Single-Molecule Nanocatalysis of Pt Nanoparticles

Because of the inhomogeneous structure of nanoparticles, many underlying catalytic details of these catalysts are hidden in the ensemble-averaged measurements. The single-molecule approach enables studying the catalytic behavior of nanoparticles at the single-particle level in single-turnover resolution. Here, on the basis of such a method, we study the catalytic behaviors of individual Pt nanoparticles to reveal the catalytic properties of nanoparticles of the product formation and desorption process. It is found that the catalytic reaction on Pt nanoparticles follows competitive mechanism in product formation process, while the product desorption process shows no selectivity between the indirect and direct desorption pathways. Moreover, the dynamic heterogeneity of Pt nanoparticles in product formation and desorption process is revealed to be due to the catalysis-induced surface restructuring. Surprisingly, it is found both experimentally and theoretically that the tiny difference in substrate molecules could lead to a huge difference in surface restructuring even on the same type of nanoparticle.