Adsorption of formyl on Ni(100)
- North Carolina State Univ., Raleigh, NC (United States)
The adsorption of formyl radicals (HCO) on Ni(100) is treated using a many-electron embedding theory, modeling the lattice as a 30-atom, three-layer cluster with the Ni atoms fixed at bulk. Ab initio valence orbital configuration interaction (multiple parent) calculations carried out on a local surface region permit an accurate description of bonding at the surface. The 3d orbitals are explicitly used for six Ni atoms in the local surface region. The Ni(100) potential surface is very flat for {eta}{sup 1}-formyl-C adsorption. {eta}{sup 1}-Formyl-C binds to the surface mainly via the C atom, and the energy minimum occurs for an O-C-surface normal angle of 90{degree}, 90{degree}, and 110{degree} at four-fold, bridge, and atop sites, respectively. The HCO bond angle is 120{degree}. Calculated adsorption energies are 63.7, 63.5, and 63.6 kcal/mol at four-fold, bridge, and atop sites, with C-surface distances of 1.93, 1.94, and 2.04 A, respectively. Calculated C-O stretching frequencies are around 1760 cm-1 and C-H stretching frequencies are around 2940 cm{sup -1} for HCO at all adsorption sites and equilibrium geometries. The bonding of formyl to the nickel surface involves ionic and covalent contributions and substantial mixing with Ni 3d orbitals. Calculated {eta}{sup 1}-formyl-O, bonding to the surface via the O atom, is energetically less stable than {eta}{sup 1}-formyl-C by 16.3 kcal/mol. 47 refs., 8 figs., 4 tabs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 41629
- Journal Information:
- Langmuir, Journal Name: Langmuir Journal Issue: 3 Vol. 11; ISSN LANGD5; ISSN 0743-7463
- Country of Publication:
- United States
- Language:
- English
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