Chemisorption probes of metal-metal bonding in ultrathin metal films
- Univ. of Southern California, Los Angeles, CA (United States)
Chemisorption properties and reactions of adsorbed molecules are sensitive chemical probes of the electronic structure and reactivity of metal surfaces. We can use information provided by adsorbate studies to help understand metal-metal bonding in metal monolayers and ultrathin (bilayer, trilayer, etc.) films and how the electronic structure at metal surfaces controls surface chemistry. We have characterized CO, H{sub 2}, C{sub 2}H{sub 4}, and C{sub 2}H{sub 2} adsorption on Pd films on Ta(l 10) and Mo(100) substrates, providing rich details of the bonding and structure at these surfaces and illuminating several adsorbate-induced processes that can occur including changes in both the electronic and geometric structure of the surface layer. A key result is that the interaction of NO with a Pd monolayer film closely resembles that on a Ag(111) surface, supporting previous interpretations that Pd-Ta bonding interactions lead to a filled Pd d-band and thus produce a Pd monolayer with the chemical properties of Ag. The chemical properties and reactivity of the {open_quotes}flat{close_quotes} Pd films rapidly return to that of bulk Pd (111) surfaces (after at most 2-3 layers), however clustering can lead to more extensive {open_quotes}tuning.{close_quotes}
- OSTI ID:
- 126816
- Report Number(s):
- CONF-950402--
- Country of Publication:
- United States
- Language:
- English