COMP 230 |
| Two reaction systems will be chosen to discuss theoretically the relation between catalyst structure and catalytic performance. For transition metal catalysis we select for discussion the Fischer-Tropsch reaction that converts synthesis gas into higher hydrocarbons. We will discuss the quantum-chemical aspects of CO activation as well as CH4 formation and C-C bond formation. This catalytic reaction is of interest theoretically, because selectivity strongly depends on choice of metal as well as particle size and shape. Reactivity-free energy relations can be formulated that enable a rational analysis of reactivity trends. A heterogeneous catalytic system with steric constraints is the microporous zeolite. In protonic form these materials are widely used. We will address the question of the interplay between the reactivity of these protons and the size and shape of zeolite cavity. More recent is the use of reactive cations or cationic clusters to activate hydrocarbons. Chemical interaction between the zeolite channel wall and the cationic systems in the zeolite micropore determine the relative stability of cationic clusters and hence their catalytic activity. This will be discussed for Zn and Ga cationic clusters. Progress in these two topics illustrates the great advances in catalytic science due to access to efficient high quality computer codes as well as hard ware computer performance. The complexity of model systems we can discuss today was unthinkable only ten years ago.
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Bold Predictions in Theoretical Chemistry: A Symposium in Honor of One of the Boldest, Bill Goddard, on the Occasion of his 70th Birthday
2:00 PM-5:10 PM, Tuesday, August 21, 2007 BCEC -- 160B, Oral
Division of Computers in Chemistry |