“Single-atom” catalysis: An opportunity for surface science

• Exploring surface science’s role in advancing single-atom catalysis, focusing on breakthroughs in stability and mechanisms. • Highlighting synergy between surface science and computation, stressing the need for benchmarking to validate SAC predictions. • Focusing on advanced surface science techniques, I highlight pathways to optimize SAC activity on oxides, nitrides, and MOFs. Over the past decade, extensive research into ``single-atom'' catalysts (SACs) has revealed that the catalytic behavior of metal adatoms is highly dependent on how they interact with their support. A strong dependence on the local coordination environment has led to comparisons with metal-organic complexes, and there is growing excitement about the potential to fine-tune SACs by controlling the adsorption geometry. The rise of computational screening to identify the optimal support/metal combinations underscores the need for rigorous benchmarking of theoretical methods, to validate realistic geometries, mechanisms, and the impact of adsorption on stability and catalytic activity. The surface science approach is particularly well-suited for this task because it allows to precisely determine the geometry of the metal atom and interpret its catalytic behavior. Moreover, the effects of temperature and molecular adsorption on the model catalysts stability can be studied in isolation, and conclusions drawn from UHV studies tested in increasingly common near-ambient pressure and electrochemical setups. This perspective highlights recent breakthroughs and specific systems—including metal oxides, metal-organic frameworks, and carbon nitrides—where insights from surface science experiments can significantly advance understanding in this rapidly evolving field.