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

Journal Article · Sat May 01 04:00:00 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), Journal Name: Journal of Catalysis; (United States) Vol. 141:1; 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
ABSORPTION SPECTROSCOPY
ADSORPTION
ALKENES
BUTENES
CALCINATION
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHARGED PARTICLES
CHEMICAL REACTIONS
COHERENT SCATTERING
DECOMPOSITION
DESULFURIZATION
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
HETEROCYCLIC COMPOUNDS
HETEROGENEOUS CATALYSIS
HYDROCARBONS
HYDROGENATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
IONS
MATERIALS
MICROSCOPY
MINERALS
NITRIC OXIDE
NITROGEN
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDES
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PH VALUE
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REFRACTORY METAL COMPOUNDS
SCANNING ELECTRON MICROSCOPY
SCATTERING
SILICATE MINERALS
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
SURFACE AREA
SURFACE PROPERTIES
THERMOCHEMICAL PROCESSES
THIOPHENE
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN COMPOUNDS
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY
ZEOLITES