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dc.contributor.advisorLunsford, Jack H.
dc.creatorMartir, Wilson
dc.descriptionIncludes bibliographical references (leaves 123-127)en
dc.description.abstractThe formation of gas phase radicals during the partial oxidation of propylene, 1-butene, isobutylene, and methane over several metal oxides was investigated. The radicals were isolated by employing a matrix isolation unit in tandem with a flow reactor and identified by epr spectroscopy. In a separate experiment the stable products of these reactions were studied, under similar experimental conditions as those used for the gas phase radical studies. Gas phase allyl radicals were formed during the oxidation of propylene over Bi(,2)O(,3) and (gamma)-bismuth molybdate. The amounts of 1,5-hexadiene and gas phase allyl radicals obtained during the oxidation of propylene over Bi(,2)O(,3) indicate that a heterogeneous-homogeneous mechanism was a major route for the formation of 1,5-hexadiene. During the oxidation of 1-butene over Bi(,2)O(,3), in the presence of molecular oxygen, and during the oxidation of isobutylene over Bi(,2)O(,3) 1-methylallyl radicals and 2-methylallyl peroxy radicals were found, respectively. The radical selectivity and the energy of activation obtained in the oxidation of propylene and 1-butene was sensitive to the degree of oxidation of the catalyst surface. Over a highly oxidized Bi(,2)O(,3) catalyst, the main surface reaction with small olefins, however, was the abstraction of a hydrogen atom forming allylic radicals. The partial oxidation of methane over magnesium oxide, silica gel, and alumina, under reducing and oxidizing conditions, produced gas phase methyl radicals. The principal stable products obtained over MgO were ethane, ethylene and methanol. Both radical and stable product formation were enhanced by the presence of N(,2)O or molecular oxygen in the gas feed composition. These results were interpreted by assuming the formation of O('-) ions, from N(,2)O or molecular oxygen, which rapidly reacted with methane via hydrogen atom abstraction, to form methyl radicals.en
dc.format.extentxii, 151 leaves : illustrationsen
dc.rightsThis thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use.en
dc.subject.lcshRadicals (Chemistry)en
dc.subject.lcshHeterogeneous catalysisen
dc.subject.lcshMatrix isolation spectroscopyen
dc.titleGas phase radicals formed on metal oxide surfacesen
dc.typeThesisen A&M Universityen of Philosophyen
dc.format.digitalOriginreformatted digitalen
dc.publisher.digitalTexas A&M University. Libraries

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