Characterization of tungsten-modified ultrastable Y zeolite catalysts and their activity in thiophene hydrodesulfurization

Journal Article · Sat May 01 00:00:00 EDT 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1130· OSTI ID:6216428

Cid, R; Neira, J; Godoy, J ^[1]; Palacios, J M; Mendioroz, S; Agudo, A L ^[2]

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1. Universidad de Concepcion (Chile)
2. Instituto de Catalisis y Petroleoquimica, Madrid (Spain)

Tungsten-modified ultrastable Y (USY) zeolite catalysts, prepared by conventional impregnation with ammonium metatungstate solutions at three different pHs and calcined at 350, 450, and 550[degrees]C have been characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX), and acidity and surface area measurements. They have also been evaluated for hydrodesulfurization (HDS) of thiophene and subsequent hydrogenation (HYD) of butenes in both oxidic and sulfided states. The incorporation of tungstate ions in the USY followed by calcination at high temperature was found to cause a small loss of crystallinity, particularly for the catalysts impregnated at acidic pH. In this case, the EDX and N[sub 2] adsorption results indicated that most of tungsten was inhomogeneously deposited outside the zeolite cavities, but without forming WO[sub 3] species that could be detected by XRD. This location of tungsten and the increased acidity after sulfidation with H[sub 2]S generated a substantial increase in HDS activity relative to the parent USY, and the appearance of HYD activity. Conversely, in the catalysts prepared at basic pH, a large part of the tungsten is inside the zeolite cavities, most probably in the supercages. This tungsten location and the loss of acidity resulted in a very low HDS activity and no HYD activity for both calcined and sulfided catalysts.

• OSTI ID: 6216428
• Journal Information: Journal of Catalysis; (United States), Vol. 141:1; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
01 COAL, LIGNITE, AND PEAT
BUTENES
HYDROGENATION
THIOPHENE
DESULFURIZATION
TUNGSTEN COMPOUNDS
CATALYTIC EFFECTS
ZEOLITES
ABSORPTION SPECTROSCOPY
ADSORPTION
CALCINATION
CATALYSTS
HETEROGENEOUS CATALYSIS
IONS
NITRIC OXIDE
NITROGEN
PH VALUE
SCANNING ELECTRON MICROSCOPY
SORPTIVE PROPERTIES
SURFACE AREA
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY
ALKENES
CATALYSIS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL REACTIONS
COHERENT SCATTERING
DECOMPOSITION
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
MICROSCOPY
MINERALS
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PYROLYSIS
REFRACTORY METAL COMPOUNDS
SCATTERING
SILICATE MINERALS
SORPTION
SPECTROSCOPY
SURFACE PROPERTIES
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
400201* - Chemical & Physicochemical Properties
010402 - Coal
Lignite
& Peat- Purification & Upgrading