Transient kinetic study of the reaction of CH[sub 4] and C[sub 2]H[sub 6] with the lattice oxygen of Li[sup +]-doped TiO[sub 2] catalyst

Journal Article · Tue Jun 01 04:00:00 EDT 1993 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1006/jcat.1993.1168· OSTI ID:6154098

Efstathiou, A M; Papageorgiou, D; Verykios, X E ^[1]

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1. Univ. of Patras (Greece)

A transient kinetic study of the reaction of CH[sub 4]/He and C[sub 2]H[sub 6]/He with the lattice oxygen of Li[sup +]-doped TiO[sub 2] catalyst was performed. The results obtained indicate that lattice oxygen species must be considered as oxidation sites for both CH[sub 4] and C[sub 2]H[sub 6] molecules leading mainly to the formation of gas-phase CO[sub 2]. It was also found that more than one kind of carbon species accumulate on the catalyst surface in large quantities, following reaction with C[sub 2]H[sub 6]/He mixture in the range 700-845[degrees]C, a result opposite to that found with the CH[sub 4]/He mixture. The amount of these carbon species removed by reaction with gas-phase oxygen (O[sub 2] titration) was found to strongly depend on the temperature of titration. A kinetic model, based on a sequence of elementary steps is proposed to interpret the transient oxygen titration results. An activation energy of 15.3 kcal [center dot] mol[sup -1] for the reaction of carbon species with gas-phase oxygen is estimated. Activation energies of 34 and 28 kcal [center dot] for CH[sub 4] and C[sub 2]H[sub 6] reactions with lattice oxygen, respectively, are calculated from initial rates. 45 refs., 6 figs., 3 tabs.

• OSTI ID: 6154098
• Journal Information: Journal of Catalysis; (United States), Journal Name: Journal of Catalysis; (United States) Vol. 141:2; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ACTIVATION ENERGY
ALKALI METAL COMPOUNDS
ALKANES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DOPED MATERIALS
ENERGY
ETHANE
HYDROCARBONS
KINETICS
LITHIUM COMPOUNDS
MATERIALS
METHANE
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TITRATION
TRANSITION ELEMENT COMPOUNDS