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

• We studied the surface properties of AuPd(1 1 0) under elevated pressure of CO.
• Under elevated pressure of CO, nano-sized rice-grains forms on AuPd(1 1 0) surface.
• New adsorption sites of CO are found with the analysis of PM-IRRAS and AP-XPS.

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] and [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.

STM images showing surface restructuring due to high CO pressure.Figure optionsDownload high-quality image (363 K)Download as PowerPoint slide