Thèse soutenue

Synthèse et utilisation des thiophosphates et des phosphures comme catalyseurs pour l'hydrotraitement
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Auteur / Autrice : Moulia Hermione Loboué
Direction : Christophe Geantet
Type : Thèse de doctorat
Discipline(s) : Catalyse
Date : Soutenance en 2007
Etablissement(s) : Lyon 1

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Résumé

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Active hydrodesulfurization (HDS) nickel phosphides catalysts are obtained through reduction of phosphate precursors at high temperature. Low temperature synthesis was developed based on the use of the NiPS3 thiophosphate and was compared to the phosphate route. NiPS3 was synthesized by soft chemistry and allowed obtaining Ni2P through reduction at 300°C versus 550°C from phosphates. A very active phosphide phase, Ni5P4 was also obtained. The synthesis of NixPy/SiO2 through reduction of phosphates led to mainly the Ni5P4 phase. These catalysts are very active in HDS. Alternative synthesis routes were also evaluated. The as-obtained catalysts are less active than those from the phosphate route due both to the presence of Ni12P5 (low HDS active phase) and of Li impurities. To avoid the use of alkalis, catalysts were then prepared from oxisulfides. This approach led to very active phosphide catalysts