Revealing the catalytic kinetics and dynamics of individual Pt atoms at the single-molecule level

Abstract

Due to the importance of single-atom catalysts (SAC), here, the catalysis of Pt SAC was studied at the single-molecule single-atom level. Both static and dynamic activity heterogeneity are observed in Pt SAC. It reveals that the intrinsic catalytic activity of Pt SAC is higher than that of Pt nanoparticles (NPs), although they follow the same bimolecular competition mechanism. Significantly, Pt SAC presents no catalysis-induced surface restructuring, meaning that the dynamic activity fluctuation of Pt SAC can only be attributed to the spontaneous surface restructuring, and the catalysis process does not affect much of the structure of Pt1-based active sites, all different from Pt NP catalysis, in which the surface restructuring and the catalysis can affect each other. Further, density functional theory (DFT) calculation indicates that the unique catalytic properties of Pt SAC or the different catalytic properties between Pt SAC and NPs could be attributed to the strong adsorptions of both reactant and product on Pt SAC, large surface energy of Pt SAC, and strong binding of Pt1 on support. Knowledge revealed here provides fundamental insights into the catalysis of atomically dispersed catalyst.