C2Hn Fragments on Metal Surfaces.
Abstract
The chemisorption of an acetylene (HCCH), a vinylidene (CCH2) and an ethylidyne (CCH3) on metal surfaces, especially Pt(111) is analyzed in some detail, with an emphasis on the electronic rearrangements ensuing. The bonding is described in terms of semi-localized states, in turn obtained via a deconvolution of the total density of states into fragment orbitals of the hydrocarbon and the surface. The geometrical choices made by the various fragments on surfaces are analyzed by simple perturbation theory. It is found that in general the bonding within both the hydrocarbon fragment and the surface is dramatically weakened, as indicated by the changes in overlap populations that result. The more surface atoms are involved in anchoring the adsorbate, the weaker the bonding within the surface becomes. A non-dissociative chemisorption is the result of a compromise and its operative when the price of the binding energy is evenly distributed over the loss of bonding within the adsorbate and the surface.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 22, 1985
- Accession Number
- ADA151474
Entities
People
- J. Silvestre
- Ryan Hoffmann
Organizations
- Cornell Laboratory of Atomic and Solid State Physics