Real-Space Observations of Multiple Reaction Pathways Enabled by Plasmonic Hot Carriers

Plasmonic hot carriers generated by the decay of localized surface plasmons have the potential to enable chemical reactions at energies lower than those required for photochemical reactions as well as reactions impossible to achieve with light alone. A broad energy distribution of the hot carriers would enable multiple reaction pathways by the transfer of the hot carriers to molecular electronic states of different energies. However, it is difficult to distinguish reaction pathways by detecting products using conventional macroscopic methods, and the mechanistic details are still unclear. In this study, we demonstrate that multiple reaction pathways are available with plasmonic hot carriers on the basis of the real-space observation of molecular motions as well as dissociation of O 2 molecules chemisorbed on the Ag(110) surface using a scanning tunneling microscope. This real-space study at a single-molecule level reveals that plasmonic hot carriers enable multiple reaction pathways due to their broad energy distribution, allowing access to various adsorbate states.