Loboue, H., Guillot-Deudon, C., Popa, A. F., Lafond, A., Rebours, B., Pichon, C., Cseri, T., Berhault, G. & Geantet, C. (2008) A novel approach to the synthesis of unsupported nickel phosphide catalysts using nickel thiophosphate as precursor. Catal. Today, 130 63–68.
Added by: Laurent Cournède (2016-03-10 21:58:42)
|Type de référence: Article
Numéro d'identification (ISBN etc.): 0920-5861
Clé BibTeX: Loboue2008
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Mots-clés: EXAFS, hydrodesulfurization, in-situ, mo-free catalysts, ni2p, ni2p/sio2, nickel phosphide, NiPS3, phases, phosphorus promotion, soft chemistry, thiophene hydrodesulfurization, transition-metal phosphides
Créateurs: Berhault, Cseri, Geantet, Guillot-Deudon, Lafond, Loboue, Pichon, Popa, Rebours
Collection: Catal. Today
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Nickel thiophosphate, NiPS3 synthesized at room temperature using a soft chemistry approach (a-NiPS3) has been successfully used as precursor for low-temperature preparation of unsupported nickel phosphide. Using Raman spectroscopy and EXAFS, comparison with a wellcrystallized NiPS3 reference (c-NiPS3) first Confirmed that nickel thiophosphate can be effectively obtained at low temperatures of preparation. In situ XRD diffraction and EXAFS showed that Ni2P was obtained by the reduction of a-NiPS3 at a temperature as low as 573 K. For c-NiPS3, slower kinetics of reduction first led to the formation of an intermediate richer phosphorus-containing nickel phosphide phase, Ni5P4 at a temperature of reduction of 623 K while Ni2P started being formed at 773 K. Under hydrodesulfurization (HDS) thiophene catalytic conditions (613 K, 2.8 mol\% thiophene/H-2), a-NiPS3 was decomposed into a mixture of Ni2P and Ni5P4 while c-NiPS3 was converted into Ni5P4. Both nickel phosphide catalysts exhibit much higher activities compared to a MoS2 reference. Ni5P4 exhibited a specific activity (per gram of catalyst) seven times as high as for MoS2. (C) 2007 Elsevier B.V. All rights reserved.
Added by: Laurent Cournède