The Prospect of Single-Atom Catalysis Empowered by Designer Dynamics and Machine Intelligence

Heterogeneous single-atom catalysts (SACs) represent a vibrant frontier in catalysis science and technology and are characterized by well-defined, atomically precise catalytic active centers and maximized metal atom utilization, enabling chemical transformation with exceptional activity and selectivity. The local coordination environments of SACs can be precisely tailored by surrounding atoms, akin to homogeneous catalysts where metal atoms are coordinated by organic ligands. Unlike adaptive ligands in homogeneous catalysts, heterogeneous SACs immobilized on stable and rigid supports are typically less dynamic even under relatively harsh reaction conditions. This can enhance the stability of the catalyst but constrain their catalytic capabilities and limit their reaction scope. However, with the rapid advancement of in situ and operando characterization tools, the reversible evolution of structural and electronic properties at active sites during reactions has been revealed in SACs, which exhibit extraordinary dynamic behaviors. These SACs feature unique local coordination environments that enable highly adaptive behaviors, enhancing their activity and selectivity while maintaining stability and preventing metal leaching during reactions. This perspective highlights recent progress in the development of such adaptive SACs and provides molecular-level insights into their adaptive and reversible structural changes during reactions. It offers a comprehensive overview of the transformative implications of SACs' dynamics and illustrates how these properties can be modeled and harnessed. Finally, we discuss the challenges and opportunities in designing adaptive SACs by leveraging molecular-level insights and machine intelligence with high-throughput automation platforms to drive industrially crucial sustainable chemical transformations.