Energy dependent transient reaction kinetics of CO oxidation on Pd{110}

Citation
M. Hirsimaki et al., Energy dependent transient reaction kinetics of CO oxidation on Pd{110}, SURF SCI, 482, 2001, pp. 147-152
Citations number
15
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
SURFACE SCIENCE
ISSN journal
0039-6028 → ACNP
Volume
482
Year of publication
2001
Part
1
Pages
147 - 152
Database
ISI
SICI code
0039-6028(20010620)482:<147:EDTRKO>2.0.ZU;2-8
Abstract
Translational energy dependence of CO adsorption and CO oxidation have been investigated by performing molecular beam surface scattering experiments o n Pd{1 1 0}. We find that CO adsorbs molecularly on clean and oxygen precov ered Pd{1 1 0} over a range of surface temperatures (300-500 K) and transla tional energies (4.8-21 kJ/mol). The initial sticking probability (S-0) of CO on clean Pd{1 1 0} is shown to be strongly energy dependent. Only a weak surface temperature dependence is observed. Evidence is provided for the C O adsorption process being weakly activated. S-0 of CO on the Pd{1 1 0}c(2 x 4)-O surface is largely energy independent. The initial reaction probabil ity is, however, determined to depend on the CO translational energy. Both the surface temperature and the translational energy of CO are shown to enh ance the initial reaction rate and shorten the reaction induction time requ ired for the CO, formation rate to reach its maximum. The role of the CO tr anslational energy is discussed in terms of the weakening of the Pd-O bond. (C) 2001 Elsevier Science B.V. All rights reserved.