Single-atom catalysis: an introduction to model studies based on surface science approaches

Since the introduction of the concept of single-atom catalysis in 2011, this area has rapidly emerged as one of the most dynamic and influential directions in contemporary catalytic science. Model catalytic studies based on surface science can provide insights into the complex reaction processes in catalytic systems at both the atomic and molecular levels. In this review, we focus on single-atom model catalysts and highlight the unique perspectives that surface science and model studies contribute to understanding the atomic and electronic structures of active sites, the adsorption behavior of reactant molecules, and the underlying reaction mechanisms. We further discuss the anchoring mechanisms of single atoms on different supports and their dynamic evolution under reaction atmospheres and provide an intuitive, atomically resolved interpretation of several fundamental concepts and phenomena in single-atom catalysis.