Identification of Catalytic Sequence at a Single Active Site on a Single-Cluster Catalyst

Understanding the local coordination environments and dynamic catalytic events at the scale of the active site is crucial for the precise design of efficient catalysts under operating conditions. Conventional characterizations often provide only average structural information on bulk catalytic materials, overlooking local site-specific behaviors. Here, we monitor conductance signatures consistent with local coordination changes and stepwise catalytic events at a single active site under catalytically relevant solution conditions. This approach allows us to infer a catalytic sequence, including adsorption, bond activation, intermediate formation, and product release, while elucidating microenvironment-induced coordination changes at this localized scale. We establish a quantitative correlation between local steric effects and catalytic activity in experiments and propose the creation of a local structure with low steric hindrance at the active site to enhance performance. Our findings highlight the potential of single-cluster characterizations for advancing the interpretation of molecular-level catalysis, offering new insights into catalytic material design and performance optimization.