Enhancing the reactivity of gold: Nanostructured Au(111) adsorbs CO

Low-coordinated sites are surface defects whose presence can transform a surface of inert or noble metal such as Au into an active catalyst. Starting with a well-ordered Au(111) surface we prepared by ion sputtering gold surfaces modified by pits, used microscopy (STM) for their structural characterization and CO spectroscopy (IRAS and NEXAFS) for probing reactivity of surface defects. In contrast to the Au(111) surface CO adsorbs readily on the pitted surfaces bonding to low-coordinated sites identified as step atoms forming {111} and {100} microfacets. Pitted nanostructured surfaces can serve as interesting and easily prepared models of catalytic surfaces with defined defects that offer an attractive alternative to vicinal surfaces or nanoparticles commonly employed in catalysis science. [Display omitted] •The Au(111) surface sputtered by 1keV Ne+ at 400K was characterized by STM.•Deep-pitted Au surface has about 10% of gold surface atoms present at the step edges as low-coordinated defect sites.•Infrared and X-ray absorption spectroscopies were used to probe surface activity for CO adsorption.•CO is adsorbed on the on-top configuration of the step sites in 1D arrangement.