Atomic-Scale Strain Mapping of Catalysts

Abstract The strain at the surface of a catalyst is a critical factor that alters the bonding characteristics of active sites and thereby modifies catalytic activity and stability. In situ environmental transmission electron microscopy (ETEM) provides an unprecedented opportunity to unravel atomic-scale strain distribution in individual catalyst particles. However, it remains a significant challenge to determine the evolving strain with picometer precision from the large ETEM data sets. In this work, we develop an atomic column identification framework based on denoising and iterative refinement, enabling accurate localization of atomic column positions in TEM images. Building on high-precision identified coordinates, we were able to further establish an atomic-scale strain mapping method that quantifies local strain at the individual atomic column. This approach unveils distinct strain patterns induced by surface defects in TiO2 nanocrystals and MoS2 monolayers, as well as anisotropic strain associated with particle size effects in RuO2/TiO2 catalysts. Our work enables direct visualization and quantitative analysis of strain in individual catalyst particles at the atomic-scale, providing a robust framework for correlating local structural distortions with catalytic properties and offering new insights into the rational design of supported metal catalysts.