Surface composition of clean and oxidized Pd75Ag25(100) from photoelectron spectroscopy and density functional theory calculations
Journal article, 2012

High resolution photoelectron spectroscopy and density functional theory calculations have been used to study the composition of clean and oxidized Pd75Ag25( 100). The results for the clean surface confirm earlier reports of surface segregation by Wouda et al. (1998), where the top most layers are rich in Ag. The Pd 3d core level component from the surface region is observed at higher binding energies than the contribution from the bulk which is found to be a signature of Pd embedded in Ag. Low energy electron diffraction and scanning tunneling microscopy measurements reveal that oxidation of the Pd75Ag25(100) surface results in a (root 5 x root 5)R27 degrees-O structure similar to the one reported for Pd(100). The calculations suggest that the stable structure is a PdO(101) monolayer supported on a (100) surface rich in Ag at the interface to the stoichiometric alloy. The calculated core level shifts for the oxidized surface are in good agreement with the experimental observations.

pd-ag

mu-m

Pd75Ag25(100)

segregation

PdAg alloy

Surface oxide

Density

hydrogen

oxidation

pd(111)

heat-treatment

Core level shifts

Photoelectron spectroscopy

alloys

palladium-silver

electron-spectroscopy

Author

[Person 55660af1-72da-43b5-84bd-464c1faddac9 not found]

Norwegian University of Science and Technology (NTNU)

[Person 7ff1ff2d-3fe1-420c-9bfd-04be85d476b2 not found]

Chalmers, Applied Physics, Chemical Physics

Competence Centre for Catalysis (KCK)

[Person ace58019-2f5c-4009-9291-2a0f50693746 not found]

Norwegian University of Science and Technology (NTNU)

[Person ebd1a342-fd21-43f8-8852-a9e4bc705ee1 not found]

Lund University

[Person 4f7aed8b-0135-4005-902e-88b21c2b3d4d not found]

Norwegian University of Science and Technology (NTNU)

[Person 97197a3f-2254-46ba-b4bb-4a0e24480e6e not found]

Lund University

[Person 6905d375-3e30-43de-92ee-ab36673d25b0 not found]

Lund University

[Person d859416a-214b-4f6d-ade6-0356ec851d05 not found]

Lund University

[Person d6cd0e23-1687-43a7-83f6-a6ea74979852 not found]

Lund University

[Person f207657f-30ff-45da-b790-269373283a60 not found]

Norwegian University of Science and Technology (NTNU)

Surface Science

0039-6028 (ISSN)

Vol. 606 23-24 1777-1782

Subject Categories

Chemical Sciences

DOI

10.1016/j.susc.2012.07.006

More information

Latest update

4/20/2018