Analyse de l'interface catalyseur supporté-milieu aqueux dans l'oxydation d'espèces dissoutes

Abstract : The role of the adsorption was studied in the heterogeneous catalytic oxidation of the organic molecule and hydrogen sulfide with the dispersed support metal oxide. The physical and superficial properties was measured before and after dispersion of metal oxide. We have studied the catalyst behavior with the natural water mineraI ions. The knowledge of the superficial properties of metal oxide or support and their affinities for mineraI ions has allowed for clarifying their role in the adsorption of four organic molecules. It has also allowed for knowing the adsorption mecanisms of the salicylate (humic matter model) on two supports. Then, the role of the adsorption in catalytic oxidation was estimated with ozonation experimentations. It appears that the catalytic oxidation is happening whether the molecule is adsorbed or not. The mecanisrns of catalytic oxidation are similar to the ones of homogeneous oxidation and therefore pH sensitive. The metal oxide and supports have adsorbed ozone and have participated at its initial decomposition in presence of hydroxile or peroxide ions. The kinetic of this reaction is slow and the adsorption or direct oxidation are possible. The study of catalytic oxidation of hydrogen sulfide shows three adsorption-oxidation forms. Two forms are easily reversible and represent the major adsorbed sulfur for low values of concentration. The most stable form, metallic sulfide, corresponds at a weak poisonning of the metal oxide. The catalyst support is inert in regards to hydrogen sulfur when the metal oxide is present
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Theses
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http://docnum.univ-lorraine.fr/prive/INPL_T_1997_MARCHAND_CURY_H.pdf
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Submitted on : Thursday, March 29, 2018 - 1:17:34 PM
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Hélène Marchand-Cury. Analyse de l'interface catalyseur supporté-milieu aqueux dans l'oxydation d'espèces dissoutes. Sciences de la Terre. Institut National Polytechnique de Lorraine, 1997. Français. ⟨NNT : 1997INPL034N⟩. ⟨tel-01751358⟩

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