Research Interests:

S.H. Overbury is a Distinguished Research Staff and Group Leader for the Surface Chemistry and Heterogeneous Catalysis group in the Chemical Sciences Division at ORNL and is also serving as leader of the Catalytic Nanosystems task at ORNL’s Center for Nanophase Materials Sciences (CNMS) Division. The Surface Chemistry group conducts research in UHV based structure, properties, and catalytic reactivity of model surfaces and highly dispersed catalysts. The approach for model surfaces involves the use of ultra-high vacuum based techniques for surface analysis including synchrotron based systems. Highly dispersed catalysts are synthesized and structurally characterized by a variety of techniques. Their catalytic behavior and reaction mechanisms are probed under steady state and transient reaction conditions. Dr. Overbury’s current and past interests include mechanisms of oxidation reactions on Au catalysts; metal support interactions and anchoring; synthetic routes for stabilizing supported metal catalysts; probing structure and reactivity of model catalysts systems in UHV including surfaces of oxides, metals, metal-on-metals; use of ion scattering as a probe of surface structure. Basic and applied research is conducted under the sponsorship of the Department of Energy, other federal agencies and private corporations. Work is performed and in collaboration with Universities, industrial researchers and several other groups at ORNL. The research group consists of multi-disciplinary permanent staff, postdoctoral associates, and guests on short-term assignments such as Users at the CNMS.

Selected current research themes include:

• Catalysis by nanostructured Au catalysts. Kinetics and reaction mechanisms determined by infra-red and Raman spectroscopy under operando and transient reaction conditions.
• Support metal interactions in oxidation catalysts. Effect of support composition, particle size, surface termination, modifying overlayers, porosity and upon catalytic performance.
• Analysis of chemisorption and reaction pathways of small molecules on model reducible oxides and supported metals.
• Catalysis in synthetic carbon catalysts. Selectivity, activity, and reaction pathway under ambient and high pressure conditions.