Mechanism of hydrodenitrogenation low temperature oxygen chemisorption over acidic molybdenum catalysts: Part 7

Technical Report · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5369461

Miranda, R

The low temperature oxygen chemisorption over acidic molybdena catalysts has evidenced the strong reducibility of near-surface Mo, and the effect of catalyst loading and support composition on such reducibility. It was determined that for supports with compositions under 50% silica, the optimum loading producing maximum surface reducibility is 8 wt% MoO{sub 3}, while for supports with more than 50% silica, the optimum loading is 4 wt% MoO{sub 3}. At this loading, a substantial portion of the support (containing acidic sites) is also exposed. The role of Lewis sites produced on the molybdena surface by coordinative unsaturation is the strong adsorption of aromatic or unsaturated amines, and the destabilization of C-C and C-N bonds. Hydrogenation and hydrogenolysis can then occur by H addition. The highly acidic Bronsted sites, present on the support as well as on the molybdena, strongly chemisorb the hydrogenated amines. The acidic sites contribute to denitrogenation by Hofmann elimination mechanism, as shown by the the abundance of unsaturated hydrocarbons produced, and are also active for cracking and cyclization, as shown by the selectivity towards methane and cyclopentene. 13 refs., 3 figs., 1 tab.

• Research Organization: Louisville Univ., KY (United States). Dept. of Chemical Engineering
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG22-89PC89771
• OSTI ID: 5369461
• Report Number(s): DOE/PC/89771-7; ON: DE91018331
• Country of Publication: United States
• Language: English

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AMINES
BROENSTED ACIDS
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISORPTION
DENITRATION
DOCUMENT TYPES
ELEMENTS
HYDROGEN COMPOUNDS
HYDROGENATION
INORGANIC ACIDS
LEWIS ACIDS
MINERALS
MOLYBDENUM COMPOUNDS
MOLYBDENUM OXIDES
NITROGEN
NONMETALS
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PROGRESS REPORT
REFRACTORY METAL COMPOUNDS
REMOVAL
SEPARATION PROCESSES
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
SPECIFICITY
TRANSITION ELEMENT COMPOUNDS