Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published August 1988 | public
Journal Article

Kinetics and mechanism of the catalytic oxidation of methane over lithium-promoted magnesium oxide

Abstract

The kinetics of methane oxidation in CH_4/O_2 mixtures over 7% lithium-promoted magnesium oxide has been investigated by dynamic mass spectrometry between 800 and 1100 K. At low pressures, rates become first order and half-order with respect to methane and oxygen, respectively, directly revealing the reversible dissociative chemisorption of O_2 on the catalyst. Otherwise, the complex rate law applicable over the entire range of pressures studied here can be accounted for by assuming competitive Langmuir adsorption of both reactants followed by chemical reaction of CH_4 (g) with chemisorbed oxygen. The rate constant for methane oxidation exhibits Arrhenius behavior with E_s = 86 kJ mol^(-1). Trapping of reactive species with iodine in a tandem reactor confirms the presence of methyl radical in the gas phase.

Additional Information

© 1988 American Chemical Society. (Received: April 19, 1988)

Additional details

Created:
August 19, 2023
Modified:
October 23, 2023