Date of Award

5-2012

Level of Access Assigned by Author

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Advisor

Howard Patterson

Second Committee Member

Scott Collins

Third Committee Member

Rachel Austin

Abstract

Catalysts containing nanoclusters of Ag(I) and Fe2O3 as dopants with sodalite and Y zeolite supports have been investigated in order to develop a more efficient catalyst for the photodecomposition of the pesticide carbaryl and to gain insight about the reaction mechanism. Ag(I)-sodalite, Ag(I)/Fe203-sodalite, Ag(I)-Y zeolite and Ag(I)/Fe2O3-Y zeolite were synthesized by ion exchange techniques and characterized by powder X-ray diffraction (XRD), solid state luminescence, UV-visible absorption, and atomic absorption spectroscopy measurements. The sodalite-supported and Y zeolite-supported catalysts showed significant differences in luminescence activity. Catalyst performance studies were conducted using carbaryl as the target compound and specific wavelengths of UV light as photon sources for the experiments. The studies showed that each catalyst's performance was determined primarily by the specific wavelength of UV light that was irradiated with the system. The studies also showed that the inclusion of Fe2O3 as a dopant enhanced the reactivity of the catalysts in several instances, with the Ag(I)/Fe2O3-sodalite catalyst and 298 nm irradiation exhibiting the best reactivity of the catalysts studied. Additional reactions using each catalyst and 298 nm irradiation and including either sodium bicarbonate as a hydroxyl radical scavenger or D2O as a solvent showed that hydroxyl radicals were likely intermediates in the catalyzed photodecomposition reaction.

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