Unique size-dependent nanocatalysis revealed at the single atomically precise gold cluster level

Significance Here, by real-time monitoring with single-molecule fluorescence microscopy the size-dependent catalytic process of individual Au clusters at single-turnover resolution, we study the size-dependent catalytic behaviors of gold (Au) clusters at the single-cluster level, and then observe the strong unique size effect on the catalytic properties of individual Au clusters, in both catalytic product formation and dissociation processes. Such a unique size effect on the nanocatalysis could be attributed intrinsically to the size-dependent electronic structure of Au clusters, leading to a more comprehensive understanding of the catalytic mechanism of Au particles.