CO adsorption on Co(0001)-supported Pt overlayers

P. LEGARÉ; B. MADANI; G.F. CABEZA; N.J. CASTELLANI

INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

Molecular Diversity Preservation International

Lugar: Basel; Año: 2001 vol. 2 p. 246 - 250

1422-0067

the growth of Pt deposits on Co(0001) was followed by STM and XPS. The chemical reactivity of the resulting surface was checked by CO adsorption. Pt grows as dendritic islands on the Co terraces whereas forming stripes at the Co step edges. Annealing the sample has no apparent effect on the STM pictures. However, XPS suggests that a limited dilution of Pt in Co takes place. The adsorption of CO on the surface is drastically affected by the presence of Pt even for minute traces. The adsorption energy on the Pt areas is decreased by 40 %. The maximum coverage on the Co areas is also decreased. This indicates that Pt impurities diluted in Co have a high passivating power as a consequence of the induced electronic changes.