Supported f-element complexes: surface chemistry and catalysis. Progress report, August 15, 1981-August 14, 1982

Technical Report · Mon Mar 01 04:00:00 EST 1982

OSTI ID:5317453

Marks, T J; Burwell, Jr, R L

During the past year, significant progress was made in three connected areas related to the interaction of f-element organometallic complexes with high surface area metal oxide supports. A detailed study of the reaction of Cp/sub 2/U(CH/sub 3/)/sub 2/ (Cp* = eta/sup 5/-(CH/sub 3/)/sub 5/C/sub 5/) with both partially dehydroxylated and dehydroxylated alumina, under a variety of conditions, identified four major reaction pathways which evolve methane: (1) protolysis by surface OH units; (2) hydrogen atom abstraction from a Cp* ligand; (3) hydrogen atom abstraction from another CH/sub 3/ ligand; and (4) hydrogenolysis in the presence of H/sub 2/. Closely coupled studies of the catalytic properties of the adsorbed species indicate a strong correlation between propylene hydrogenation activity and pretreatment conditions which prevent pathway (1) and promote pathways (3) and/or (4). At -63/sup 0/C, turnover frequencies (N/sub t/) as high as 1 sec/sup -1/ are observed; these values are comparable to those of the most active heterogeneous hydrogenation catalysts known. Furthermore, poisoning experiments indicate that only ca. 2% of the uranium sites are responsible for this activity. Hence, the true N/sub t/ approaches ca. 50 sec/sup -1/ at -63/sup 0/C. Solution studies of the near-infrared f-f transition spectra of a series of organouranium model compounds indicate that the observed patterns are a sensitive finger-print of actinide ligation array and oxidation state. Furthermore, we have now demonstrated that such transitions can be observed in supported organouranium complexes.

• Research Organization: Northwestern Univ., Evanston, IL (USA). Dept. of Chemistry
• DOE Contract Number: AC02-81ER10980
• OSTI ID: 5317453
• Report Number(s): DOE/ER/10980-1; ON: DE82012325
• Country of Publication: United States
• Language: English

Related Subjects

090121 -- Hydrocarbon Fuels-- Chemical Synthesis-- (1976-1989)
10 SYNTHETIC FUELS
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400702* -- Radiochemistry & Nuclear Chemistry-- Properties of Radioactive Materials
ACTINIDE COMPLEXES
ALKENES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CATALYSIS
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COMPLEXES
CORRELATIONS
DEACTIVATION
HYDROCARBONS
HYDROGENATION
KINETICS
METHANATION
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PROPYLENE
REACTION KINETICS
RESEARCH PROGRAMS
SURFACES
URANIUM COMPLEXES