Mechanistic studies of direct ethylene glycol synthesis from carbon monoxide and hydrogen 2. Homogeneous ruthenium catalyst
- Sumitomo Chemical Co., Ltd., Osaka (Japan)
Mechanistic studies on direct syngas conversion to ethylene glycol by a homogeneous Ru catalyst combined with N-methylbenzimidazole (NMBI) were performed. High-pressure IR studies showed that Ru(CO){sub 5} (A), Ru(CO){sub 4}L (B), and (LH){sup +}(Ru{sub 3}H(CO){sub 11}){sup {minus}} (C) (L = NMBI) coexist at equilibrium in the catalyst solution as major species. It was found that the activity of CO hydrogenation was proportional to the concentration of the complex (B). A neutral hydride complex, H{sub 2}Ru(CO){sub 3}L, derived from the complex (B) was considered to be the active form. Kinetic studies by means of complete-mixing flow-reaction experiments indicated that NMBI added to the Ru catalyst enhanced both the formation and the hydroformylation of formaldehyde (FAL), the key intermediate, and the subsequent reactions of FAL were rate-determining. It was suggested that NMBI enriches the Ru hydride species and accelerates the CO insertion to the hydride and the hydroxymethyl species by acting as a ligand and a base. The Ru anionic hydride species has a much lower activity for the CO hydrogenation to form FAL and a higher activity for the MeOH formation that proceeds via the methoxy species. The studies on catalyst concentration dependencies by means of batchwise reaction revealed the involvement of dinuclear mechanisms, which probably worked in the reductive elimination of the acyl complexes.
- OSTI ID:
- 7107071
- Journal Information:
- Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 133:2; ISSN 0021-9517; ISSN JCTLA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Mechanistic Studies at the Interface Between Organometallic Chemistry and Homogeneous Catalysis
Hydroformylation of 1-heptene catalyzed by ruthenium cluster
Related Subjects
010408* -- Coal
Lignite
& Peat-- C1 Processes-- (1987-)
10 SYNTHETIC FUELS
100200 -- Synthetic Fuels-- Production-- (1990-)
ABSORPTION SPECTROSCOPY
ALCOHOLS
ALDEHYDES
AZOLES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONYLS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
FLUIDS
FORMALDEHYDE
GASES
GLYCOLS
HETEROCYCLIC COMPOUNDS
HYDRIDES
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGENATION
HYDROXY COMPOUNDS
INFRARED RADIATION
KINETICS
METALS
METHANATION
NONMETALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
RADIATIONS
REACTION INTERMEDIATES
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
RUTHENIUM
RUTHENIUM COMPOUNDS
RUTHENIUM HYDRIDES
SPECTROSCOPY
SYNTHESIS
SYNTHESIS GAS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS