The invention provides a method of polishing a substrate comprising contacting a substrate comprising a noble metal on a surface of the substrate with a chemical-mechanical polishing system comprising (a) a polishing component selected from the group consisting of an abrasive, a polishing pad, and a combination thereof, (b) an oxidizing agent, (c) an ethylene-oxide containing polymer, and (d) a liquid carrier, and abrading at least a portion of the noble metal with the chemical-mechanical polishing system to polish the substrate.