Development of molybdena catalysts supported on. gamma. -alumina extrudates with four different Mo profiles: Preparation, characterization, and catalytic properties

Journal Article · Thu Oct 01 00:00:00 EDT 1992 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(92)90158-E· OSTI ID:7141941

Goula, M A; Kordulis, Ch; Lycourghiotis, A ^[1]; Fierro, J L.G. ^[2]

---

1. Univ. of Patras (Greece)
2. Inst. de Catalisis y Petroleoquimica, Madrid (Spain)

The main goal of this work is to prepare, characterize, and determine the catalytic properties of molybdena supported {gamma}-alumina extrudates with four Mo profiles. Concerning preparation, a procedure was established allowing the authors to prepare (both axially and radially) egg-shell, egg-white, egg-yolk, and uniform profiles with the same, relatively high, Mo loading. The preparation of the egg-shell and uniform profiles was achieved by impregnating {gamma}-alumina extrudates with acidic and alkaline ammonium heptamolybdate solution, respectively. Moreover, it was found that an egg-white (egg-yolk) profile nondry impregnations of the Mo-supported extrudes with NH{sub 4}OH aqueous solutions. Kinetic experiments were done, using the HDS of thiophene as a probe reaction, over the characterized samples being in the form of extrudates and powders produced by crushing the extrudates. It was found that HDS activity was mainly determined by the number and the quality of active centers and not by the type of Mo profile, though these suggested the presence of no significant diffusional effects. The relative yield of butane, produced by the hydrogenation of the unsaturated hydrocarbons formed during HDS, increased with the distance of the maximum of the Mo profile from the periphery of the extrude to its center. Finally, it is important to note that the most active radial profile proved to be the egg-white for HDS and the egg-yolk for hydrogenation.

• OSTI ID: 7141941
• Journal Information: Journal of Catalysis; (United States), Vol. 137:2; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
02 PETROLEUM
01 COAL, LIGNITE, AND PEAT
BUTANE
HYDROGENATION
CATALYSTS
CHEMICAL PREPARATION
MOLYBDENUM OXIDES
CATALYTIC EFFECTS
THIOPHENE
DESULFURIZATION
ADSORPTION
ALUMINIUM OXIDES
AMMONIUM COMPOUNDS
AMMONIUM HYDROXIDES
CATALYST SUPPORTS
CONFIGURATION INTERACTION
DESORPTION
DIFFUSION
IMPREGNATION
MICROSTRUCTURE
MOLYBDATES
NITRIC OXIDE
QUANTITY RATIO
SURFACE PROPERTIES
ALKANES
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROXIDES
MOLYBDENUM COMPOUNDS
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
SORPTION
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
400201* - Chemical & Physicochemical Properties
020400 - Petroleum- Processing
010402 - Coal
Lignite
& Peat- Purification & Upgrading