On-surface synthesis of tailored organic platforms for single metal atoms

Recent advances in nanomaterials have pushed the boundaries of nanoscale fabrication to the limit of single atoms, particularly in heterogeneous catalysis. Single atom catalysts, comprising minute amounts of transition metals dispersed on inert substrates, have emerged as prominent materials in this domain. However, overcoming the tendency of these single atoms to cluster beyond cryogenic temperatures and precisely arranging them on surfaces with desired local environments pose significant challenges. Employing organic templates for orchestrating and modulating the activity of single atoms holds promise. Here, we introduce an on-surface synthesis of a single atom platform wherein atoms are firmly anchored to specific coordination sites distributed along carbon-based polymers. These platforms exhibit atomic-level structural precision and stability, even at elevated temperatures, offering arrays of undercoordinated metal centers as model active sites for single-atom catalysis. We theoretically reveal the pronounced ability of these architectures to coordinate several gas molecules and experimentally visualize their interaction with CO and CO₂. Fine-tuning the structure and properties of the coordination sites offers unparalleled flexibility in tailoring functionalities, thus opening avenues for previously untapped potential in catalytic applications.