Temperature-programmed reduction of oxidic and sufidic alumina-supported NiO, WO[sub 3], and NiO-WO[sub 3] catalysts

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1994.1081· OSTI ID:7036635

Mangnus, P J; Bos, A; Moulijn, J A ^[1]

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1. Univ. of Amsterdam (Netherlands)

The reduction behavior of oxidic and sulfidic alumina-supported Ni, W, and NiW catalysts has been studied using temperature-programmed reduction (TPR). Besides giving structural information on the oxidic and sulfidic state, the TPR patterns gave detailed information on the sulfidability of the various oxidic species. From the oxidic species only dispersed NiO was completely sufidable at 673 K, whereas the other species were partly sulfidable (mixed Ni-W phase, dispersed WO[sub 3], and Ni in the surface alumina layer) or not sulfidable (Ni in subsurface alumina layers and NiWO[sub 4]). The sulfided catalysts contained at least four types of sulfur, viz. stochiometric sulfur behaving as S in a bulk analogue (WS[sub 2], Ni[sub 3]S[sub 2], NiS[sub 1+x]) or in NiWS (NiWS is not directly observed under TPR conditions due to sintering into Ni[sub 3]S[sub 2] and WS[sub 2]), a reactive type of sulfur indicated as AS[sub x], S-H groups, and adsorbed H[sub 2]S. Except NiS[sub 1+x] and S[sub x], no sulfided phase reduces under HDS conditions. Although hydrogenation of sulfur might well be an elementary step in the desulfurization reaction, only a weak correlation was observed between the HDS activity and the reduction rate of the S[sub x] species. 30 refs., 14 figs., 4 tabs.

• OSTI ID: 7036635
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 146:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DESULFURIZATION
KINETICS
NICKEL COMPOUNDS
NICKEL OXIDES
NICKEL SULFIDES
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
REDUCTION
REFRACTORY METAL COMPOUNDS
SULFIDES
SULFUR COMPOUNDS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN COMPOUNDS
TUNGSTEN OXIDES
TUNGSTEN SULFIDES