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The Adsorption of Oxygen and Coadsorption of CO and Oxygen on Structurally Well‐Defined PdAg Surface Alloys
Author(s) -
Farkas Arnold P.,
Diemant Thomas,
Bansmann Joachim,
Behm R. Jürgen
Publication year - 2012
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201200477
Subject(s) - bimetallic strip , adsorption , chemistry , oxygen , desorption , monolayer , high resolution electron energy loss spectroscopy , electron energy loss spectroscopy , thermal desorption spectroscopy , transition metal , inorganic chemistry , catalysis , materials science , nanotechnology , transmission electron microscopy , biochemistry , organic chemistry
The dissociative interaction of oxygen with structurally well‐defined monolayer Pd x Ag 1−x /Pd(111) surface alloys of different compositions, with well‐known distributions of the respective surface atoms (A. K. Engstfeld et al., Phys. Chem. Chem. Phys. 2012 , 14 , 10754–10761), and the coadsorption of/reaction with CO on oxygen pre‐covered surfaces were studied by high‐resolution electron energy loss spectroscopy (HREELS) and temperature‐programmed desorption/reaction spectroscopy (TPD/TPR). The impact of geometric ensemble effects as well as electronic ligand and strain effects on the adsorption and reaction behaviour of the respective species on the bimetallic surfaces is elucidated and compared with related systems such as CO adsorption on similar surfaces and oxygen adsorption on a Pd 67 Ag 33 (111) bulk alloy surface. The data show a clear dominance of ensemble effects on the oxygen adsorption and CO coadsorption behaviour, with oxygen adsorption limited to threefold‐hollow sites on Pd 3 sites, while the combined electronic effects, as evident from modifications in the adsorption and reaction characteristics on the Pd sites, are small.