In situ spectroscopic study of the oxidation and reduction of Pd(111).
Using a photoemission spectroscometer that operates close to ambient conditions of pressure and temperature we have determined the Pd-O phase diagram and the kinetic parameters of phase transformations. We found that on the (111) surface oxidation proceeds by formation of stable and metastable structures. As the chemical potential of O2 increases chemisorbed oxygen forms followed by a thin surface oxide. Bulk oxidation is a two-step process that starts with the metastable growth of the surface oxide into the bulk, followed by a first-order transformation to PdO.
Ketteler
Guido
G
Lawrence Berkeley National Laboratories, Materials Sciences Division, University of California, Berkeley, California 94720, USA. gketteler@lbl.gov
Ogletree
D Frank
DF
Bluhm
Hendrik
H
Liu
Hongjian
H
Hebenstreit
Eleonore L D
EL
Salmeron
Miquel
M