(A study of catalysts and mechanisms in synthesis reactions)
Recent interest in the partial oxidation of alkanes has focused attention on the role of surface-generated gas-phase radicals in catalysis. During the oxidative coupling of methane the importance of gas phase CH{sub 3}{center dot} radicals has been demonstrated using a matrix-isolation electron spin resonance (MIESR) system. This technique will be employed to study several important problems associated with the formation and reactions of hydrocarbon radicals. The production of gas phase propyl radicals over a V-MgO-O catalyst will be investigated to determine the intermediate that is responsible for the observed heterogeneous-homogeneous reaction. The nonoxidative formation of hydrocarbon radicals over supported CrO will be explored to establish whether radical reactions over this catalyst involve gas phase intermediates. In the proposed experiments the cross coupling of methyl radicals with benzyl, allyl, 1-methylallyl and 2-methylallyl radicals will be investigated, again to determine the role of surface-generated gas-phase radicals in these reactions. Secondary reactions of radicals with metal oxide surfaces often dictate product selectivity, therefore reactive sticking coefficients for methyl and allyl radicals colliding with metal oxides will be determined. Such quantitative information is essential for modeling complex heterogeneous-homogeneous reactions. A newly constructed laser-induced fluorescence (LIF) spectrometer will be used to complement the data obtained using the MIESR technique. An initial LIF investigation will focus on the OH{center dot} radical, which is a key intermediate in hydrocarbon oxidation reactions. The research will be extended to include CH and possibly CH{sub 2} radicals. The proposed projects will provide conceptual information and quantitative data on an important class of catalytic reactions. 29 refs., 5 figs.
- Research Organization:
- Texas A and M Univ., College Station, TX (USA). Dept. of Chemistry
- Sponsoring Organization:
- DOE/ER
- DOE Contract Number:
- FG05-88ER13829
- OSTI ID:
- 6716937
- Report Number(s):
- DOE/ER/13829-3; ON: DE90015064
- Country of Publication:
- United States
- Language:
- English
Similar Records
A study of catalysts and mechanisms in synthesis reactions
A study of catalysts and mechanism in synthesis reactions
Related Subjects
400201* -- Chemical & Physicochemical Properties
ALKALINE EARTH METAL COMPOUNDS
ALKANES
ALKYL RADICALS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DOCUMENT TYPES
ELECTRON SPIN RESONANCE
FLUORESCENCE
HYDROCARBONS
KINETICS
LUMINESCENCE
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MAGNETIC RESONANCE
METHYL RADICALS
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PROGRESS REPORT
RADICALS
REACTION KINETICS
RESONANCE
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
VANADIUM OXIDES