Supported molecular catalysts for CO hydrogenation

Conference · Wed Jan 01 04:00:00 EST 1986 · Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States)

OSTI ID:7060272

Lamb, H H; Gates, B C

The metal-oxide support is known to exert a strong influence on the activity and selectivity of heterogeneous CO hydrogenation catalysts. Ichikawa demonstrated that catalysts derived from (Rh/sub 4/(CO)/sub 12/) deposited on basic MgO produced methanol from CO + H/sub 2/ with >95% selectivity, whereas (RH/sub 4/(CO)/sub 12/)-derived catalysts supported on more acidic metal oxides such as ..gamma..-Al/sub 2/O/sub 3/ and SiO/sub 2/ produced chiefly methane with only traces of oxygenated products being formed. Only limited data is currently available relating these differences in catalytic performance to differences in catalyst structure. However, it was recently demonstrated that under high-temperature CO hydrogenation conditions (275/sup 0/C, 10 atm) anionic osmium carbonyl clusters (e.g., (Os/sub 10/C(CO)/sub 24/)/sup 2-/) are formed on MgO from adsorbed (H/sub 2/Os(CO)/sub 4/). This finding is in contrast to the cluster fragmentation and Os(II) subcarbonyl formation observed under similar conditions for osmium clusters adsorbed on ..gamma..-Al/sub 2/O/sub 3/ and SiO/sub 2/; the nature of the support dictates the surface organometallic chemistry. Here the authors present the results of an investigation confirming the presence of (Os/sub 10/C(CO)/sub 24/)/sup 2-/ on the surfaces of conventional MgO-supported CO hydrogenation catalysts prepared by aqueous impregnation with (H/sub 2/OsCl/sub 6/). The carbido carbonyl cluster is synthesized in high yield from Os(IV) on MgO exposed to CO hydrogenation conditions.

• Research Organization: Center for Catalytic Science and Technology, Dept. of Chemical Engineering, Univ. of Delaware, Newark, DE 19711
• OSTI ID: 7060272
• Report Number(s): CONF-8609181-
• Conference Information: Journal Name: Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States) Journal Volume: 31:3
• Country of Publication: United States
• Language: English

Related Subjects

090121* -- Hydrocarbon Fuels-- Chemical Synthesis-- (1976-1989)
10 SYNTHETIC FUELS
ALKALINE EARTH METAL COMPOUNDS
ALKANES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONYLS
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
COMPLEXES
HALIDES
HALOGEN COMPOUNDS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGENATION
IMPREGNATION
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
METHANATION
METHANE
ORGANIC COMPOUNDS
OSMIUM CHLORIDES
OSMIUM COMPLEXES
OSMIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METAL COMPOUNDS
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
TRANSITION ELEMENT COMPOUNDS