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

Journal Article · Sun Sep 01 04:00:00 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), Journal Name: Journal of Catalysis; (United States) Vol. 131:1; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

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