction, and active site evolution, thereby providing mechanistic insights at high resolution. The integration of complementary spectroscopic techniques and emerging analytical methods has further empowered the correlation of structural dynamics with catalytic performance. Despite these advances, fundamental challenges persist in temporal resolution limits, electron-beam-induced perturbations, and high-dimensional data interpretation. By establishing direct connections between microscopic catalyst dynamics and macroscopic catalytic performance, in situ transmission electron microscopy has become highly valuable for developing high-performance catalysts for clean energy applications, including water electrolysis, fuel cells, and CO2 reduction. This review aims to bridge the gap between fundamental characterization and rational catalyst design, offering actionable insights for the development of high-efficiency catalytic systems.