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Seminar AbstractElucidation and Control of Catalytic Sites and Their Environments for Hydrocarbon OxidationUniversity of Virginia Tuesday, October 27th 1:25 PM
An atomic scale understanding of the active sites that control catalytic and electrocatalytic systems and their local reaction environment could lead to tremendous breakthroughs in our ability to design more active and selective materials. While the intrinsic chemical bonds that are formed and broken as part of the operative catalytic cycle are critical, the influence of defect sites, alloy composition and specific arrangement, support effects, coadsorbed intermediates, surface coverage effects and solution can be just as important. An understanding how these features form and their subsequent influence on the reaction kinetics could ultimately be used to aid the design of next generation materials with improved catalytic performance. Ab initio quantum mechanical methods have reached the stage where they can be used to model the atomic structure along with the local molecular topography about proposed active sites and establish the influence of their environment on their catalytic reactivity. The results from theory can subsequently be integrated with atomic scale simulations in order to track individual transformations of molecules over catalytic substrates thus connecting catalytic structure with performance. This allows for an "in-silico" approach that can be used in order to tailor these structural features toward the control of specific catalytic properties. In this talk, we will describe the application of theory and simulation to the partial oxidation of methane over supported metal particles and the electrocatalytic conversion of oxygenates over metal and alloys surfaces. Theory is coupled together with kinetic and dynamic simulations to interrogate the nature of the catalytically active surfaces sites and ensembles, the influence of surface coverage and the influence of solution as well as electrochemical potential for these two processes. |
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