In situ FTIR study of CO/H[sub 2] reactions over Ru/SiO[sub 2] at high pressure and temperature
- University, Dundee (United Kingdom)
Infrared spectra are reported of Ru/SiO[sub 2] at 473, 503, or 553 K and exposed to CO/H[sub 2] mixtures at 3, 15, or 30 bar and CO: H[sub 2] ratios of 14:1, 1:2, and 1:14. A band due to linearly adsorbed CO, which shifted to lower wavenumbers with increasing temperature and was both shifted and weakened with increasing time, was influenced by the dissociative adsorption of CO, structural reorganisation and sintering of Ru, and the build-up of surface hydrocarbon in situ during reaction. Both linear RuCO and a [mu]-bonded Ru carbonyl were precursors of active intermediates in reactions leading to methane and higher hydrocarbon products. Three types of surface hydrocarbon were present in situ during reaction: these were ethoxy groups on the silica support, probably derived from reaction of ethene with silanol groups, methylene chains (with methyl end groups) possibly bonded to Ru via a single CH[sub 2] end group, and CH[sub 2] groups specifically bonded to Ru. The formation of methylene-containing adsorbed species was favoured by increasing pressure, but the effect of temperature depended on the total reaction pressure. Increasing the CO:H[sub 2] ratio favoured C-C chain growth. The infrared results support the proposal that hydrocarbonaceous species may be further hydrogenated on the Ru surface to give methane. 29 refs., 8 figs.
- OSTI ID:
- 6216237
- Journal Information:
- Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 141:2; ISSN 0021-9517; ISSN JCTLA5
- Country of Publication:
- United States
- Language:
- English
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ALKENES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
CONCENTRATION RATIO
ELEMENTS
ETHYLENE
FABRICATION
HYDROCARBONS
HYDROGEN
HYDROGENATION
METALS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
PRESSURE DEPENDENCE
REACTION INTERMEDIATES
RUTHENIUM
SILICON COMPOUNDS
SILICON OXIDES
SINTERING
SPECTROSCOPY
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
TRANSITION ELEMENTS