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

Plasmonic hot carriers generated by the decay of localizedsurfaceplasmons have the potential to enable chemical reactions at energieslower than those required for photochemical reactions as well as reactionsimpossible to achieve with light alone. A broad energy distributionof the hot carriers would enable multiple reaction pathways by thetransfer of the hot carriers to molecular electronic states of differentenergies. However, it is difficult to distinguish reaction pathwaysby detecting products using conventional macroscopic methods, andthe mechanistic details are still unclear. In this study, we demonstratethat multiple reaction pathways are available with plasmonic hot carrierson the basis of the real-space observation of molecular motions aswell as dissociation of O-2 molecules chemisorbed on theAg(110) surface using a scanning tunneling microscope. This real-spacestudy at a single-molecule level reveals that plasmonic hot carriersenable multiple reaction pathways due to their broad energy distribution,allowing access to various adsorbate states.