Spatio-Temporal and Site-Specific Chemical Dynamics at Interfaces

University Of Chicago, Chicago IL

Investigators

Abstract

In this project funded by the Chemical Structure, Dynamics and Mechanisms A program of the Chemistry Division, Professor Steven J. Sibener of The University of Chicago addresses several key issues in surface reaction dynamics, leading to advances in the fundamental understanding of molecular reactivity at interfaces. This scientific program has direct implications for advanced materials fabrication, heterogeneous catalysis, combustion, and the design of protective thin film coatings. This project focuses on surface chemical dynamics that include site specific reactivity, adiabatic and non-adiabatic gas-surface interactions such as dissociative chemisorption including energy dissipation and surface mobility, directionally-controlled deposition and film growth, and geometry-constrained and stereo-specific reaction studies in which energetic atomic species react with molecules that are pre-aligned due to the nature of their bonding and film structure. This is being accomplished using a combination of supersonic molecular beams, scanning tunneling/atomic force microscopy, and surface spectroscopies. Comparisons with theory and numerical simulations provide precision tests of calculated reaction potential energy surfaces and mechanistic reaction pathways. Direct visualization of reacting interfaces helps to reveal site-specific reactivity and spatio-temporal correlations as a function of local structure and reaction extent. In these studies, precise control over reagent energy, incident angle, intensity, and quantum state are applied. Interfacial chemistry is examined under non-equilibrium conditions. Societal broader impact occurs via outreach to the local minority community, including local public, charter, and private schools, and museum science activities that have substantial representation from underrepresented south-side Chicago populations.