New Tools for the Study of Combustion Chemistry and Complex Gas-Surface Interactions from First Principles
Abstract
Molecular and radical chemisorption on ferroelectric oxides and on metals (Rh, Cu, Pt, Al, Pd, Ag) was studied with first-principles density functional theory (DFT). New methods were developed for computing the chemisorption energies of molecules to surfaces accurately within DFT. Oxide-supported metals were modeled as well, examining how oxide-metal bonding affects metal surface chemistry. Quantum Monte Carlo (QMC) calculations were performed on diatomic and polyatomic molecules, establishing the capability of computing atomic forces in molecules with QMC. Intermolecular interactions resulting from high molecular coverage were analyzed to understand saturation coverage. A direct dynamics approach was developed for computing the infrared emission signatures of combustion products, including vibrationally excited radicals and closed-shell molecules. The emission spectrum of vinyl radical C2H3 was computed and compared with recent experiments. It was demonstrated that molecular radicals stabilize ferroelectric polarization in BaTiO3 nanowires and PbTiO(sub-3) thin films. It was found that metal monolayers are significantly influenced by ferroelectric oxide supports, opening the possibility of "switchable nanocatalysts."
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 06, 2007
- Accession Number
- ADA473091
Entities
People
- Andrew M Rappe
Organizations
- University of Pennsylvania