In-situ surface analysis of AuPd(1 1 0) under elevated pressure of CO

Abstract With the combination of various in-situ surface science tools, surface chemical and structural properties of bimetallic AuPd(1 1 0) alloys are characterized under elevated CO pressure. Under 1 Torr of CO gas pressure, STM images show the formation of nano-sized surface rice-grains along the index direction of [1] , [2] , [3] , [4] , [5] , [6] , [7] , [8] , [9] , [10] while PM-IRRAS shows new CO vibrational band. This new vibrational band of PM-IRRAS is confirmed as the CO molecules attached to atop site of Pd with the results of ambient pressure XPS. In the case of adsorption of CO on AuPd(1 1 0) alloys, the so-called “pressure gap” exists and the surface morphology and its chemical states change at elevated pressure conditions.