COLL 190 |
| Tatyana A. Konovalova, Lowell D. Kispert, and Yunlong Gao. Department of Chemistry, University of Alabama, Box 870336, Tuscaloosa, AL 35487 |
| Incorporation of transition metals into framework of molecular sieves has received considerable attention due to the new catalytic properties of the modified materials. We report characterization of Fe(III)-MCM-41 molecular sieves by multifrequency EPR. The 95-287 GHz measurements provide resolution of the unresolved at 9 GHz EPR line due to overlapping signals from different Fe(III) sites. The peak with g=2.45 is assigned to aggregated iron species. The signal with g=2.07 was attributed to Fe(III) coordinated to oxygen atoms on the surface of the pore. A sharp line with gx=gy=2.003, gz=1.99 was attributed to a single Fe(III) site. The 9-95 GHz EPR measurements indicated that extra-framework iron at the surface of the mesopores are mostly responsible for carotenoid oxidation in Fe(III)-MCM-41. |
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Posters: Fundamental Research in Surface and Colloid Chemistry
6:00 PM-8:00 PM, Monday, March 29, 2004 Disneyland -- North Exhibit Hall, Poster
Division of Colloid and Surface Chemistry |