INOR 367 |
| Mark A. Barteau, Department of Chemical Engineering, Department of Chemical Engineering, University of Delaware, Newark, DE 19716 |
| The case for oxametallacycles (metallaoxetanes) as key intermediates in the direct epoxidation of olefins by heterogeneous silver catalysts has grown considerably of late. Surface science experiments, density functional theory calculations, kinetic isotope effect measurements, and catalytic reaction studies have all contributed to a much better understanding of the chemistry of these species. These species not only lead to desirable products such as ethylene oxide and epoxybutene, but their competing branching reactions may control epoxidation selectivity. Quantitative DFT calculations and microkinetic models have demonstrated that branching reactions of oxametallacycles are sufficient to account for epoxidation selectivity, kinetic isotope effects on selectivity, effects of alkali and halide promoters, and they have even led to the successful prediction and realization of more selective bimetallic ethylene epoxidation catalysts. Interesting opportunities may exist to link this chemistry to that of homogeneous oxidation catalysts. |
|
Homogeneous and Heterogeneous Oxidation Catalysis
8:30 AM-12:05 PM, Tuesday, August 24, 2004 Pennsylvania Convention Center -- 108A, Oral
Division of Inorganic Chemistry |