[摘要]:Ionic liquids (ILs), such as [BMIM][Tf(2)N], on well-defined SCILL model catalysts are able to replace weakly adsorbed CO. On Pt, on-top CO remains adsorbed under the ionic liquid layer, but its IR signal red-shifts by over 30 cm(-1). IL-adsorbate interactions are mediated by the noble metal and similar to ligands.