Oxidation Processes on Aluminum and Rhodium
Final rept. 1 Mar 2000-30 Nov 2003
PENNSYLVANIA UNIV PHILADELPHIA DEPT OFCHEMISTRY
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During the reporting period, we have made new discoveries in the areas of oxide-supported nanocatalysts, quantum Monte Carlo methodlolgy, subsurface vacancies in metals, fundamental understanding of chemisorption, and self-assembled monolayers. We have completed the first major theoretical study of Pt chemisorbed on alumina. We contrast Pt nanoparticle and layer adsorption, focusing on how oxide defects influence the Pt growth, and the CO chemisorption properties on the nanoparticles. We have completed an initial demonstration that our new formulation of atomic forces in quantum Monte Carlo is both efficient and accurate. We have extended this formalism to electronically more complex dimers, and to multiconfigurational wave functions. During the past year, we have developed a deep understanding of molecular chemisorption we are now able to rationalize site preferences on different surfaces and different metals, as well as explain trends in saturation coverage. We find that vacancies below the surface of palladium have a significant effect on the surface. We have investigated thiol chemisorption on the noble metals, demonstrating how changes in metal electronic structure give rise to different overlayers. We also completed the first study of thiol chemisorption on aluminum, computationally demonstrating that thiols strongly inhibit O2 chemisorption on Al.
- Inorganic Chemistry
- Organic Chemistry