Surface phenomena during the oxidative coupling of methane over Li/MgO

Journal Article · Sun Sep 01 00:00:00 EDT 1991 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(91)90331-W· OSTI ID:5792992

Peil, K P; Goodwin, Jr, J G; Marcelin, G ^[1]

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1. Univ. of Pittsburgh, PA (United States)

This paper details an investigation of the oxidative coupling of methane for reaction temperatures up to 645 C over MgO and Li/MgO catalysts using steady-state isotopic transient kinetic analysis (SSITKA). Oxygen-exchange experiments in the absence of methane resulted in a quantification of the lattice oxygen diffusivity and total oxygen uptake. The catalyst had three more-or-less distinct regions: (1) the physical surface at which exchange between the gas phase and the solid occurred, (2) several subsurface atomic layers readily available for exchange, and (3) the bulk oxide. Using isotopic switches of oxygen and methane under steady-state reaction, the active intermediates along the carbon and oxygen reaction pathways are quantified. Lattice oxygen was found to play a significant role in the oxidation process under steady-state reaction. CO and CO{sub 2} appeared to be formed via a multistep surface oxidation pathway while ethane was formed via surface-generated intermediates along a parallel pathway. Sites involved with the generation of intermediates for selective coupling were found to have a lower activity than sites active for the generation of nonselective intermediates.

• OSTI ID: 5792992
• Journal Information: Journal of Catalysis; (United States), Vol. 131:1; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
10 SYNTHETIC FUELS
LITHIUM
CATALYTIC EFFECTS
MAGNESIUM OXIDES
METHANE
CATALYTIC REFORMING
OXIDATION
CARBON DIOXIDE
CARBON MONOXIDE
CHEMICAL REACTION KINETICS
ETHANE
ETHYLENE
OXYGEN
REACTION INTERMEDIATES
SURFACE PROPERTIES
SYNTHESIS
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
ALKALI METALS
ALKALINE EARTH METAL COMPOUNDS
ALKANES
ALKENES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
HYDROCARBONS
KINETICS
MAGNESIUM COMPOUNDS
METALS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
REFORMER PROCESSES
TEMPERATURE RANGE
030300* - Natural Gas- Drilling
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100200 - Synthetic Fuels- Production- (1990-)