Methane activation by the lanthanide oxides
The catalytic production of gas-phase methyl radicals from methane over the lanthanide oxides was measured by using a matrix isolation electron spin resonance (MIESR) technique. The results show that metal centers with multiple stable oxidation states are not a requirement for activity. The oxide with the greatest activity per gram was hydrothermally treated La/sub 2/O/sub 3/, which was ca. 5 times more active than the next highest oxide. Hydrothermally treated La/sub 2/O/sub 3/ and Sm/sub 2/O/sub 3/ have the largest activities per square meter. Results obtained in a conventional flow reactor for selected oxides indicate that the CH/sub 4/ conversions per square meter are in the order Nd/sub 2/O/sub 3/ > La/sub 2/O/sub 3/ > Sm/sub 2/O/sub 3/ > Dy/sub 2/O/sub 3/ > CeO/sub 2/. Oxidative coupling of CH/sub 4/ results in the C/sub 2/H/sub 6/ and C/sub 2/H/sub 4/ (C/sub 2/ compounds), and the combined C/sub 2/ yields follow the same order with Dy/sub 2/O/sub 3/ >> CeO/sub 2/. The MIESR and flow reactor results are in qualitative agreement, with the exception of Nd/sub 2/O/sub 3/.
- Research Organization:
- Texas A and M Univ., College Station (USA)
- OSTI ID:
- 5277699
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 92:3; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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10 SYNTHETIC FUELS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
ALKYL RADICALS
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CERIUM COMPOUNDS
CERIUM OXIDES
CHALCOGENIDES
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
DATA
DYSPROSIUM COMPOUNDS
DYSPROSIUM OXIDES
EXPERIMENTAL DATA
HYDROCARBONS
INFORMATION
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
METHANE
METHYL RADICALS
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
NUMERICAL DATA
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
RADICALS
RARE EARTH COMPOUNDS
SAMARIUM COMPOUNDS
SAMARIUM OXIDES
YIELDS