Contribution of gas-phase radical coupling in the catalytic oxidation of methane

Journal Article · Thu Oct 06 04:00:00 EDT 1988 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100331a049· OSTI ID:6255147

Campbell, K D; Lunsford, J H

The oxidative dimerization of methane over MgO and CaO promoted with group IA ions is accompanied by the formation of methyl radicals which enter the gas phase. Both qualitative and quantitative results provide evidence that the gas-phase coupling of these radicals is a major pathway for the formation of C/sub 2/ products (ethane and ethylene). The rate of CH/sub 3//sup /center dot// radicals exiting a Na/sup +/-promoted CaO catalyst bed has been determined by using a matrix isolation electron spin resonance (MIESR) system, and this rate has been compared with the production of C/sub 2/ molecules are accounted for by the coupling of gas-phase radicals. An activation energy for radical formation of ca. 27 kcal mol/sup /minus/1/ is consistent with an overall activation energy for methane oxidation of 55 kcal mol/sup /minus/1/ if one considers that a bimolecular radical reaction results in the formation of the C/sub 2/ products.

• Research Organization: Texas A and M Univ., College Station (USA)
• OSTI ID: 6255147
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 92:20; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

090110 -- Hydrocarbon Fuels-- Properties-- (1979-1989)
10 SYNTHETIC FUELS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ACTIVATION ENERGY
ALKALINE EARTH METAL COMPOUNDS
ALKANES
ALKENES
ALKYL RADICALS
CALCIUM COMPOUNDS
CALCIUM OXIDES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
DIMERIZATION
ENERGY
ETHANE
ETHYLENE
FLUIDS
GASES
HYDROCARBONS
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
METHANE
METHYL RADICALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POLYMERIZATION
RADICALS