| AVS 65th International Symposium & Exhibition | |
| Fundamental Discoveries in Heterogeneous Catalysis Focus Topic | Wednesday Sessions |
| Session HC+SS-WeA |
| Session: | Theory and Dynamics of Heterogeneously Catalyzed Reactions |
| Presenter: | Arthur Utz, Tufts University |
| Correspondent: | Click to Email |
Gas-surface reactions on a metal surface can be far more complex than their net chemical equation would suggest. The heterogeneity of the surface, and its ability to restructure, impact the availability and energetics of reaction sites, energy redistribution processes triggered by the gas-surface collision dictate transition state access, and many coupled chemical processes can influence the reaction's outcome.
The talk will survey the ability to vibrational state selected measurements of gas-surface reactivity to systematically unravel important aspects of this complexity and provide molecular-level mechanistic insights that can guide our understanding and predictions about these processes. The experiments use infrared light to excite a single quantum rotational and vibrational level of the gas-surface reagent molecule and a molecular beam to define its incident kinetic energy. In this way, we are able to make energy-resolved measurements of reactivity while systematically varying the distribution of energy among the system's energetic degrees of freedom. Computational studies by our collaborators inform and guide our interpretation of the data.
Recent results will be featured and examine the impact of a vibrationally excited reagent molecule's symmetry on surface-induced energy redistribution, the quenching lifetime of a vibrationally excited molecule on a metal surface, the role of surface atom motion on reaction energetics, the ability to use these measurements to benchmark DFT electronic structure calculations, and how isolated surface structural features, including steps and adatoms, modify reaction energetics.