Plasmon-Induced O$_{\mathrm{2}}$ Dissociation on Ag(111)

Dissociation of O$_{\mathrm{2}}$ molecules is the rate limiting process in many catalytic reactions on metal catalysts. Ordinarily the O$_{\mathrm{2}}$ dissociation process requires a large input of thermal energy and is therefore conducted at high temperatures. We have studied this reaction by exploitation of localized plasmon resonances at conducting nanoparticles at relatively low temperatures. Nanostructures were prepared on Ag(111) by roughening the surface via Ar$^{\mathrm{+}}$ sputtering. Localized plasmonic resonances were excited with an incident 532nm laser. Excitation of the O$_{\mathrm{2}}$ by the enhanced electric fields near nanostructures can lead to dissociation of the molecule into its constituent components. This dissociation is evidenced by adsorbate oxygen atoms on surface of Ag(111) in proximity to nanostructures, observable by Scanning Tunneling Microscope.